Revistas
Revista:
FOOD HYDROCOLLOIDS
ISSN:
0268-005X
Año:
2023
Vol.:
136
N°:
Part. A
Págs.:
108213
The current work describes the capability of casein-chitosan microparticles to encapsulate Lactobacillus plantarum (CECT 220 and WCFS1 strains) and evaluates their ability to target the distal areas of the gut and to stimulate the immune system. Microparticles were prepared by complex coacervation, between sodium caseinate and chitosan in an aqueous suspension of the bacteria, and dried by spray-drying. In order to increase the survival rate of the loaded bacteria, microparticles were cross-linked with one of the following cross-linkers: tripolyphosphate, calcium salts or vanillin.Overall, microparticles displayed a mean size of about 7.5 mu m with a bacteria loading of about 11 Log CFU/g, when cross-linked with vanillin (MP-LP-V). For conventional microparticles, the payload was 10.12 Log CFU/g. The storage stability study at 25 degrees C/60% RH, MP-LP-V offered the highest degree of protection without signif-icant modification of the payload in 260 days. Compared with control (aqueous suspension of bacteria), MP-LP-V also displayed a significantly higher degree of protection against probiotic inactivation in simulated gastric and intestinal fluids. In vivo results evidenced that microparticles, orally administered to rats, were able to reach the distal ileum and colon in about 4 h post-administration. Additionally, the effect of the daily administration of 107 CFU/mouse of MP-LP-V, for 3 weeks, induced an immunomodulatory effect characterized by an important enhancement of Th1 and Th17 responses. In conclusion, these microparticles seem to be a promising strategy for increasing survival and efficacy of probiotics, allowing the formulation of cost-effective and more stable and effective probiotic-based nutraceuticals.
Revista:
MICROORGANISMS
ISSN:
2076-2607
Año:
2023
Vol.:
11
N°:
8
Págs.:
2088
The study addresses Enterotoxigenic Escherichia coli (ETEC), a significant concern in low-income countries. Despite its prevalence, there is no licensed vaccine against ETEC. Bacterial vesicle-based vaccines are promising due to their safety and diverse virulence factors. However, cost-effective production requires enhancing vesicle yield while considering altered properties due to isolation methods. The proposed method involves heat treatment and ultrafiltration to recover vesicles from bacterial cultures. Two vesicle types, collected from heat-treated (HT-OMV) or untreated (NT-OMV) cultures, were compared. Vesicles were isolated via ultrafiltration alone ("complete") or with ultracentrifugation ("sediment"). Preliminary findings suggest complete HT-OMV vesicles are suitable for an ETEC vaccine. They express important proteins (OmpA, OmpX, OmpW) and virulence factors (adhesin TibA). Sized optimally (50-200 nm) for mucosal vaccination, they activate macrophages, inducing marker expression (CD40, MHCII, CD80, CD86) and Th1/Th2 cytokine release (IL-6, MCP-1, TNF-¿, IL12p70, IL-10). This study confirms non-toxicity in RAW 264.7 cells and the in vivo ability of complete HT-OMV to generate significant IgG2a/IgG1 serum antibodies. Results suggest promise for a cost-effective ETEC vaccine, requiring further research on in vivo toxicity, pathogen-specific antibody detection, and protective efficacy.
Revista:
JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY
ISSN:
0305-7453
Año:
2022
Vol.:
77
N°:
4
Págs.:
1072 - 1081
Objectives More effective topical treatments remain an unmet need for the localized forms of cutaneous leishmaniasis (CL). The aim of this study was to evaluate the efficacy and safety of a topical berberine cream in BALB/c mice infected with Leishmania major parasites. Methods A cream containing 0.5% berberine-beta-glycerophosphate salt and 2.5% menthol was prepared. Its physicochemical and stability properties were determined. The cream was evaluated for its capacity to reduce lesion size and parasitic load as well as to promote wound healing after twice-a-day administration for 35 days. Clinical biochemical profile was used for estimating off-target effects. In vitro time-to-kill curves in L. major-infected macrophages and skin and plasma pharmacokinetics were determined, aiming to establish pharmacokinetic/pharmacodynamic relationships. Results The cream was stable at 40 degrees C for 3 months and at 4 degrees C for at least 8 months. It was able to halt lesion progression in all treated mice. At the end of treatment, parasite load in the skin was reduced by 99.9% (4 log) and genes involved in the wound healing process were up-regulated compared with untreated mice. The observed effects were higher than expected from in vitro time-to-kill kinetic and plasma berberine concentrations, which ranged between 0.07 and 0.22 mu M. Conclusions The twice-a-day administration of a topical berberine cream was safe, able to stop parasite progression and improved the appearance of skin CL lesions. The relationship between drug plasma levels and in vivo effect was unclear.
Revista:
PHARMACEUTICS
ISSN:
1999-4923
Año:
2022
Vol.:
14
N°:
2
Págs.:
239
Enterotoxigenic Escherichia coli (ETEC) infections have been identified as a major cause of acute diarrhoea in children in developing countries, associated with substantial morbidity and mortality rates. Additionally, ETEC remains the most common cause of acute diarrhea of international travellers to endemic areas. The heat-labile toxin (LT) is a major virulence factor of ETEC, with a significant correlation between the presence of antibodies against LT and protection in infected patients. In the present work, we constructed a recombinant LTB unit (rLTB) and studied the capacity of this toxoid incorporated in microneedles (rLTB-MN) to induce a specific immune response in mice. MN were prepared from aqueous blends of the polymer Gantrez AN® [poly (methyl vinyl ether-co-maleic anhydride)], which is not cytotoxic and has been shown to possess immunoadjuvant properties. The mechanical and dissolution properties of rLTB-MNs were evaluated in an in vitro Parafilm M® model and in mice and pig skin ex vivo models. The needle insertion ranged between 378 µm and 504 µm in Parafilm layers, and MNs fully dissolved within 15 min of application inside porcine skin. Moreover, female and male BALB/c mice were immunized through ear skin with one single dose of 5 ¿g·rLTB in MNs, eliciting significant fecal anti-LT IgA antibodies, higher in female than in male mice. Moreover, we observed an enhanced production of IL-17A by spleen cells in the immunized female mice, indicating a mucosal non-inflammatory and neutralizing mediated response. Further experiments will now be required to validate the protective capacity of this new rLTB-MN formulation against this deadly non-vaccine-preventable disease.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2022
Vol.:
628
Págs.:
122255
The aim was to evaluate the effect of zein-based nanoparticles on the glucose homeostasis, following oral administration to Wistar rats. For this purpose, bare nanoparticles (NP, with tropism for the upper intestinal regions) and poly(ethylene glycol)-coated nanoparticles (NP-PEG), with the capability to reach the ileum and cecum of animals, were evaluated. Both formulations were spherical in shape, displaying sizes around 200 nm and a negative surface zeta potential. The oral administration of a single dose of these nanoparticles to animals (50 mg/kg) induced a significant decrease of the glycemia, compared control rats and in animals treated with the free protein (p < 0.001). Moreover, these nanoparticles improved the glycemic control against an intraperitoneal glucose tolerance test; particularly NP-PEG. These findings would be due to an increased release of glucagon-like peptide-1 (GLP-1) by L-cells, which are more abundant in distal regions of the intestine. In fact, the GLP-1 blood levels of animals treated with nanoparticles were significantly higher than controls (about 40 % and 60 % for NP and NP-PEG groups, respectively). This higher capability of NP-PEG, with respect to NP, to increase the release of GLP-1 and control glycemia would be related to its ability to reach the distal areas of the small intestine.
Revista:
PHARMACEUTICS
ISSN:
1999-4923
Año:
2022
Vol.:
14
N°:
1
Págs.:
123
Enterotoxigenic Escherichia coli (ETEC) represents a major cause of morbidity and mortality in the human population. In particular, ETEC infections affect children under the age of five from low-middle income countries. However, there is no licensed vaccine against this pathogen. ETEC vaccine development is challenging since this pathotype expresses a wide variety of antigenically diverse virulence factors whose genes can be modified due to ETEC genetic plasticity. To overcome this challenge, we propose the use of outer membrane vesicles (OMVs) isolated from two ETEC clinical strains. In these OMVs, proteomic studies revealed the presence of important immunogens, such as heat-labile toxin, colonization factors, adhesins and mucinases. Furthermore, these vesicles proved to be immunogenic after subcutaneous administration in BALB/c mice. Since ETEC is an enteropathogen, it is necessary to induce both systemic and mucosal immunity. For this purpose, the vesicles, free or encapsulated in zein nanoparticles coated with a Gantrez(R)-mannosamine conjugate, were administered orally. Biodistribution studies showed that the encapsulation of OMVs delayed the transit through the gut. These results were confirmed by in vivo study, in which OMV encapsulation resulted in higher levels of specific antibodies IgG2a. Further studies are needed to evaluate the protection efficacy of this vaccine approach.
Revista:
PHARMACEUTICS
ISSN:
1999-4923
Año:
2022
Vol.:
14
N°:
1
Págs.:
39
Zein, the major storage protein from corn, has a GRAS (Generally Regarded as Safe) status and may be easily transformed into nanoparticles, offering significant payloads for protein materials without affecting their stability. In this work, the capability of bare zein nanoparticles (mucoadhesive) and nanoparticles coated with poly(ethylene glycol) (mucus-permeating) was evaluated as oral carriers of insulin (I-NP and I-NP-PEG, respectively). Both nanocarriers displayed sizes of around 270 nm, insulin payloads close to 80 mu g/mg and did not induce cytotoxic effects in Caco-2 and HT29-MTX cell lines. In Caenorhabditis elegans, where insulin decreases fat storage, I-NP-PEG induced a higher reduction in the fat content than I-NP and slightly lower than the control (Orlistat). In diabetic rats, nanoparticles induced a potent hypoglycemic effect and achieved an oral bioavailability of 4.2% for I-NP and 10.2% for I-NP-PEG. This superior effect observed for I-NP-PEG would be related to their capability to diffuse through the mucus layer and reach the surface of enterocytes (where insulin would be released), whereas the mucoadhesive I-NP would remain trapped in the mucus, far away from the absorptive epithelium. In summary, PEG-coated zein nanoparticles may be an interesting device for the effective delivery of proteins through the oral route.
Revista:
ACTA TROPICA
ISSN:
0001-706X
Año:
2021
Vol.:
215
Págs.:
105801
Compounds 1 and 2 (selenocyanate and diselenide derivatives, respectively) were evaluated for their potential use in vivo against visceral leishmaniasis (VL). Both entities showed low cytoxicity in vitro in Vero and Caco-2 cell lines. However, the compounds were not suitable for their oral administration, since they exhibited poor values of intestinal permeability in vitro. Microsomal stability assays did not show any metabolite for compound 1 after 120 min, whereas 2 was highly metabolized by the enzyme CYP450. Thus, the in vivo efficacy of compound 1 was assessed in a murine model of L. infantum VL. The daily i.v. administration of 1 mg/kg of compound 1 during 5 consecutive days reduced parasite load in liver, spleen and bone marrow (99.2%, 91.7% and 61.4%, respectively) compared to non-treated mice. To the best of our knowledge, this is the first time that a selenium compound has been tested in vivo against VL. Thus, this work evidences the possible usefulness of selenocyanate derivatives for the treatment of this disease.
Revista:
NANOSCALE
ISSN:
2040-3364
Año:
2021
Vol.:
13
N°:
41
Págs.:
17486 - 17503
This study investigates if visceral leishmaniasis (VL) infection has some effects on the organ and cellular uptake and distribution of 100-200 nm near-infrared fluorescently labelled non-biodegradable polystyrene latex beads (PS NPs) or biodegradable polylactic-co-glycolic nanoparticles (PLGA NPs), as this parasitic infection produces morphological alterations in liver, spleen and bone marrow, organs highly involved in NP sequestration. The results showed that the magnitude of the effect was specific for each organ and type of NP. With the exception of the liver, the general trend was a decrease in NP organ and cellular uptake, mostly due to immune cell mobilization and/or weight organ gain, as vascular permeability was increased. Moreover, NPs redistributed among different phagocytic cells to adapt infection associated changes and cellular alterations. In the liver, it is noteworthy that only isolated Kuffer cells (KCs) captured NPs, whereas they were not taken up by KC forming granulomas. In the spleen, NPs redistributed from macrophages and dendritic cells towards B cells and inflammatory monocytes although they maintained their preferential accumulation in the marginal zone and red pulp. Comparatively, the infection rarely affected the NP cellular distribution in the bone marrow. NP cellular target changes in VL infection could affect their therapeutic efficacy and should be considered for more efficient drug delivery.
Revista:
JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
ISSN:
1773-2247
Año:
2021
Vol.:
64
Págs.:
101809
The aim of this work was to study the biodistribution of bevacizumab-loaded HSA nanoparticles (NP-Ab) crosslinked with PEG35000 by SPECT/CT in vivo imaging. For this purpose, NP-Abs were prepared by a desolvation process, coated with PEG35000 and radiolabeled with technetium-99 m using a pre-tinning method ([99mTc]TcNP-Ab). The Ab was labeled using [99mTc][Tc(CO)3(H2O)3]+ and used to prepare nanoparticles (NP-[99mTc]TcAb). Particle size was similar in both formulations. Chemical and radiochemical purity of the two nanosystems were >95%. Bevacizumab-labeling conditions were tested by in vitro stability studies. More than 87% of the radiolabeled antibody remained intact for 24 h after incubation with plasma. SPECT/CT imaging of the two nanoparticles was performed in healthy female Wistar rats. Ex vivo gamma counting of selected organs was also carried out in all animals. The results showed different clearance rates of the nanoparticle shell and the antibody, providing valuable information by the use of molecular imaging in the evaluation of drug delivery nanosystems.
Revista:
ACTA PHARMACEUTICA SINICA B
ISSN:
2211-3835
Año:
2021
Vol.:
11
N°:
4
Págs.:
989 - 1002
The aim was to evaluate the potential of mucus-permeating nanoparticles for the oral administration of insulin. These nanocarriers, based on the coating of zein nanoparticles with a polymer conjugate containing PEG, displayed a size of 260 nm with a negative surface charge and an insulin payload of 77 µg/mg. In intestinal pig mucus, the diffusivity of these nanoparticles (PPA-NP) was found to be 20-fold higher than bare nanoparticles (NP). These results were in line with the biodistribution study in rats, in which NP remained trapped in the mucus, whereas PPA-NP were able to cross this layer and reach the epithelium surface. The therapeutic efficacy was evaluated in Caenorhabditis elegans grown under high glucose conditions. In this model, worms treated with insulin-loaded in PPA-NP displayed a longer lifespan than those treated with insulin free or nanoencapsulated in NP. This finding was associated with a significant reduction in the formation of ROS as well as an important decrease in the glucose and fat content in worms. These effects would be related with the mucus-permeating ability of PPA-NP that would facilitate the passage through the intestinal peritrophic-like dense layer of worms (similar to mucus) and, thus, the absorption of insulin.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS. X
ISSN:
2590-1567
Año:
2021
Vol.:
3
Págs.:
100104
Camptothecin (CPT) exhibits a number of challenges for its oral administration, including a low aqueous solu-bility, a lactone ring susceptible to hydrolysis, and an affinity to the intestinal P-gp. The aim of this work was to evaluate nanoparticles from Gantrez-based conjugates as carriers for the oral delivery of CPT. For this purpose two different conjugates (G-mPEG and G-HPCD), obtained by the covalent binding of either HP-beta-CD or methoxy-PEG (m-PEG) to the polymer backbone of GantrezTM AN, were synthetized and characterized. Both excipients (m -PEG and HPCD) were selected due to their reported abilities to stabilize the lactone ring of CPT and disturb the effect of intestinal P-gp. The resulting nanoparticles (G-mPEG-NP and G-HPCD-NP) presented a similar size (about 200 nm) and zeta potential (close to-35 mV); although, G-mPEG-NP presented a higher CPT payload than G-HPCD-NP. On the contrary, in rats, nanoparticles based on Gantrez conjugates appeared to be capable of crossing the protective mucus layer and reach the intestinal epithelium, whereas conventional Gantrez nano-particles displayed a mucoadhesive profile. Finally, the pharmacokinetic study revealed that both formulations were able to enhance the relative oral bioavailability of CPT; although this value was found to be 2.6-times higher for G-mPEG-NP than for G-HPCD-NP.
Revista:
ACS INFECTIOUS DISEASES
ISSN:
2373-8227
Año:
2021
Vol.:
7
N°:
12
Págs.:
3197 - 3209
Leishmaniasis urgently needs new oral treatments, as it is one of the most important neglected tropical diseases that affects people with poor resources. The drug discovery pipeline for oral administration currently discards entities with poor aqueous solubility and permeability (class IV compounds in the Biopharmaceutical Classification System, BCS) such as the diselenide 2m, a trypanothione reductase (TR) inhibitor. This work was assisted by glyceryl palmitostearate and diethylene glycol monoethyl ether-based nanostructured lipid carriers (NLC) to render 2m bioavailable and effective after its oral administration. The loading of 2m in NLC drastically enhanced its intestinal permeability and provided plasmatic levels higher than its effective concentration (IC50). In L. infantum-infected BALB/c mice, 2m-NLC reduced the parasite burden in the spleen, liver, and bone marrow by at least 95% after 5 doses, demonstrating similar efficacy as intravenous Fungizone. Overall, compound 2m and its formulation merit further investigation as an oral treatment for visceral leishmaniasis.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2021
Vol.:
597
Págs.:
120287
The aim was to produce PEG-coated nanoparticles (NP-PEG), with mucus-permeating properties, for oral drug delivery purposes by using simple procedures and regulatoryapproved compounds in order to facilitate a potential clinical development. For this purpose, zein nanoparticles were prepared by desolvation and, then, coated by incubation with PEG 35,000. The resulting nanocarriers displayed a mean size of about 200 nm and a negative zeta potential. The presence of PEG on the surface of nanoparticles was evidenced by electron microscopy and confirmed by FTIR analysis. Likely, the hydrophobic surface of zein nanoparticles (NP) was significantly reduce by their coating with PEG. This increase of the hydrophilicity of PEG-coated nanoparticles was associated with an important increase of their mobility in pig intestinal mucus. In laboratory animals, NP-PEG (fluorescently labelled with Lumogen® Red 305) displayed a different behavior when compared with bare nanoparticles. After oral administration, NP appeared to be trapped in the mucus mesh, whereas NP-PEG were capable of crossing the protective mucus layer and reach the epithelium. Finally, PEGcoated zein nanoparticles, prepared by a simple and reproducible method without employing reactive reagents, may be adequate carriers for promoting the oral bioavailability of biomacromolecules and other biologically active compounds with low permeability properties.
Revista:
VACCINES
ISSN:
2076-393X
Año:
2021
Vol.:
9
N°:
3
Págs.:
216
Salmonellosis remains a major medical and an unmet socioeconomic challenge. Worldwide, more than three million deaths per year are associated with Salmonella enterica serovar Enteritidis infections. Although commercially available vaccines for use in poultry exist, their efficacy is limited. We previously described a method for isolating a heat extract (HE) fraction of the cell surface of S. Enteritidis that contained major antigenic complexes immunogenic in hens naturally infected with the bacterium. One single dose of S. Enteritidis' HE induced protection against lethal salmonellosis in mice. Furthermore, HE encapsulation in nanoparticles of the copolymer of methyl vinyl ether and maleic anhydride (PVM/MA), Gantrez AN, improved and prolonged the protection against the disease in mice. We formulated new preparations of Gantrez AN nanoparticles with HE S. Enteritidis and assessed their stability in drinking water and their efficacy in hens after experimental infection. The oral treatment of six-week-old hens with two doses of HE nanoparticles significantly reduced the Salmonella excretion in hens. Due to the effectiveness of the treatment in reducing bacterial excretion, we conclude that HE nanoencapsulation obtained from S. Enteritidis is a viable novel vaccination approach against salmonellosis in farms.
Revista:
DRUG DELIVERY AND TRANSLATIONAL RESEARCH
ISSN:
2190-3948
Año:
2021
Vol.:
11
N°:
2
Págs.:
647 - 658
The aim was to evaluate the potential of nanocarriers, based on the coating of zein nanoparticles (ZNP) with a Gantrez (R) AN-PEG conjugate (GP), for the oral delivery of insulin. ZNP-GP displayed less negative surface charge and a 14-fold higher diffusion coefficient in pig intestinal mucus than ZNP. Both nanoparticles showed a spherical shape and an insulin load of 77.5 mu g/mg. Under simulated gastric conditions, ZNP-GP released significantly lower amount of insulin than ZNP, while under simulated intestinal conditions, both types of nanoparticles displayed similar behaviour. In Caenorhabditis elegans wild-type N2, grown under high glucose conditions, insulin treatments reduced glucose and fat accumulation without altering the growth rate, the worm length, or the pumping rate. The effect was significantly greater (p < 0.001) when insulin was nanoencapsulated in ZNP-GP compared with that encapsulated in ZNP or formulated in solution. This would be related to the highest capability of ZNP-GP to diffuse in the dense peritrophic-like layer covering intestinal cells in worms. In daf-2 mutants, the effect on fat and glucose reduction by insulin treatment was suppressed, indicating a DAF-2 dependent mechanism. In summary, ZNP-GP is a promising platform that may offer new opportunities for the oral delivery of insulin and other therapeutic proteins.
Revista:
PHARMACEUTICS
ISSN:
1999-4923
Año:
2020
Vol.:
12
N°:
9
Págs.:
E858
Berberine (BER)-an anti-inflammatory quaternary isoquinoline alkaloid extracted from plants-has been reported to have a variety of biologic properties, including antileishmanial activity. This work addresses the preparation of BER-loaded liposomes with the aim to prevent its rapid liver metabolism and improve the drug selective delivery to the infected organs in visceral leishmaniasis (VL). BER liposomes (LP-BER) displayed a mean size of 120 nm, negative Z-potential of -38 mV and loaded 6 nmol/¿mol lipid. In vitro, the loading of BER in liposomes enhanced its selectivity index more than 7-fold by decreasing its cytotoxicity to macrophages. In mice, LP-BER enhanced drug accumulation in the liver and the spleen. Consequently, the liposomal delivery of the drug reduced parasite burden in the liver and spleen by three and one logarithms (99.2 and 93.5%), whereas the free drug only decreased the infection in the liver by 1-log. The organ drug concentrations-far from IC50 values- indicate that BER immunomodulatory activity or drug metabolites also contribute to the efficacy. Although LP-BER decreased 10-fold-an extremely rapid clearance of the free drug in mice-the value remains very high. Moreover, LP-BER reduced plasma triglycerides levels.
Revista:
JOURNAL OF MICROENCAPSULATION
ISSN:
0265-2048
Año:
2020
Vol.:
37
N°:
3
Págs.:
242 - 253
The influence on the stability of Lactobacillus plantarum CECT 220 (25 C/60% relative humidity) of microencapsulation by simple coacervation followed by spray-drying using different Ca2þ-tosoybean protein isolate ratios was evaluated. After optimisation, the selected soybean protein
concentrate (SPC) microparticles were used to evaluate the tolerance of L. plantarum under acidic conditions (lactic acid, pH¿4; and HCl, pH¿3) and heat stress (80 C for 1 min) in contrast to free cells. Moreover, after the heat treatment, the influence of the simulated gastric fluid was evaluated. Additionally, different foods were formulated using either microencapsulated or freeze-dried L. plantarum, and the stability of cells during the shelf-life of the formulated foods was studied. Results show that encapsulation with SPC enhanced significantly the stability of the Lactic Acid Bacteria all along the probiotic food value chain, from production to the end of the food shelf-life.
Revista:
DRUG DELIVERY AND TRANSLATIONAL RESEARCH
ISSN:
2190-393X
Año:
2020
Vol.:
10
N°:
3
Págs.:
635 - 645
Bevacizumab (as other monoclonal antibodies) has now become a mainstay in the treatment of several cancers in spite of some limitations, including poor tumour penetration and the development of resistance mechanisms. Its nanoencapsulation may be an adequate strategy to minimize these problems. The aim of this work was to evaluate the efficacy of bevacizumab-loaded nanoparticles (B-NP-PEG) on a xenograft model of human colorectal cancer. For this purpose, human serum albumin nanoparticles were prepared by coacervation, then coated with poly(ethylene glycol) and freeze-dried. B-NP-PEG displayed a mean size of about 300 nm and a bevacizumab loading of approximately 145 ¿g/mg. An in vivo study was conducted in the HT-29 xenograft model of colorectal cancer. Both, free and nanoencapsulated bevacizumab, induced a similar reduction in the tumour growth rate of about 50%, when compared to controls. By microPET imaging analysis, B-NP-PEG was found to be a more effective treatment in decreasing the glycolysis and metabolic tumour volume than free bevacizumab, suggesting higher efficacy. These results correlated well with the capability of B-NP-PEG to increase about fourfold the levels of intratumour bevacizumab, compared with the conventional formulation. In parallel, B-NP-PEG displayed six-times lower amounts of bevacizumab in blood than the aqueous formulation of the antibody, suggesting a lower incidence of potential undesirable side effects. In summary, albumin-based nanoparticles may be adequate carriers to promote the delivery of monoclonal antibodies (i.e. bevacizumab) to tumour tissues.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2020
Vol.:
579
Págs.:
119154
Thermosensitive hydrogels have been studied as feasible needle-avoidance alternative to vaccine delivery. In this work, we report the development of a new thermal-sensitive hydrogel for intranasal vaccine delivery. This delivery system was formulated with a combination of the polymer Gantrez AN119 and the surfactant Pluronic F127 (PF127), with a high biocompatibility, biodegradability and immunoadjuvant properties. Shigella flexneri outer membrane vesicles were used as the antigen model. A stable and easy-to-produce thermosensitive hydrogel which allowed the incorporation of the OMV-antigenic complex was successfully synthetized. A rapid gel formation was achieved at body temperature, which prolonged the OMV-antigens residence time in the nasal cavity of BALB/c mice when compared to intranasal delivery of free-OMVs. In addition, the bacterial antigens showed a fast release profile from the hydrogel in vitro, with a peak at 30min of incubation at 37°C. Hydrogels appeared to be non-cytotoxic in the human epithelial HeLa cell line and nose epithelium as well, as indicated by the absence of histopathological features. Immunohistochemical studies revealed that after intranasal administration the OMVs reached the nasal associated lymphoid tissue. These results support the use of here described thermosensitive hydrogels as a potential platform for intranasal vaccination.
Revista:
VACCINES
ISSN:
2076-393X
Año:
2020
Vol.:
8
N°:
1
Págs.:
11
Enterotoxigenic Escherichia coli (ETEC) strains are a major cause of illness and death in neonatal and recently weaned pigs. The immune protection of the piglets derives from maternal colostrum, since this species does not receive maternal antibodies through the placenta. In the present study, outer membrane vesicles (OMVs) obtained from main ETEC strains involved in piglet infection (F4 and F18 serotypes), encapsulated into zein nanoparticles coated with Gantrez((R)(R)) AN-mannosamine conjugate, were used to orally immunize mice and pregnant sows. Loaded nanoparticles were homogeneous and spherical in a shape, with a size of 220-280 nm. The diffusion of nanoparticles through porcine intestinal mucus barrier was assessed by a Multiple Particle Tracking technique, showing that these particles were able to diffuse efficiently (1.3% diffusion coefficient), validating their oral use. BALB/c mice were either orally immunized with free OMVs or encapsulated into nanoparticles (100 mu g OMVs/mouse). Results indicated that a single dose of loaded nanoparticles was able to elicit higher levels of serum specific IgG1, IgG2a and IgA, as well as intestinal IgA, with respect to the free antigens. In addition, nanoparticles induced an increase in levels of IL-2, IL-4 and IFN-gamma with respect to the administration of free OMVs. Orally immunized pregnant sows with the same formulation elicited colostrum-, serum- (IgG, IgA or IgM) and fecal- (IgA) specific antibodies and, what is most releva
Autores:
de Arcocha-Torres, M. (Autor de correspondencia); Quincoces, Gemma; Martinez-Lopez, A. L.; et al.
Revista:
REVISTA ESPAÑOLA DE MEDICINA NUCLEAR E IMAGEN MOLECULAR
ISSN:
2253-654X
Año:
2020
Vol.:
39
N°:
4
Págs.:
225 - 232
Revista:
VACCINES
ISSN:
2076-393X
Año:
2020
Vol.:
8
N°:
2
Págs.:
286
Enterotoxigenic Escherichia coli (ETEC) strains are a major cause of illness and death in mammals, including neonatal, recently weaned pigs and infant human beings. We have previously shown that outer membrane vesicles (OMV) obtained from ETEC serotypes encapsulated into zein nanoparticles, coated with a Gantrez-mannosamine polymer conjugate (OMV-NP), were immunogenic in mice and sows. In the present study, we show that pups from vaccinated mice were protected against ETEC F4 serotype challenge through maternal passive immunization. OMV from F4 cultures were collected and characterized. Two-week-pregnant BALB/c mice were orally immunized with a single dose of vesicles (0.2 mg) either free (OMV) or encapsulated into nanoparticles (OMV-NP). Evaluation of the antibodies in serum (IgG1, Ig2a or IgA) and feces (IgA) of dams immunized with OMV-NP revealed an enhancement of specific immunogenicity. The antibody response conferred by the nanoparticle adjuvant was also correlated with IL-6 and IL-10 splenic levels. Each mother was allowed to feed her progeny for one week. Suckling pups presented specific IgA in feces demonstrating their passive immunization through colostrum intake. Two weeks after the pups were born, they were infected orally with a single dose of F4E. coli (1.2 x 10(8)CFU/pup). Results showed that 70% of the pups from dams immunized with OMV-NP were protected. In contrast, 80% of the pups from dams immunized with free OMV died as a result of the experimental challen
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2020
Vol.:
581
Págs.:
119289
Proteins represent a group of biopolymers with interesting properties to be employed as raw materials in the preparation of nanoparticles for drug delivery purposes. Due to the inherent properties of proteins (i.e., biodegradability, amphiphilic properties, etc.) the resulting nanoparticles can be considered as versatility platforms for a variety of applications. Moreover, some proteins possess a GRAS (Generally Recognized as Safe) status or are considered as excipients by different Regulatory Agencies. As result of this, the resulting nanoparticles and potential translation to clinic would be facilitated, compared to other materials (i.e., polymers). This review is focused on the main proteins employed in the preparation of nanoparticles as well as the procedures permitting their transformation into nanoparticles able of accommodating a high variety of bioactive compounds and drugs. Moreover, the review also provides examples of application of nanoparticles prepared from albumins, globulins, prolamins or macromolecules derived from proteins.
Revista:
JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
ISSN:
1773-2247
Año:
2020
Vol.:
57
Págs.:
101704
Revista:
DRUG DELIVERY AND TRANSLATIONAL RESEARCH
ISSN:
2190-393X
Año:
2020
Vol.:
10
N°:
6
Págs.:
1601 - 1611
The aim of this work was to evaluate oral nanocarriers, prepared from zein nanoparticles coated with a poly(anhydride)-thiamine conjugate (GT), for the delivery of insulin. Nanoparticles displayed a size of 250 nm with a negative surface charge, and an insulin loading of 80 mu g/mg. Under simulated gastric conditions, GT-coated nanoparticles released a significantly lower amount of insulin than bare ones; whereas in simulated intestinal conditions, both types of nanoparticles displayed a similar behavior. The effect of insulin on the lipid metabolism of C. elegans under high glucose conditions, characterized by a reduction of the fat content, was also investigated. The effect was significantly higher for the nanoencapsulated forms of insulin than for the free protein (p < 0.001). This effect was two times higher for GT-coated nanoparticles than for bare ones. In rats, the hypoglycemic effect and the pharmacokinetic profile of insulin-loaded nanoparticles orally administered (50 IU/kg) were evaluated. The glycemia of animals slowly decreased reaching a minimum 6-10-h post-administration, with a maximum decrease of about 60%. The pharmacological availability of nanoencapsulated insulin was 13.5%. In serum, nanoparticles provided a maximum of insulin 4-h post-administration, and its relative oral bioavailability was 5.2% (compared with a sc formulation of insulin).
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2019
Vol.:
570
Págs.:
118652
The aim of this work was to optimize the preparative process of quercetin loaded casein nanoparticles as well as to evaluate the pharmacokinetics of this flavonoid when administered orally in Wistar rats. Nanoparticles were obtained by coacervation after the incubation of casein, 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and quercetin in an aqueous environment. Then, nanoparticles were purified and dried. The resulting nanoparticles displayed a size of 200 nm with a negative zeta potential and a payload of about 32 mu g/mg. Release studies showed a zero-order kinetic, suggesting a mechanism based on erosion of the nanoparticle matrix. For the pharmacokinetic study, quercetin was orally administered to rats as a single dose of 25 mg/kg. Animals treated with quercetin-loaded casein nanoparticles displayed higher plasma levels than those observed in animals receiving the solution of the flavonoid (control). Thus, the relative oral bioavailability of quercetin when administered as casein nanoparticles (close to 37%) was found to be about 9-times higher than the oral solution of the flavonoid in a mixture of PEG 400 and water. In summary, the combination of casein and 2-hydroxypropyl-beta-cyclodextrin produces nanoparticles that may be a good option to load quercetin for both nutraceutical and pharmaceutical purposes.
Revista:
VACCINE
ISSN:
0264-410X
Año:
2019
Vol.:
7
N°:
4
Págs.:
159
Intradermal (ID) immunization is of increasing interest due to the easy accessibility and excellent immunogenic properties of the skin. Among ID immunization methods, dissolving microneedles (MNs) have appeared as an alternative to traditional hypodermic immunization, offering many advantages, such as being an easily administered method, with no need for health personnel, painless, and avoiding the use of needles and sharp wastage. In this study, an affordable and easy-to-produce MNs method was developed based on aqueous blends of 30% w/w poly (methyl vinyl ether-co-maleic anhydride). As an antigen model, a subunit vaccine candidate based on outer membrane vesicles from Shigella flexneri was used. Both unloaded and antigen-loaded MNs were synthetized and characterized. The MNs were successfully validated in an in vitro Parafilm M skin model and in a pig skin ex vivo model. Biodistribution studies were performed in BALB/c mice using 99mTcO4- radiolabeled samples. Results indicated that the vesicle vaccine was successfully released from the MNs and targeted gastrointestinal tract after 6 h post-administration. In vivo immunization and protection studies were performed in BALB/c mice. Mice were intradermally immunized through ear skin with one single dose of 200 g antigenic complex, eliciting the production of specific systemic IgG and mucosal IgA.
Revista:
PHARMACEUTICS
ISSN:
1999-4923
Año:
2019
Vol.:
11
N°:
11
Págs.:
607
The oral administration of dapsone (DAP) for the treatment of cutaneous leishmaniasis (CL) is effective, although serious hematological side effects limit its use. In this study, we evaluated this drug for the topical treatment of CL. As efficacy depends on potency and skin penetration, we first determined its antileishmanial activity (IC50 = 100 ¿M) and selectivity index in vitro against Leishmania major-infected macrophages. In order to evaluate the skin penetration ex vivo, we compared an O/W cream containing DAP that had been micronized with a pluronic lecithin emulgel, in which the drug was solubilized with diethylene glycol monoethyl ether. For both formulations we obtained similar low flux values that increased when the stratum corneum and the epidermis were removed. In vivo efficacy studies performed on L. major-infected BALB/c mice revealed that treatment not only failed to cure the lesions but made their evolution and appearance worse. High plasma drug levels were detected and were concomitant with anemia and iron accumulation in the spleen. This side effect was correlated with a reduction of parasite burden in this organ. Our results evidenced that DAP in these formulations does not have an adequate safety index for use in the topical therapy of CL.
Revista:
JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
ISSN:
1773-2247
Año:
2019
Vol.:
52
Págs.:
379 - 385
The aim of this work was to study the preparation process and the in vitro release of human serum albumin nanoparticles stabilized by Gantrez (R) ES-425, which was loaded with antiangiogenic drugs (suramin and bevacizumab). Nanoparticles were prepared by coacervation and stabilized with Gantrez (R) ES-425(Nps-Ga). As control, albumin nanoparticles cross-linked with glutaraldehyde (Nps-Glu) were prepared. Nps-Ga displayed a mean size of about 210 nm whereas Nps-Glu showed a mean size of 158 nm. For suramin-loaded nanoparticles, the stabilization process did not show any significant effect on the drug with neither glutaraldehyde nor Gantrez (R). On the contrary, for bevacizumab, only nanoparticles stabilized with Gantrez (R) displayed important payloads (97 mu g/mg nanoparticle) of the active form of the antibody. For nanoparticles with glutaraldehyde, only a very low amount of the loaded bevacizumab remained active. Regarding the in vitro release studies, suramin showed a release mechanism influenced by the type of stabilizing agent. Finally, bevacizumab released from Nps-Ga was characterized by a small burst effect followed by a sustained release rate. In summary, albumin nanoparticles stabilized by polymer coating were successfully obtained and are a promising delivery system for the topical treatment of CNV.
Revista:
EXPERIMENTAL EYE RESEARCH
ISSN:
0014-4835
Corneal neovascularization (CNV) is associated with different ocular pathologies, including infectious keratitis, trachoma or corneal trauma. Pharmacological treatments based on the topical application of anti-VEGF therapies have been shown to be effective in the treatment and prevention of CNV. The aim of this work was to evaluate the effect of bevacizumab-loaded albumin nanoparticles in a rat model of CNV. Bevacizumab-loaded nanoparticles, either "naked" (B-NP) or coated with PEG 35,000 (B-NP-PEG), were administered once a day in the eyes of animals (10 mu L, 4 mg/mL every 24 h) during 7 days. Bevacizumab and dexamethasone were employed as controls and administered at the same dose every 12 h. At the end of the study, the area of the eye affected by neovascularization was about 2-times lower for animals treated with B-NP than with free bevacizumab. In the study, dexamethasone did not demonstrate an inhibitory effect on CNV at the employed dose. All of these results were confirmed by histopathological analysis, which clearly showed that eyes treated with nanoparticles displayed lower levels of fibrosis, inflammation and edema. In summary, the encapsulation of bevacizumab in human serum albumin nanoparticles improved its efficacy in an animal model of CNV.
Revista:
JOURNAL OF PHARMACEUTICAL SCIENCES
ISSN:
0022-3549
Año:
2019
Vol.:
108
N°:
7
Págs.:
2421 - 2429
Peanut allergy is one of the most prevalent and severe of food allergies with no available cure. The aim of this work was to evaluate the potential of an oral immunotherapy based on the use of a roasted peanut extract encapsulated in nanoparticles with immunoadjuvant properties. For this, a polymer conjugate formed by the covalent binding of mannosamine to the copolymer of methyl vinyl ether and maleic anhydride was first synthetized and characterized. Then, the conjugate was used to prepare nanoparticles with an important capability to diffuse through the mucus layer and reach, in a large extent, the intestinal epithelium, including Peyer's patches. Their immunotherapeutic potential was evaluated in a model of presensitized CD1 mice to peanut. After completing therapy, mice underwent an intraperitoneal challenge with peanut extract. Nanoparticle-treatment was associated with both less serious anaphylaxis symptoms and higher survival rates than control, confirming the protective effect of this formulation against the challenge.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS. X
ISSN:
2590-1567
Año:
2019
Vol.:
1
Págs.:
100006
The aim of this work was to evaluate the mucus-permeating properties of nanocarriers using zein nanoparticles (NPZ) coated with a Gantrez (R) AN-thiamine conjugate (GT). NPZ were coated by incubation at different GT-to-zein ratios: 2.5% coating with GT (GT-NPZ1), 5% (GT-NPZ2) and 10% (GT-NPZ3). During the process, the GT conjugate formed a polymer layer around the surface of zein nanoparticles. For GT-NPZ2, the thickness of this corona was estimated between 15 and 20 nm. These nanocarriers displayed a more negative zeta potential than uncoated NPZ. The diffusivity of nanoparticles was evaluated in pig intestinal mucus by multiple particle tracking analysis. GT-NPZ2 displayed a 28-fold higher diffusion coefficient within the mucus layer than NPZ particles. These results align with in vivo biodistribution studies in which NPZ displayed a localisation restricted to the mucus layer, whereas GT-NPZ2 were capable of reaching the intestinal epithelium. The gastro-intestinal transit of mucoadhesive (NPZ) and mucus-permeating nanoparticles (GT-NPZ2) was also found to be different. Thus, mucoadhesive nanoparticles displayed a significant accumulation in the stomach of animals, whereas mucus-penetrating nanoparticles appeared to exit the stomach more rapidly to access the small intestine of animals.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2019
Vol.:
571
Págs.:
118699
The oral delivery of docetaxel (DTX) is challenging due to a low bioavailability, related to an important presystemic metabolism. With the aim of improving the bioavailability of this cytotoxic agent, nanoparticles from conjugates based on the copolymer of methyl vinyl ether and maleic anhydride (poly(anhydride)) and two different types of PEG, PEG2000 (PEG2) or methoxyPEG2000 (mPEG2), were evaluated. Nanoparticles, with a DTX loading close to 10%, were prepared by desolvation and stabilized with calcium, before purification and lyophilization. For the pharmacokinetic study, nanoparticles were orally administered to mice at a single dose of 30 mg/kg. The plasma levels of DTX were high, prolonged in time and, importantly, quantified within the therapeutic window. The relative oral bioavailability was calculated to be up to 56% when DTX was loaded in nanoparticles from poly(anhydride)-mPEG2000 conjugate (DTX-NP-mPEG2). Finally, a comparative toxicity study between equitoxic doses of free iv DTX and oral DTX-NP-mPEG2 was conducted in mice. Animals orally treated with DTX-loaded nanoparticles displayed less severe signs of hypersensitivity reactions, peripheral neurotoxicity, myelosuppression and hepatotoxicity than free iv docetaxel. In summary, poly(anhydride)-PEG conjugate nanoparticles appears to be adequate carries for the oral delivery of docetaxel.
Revista:
EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES
ISSN:
0928-0987
Año:
2019
Vol.:
128
Págs.:
81 - 90
Thiamine-coated nanoparticles were prepared by two different preparative methods and evaluated to compare their mucus-penetrating properties and fate in vivo. The first method of preparation consisted of surface modification of freshly poly(anhydride) nanoparticles (NP) by simple incubation with thiamine (T-NPA). The second procedure focused on the preparation and characterization of a new polymeric conjugate between the poly (anhydride) backbone and thiamine prior the nanoparticle formation (T-NPB). The resulting nanoparticles displayed comparable sizes (about 200 nm) and slightly negative surface charges. For T-NPA, the amount of thiamine associated to the surface of the nanoparticles was 15 mu g/mg. For in vivo studies, nanoparticles were labelled with either Tc-99m or Lumogen (R) Red. T-NPA and T-NPB moved faster from the stomach to the small intestine than naked nanoparticles. Two hours post-administration, for T-NPA and T-NPB, > 30% of the given dose was found in close contact with the intestinal mucosa, compared with a 13.5% for NP. Interestingly, both types of thiamine-coated nanoparticles showed a greater ability to cross the mucus layer and interact with the surface of the intestinal epithelium than NP, which remained adhered in the mucus layer. Four hours post-administration, around 35% of T-NPA and T-NPB were localized in the ileum of animals. Overall, both preparative processes yielded thiamine decorated carriers with similar physico-chemical and biodistribution properties, increasing the versatility of these nanocarriers as oral delivery systems for a number of biologically active compounds.
Revista:
COLLOIDS AND SURFACES B-BIOINTERFACES
ISSN:
0927-7765
Año:
2018
Vol.:
163
Págs.:
64 - 72
This work describes the feasibility of poly(anhydride) nanoparticles as carriers for the oral administration of glibenclamide (GB) as well as the in vivo evaluation of their hypolipidemic effect in a C. elegans model. For this purpose, and in order to increase the GB payload, the drug was encapsulated in nanoparticles in presence of cyclodextrins (either ßCD or HPßCD). The optimized nanoparticles displayed a size of about 220¿nm and a negative zeta potential (-40¿mV), with a drug loading up to 52¿¿g/mg. Small-angle neutron scattering studies suggested an internal fractal-like structure, based on the repetition of spherical blocks of polymeric units (about 5¿nm) grouped to form the nanoparticle. X-ray diffraction study confirmed the absence of crystalline GB molecules due to its dispersion into the nanoparticles, either entrapped in the polymer chains and/or included into cyclodextrin cavities. GB-loaded nanoparticles induced a significant reduction in the fat content of C. elegans. This hypolipidemic effect was slightly higher for the nanoparticles prepared with coencapsulated HPßCD (8.2%) than for those prepared with ßCD (7.9%) or in the absence of cyclodextrins (7.0%). In summary, the coencapsulation of cyclodextrins into poly(anhydride) nanoparticles could be an interesting strategy to develop new oral formulations of glibenclamide.
Revista:
JOURNAL OF DERMATOLOGICAL SCIENCE
ISSN:
0923-1811
Año:
2018
Vol.:
92
N°:
1
Págs.:
78 - 88
Background: Cutaneous leishmaniasis (CL) skin lesions are the result of a deregulated immune response, which is unable to eliminate Leishmania parasites. The control of both, parasites and host immune response, is critical to prevent tissue destruction. The skin ulceration has been correlated with high TNF-alpha level. Objective: Because human anti-TNF-alpha antibodies (Ab) have been successfully assayed in several mice inflammatory diseases, we hypothesized that their anti-inflammatory effect could optimize the healing of CL lesions achieved after topical application of paromomycin (PM), the current chemotherapy against CL. Methods and results: We first compared the in vitro efficacy of PM and Ab alone and the drug given in combination with Ab to assess if the Ab could interfere with PM leishmanicidal activity in L. major-infected bone marrow-derived macrophages. The combination therapy had similar antileishmanial activity to the drug alone and showed no influence on NO production, which allows macrophage-mediated parasite killing. Next, we demonstrated in an in vivo model of Imiquimod (R)-induced inflammation that topical Ab and PM inhibit the infiltration of inflammatory cells in the skin. In the efficacy studies in L. major-infected BALB/c mice, PM combined with Ab led to a sharp infection reduction and showed a stronger anti-inflammatory activity than PM alone. This was confirmed by the down-regulation of TNE-alpha, IL-1 beta, iNOS, IL 17, and CCL3 as well as by a decrease of the neutrophilic infiltrate during infection upon treatment with the Ab. Conclusions: In terms of parasite elimination and inflammation reduction, topical application of Ab in combination with PM was more effective than the drug alone. (C) 2018 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2018
Vol.:
547
N°:
1 - 2
Págs.:
97 - 105
The aim of this work was to prepare and evaluate cyclodextrins-modified poly(anhydride) nanoparticles to enhance the oral administration of glibenclamide. A conjugate polymer was synthesized by incorporating hydroxypropyl-beta-cyclodextrin to the backbone of poly(methylvinyl ether-co-maleic anhydride) via Steglich reaction. The degree of substitution of anhydride rings by cyclodextrins molecules was calculated to be 4.9% using H-NMR spectroscopy. A central composite design of experiments was used to optimize the preparative process. Under the optimal conditions, nanoparticles displayed a size of about 170 nm, a surface charge of - 47 mV and a drug loading of 69 mu g GB/mg. X-ray diffraction studies confirmed the loss of the crystalline structure of GB due to its dispersion into the nanoparticles, either included into cyclodextrin cavities or entrapped in the polymer chains. Glibenclamide was mainly release by Fickian-diffusion in simulated intestinal fluid. GB-loaded nanoparticles produced a hypolipidemic effect over C. elegans N2 wild-type and daf-2 mutant. The action mechanism included daf-2 and daf-28 genes, both implicated in the insulin signaling pathway of C. elegans. In summary, the covalent linkage of cyclodextrin to the poly(anhydride) backbone could be an interesting strategy to prepare nanoparticles for the oral administration of glibenclamide.
Revista:
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
ISSN:
0141-8130
Año:
2018
Vol.:
110
Págs.:
328 - 335
The aim of this work was to evaluate the potential application of an original oral immunotherapy, based on the use of nanoparticles, against an experimentally induced peanut allergy. In this context, a roasted peanut extract, containing the main allergenic proteins, were encapsulated into poly(anhydride) nanoparticles. The resulting peanut-loaded nanoparticles (PE-NP) displayed a mean size of about 150nm and a significantly lower surface hydrophobicity than empty nanoparticles (NP). This low hydrophobicity correlated well with a higher in vitro diffusion in pig intestinal mucus than NP and an important in vivo capability to reach the intestinal epithelium and Peyer's patches. The immunotherapeutic capability of PE-NP was evaluated in a model of pre-sensitized CDI mice to peanut. After completing therapy of three doses of peanut extract, either free or encapsulated into nanoparticles, mice underwent an intraperitoneal challenge. Anaphylaxis was evaluated by means of assessment of symptom scores and mouse mast cell protease-1 levels (mMCPT-1). PE-NP treatment was associated with significant lower levels of mMCPT-1, and a significant survival rate after challenge, confirming the protective effect of this formulation against the challenge. In summary, this nanoparticle-based formulation might be a valuable strategy for peanut-specific immunotherapy.
Autores:
Borges, S. C.; Ferreira, P. E. B.; da Silva, L. M.; et al.
Revista:
TOXICOLOGY
ISSN:
0300-483X
Año:
2018
Vol.:
396
Págs.:
13 - 22
The gastrointestinal tract is extremely sensitive to ischemia and reperfusion (I/R). Studies have reported that resveratrol (RSV) is able to combat damage caused by intestinal I/R. Because of its effectiveness in increasing the permanence and bioavailability of resveratrol in the intestinal epithelium, we investigated whether the effect of resveratrol-loaded in poly(anhydride) nanoparticles reduce oxidative stress and promote myenteric neuroprotection in the ileum of rats subjected to I/R. Physicochemical evaluations were performed on nanoparticles. The animals were divided into nine groups (n = 6/group) and treated every 48 h. Treatments with resveratrol (7 mg/kg of body weight) were applied 5 days before surgery and continued for 7 days after surgery (reperfusion period). The superior mesenteric artery was occluded to cause I/R injury. Oxidative stress, myeloperoxidase, nitrite, aspartate aminotransferase, alanine aminotransferase, immunolabeling of myenteric neurons and glial cells, and gastrointestinal transit was evaluated. Both nanoparticle formulations presented negative charge with homogeneous distribution, and the payload, showed an encapsulation efficiency of 60%. Resveratrol administered in free form prevented alterations that were caused by I/R. The results of the groups treated with RSV loaded nanoparticles presented similar results to the group treated with free resveratrol. Treatment with empty nanoparticles showed that poly(anhydride) is not an ideal nanocarrier for application in in vivo models of intestinal I/R injury, because of hepatotoxicity that may be caused by epithelial barrier dysfunction that triggers the translocation of nanoparticles.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2018
Vol.:
541
N°:
1 - 2
Págs.:
214 - 223
Bevacizumab-loaded nanoparticles (B-NP) were prepared by a desolvation process followed by freeze-drying, without any chemical, physical or enzymatic cross-linkage. Compared with typical HSA nanoparticles crosslinked with glutaraldehyde (B-NP-GLU), B-NP displayed a significantly higher mean size (310 nm vs. 180 nm) and a lower negative zeta potential (-15 mV vs. -36 mV). On the contrary, B-NP displayed a high payload of approximately 13% when measured by a specific ELISA, whereas B-NP-GLU presented a very low bevacizumab loading (0.1 mu g/mg). These results could be related to the inactivation of bevacizumab after reacting with glutaraldehyde. From B-NP, bevacizumab was released following an initial burst effect, proceeded by a continuous release of bevacizumab at a rate of 6 mu g/h. Cytotoxicity studies in ARPE cells were carried out at a single dose up to 72 h and with repeated doses over a 5-day period. Neither bevacizumab nor B-NP altered cell viability even when repeated doses were used. Finally, B-NP were labeled with Tc-99m and administered as eye drops in rats. Tc-99m-B-NP remained in the eye for at least 4 h while Tc-99m-HSA was rapidly drained from the administration point. In summary, HSA nanoparticles may be an appropriate candidate for ocular delivery of bevacizumab.
Revista:
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
ISSN:
1422-0067
Año:
2018
Vol.:
19
N°:
9
Págs.:
2816
Resveratrol is a naturally occurring polyphenol that provides several health benefits including cardioprotection and cancer prevention. However, its biological activity is limited by a poor bioavailability when taken orally. The aim of this work was to evaluate the capability of casein nanoparticles as oral carriers for resveratrol. Nanoparticles were prepared by a coacervation process, purified and dried by spray-drying. The mean size of nanoparticles was around 200 nm with a resveratrol payload close to 30 ¿g/mg nanoparticle. In vitro studies demonstrated that the resveratrol release from casein nanoparticles was not affected by the pH conditions and followed a zero-order kinetic. When nanoparticles were administered orally to rats, they remained within the gut, displaying an important capability to reach the intestinal epithelium. No evidence of nanoparticle "translocation" were observed. The resveratrol plasma levels were high and sustained for at least 8 h with a similar profile to that observed for the presence of the major metabolite in plasma. The oral bioavailability of resveratrol when loaded in casein nanoparticles was calculated to be 26.5%, 10 times higher than when the polyphenol was administered as oral solution. Finally, a good correlation between in vitro and in vivo data was observed.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2018
Vol.:
543
N°:
1 - 2
Págs.:
245 - 256
Nimodipine may be of interest to treat behavioral alterations and memory deficits. However, its oral administration is hampered by a low bioavailability. The aim of this work was to develop pegylated nanoparticles as oral carriers of nimodipine and test their capability to both reverse the anxiety and protect against cognitive impairment of in stressed mice. Pegylated nanoparticles (NMD-NP/PEG), with a size of 190 nm and a payload of 68 mu g/mg, significantly improve the oral bioavailability of nimodipine; about 7-times higher than for the control drug solution (62% vs 9%). The effect of oral nimodipine on the anxiety and cognitive capabilities in a model of stressed mice was also evaluated. NMD-NP/PEG displayed a poor effect on the anxiety-like behavior of animals. Nevertheless, only the treatment with NMD-NP/PEG exerted a protective effect against the memory impairments induced by chronic corticosterone administration, improving the cognitive capabilities of animals when compared with controls. These pegylated nanocarriers may represent a useful strategy to develop new oral treatments for preventing from cognitive impairments.
Revista:
EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES
ISSN:
0928-0987
Año:
2018
Vol.:
118
Págs.:
165 - 175
The aim of this work was to investigate the potential of pegylated poly(anhydride) nanoparticles to enhance the oral bioavailability of docetaxel (DTX). Nanoparticles were prepared after the incubation between the copolymer of methyl vinyl ether and maleic anhydride (Gantrez (R) AN), poly(ethylene glycol) (PEG2000 or PEG6000) and docetaxel (DTX). The oral administration of a single dose of pegylated nanoparticles to mice provided sustained and prolonged therapeutic plasma levels of docetaxel for up 48-72 h. In addition, the relative oral bioavailability of docetaxel was around 32%. The organ distribution studies revealed that docetaxel underwent a similar distribution when orally administered encapsulated in nanoparticles as when intravenously as Taxotere (R). This observation, with the fact that the clearance of docetaxel when loaded into the oral pegylated nanoparticles was found to be similar to that of intravenous formulation, suggests that docetaxel would be released at the epithelium surface and then absorbed to the circulation.
Revista:
EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS
ISSN:
0939-6411
Año:
2018
Vol.:
127
Págs.:
51 - 60
Cashew nut allergy is the second most commonly reported tree nut allergy. Traditional allergen immunotherapy presents several clinical drawbacks that can be reduced by using nanoparticles-basedallergen-delivery systems, modulating the immune response towards a protective one. In this context, the goal of this work was to assess the potential of poly(anhydride) nanoparticles (NP) for cashew nut oral immunization. Cashew nut allergens-loaded nanoparticles (CNE-NP) were prepared by solvent displacement method. After nanoparticles characterization, oral immunomodulation ability was evaluated in BALB/c mice. Our results demonstrated that CNE-NP induced a higher Th1/Th2 ratio in comparison with animals immunized with free cashew nut proteins. Indeed, a decrease in splenic Th2 cytokines (IL-4, IL-5, and IL-13), and an enhancement of pro-Th1 (IL-12 and IFN-¿) and regulatory (IL-10) cytokines was observed. Furthermore, mice orally immunized with CNE-NP presented an increased expansion of CD4+ T regulatory cells, such as CD4+Foxp3+ and CD4+LAP+, in the mesenteric lymph nodes. In conclusion, oral immunization with a single dose of poly(anhydride) nanoparticles loaded with cashew nut proteins leaded to a pro-Th1 and Treg immune response. Furthermore, their immunomodulatory properties could be introduced as a new approach for management of cashew nut allergy.
Revista:
FOOD CHEMISTRY
ISSN:
0308-8146
Año:
2018
Vol.:
239
Págs.:
879 - 888
The present work describes the encapsulation of probiotics using a by-product as wall material and a process feasible to be scaled-up: coacervation of soybean protein concentrate (SPC) by using calcium salts and spray-drying. SPC was extracted from soybean flour, produced during the processing of soybean milk, by alkaline extraction following isoelectric precipitation. Two probiotic strains were selected for encapsulation (Lactobacillus plantarum CECT 220 and Lactobacillus casei CECT 475) in order to evaluate the ability of SPC to encapsulate and protect bacteria from stress conditions. The viability of these encapsulated strains under in vitro gastrointestinal conditions and shelf-life during storage were compared with the most common forms commercialized nowadays. Results show that SPC is a feasible material for the development of probiotic microparticles with adequate physicochemical properties and enhanced significantly both probiotic viability and tolerance against simulated gastrointestinal fluids when compared to current available commercial forms.
Revista:
VACCINE
ISSN:
0264-410X
Año:
2018
Vol.:
36
N°:
49
Págs.:
7509 - 7519
Disruption of one or more components of the Tol-Pal system, involved in maintaining the integrity of the outer membrane of Gram-negative bacteria, has been proposed as a method to increase the yield obtained from natural production of outer membrane vesicles (OMV). We present a new OMV-based product, obtained from genetically modified Shigella flexneri 2a with a non-polar deletion in tolR and heat-inactivated (HT-Delta tolR). The S. flexneri Delta tolR strain lead to a higher release of vesicles, more than 8-times when compared to the yield obtained from chemically inactivated wild type strain. S. flexneri mutant strain appeared to be more sensitive to different chemical compounds, including antibiotics, bile salts or human complement and it was also less virulent in both in vitro and in vivo assays. The mutation produced some changes in the LPS O-chain and protein expression. S. flexneri Delta tolR was enriched in long and very long LPS O-chain and expressed a different pattern of surface proteins or lipoproteins. In vitro toxicity and activation properties were determined in Raw 267.4 macrophage cell line. HT-Delta tolR antigenic complex was non-cytotoxic and activation markers, such as MHC-II or CD40, were highly expressed during incubation with this product. Finally, preliminary studies on the antibody response elicited by HT-Delta tolR demonstrated a robust and diverse response in mice. Considering these promising results, HT-Delta toIR antigenic extract appears as a new potential vaccine candidate to face shigellosis.
Revista:
PHARMACOLOGICAL RESEARCH
ISSN:
1043-6618
Año:
2017
Vol.:
126
Págs.:
77 - 83
IDO is an enzyme that tumors use to create a state of immunosupression. 1-d-methyltryptophan (1-MT) is an IDO pathway inhibitor. After being successfully evaluated in preclinical studies, current clinical trials are actually analyzing its efficacy as monotherapy or in combination with multiple chemotherapeutic agents such as paclitaxel. 1-MT very poor solubility in water and many other solvents precludes its ease parenteral administration. It is currently administered by oral route because high daily doses were well-tolerated and effectively inhibited the IDO activity although only 25% of dose was recovered in plasma. The present work describes the preparation and characterization of 1-MT nanocrystals in order to enhance its solubility, dissolution rate, biodisponibility as well as facilitate its administration by parenteral route. A bottom-down approach of nanoprecipitation with an antisolvent was used for the fabrication of the nanocrystals and the choice of stabilizers was critical for reducing the size. Thermal analysis and x-ray diffraction indicated modifications in the drug crystalline state by the process. Through the reduction size and crystalline state modifications the dissolution characteristics of raw material were significantly increased. In a Lewis Lung cancer mice model, the nanocrystals strategy facilitated the sc administration and its antitumoral activity was similar to that of i.v. paclitaxel. The best efficacy was achieved when sc 1-MT nanocrystals were administered in combination with oral paclitaxel loaded in poly(anhydride) nanoparticles. Take together, 1-MT nanocrystals delivery performs a nanotechnological strategy suitable to modify the current route and schedule for its administration.
Autores:
Alvarez-Lorenzo, C. (Autor de correspondencia); Alonso, M. J.; Blanco, María José; et al.
Revista:
JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
ISSN:
1773-2247
Año:
2017
Vol.:
42
Págs.:
1 - 1
Autores:
Moreno, L. C.; Puerta, Elena; Suárez-Santiago, J. E.; et al.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2017
Vol.:
517
N°:
1 - 2
Págs.:
50 - 57
Quercetin has been identified as a promising compound with a neuroprotective potential against age-related neurodegenerative diseases such as Alzheimer's disease (AD). Nevertheless, the clinical application of quercetin is hampered by its low oral bioavailability. The aim of this work was to evaluate the capability of nanoencapsulated quercetin in zein nanoparticles (NPQ), that significantly improves the oral absorption and bioavailability of the flavonoid, as potential oral treatment for AD. For this purpose, SAMP8 mice were orally treated for two months with either NPQ (25mg/kg every 48h) or a solution of quercetin (Q; 25mg/kg daily). NPQ displayed a size of 260nm and a payload of about 70¿g/mg. For Q, no significant effects were observed in animals. On the contrary, the oral administration of NPQ improved the cognition and memory impairments characteristics of SAMP8 mice. These observations appeared to be related with a decreased expression of the hippocampal astrocyte marker GFAP. Furthermore, significant levels of quercetin were quantified in the brain of mice treated with nanoparticles. These findings highlight the potential of zein nanoparticles to promote the oral absorption of quercetin as well as the therapeutic potential of this flavonoid in AD pathogenesis.
Revista:
JOURNAL OF MEDICAL MICROBIOLOGY
ISSN:
0022-2615
Año:
2017
Vol.:
66
N°:
7
Págs.:
946 - 958
Purpose. The aim of this study was to develop an immunogenic protective product against Shigella flexneri by employing a simple and safe heat treatment-based strategy. Methodology. The physicochemical characteristics of naturally produced (OMV) and heat-induced (HT) outer-membrane vesicles from S. flexneri were examined, including a comparison of the protein content of the products. Toxicological and biodistribution studies, and a preliminary experiment to examine the protective effectiveness of HT in a murine model of S. flexneri infection, were also included. Results. This method simultaneously achieves complete bacterial inactivation and the production of the HT vaccine product, leading to a safe working process. The obtained HT complex presented a similar morphology (electron microscopy) and chemical composition to the classical OMV, although it was enriched in some immunogens, such as lipoproteins, OmpA or OmpC, among others. The HT formulation was not toxic and biodistribution studies performed in mice demonstrated that the vaccine product remained in the small intestine after nasal administration. Finally, a single dose of HT administered nasally was able to protect mice against S. flexneri 2a. Conclusion. The convenient and safe manufacturing process, and the preliminary biological evaluation, support the use of the self-adjuvanted HT complex as a new vaccine candidate to face shigellosis. Further development is required, such as additional immune analyses, to evaluate whether this new subunit vaccine can be useful in achieving full protection against Shigella.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2017
Vol.:
517
N°:
1 - 2
Págs.:
67 - 79
he main concerns with drugs designed for oral administration are their inactivation or degradation in the harsh conditions of the gastrointestinal tract, their poor solubility through the gastrointestinal mucus gel layer, the poor intestinal epithelium permeability that limits their absorption, and their toxicity. In this context, poly(anhydride) nanoparticles are capable of protecting the drug from the harsh environment, reduce the drug's toxicity and, by virtue of surface modification, to enhance or reduce their mucus permeability and the bioadhesion to specific target cells. The copolymer between methyl vinyl ether and maleic anhydride (commercialized as Gantrez® AN 119) are part of the poly(anhydride) nanoparticles. These biocompatible and biodegradable nanoparticles (NPs) can be modified by using different ligands. Their usefulness as drug carriers and their bioadhesion with components of the intestinal mucosa have been described. However, their toxicity, genotoxicity and mucus permeation capacity has not been thoroughly studied. The aim of this work was to evaluate and compare the in vitro toxicity, cell viability and in vitro genotoxicity of the bioadhesive empty Gantrez® AN 119 NPs modified with dextran, aminodextran, 2-hydroxypropyl-ß-cyclodextrin, mannosamine and poly-ethylene glycol of different molecular weights. Results showed that, in general, coated NPs exhibit better mucus permeability than the bare ones, those coated with mannosamine being the most permeable ones. The NPs studied did not affect cell metabolism, membrane integrity or viability of Caco-2 cells at the different conditions tested. Moreover, they did not induce a relevant level of DNA strand breaks and FPG-sensitive sites (as detected with the comet assay).
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2017
Vol.:
530
N°:
1-2
Págs.:
187 - 194
Gantrez (R) AN 119-based NPs have been developed as oral drug carriers due to their strong bioadhesive interaction with components of the gastrointestinal mucosa and to their adaptable surface. The use of mannosamine to coat Gantrez (R) AN 119-based NPs results in a high mucus-permeable carrier, able to reach the gastrointestinal epithelium. Although their efficacy to transport a therapeutic agent has been demonstrated, their safety has not yet been thoroughly studied. They have proved to be non-cytotoxic, non-genotoxic and non-mutagenic in vitro; however, the in vivo toxicity profile has not yet been determined. In this study, the in vivo genotoxic potential of Gantrez (R) AN 119 NPs coated with mannosamine (GN-MA-NP) has been assessed using the in vivo comet assay in combination with the enzyme formamidopyrimidine DNA glycosylase in mice, following the OECD test guideline 489. To determine the relevant organs to analyse and the sampling times, an in vivo biodistribution study was also carried out. Results showed a statistically significant induction of DNA strand breaks and oxidized bases in the duodenum of animals exposed to 2000 mg/kg bw. However, this effect was not observed at lower doses (i.e. 500 and 1000 mg/kg which are closer to the potential therapeutic doses) or in other organs. In conclusion, GN-MA-NP are promising nanocarriers as oral drug delivery systems.
Autores:
Sabaeifard, P.; Abdi-Ali, A.; Gamazo, C; et al.
Revista:
JOURNAL OF MEDICAL MICROBIOLOGY
ISSN:
0022-2615
Año:
2017
Vol.:
66
N°:
2
Págs.:
137 - 148
Purpose. Amikacin is one of the most effective antibiotics against Pseudomonas aeruginosa infections, but because of its high toxicity, the use of this antibiotic has been clinically limited. In the present study, amikacin was successfully loaded into a new formulation of nanoparticles (NPs) based on poly(D, L-lactide-co-glycolide) 50 : 50 in order to enhance the treatment efficacy. The synthetized amikacin-loaded PLGA nanoparticles with high drug loading and stability were used to eliminate P. aeruginosa cells in planktonic and biofilm states.
Methodology. P. aeruginosa PAO1 biofilm susceptibility studies were done using the minimum biofilm eradication concentration assay. The association of fluorescently labeled amikacin-loaded nanoparticles (A-NPs) with mouse monocyte macrophage cells (RAW 264.7), and the nanoparticles ability to interact and eradicate the bacterial cells even in the form of biofilms, was investigated using Flow cytometric studies and confocal laser scanning microscopy.
Results. Flow cytometric studies showed that these NPs were able to interact with planktonic and biofilm bacterial cells. Moreover, following 1 h of incubation of A-NPs with 1-day-old biofilm, it was found that particles penetrate through the entire biofilm thickness. Live/dead fluorescent staining followed by CLSM analysis showed that the A-NPs were more effective than free drug in biofilm eradication.
Conclusion. The good antibacterial and antibiofilm activities of A-NPs, in addition to their ability to enter macrophages without any cytotoxicity for these cells, make them a potential candidate to treat P. aeruginosa infections.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2017
Vol.:
523
N°:
1
Págs.:
418 - 426
In the last years, the development of nanomaterials has significantly increased due to the immense variety of potential applications in technological sectors, such as medicine, pharmacy and food safety. Focusing on the nanodevices for oral drug delivery, poly(anhydride) nanoparticles have received extensive attention due to their unique properties, such as their capability to develop intense adhesive interactions within the gut mucosa, their modifiable surface and their biodegradable and easy-to produce profile. However, current knowledge of the possible adverse health effects as well as, toxicological information, is still exceedingly limited. Thus, we investigated the capacity of two poly(anhydride) nanoparticles, Gantrez (R) AN 119 -NP (GN-NP) and Gantrez (R) AN 119 covered with mannosamine (GN-MA-NP), and their main bulk material (Gantrez (R) AN 119-Polymer), to induce DNA damage and thymidine kinase (TK+/-) mutations in L5178Y TK+/- mouse lymphoma cells after 24 h of exposure. The results showed that GN-NP, GN-MA-NP and their polymer did not induce DNA strand breaks or oxidative damage at concentrations ranging from 7.4 to 600 mu g/mL. Besides, the mutagenic potential of these nanoparticles and their polymer revealed no significant or biologically relevant gene mutation induction at concentrations up to 600 mu g/mL under our experimental settings. Considering the non-genotoxic effects of GN-NP and GN-MA-NP, as well as their exceptional properties, these nanoparticles are promising nanocarriers for oral medical administrations. (C) 2017 Elsevier B.V. All rights reserved.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2017
Vol.:
519
N°:
1 - 2
Págs.:
263 - 271
Glibenclamide is a sulfonylurea used for the oral treatment of type II diabetes mellitus. This drug shows low bioavailability as consequence of its low solubility. In order to solve this problem, the interaction with cyclodextrin has been proposed. This study tries to provide an explanation about the processes involved in the formation of GB-beta CDs complexes, which have been interpreted in different ways by several authors. Among native cyclodextrins, beta CD presents the most appropriate cavity to host glibenclamide molecules showing A(L) solubility diagrams (K-1:1 approximate to 1700 M-1). However, A(L)- solubility profiles were found for pa) derivatives, highlighting the coexistence of several phenomena involved in the drug solubility enhancement. At low CD concentration, the formation of inclusion complexes can be studied and the stability constants can be calculated (K-1:1 approximate to 1700 M-1) Whereas at high CD concentration, the enhancement of GB solubility would be mainly attributed to the formation of nanoaggregates of CD and GB-CD complexes (sizes between 100 and 300 nm). The inclusion mode into beta CD occurs through the cyclohexyl ring of GB, adopting a semi-folded conformation which maximizes the hydrogen bond network. As consequence of all these phenomena, a 150-fold enhancement of drug solubility has been achieved using beta-cyclodextrin derivatives. Thus, its use has proven to be an interesting tool to improve the oral administration of glibenclamide in accordance with dosage bulk and dose/solubility ratio requirements. (C) 2017 Elsevier B.V. All rights reserved.
Revista:
EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS
ISSN:
0939-6411
Año:
2017
Vol.:
121
Págs.:
104 - 112
The aim of this work was to evaluate the capability of zein nanoparticles as oral carriers for glibenclamide (GB). Nanoparticles were prepared by a desolvation procedure in the presence of lysine as stabilizer. A central composite design was used to optimize this preparative process. Under the selected conditions, nanoparticles displayed a size of about 190 nm, a surface charge of -37 mV and a payload of 45 mu g GB/mg. Small-angle neutron scattering and X-ray diffraction techniques suggested an internal fractal-like structure, based on the repetition of spherical blocks of zein units (about 20 nm) grouped to form the nanoparticles. This structure, stabilized by lysine molecules located at the surface, would determine the release of GB (molecularly trapped into the nanoparticles) by a pure diffusion mechanism. Moreover, GB-loaded nanoparticles induced a significant hypolipidemic effect with a reduction of about 15% in the fat content of C. elegans worms. In addition, did not induce any significant modification in the lifespan of worms. In summary, the employment of zein nanoparticles as delivery systems of glibenclamide may be an interesting approach to develop new oral formulations of this antidiabetic drug.
Revista:
IMMUNOTHERAPY
ISSN:
1750-743X
Año:
2017
Vol.:
9
N°:
15
Págs.:
1205 - 1218
Background: Peanut allergy is the most common cause of anaphylaxis and food-related death. However, there is currently no approved immunotherapy treatment. Hence, this warrants the need for relevant and convenient animal models to test for adequate immunotherapies. Materials & methods: In this study, we compared three mouse strains: CD1, BALB/c and C57, to select a model of peanut allergy. After that, we conducted then a therapeutic study using an immunogenic peanut extract encapsulated in nanoparticles made with polymer Gantrez((R)) following the solvent displacement method. Results & conclusion: After implementing a dosing schedule with oral commercial peanut butter, the antibody responses, cytokine profiles and, above all, the anaphylaxis induced after a challenge with peanut proteins, showed that the outbred CD1 strain was the most susceptible to peanut sensitization. CD1 sensitized mice were orally immunized with three doses of the nanoparticle formulation capable of protecting them against the severe anaphylactic symptoms induced by the peanut challenge.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2017
Vol.:
533
N°:
1
Págs.:
236 - 244
Vaccine delivery using microneedles (MNs) represents a safe, easily disposable and painless alternative to traditional needle immunizations. The MN delivery of DNA vaccines to the dermis may result in a superior immune response and/or an equivalent immune response at a lower vaccine dose (dose-sparing). This could be of special interest for immunization programs against neglected tropical diseases such as leishmaniasis. In this work, we loaded a MN device with 60 mu g of a plasmid DNA cocktail encoding the Leishmania infantum nucleosomal histones H2A, H2B, H3 and H4 and compared its immunogenicity and protective capacity against conventional s.c. or i.d. injection of the plasmid. Mice immunized with MNs showed increased ratios of IFN-gamma/IL-10, IFN-gamma/IL-13, IFN-gamma/IL-4, and IFN-gamma/TGF-beta in the spleens and lymph nodes compared with mice immunized by s.c. and i.d. routes. Furthermore, CCXCL9, CXCL10 and CCL2 levels were also higher. These data suggest that the nucleic acid immunization using MNs produced a better bias towards a Th1 response. However, none of the immunizations strategies were able to control Leishmania major infection in BALB/c mice, as illustrated by an increase in lesion size and parasite burden.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2017
Vol.:
530
N°:
1 - 2
Págs.:
377 - 386
Glibenclamide is an antidiabetic drug showing low bioavailability as consequence of its low solubility. To solve this drawback, the interaction with cyclodextrins has been proposed. The formation of GB-beta CDs inclusion complexes was carried out using different methods, beta CD derivatives and drug-to-cyclodextrin ratios. The structures of the corresponding complexes have been studied by molecular modelling, X-ray diffraction and differential thermal analysis. The dissolution behavior of inclusion complexes has been compared to that of pure GB. Dimeric inclusion complexes were obtained with different CD disposals, head-to-head for beta CD and head-to-tail for HP beta CD and RM beta CD. Amorphous inclusion complexes were obtained by employing methods of freeze-drying or coevaporation in ammonia-water. However, crystalline structures were formed by kneading and coevaporation in ethanol/water in the case of GB-beta CD complexes. The arrangement of these structures depended on the GB:beta CD ratio, yielding cage type structures for 1:3 and 1:5 ratios and channel-type structures for higher GB contents. The amount of GB released and its dissolution rate was considerably increased by the use of amorphous inclusion complexes; whereas, slower GB release rates were found from crystalline inclusion complexes formed by kneading or coevaporation in ethanol/water. In addition, it was found that the porous structure strongly conditioned the GB dissolution rate from crystalline products.
Revista:
JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
ISSN:
1773-2247
Año:
2017
Vol.:
42
Págs.:
207 - 214
This work describes the development of a nanoemulsion composition suitable for the topical administration of vaccines based on outer membrane vesicles. The application onto bare skin of outer membrane antigens from Salmonella enterica (size between 20 and 100 nm), included in a nanoemulsion, induced a clear specific antibody response. In contrast to other semisolid formulations used (i.e. simple and polyethyleneglycol ointments), the occlusive effect provided by the nanoemulsion together with the penetration enhancer effect of Labrasol® and Plurol® oleique, increased antigen uptake by epidermal and transfollicular routes. Nevertheless, when the antigenic complex was loaded into poly(anhydride) nanoparticles and then incorporated in the nanoemulsion, the specific IgG response in serum was significantly lower. These results suggest that the higher size of nanoparticles (about 230 nm) and their non-deformable nature could hamper the arrival of the antigen to the immunological inducer sites when administered on the skin. Immunohistochemistry analysis confirmed that these bacterial vesicles were able to penetrate the skin reaching the dermis only when antigens were administered in the form of nanoemulsion. Further research will determine the full potential of this formulation for topical application of this specific type of vaccines.
Revista:
FOOD AND CHEMICAL TOXICOLOGY
ISSN:
0278-6915
Año:
2017
Vol.:
106
Págs.:
477 - 486
In the last years, casein nanoparticles have been proposed as carriers for the oral delivery of biologically active compounds. However, till now, no information about their possible specific hazards in vivo was available. The aim of this work was to assess the safety of casein nanoparticles when administered orally to animals through a 90 days dose-repeated toxicity study (OECD guideline 408), that was performed in Wistar rats under GLP conditions. After 90 days, no evidences of significant alterations in animals treated daily with 50,150 or 500 mg/kg bw of nanoparticles were found. This safety agrees well with the fact that nanoparticles were not absorbed and remained within the gut as observed by radiolabelling in the biodistribution study. After 28 days, there was a generalized hyperchloremia in males and females treated with the highest dose of 500 mg/kg bw, that was coupled with hypernatremia in the females. These effects were related to the presence of mannitol which was used as excipient in the formulation of casein nanoparticles. According to these results, the No Observed Adverse Effect Level (NOAEL) could be established in 150 mg/kg bw/day and the Lowest Observed Effect Level (LOEL) could be established in 500 mg/kg bw/day. (C) 2017 Published by Elsevier Ltd.
Revista:
NANOMEDICINE
ISSN:
1743-5889
Año:
2017
Vol.:
12
N°:
11
Págs.:
1209 - 1211
Revista:
NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE
ISSN:
1549-9634
Año:
2017
Vol.:
13
N°:
1
Págs.:
103 - 110
Zein nanoparticles were evaluated as nanocarriers to promote the oral bioavailability of quercetin and, thus, improve its anti-inflammatory effect on a mouse model of induced endotoxemia. For this purpose, the flavonoid and 2-hydroxypropyl-ß-cyclodextrin were encapsulated in zein nanoparticles. The resulting nanoparticles displayed a mean size of about 300nm and the payload was calculated to be close to 70¿g/mg nanoparticle. The release of quercetin from zein nanoparticles followed a zero-order kinetic. After oral administration, nanoparticles provided high and sustained levels of quercetin in plasma and the relative oral bioavailability was calculated to be approx. 60%. Animals treated with quercetin-loaded nanoparticles (1 dose every two days; 1week) presented endotoxic symptoms less severe than those observed in animals treated with the oral solution of the flavonoid (1 dose every day; 1week). This was further corroborated by the significantly low circulating TNF-alpha in the quercetin-loaded nanoparticles treated mice.
Autores:
Sabaeifard, P.; Abdi-Ali, A.; Soudi, M. R.; et al.
Revista:
EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES
ISSN:
0928-0987
Año:
2016
Vol.:
93
Págs.:
392 - 398
Amikacin is a very effective aminoglycoside antibiotic but according to its high toxicity, the use of this antibiotic has been limited. The aim of this study was to formulate and characterize amikacin loaded PLGA nanoparticles. Nanoparticles were synthetized using a solid-in-oil-in-water emulsion technique with different ratio of PLGA 50:50 (Resomer 502H) to drug (100:3.5, 80:3.5 and 60:3.5), two different concentrations of stabilizer (pluronic F68) (0.5% or 1%) and varied g forces to recover the final products. The most efficient formulation based on drug loading (26.0±1.3mug/mg nanoparticle) and encapsulation efficiency (76.8±3.8%) was the one obtained with 100:3.5 PLGA:drug and 0.5% luronic F68, recovered by 20,000*g for 20min. Drug release kinetic study indicated that about 50% of the encapsulated drug was released during the first hour of incubation in phospahte buffer, pH7.4, 37°C, 120rpm. Using different cell viability/cytotoxicity assays, the optimized formulation showed no toxicity against RAW macrophages after 2 and 24h of exposure. Furthermore, released drug was active and maintained its bactericidal activity against Pseudomonas aeruginosa in vitro. These results support the effective utilization of the PLGA nanoparticle formulation for amikacin in further in vivo studies.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2016
Vol.:
506
N°:
1-2
Págs.:
116 - 128
Camptothecin (CPT), a molecule that shows powerful anticancer activity, is still not used in clinic due to its high hydrophobicity and poor active form's stability. In order to solve these drawbacks, the combination between poly(anhydride) nanoparticles and cyclodextrins was evaluated. CPT-loaded nanoparticles, prepared in the presence of 2-hydroxypropyl-ß-cyclodextrin, (HPCD-NP) displayed a mean size close to 170nm and a payload of 50¿g per mg (25 times higher than the one of the control nanoparticles). CPT was not released from nanoparticles under gastric conditions. However, under intestinal conditions, about 50% of the drug content was released as a burst, whereas the remained drug was released following a zero-order kinetic. Pharmacokinetic studies revealed that the CPT plasma levels, from orally administered nanoparticles, were high and sustained up to 48h. The CPT oral bioavailability was 7-fold higher than the value obtained with the control, whereas its clearance was significantly lower than for the aqueous suspension. These observations may be directly related to a prolonged residence time of nanoparticles in close contact with the intestinal epithelium, the presence of the cyclodextrin that decreases the CPT transformation into its inactive form and the generation of an acidic microenvironment during the degradation of the poly(anhydride) that would prevent the transformation of the active lactone into the inactive carboxylate conformation.
Autores:
Wang, Z.; Tan, J.; McConville, C.; et al.
Revista:
NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE
ISSN:
1549-9634
Año:
2016
Vol.:
13
N°:
2
Págs.:
641 - 657
Disulfiram (DS), an anti-alcoholism drug, shows very strong cytotoxicity in many cancer types. However its clinical application in cancer treatment is limited by the very short half-life in the bloodstream. In this study, we developed a poly lactic-co-glycolic acid (PLGA)-encapsulated DS protecting DS from the degradation in the bloodstream. The newly developed DS-PLGA was characterized. The DS-PLGA has very satisfactory encapsulation efficiency, drug-loading content and controlled release rate in vitro. PLGA encapsulation extended the half-life of DS from shorter than 2minutes to 7hours in serum. In combination with copper, DS-PLGA significantly inhibited the liver cancer stem cell population. CI-isobologram showed a remarkable synergistic cytotoxicity between DS-PLGA and 5-FU or sorafenib. It also demonstrated very promising anticancer efficacy and antimetastatic effect in liver cancer mouse model. Both DS and PLGA are FDA approved products for clinical application. Our study may lead to repositioning of DS into liver cancer treatment.
Autores:
Pu, L.; Wang, J.; Li, N.; et al.
Revista:
ACS APPLIED MATERIALS AND INTERFACES
ISSN:
1944-8244
Año:
2016
Vol.:
8
N°:
22
Págs.:
13724 - 13734
Intramuscular gene delivery materials are of great importance in plasmid-based gene therapy system, but there is limited information so far on how to design and synthesize them. A previous study showed that the peptide dendron-based triblock copolymer with its components arranged in a reversed biomembrane architecture could significantly increase intramuscular gene delivery and expression. Herein, we wonder whether copolymers with biomembrane-mimicking arrangement may have similar function on intramuscular gene delivery. Meanwhile, it is of great significance to uncover the influence of electric charge and molecular structure on the function of the copolymers. To address the issues, amphiphilic triblock copolymers arranged in hydrophilic-hydrophobic-hydrophilic structure were constructed despite the paradoxical characteristics and difficulties in synthesizing such hydrophilic but electroneutral molecules. The as-prepared two copolymers, dendronG2(L-lysine-OH)-poly propylene glycol(2k)(PPG(2k))-dendronG2(L-lysine-OH) (rL(2)PL(2)) and dendronG3(L-lysine-OH)-PPG(2k)-dendronG3(L-lysine-OH) (rL(3)PL(3)), were in similar structure but had different hydrophilic components and surface charges, thus leading to different capabilities in gene delivery and expression in skeletal muscle. rL(2)PL(2) was more efficient than Pluronic L64 and rL(3)PL(3) when mediating luciferase, beta-galactosidase, and fluorescent protein expressions. Furthermore, rL(2)PL(2)-mediated growth-hormone-releasing hormone expression could significantly induce mouse body weight increase in the first 21 days after injection. In addition, both rL(2)PL(2) and rL(3)PL(3) showed good in vivo biosafety in local and systemic administration. Altogether, rL(2)PL(2)-mediated gene expression in skeletal muscle exhibited applicable potential for gene therapy. The study revealed that the molecular structure and electric charge were critical factors governing the function of the copolymers for intramuscular gene delivery. It can be concluded that, combined with the previous study, both structural arrangements either reverse or similar to the biomembrane are effective in designing such copolymers. It also provides an innovative way in designing and synthesizing new electroneutralized triblock copolymers, which could be used safely and efficiently for intramuscular gene delivery.
Revista:
NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE
ISSN:
1549-9634
Año:
2015
Vol.:
11
N°:
8
Págs.:
2003 - 2012
Patients affected by cutaneous leishmaniasis need a topical treatment which cures lesions without leaving scars. Lesions are produced not only by the parasite but also by an uncontrolled and persistent inflammatory immune response. In this study, we proposed the loading of ß-lapachone (ß-LP) in lecithin-chitosan nanoparticles (NP) for targeting the drug to the dermis, where infected macrophages reside, and promote wound healing. Although the loading of ß-LP in NP did not influence the drug antileishmanial activity it was critical to achieve important drug accumulation in the dermis and permeation through the skin. When topically applied in Leishmania major infected BALB/c mice, ß-LP NP achieved no parasite reduction but they stopped the lesion progression. Immuno-histopathological assays in CL lesions and quantitative mRNA studies in draining lymph nodes confirmed that ß-LP exhibited anti-inflammatory activity leading to the down-regulation of IL-1ß and COX-2 expression and a decrease of neutrophils infiltrate.
Revista:
FOOD HYDROCOLLOIDS
ISSN:
0268-005X
Año:
2015
Vol.:
44
Págs.:
399 - 406
Food grade proteins can be viewed as an adequate material for the preparation of nanoparticles and microparticles. They offer several advantages such as their digestibility, price and a good capability to interact with a wide variety of compounds and nutrients. The aim of this work was to prepare and characterize casein nanoparticles for the oral delivery of folic acid. These nanoparticles were prepared by a coacervation process, stabilized with either lysine or arginine and, finally, dried by spray-drying. For some batches, the effect of a supplementary treatment of nanoparticles (before drying) with high hydrostatic pressure on the properties of the resulting carriers was also evaluated. The resulting nanoparticles displayed a mean size close to 150 nm and a folic acid content of around 25 ¿g per mg nanoparticle. From the in vitro release studies, it was observed that casein nanoparticles acted as gastro-resistant devices and, thus, folic acid was only released under simulated intestinal conditions. For the pharmacokinetic study, folic acid was orally administered to laboratory animals as a single dose of 1 mg/kg. Animals treated with folic acid-loaded casein nanoparticles displayed significantly higher serum levels than those observed in animals receiving an aqueous solution of the vitamin. As a consequence the oral bioavailability of folic acid when administered as casein nanoparticles was calculated to be around 52%, a 50% higher than the traditional aqueous solution. Unfortunately, the treatment of casein nanoparticles by high hydrostatic pressure modified neither the release profile of the vitamin nor its oral bioavailability.
Revista:
JOURNAL OF PHARMACEUTICAL SCIENCES
ISSN:
0022-3549
Año:
2015
Vol.:
104
N°:
9
Págs.:
2877 - 2886
The aim of the work was to evaluate in vitro and in vivo the effect of the addition of poly(ethylene glycol) (PEG) to paclitaxel (PTX)¿cyclodextrin poly(anhydride) nanoparticles. For this, PTX in poly(anhydride) nanoparticles complexed with cyclodextrins (either 2-hydroxypropyl-ß-cyclodextrin or ß-cyclodextrin) and combined with PEG 2000 were prepared by the solvent displacement method. Intestinal permeability in vitro and in vivo pharmacokinetic studies in C57BL/6J mice were performed. Nanoparticle formulations containing PTX increased its apparent permeability through rat intestine in vitro in the Ussing chambers, enhancing its permeability 10¿15 times compared with commercial Taxol®. In addition, in pharmacokinetic studies, drug plasma levels were observed for at least 24 h leading to a relative oral bioavailability between 60% and 80% for PTX complexed with cyclodextrin and loaded in pegylated poly(anhydride) nanoparticles after oral gavage. In all, PTX¿cyclodextrin complexes encapsulated in pegylated nanoparticles managed to promote the intestinal uptake of the drug displaying sustained plasma levels after oral administration to laboratory animals with a more prolonged plasma profile compared with the formulation with no PEG at all. Therefore, pegylated poly(anhydride) nanoparticles represent a promising carrier for the oral delivery of PTX.
Revista:
METHODS IN MOLECULAR BIOLOGY
ISSN:
1064-3745
Año:
2015
Vol.:
1225
Págs.:
139 - 149
Revista:
EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS
ISSN:
0939-6411
Año:
2015
Vol.:
97
N°:
A
Págs.:
280 - 289
The aim of this work was to investigate the mucus-permeating properties of poly(ethyleneglycol)-coated nanoparticles prepared from the copolymer of methyl vinyl ether and maleic anhydride (Gantrez® AN) after oral administration in rats. Nanoparticles were ¿decorated¿ with PEGs of different molecular masses (PEG2000, PEG6000 and PEG10000) at a PEG-to-polymer ratio of 0.125. All the PEG-coated nanoparticles displayed a mean size of ~150 nm, slightly negative ¿ values and a ¿brush¿ conformation as determined from the calculation of the PEG density. For in vivo studies, nanoparticles were labelled with either 99mTc or fluorescent tags. Naked nanoparticles displayed a higher ability to interact with the mucosa of the stomach than with the small intestine. However, these interactions were restricted to the mucus layer covering the epithelial surface, as visualised by fluorescence microscopy. On the contrary, PEG-coated nanoparticles moved rapidly to the intestine, as determined by imaging, and, then, were capable to develop important interactions with the mucosa, reaching the surface of the epithelium. These mucus permeating properties were more intense for nanoparticles coated with PEG2000 or PEG6000 than with PEG10000. However, the capability of nanocarriers to develop adhesive interactions within the mucosa decreased when prepared at excessive PEG densities.
Autores:
Gamazo, C; Bussmann, H.; Giemsa, S.; et al.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2015
Vol.:
496
N°:
2
Págs.:
922 - 930
Understanding how nanoparticles are formed and how those processes ultimately determine the nanoparticles¿ properties and their impact on their capture by immune cells is key in vaccination studies. Accordingly, we wanted to evaluate how the previously described poly (anhydride)-based nanoparticles of the copolymer of methyl vinyl ether and maleic anhydride (NP) interact with macrophages, and how this process depends on the physicochemical properties derived from the method of preparation. First, we studied the influence of the desolvation and drying processes used to obtain the nanoparticles. NP prepared by the desolvation of the polymers in acetone with a mixture of ethanol and water yielded higher mean diameters than those obtained in the presence of water (250 nm vs. 180 nm). In addition, nanoparticles dried by lyophilization presented higher negative zeta potentials than those dried by spray-drying (¿47 mV vs. ¿35 mV). Second, the influence of the NP formulation on the phagocytosis by J774 murine macrophage-like cell line was investigated. The data indicated that NPs prepared in the presence of water were at least three-times more efficiently internalized by cells than NPs prepared with the mixture of ethanol and water. Besides, lyophilized nanoparticles appeared to be more efficiently taken up by J744 cells than those dried by spray-drying. To further understand the specific mechanisms involved in the cellular internalization of NPs, different pharmacological inhibitors
Autores:
Silva, M. F.; Winkler-Hechenleitner, A. A.; Irache, Juan M.; et al.
Revista:
MATERIALS RESEARCH
ISSN:
1516-1439
Año:
2015
Vol.:
18
N°:
6
Págs.:
1400 - 1406
Poly(glycolide-co-lactide) (PLGA) nanospheres containing magnetic materials have been extensively studied because of its biomedical applications. Therefore, it is very important to know thermal properties of these materials in addition to other physical properties. Thermal degradation activation energy (E-alpha) of PLGA nanospheres with maghemite entrapment (PLGA-Mag), PLGA nanospheres (hollow spheres) (PLGA-H) obtained by an emulsion method and unprocessed PLGA (PLGA-R) were calculated by isoconversional Vyazovkin method based on data of TG analysis in order to evaluate modifications in thermal behavior caused by nanospheres obtainment process or by maghemite entrapment. Both hydrodynamic diameter in the range of 200-250 nm and polydispersity index lower than 0.3 are considered satisfactory. Thermal degradation of PLGA-R begins at higher temperatures than those of PLGA-H and PLGA-Mag, but processed samples presented increase in thermal stability, which was greater before processing by emulsion and in the presence of the magnetic materials. PLGA-Mag presents superparamagnetic behavior at room temperature.
Revista:
JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
ISSN:
1773-2247
Año:
2015
Vol.:
30
N°:
B
Págs.:
450 - 457
The aim of this work was to prepare and evaluate the capability of zein nanoparticles for oral drug delivery. More particularly, in this work, the ability of these nanoparticles to improve the oral bioavailability of folic acid is reported. The nanoparticles were prepared by a desolvation process, followed by purification via ultrafiltration and drying in a spray-drier apparatus. The resulting nanoparticles displayed a mean size close to 200 nm with negative zeta potential and a payload of 54 ¿g folic acid per mg nanoparticle. From the in vitro release studies, it was observed that folic acid was only released from nanoparticles in simulated intestinal conditions. In vivo biodistribution studies, with radiolabelled or fluorescently marked nanoparticles, revealed that nanoparticles remained within the gut and were capable of interacting with the protective mucus layer of the jejunum. For the pharmacokinetic study, folic acid was orally administered to rats as a single dose of 1 mg/kg.
The relatively oral bioavailability of folic acid, when encapsulated in zein nanoparticles, was around 70%: two-times higher than the value obtained with an aqueous solution of the vitamin. This fact might be explained by the mucoadhesive properties of these nanoparticles.
Revista:
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
ISSN:
0021-8561
Año:
2015
Vol.:
63
N°:
23
Págs.:
5603 - 5611
Resveratrol offers pleiotropic health benefits including a reported ability to inhibit lipopolysaccharide (LPS)-induced cytokine production. The aim of this work was to prepare, characterize, and evaluate a resveratrol nanoparticulate formulation based on zein. For this purpose, the oral bioavailability of the encapsulated polyphenol as well as its anti-inflammatory effects in a mouse model of endotoxic shock was studied. The resveratrol-loaded nanoparticles displayed a mean size of 307 +/- 3 nm, with a negative zeta potential (-51.1 +/- 1.55 mV), and a polyphenol loading of 80.2 +/- 3.26 mu g/mg. In vitro, the release of resveratrol from the nanoparticles was found to be pH independent and adjusted well to the Peppas-Sahlin kinetic model, suggesting a mechanism based on the combination of diffusion and erosion of the nanoparticle matrix. Pharmacokinetic studies demonstrated that zein-based nanoparticles provided high and prolonged plasma levels of the polyphenol for at least 48 h. The oral bioavailability of resveratrol when administered in these nanoparticles increased up to 50% (19.2-fold higher than for the control solution of the polyphenol). Furthermore, nanoparticles administered daily for 7 days at 15 mg/kg were able to diminish the endotoxic symptoms induced in mice by the intraperitoneal administration of LPS (i.e., hypothermia, piloerection, and stillness). In addition, serum tumor necrosis factor-alpha (TNF-alpha) levels were slightly lower (approximately 15%) than those observed in the control.
Revista:
JOURNAL OF PHARMACY AND PHARMACEUTICAL SCIENCES
ISSN:
1482-1826
Año:
2014
Vol.:
17
N°:
4
Págs.:
541 - 553
Purpose: The objective of this work was to evaluate the effect in the immune response produced by CpG oligodeoxynucleotides (ODN) co-encapsulated with the antigen ovalbumin (OVA) within poly(lactic-co-glycolic) acid (PLGA) 502 and 752 microparticles (MP). Methods: MP were prepared by blending 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) with PLGA and Total Recirculation One Machine System (TROMS) technology and contained OVA along with CpG sequences associated to DOTAP. After confirming the integrity of both encapsulated molecules, BALB/c mice were immunized with the resulting MP and OVA-specific antibodies and cytokine production were assessed in order to determine the immunological profile induced in mice. Results: One ¿m near non-charged MP co-encapsulated very efficiently both OVA and CpG ODN. The release of both OVA and CpG was slow and incomplete irrespective of polymer. The results of the immune response induced in BALB/c mice indicated that, depending on the PLGA polymer used, co-encapsulation did not improve the immunogenicity of the antigen, compared either with the simply co-administration of both antigen and CpG, or with the microencapsulated antigen. Thus, mice immunized with OVA associated to PLGA 756 displayed an IgG2a characterized response which was biased to an IgG1 profile in case of CpG co-encapsulation. On the contrary, the co-encapsulation of CpG with OVA into PLGA 502 significantly improved the isotype shifting in comparison with the one showed by mice immunized with OVA loaded PLGA 502. Conclusion: This study underlines the importance of MP characteristics to fully exploit simultaneous antigen and CpG ODN particulate delivery as effective vaccine construct.
Revista:
INDIAN JOURNAL OF PHARMACEUTICAL SCIENCES
ISSN:
0250-474X
Año:
2014
Vol.:
76
N°:
2
Págs.:
132 - 137
A simple and reliable high performance liquid chromatography method was developed and validated for the rapid determination of cyclosporine A in new pharmaceutical dosage forms based on the use of poly (methylvinylether¿co¿maleic anhydride) nanoparticles. The chromatographic separation was achieved using Ultrabase C18 column (250×4.6 mm, 5 ¿m), which was kept at 75°. The gradient mobile phase consisted of
acetonitrile and water with a flow rate of 1 ml/min. The effluent was monitored at 205 nm using diode array detector. The method exhibited linearity over the assayed concentration range (22¿250 ¿g/ml) and demonstrated good intraday and interday precision and accuracy (relative standard deviations were less than 6.5% and the deviation from theoretical values is below 5.5%). The detection limit was 1.36 ¿g/ml. This method was also applied for quantitative analysis of cyclosporine A released from poly (methylvinylether¿co¿maleic anhydride) nanoparticles.
Key words: Cyclosporine A, HPLC¿UV, nanoparticles, poly (methylvinylether¿co¿maleic anhydride), oral administration
Revista:
CLINICAL AND VACCINE IMMUNOLOGY
ISSN:
1556-6811
Año:
2014
Vol.:
21
N°:
8
Págs.:
1106 - 1112
In the last decade, peanut allergy has increased substantially. Significant differences in the prevalence among different countries are attributed to the type of thermal processing. In spite of the high prevalence and the severe reaction induced by peanuts, there is no immunotherapy available. The aim of this work was to evaluate the potential application of poly(anhydride) nanoparticles (NPs) as immunoadjuvants for peanut oral immunotherapy. NPs loaded with raw or roasted peanut proteins were prepared by a solvent displacement method and dried by either lyophilization or spray-drying. After physicochemical characterization, their adjuvant capacity was evaluated after oral immunization of C57BL/6 mice. All nanoparticle formulations induced a balanced T(H)1 and T(H)2 antibody response, accompanied by low specific IgE induction. In addition, oral immunization with spray-dried NPs loaded with peanut proteins was associated with a significant decrease in splenic T(H)2 cytokines (interleukin 4 [IL-4], IL-5, and IL-6) and enhancement of both T(H)1 (gamma interferon [IFN-¿]) and regulatory (IL-10) cytokines. In conclusion, oral immunization with poly(anhydride) NPs, particularly spray-dried formulations, led to a pro-T(H)1 immune response.
Revista:
JOURNAL OF NANOPHARMACEUTICS AND DRUG DELIVERY
ISSN:
2167-9312
Año:
2014
Vol.:
2
N°:
2
Págs.:
161 - 168
Conventional marketed formulations of cyclosporine A (CsA) have considerable limitations owing to poor drug bioavailability and extensive inter- and intrapatient variability. Nanoparticles are currently used as an alternative to solve these issues, but attainment of an effective nanoformulation loaded with CsA is a significant challenge. In this study, we described the preparation and characterization of poly[methyl vinyl ether-co-maleic anhydride (PVM/MA) nanoparticles loaded with CsA and examined in vitro release of the drug from the novel formulation. Derivatives of cyclodextrin were used to improve drug loading in the nanoparticles and modulate the CsA release profile. Nanoparticles were prepared using a solvent displacement method, and characterized based on particle size, zeta potential, encapsulation efficiency, product yield, X-ray and thermal analyses. Our results showed that the nanoparticles are ~100¿243 nm in size and the amount of CsA loaded is higher when the nanoformulation contains hydroxypropyl-ß-cyclodextrin than hydroxypropyl-¿-cyclodextrin. Furthermore, these nanoparticles showed biphasic release behaviour in physiological media, consistent with characteristics of nanoparticle drug delivery systems in general. This biphasic profile indicates that CsA is released from nanoparticles through diffusion in the initial phase and subsequent time-period. The in vitro release profile of CsA from nanoformulations with hydroxypropyl-¿-cyclodextrin additionally showed a higher initial burst effect in all simulated physiological media used. Our results collectively support the potential utility of a nanoformulation with hydroxypropyl-ß-cyclodextrin in improving the bioavailability of CsA in vivo.
Autores:
Liu, P.; Wang, Z.; Brown, S.; et al.
Revista:
ONCOTARGET
ISSN:
1949-2553
Año:
2014
Vol.:
5
N°:
17
Págs.:
7471 - 7485
Breast cancer stem cells (BCSCs) are pan-resistant to different anticancer agents and responsible for cancer relapse. Disulfiram (DS), an antialcoholism drug, targets CSCs and reverses pan-chemoresistance. The anticancer application of DS is limited by its very short half-life in the bloodstream. This prompted us to develop a liposomeencapsulated DS (Lipo-DS) and examine its anticancer effect and mechanisms in vitro and in vivo. The relationship between hypoxia and CSCs was examined by in vitro comparison of BC cells cultured in spheroid and hypoxic conditions. To determine the importance of NF¿B activation in bridging hypoxia and CSC-related pan-resistance, the CSC characters and drug sensitivity in BC cell lines were observed in NF¿B p65 transfected cell lines. The effect of Lipo-DS on the NF¿B pathway, CSCs and chemosensitivity was investigated in vitro and in vivo. The spheroid cultured BC cells manifested CSC characteristics and pan-resistance to anticancer drugs. This was related to the hypoxic condition in the spheres. Hypoxia induced activation of NF¿B and chemoresistance. Transfection of BC cells with NF¿B p65 also induced CSC characters and pan-resistance. Lipo-DS blocked NF¿B activation and specifically targeted CSCs in vitro. Lipo-DS also targeted the CSC population in vivo and showed very strong anticancer efficacy. Mice tolerated the treatment very well and no significant in vivo nonspecific toxicity was observed. Hypoxia induced NF¿B activation is responsible for stemness and chemoresistance in BCSCs. Lipo-DS targets NF¿B pathway and CSCs. Further study may translate DS into cancer therapeutics.
Revista:
NANOMEDICINE
ISSN:
1743-5889
Año:
2014
Vol.:
9
N°:
14
Págs.:
2109 - 2121
Aim: The authors report a novel approach for enhancing the oral absorption of paclitaxel (PTX) by encapsulation in poly(anhydride) nanoparticles (NPs) containing cyclodextrins and poly(ethylene glycol). Materials & methods: Formulations were prepared using the solvent displacement method. Subsequently, pharmacokinetics and organ distribution assays were evaluated after oral administration into C57BL/6J mice. In addition, antitumor efficacy studies were performed in a subcutaneous tumor model of Lewis lung carcinoma. Results: PTX-loaded NPs displayed sizes between 190-300 nm. Oral NPs achieved drug plasma levels for at least 24 h, with an oral bioavailability of 55-80%. Organ distribution studies revealed that PTX, orally administered in NPs, underwent a similar distribution to intravenous Taxol® (Bristol-Myers Squibb, NJ, USA). For in vivo antitumor assays, oral strategy maintained a slower tumor growth than intravenous Taxol. Conclusion: PTX orally administered in poly(anhydride) NPs, combined with cyclodextrins and poly(ethylene glycol), displayed sustained plasma levels and significant antitumor effect in a syngenic tumor model of carcinoma in mice.
Revista:
INTERNATIONAL JOURNAL OF PHARMACEUTICS
ISSN:
0378-5173
Año:
2014
Vol.:
459
N°:
1-2
Págs.:
1-9
Revista:
EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES
ISSN:
0928-0987
Año:
2014
Vol.:
62
Págs.:
309 - 316
Topical therapy is the ideal outpatient treatment of cutaneous leishmaniasis (CL) because of the ease of administration and lower cost. It could be suitable as monotherapy for localized cutaneous leishmaniasis (LCL) or in combination with systemic therapies for more severe forms of the disease. Although paromomycin (PM) ointment can be recommended for the treatment of LCL caused by Leishmaniamajor, a more effective topical treatment should be achieved regarding the physicochemical properties of this aminoglucoside and its rather poor intrinsic antileishmanial activity, that hampers the accumulation of enough amount of drug in the dermis (where the infected macrophages home) to exert its activity. In this work, we determined a 50% effective dose of 5.6 ¿M for a novel compound, bis-4-aminophenyldiselenide, against L. major intracellular amastigotes. This compound and PM were formulated in chitosan hydrogels and ex vivo permeation and retention studies in the different skin layers were performed with pig ear skin in Franz diffusion cells. The results showed that less than 2¿4% of the diselenide drug penetrated and permeated through the skin. In contrast, the percentage of PM penetration was about 25¿60% without important retention in the skin. When topically applied to lesions of L. major infected BALB/c mice, the novel diselenide chitosan formulation was unable to slow lesion progression and reduce parasite burden. Considerations during the process of novel drug development and
Revista:
JOURNAL OF BIOMEDICAL NANOTECHNOLOGY
ISSN:
1550-7033
Año:
2013
Vol.:
9
N°:
11
Págs.:
1891 - 1903
The use of bioadhesive polymers as nanodevices has emerged as a promising strategy for oral delivery of therapeutics. In this regard, poly(anhydride) nanoparticles have shown great potential for oral drug delivery and vaccine purposes. However, despite extensive research into the biomedical and pharmaceutical applications of poly(anhydride) nanoparticles, there are no studies to evaluate the interaction of these nanoparticles at a cellular level. Therefore, the main objectives of this study were to evaluate the cytotoxicity as well as the cell interaction of different poly(anhydride) nanoparticles: conventional (NP), nanoparticles containing 2-hydroxypropyl-beta-cyclodextrin (NP-HPCD) and nanoparticles coated with poly(ethylene glycol) 6000 (PEG-NP). For this purpose, nanoparticles were prepared by solvent displacement method and labelled with BSA-FITC. Nanoparticles displayed a size about 175 nm with negative surface charge. Cytotoxicity studies were developed by MTS and LDH assays in HepG2 and Caco-2 cells. Results showed that only in HepG2 cells, NP and NP-HPCD induced significant cytotoxicity at the highest concentrations (1 and 2 mg/mL) and incubation times (48 and 72 h) tested. Studies to discriminate between cytoadhesion and cytoinvasion were performed at 4 degrees C and 37 degrees C in Caco-2 cell line as intestinal cell model. Nanoparticles showed cytoadhesion to the cell surface but not internalization; PEG-NP was the most bioadhesive followed by NP-HPCD and NP as demonstrated by flow cytometry. Finally, cellular localization of particles by fluorescence confocal microscopy confirmed the association of these nanoparticles with cells. Thus, this study demonstrated the safety of NP, NP-HPCD and PEG-NP at cellular level and its bioadhesive properties within cells.
Revista:
VACCINE
ISSN:
0264-410X
Año:
2013
Vol.:
31
N°:
32
Págs.:
3288 - 3294
Shigellosis is one of the leading causes of diarrhea worldwide with more than 130 million cases annually. Hence, the research of an effective vaccine is still a priority. Unfortunately, a safe and efficacious vaccine is not available yet. We have previously demonstrated the capacity of outer membrane vesicles (OMVs) to protect mice against an experimental infection with Shigella flexneri. Now, we present results on the capacity of this antigenic complex to confer a longer-term protection by oral or nasal routes when encapsulated into nanoparticles. OMVs were encapsulated in poly(anhydride) nanoparticles (NP) prepared by a solvent displacement method with the copolymer poly methyl vinyl ether/maleic anhydride. OMVs loaded into nanoparticles (NP-OMVs) were homogeneous and spherical in shape, with a size of 148nm (PdI=0.2). BALB/c mice were immunized with OMVs either free or encapsulated in nanoparticles by nasal (20¿g or 10¿g of OMVs) or oral route (100¿g or 50¿g of OMVs). All immunized animals remained in good health after administration. Challenge infection was performed intranasally on week 8th with a lethal dose of 5×10(7)CFU/mouse of S. flexneri 2a. The number of dead mice after challenge was recorded daily. Results confirmed the value of OMVs as a vaccine. By oral route, the OMV-vaccine was able to protect independently either the dose or the formulation. When vaccine was delivered by nasal route, encapsulation into NPs resulted beneficial in increasing protection from 40% up to 100% when low dose was administered. These results are extraordinary promising and put in relevance the positive effect of nanoencapsulation of the OMV subcellular vaccine.
Revista:
ANNALES PHARMACEUTIQUES FRANCAISES
ISSN:
0003-4509
Año:
2013
Vol.:
71
N°:
2
Págs.:
109 - 118
Paclitaxel is an anticancer drug used as solution for perfusion for the treatment of certain types of cancers. In the last years, a number of strategies have been proposed for the development of an oral formulation of this drug. However, this task is quite complicated due to the poor aqueous solubility of paclitaxel as well as the fact that this compound is substrate of the intestinal P-glycoprotein and the cytochrome P450 enzymatic complex. In this work, we have developed pegylated nanoparticles with mucopenetrating properties in order to conduct paclitaxel onto the surface of the enterocyte. These nanoparticles displayed a size of about 180 nm and a drug loading close to 15% by weight. The pharmacokinetic study in mice has shown that these nanoparticles were capable to offer therapeutic plasma levels of paclitaxel up to 72 hours. In addition, the oral relative bioavailability of paclitaxel when loaded in nanoparticles pegylated with poly(ethylene glycol) 2000 (PEG) was found to be 85%. In a subcutaneous model of tumour in mice, these pegylated nanoparticles administered orally every 3 days have demonstrated a similar efficacy than Taxol® administered intravenously every day during 9 days. All of these results suggested that these pegylated nanoparticles were capable to cross the mucus layer of the gut and, then, reach the surface of the enterocytes. The PEG molecules would facilitate the adhesion of nanoparticles to this epithelial surface, minimise the pre-systemic metabolism of paclitaxel and, thus, promote its absorption.
Autores:
Fernandes-Silva, M.; Winkler-Hechenleitner, A. A.; de-Oliveira, D. ; et al.
Revista:
EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES
ISSN:
0928-0987
Año:
2013
Vol.:
49
N°:
3
Págs.:
343 - 351
Magnetic nanoparticles have been proposed as interesting tools for biomedical purposes. One of their promising utilization is the MRI in which magnetic substances like maghemite are used in a nanometric size and encapsulated within locally biodegradable nanoparticles. In this work, maghemite has been obtained by a modified sol-gel method and encapsulated in polymer-based nanospheres. The nanospheres have been prepared by single emulsion evaporation method. The different parameters influencing the size, polydispersity index and zeta potential surface of nanospheres were investigated. The size of nanospheres was found to increase as the concentration of PLGA increases, but lower sizes were obtained for 3 min of sonication time and surfactant concentration of 1%. Zeta potential response of magnetic nanospheres towards pH variation was similar to that of maghemite-free nanospheres confirming the encapsulation of maghemite within PLGA nanospheres. The maghemite entrapment efficiency and maghemite content for nanospheres are 12% and 0.59% w/w respectively.
Autores:
Santos, D. M.; Carneiro, M. W.; de-Moura, T. R.; et al.
Revista:
NANOMEDICINE
ISSN:
1743-5889
Año:
2013
Vol.:
9
N°:
7
Págs.:
985 - 995
We recently demonstrated that immunization with polyester poly(lactide-co-glycolide acid) (PLGA) nanoparticles loaded with the 11-kDa Leishmania vaccine candidate kinetoplastid membrane protein 11 (KMP-11) significantly reduced parasite load in vivo. Presently, we explored the ability of the recombinant PLGA nanoparticles to stimulate innate responses in macrophages and the outcome of infection with Leishmania braziliensis in vitro. Incubation of macrophages with KMP-11-loaded PLGA nanoparticles significantly decreased parasite load. In parallel, we observed the augmented production of nitric oxide, superoxide, TNF-¿ and IL-6. An increased release of CCL2/MCP-1 and CXCL1/KC was also observed, resulting in macrophage and neutrophil recruitment in vitro. Lastly, the incubation of macrophages with KMP-11-loaded PLGA nanoparticles triggered the activation of caspase-1 and the secretion of IL-1ß and IL-18, suggesting inflammasome participation. Inhibition of caspase-1 significantly increased the parasite load. We conclude that KMP-11-loaded PLGA nanoparticles promote the killing of intracellular Leishmania parasites through the induction of potent innate responses.
Autores:
Petrov, P. D.; Yoncheva, K.; Mokreva, P.; et al.
Revista:
SOFT MATTER
ISSN:
1744-683X
Año:
2013
Vol.:
9
N°:
36
Págs.:
8745 - 8753
The synthesis and aggregation behaviour in aqueous media of novel amphiphilic poly(ethylene oxide)- block-poly(n-butyl acrylate)-block-poly(acrylic acid) (PEO¿PnBA¿PAA) triblock terpolymers were studied. Terpolymers composed of two highly asymmetric hydrophilic PEO (113 monomer units) and PAA (10¿17 units) blocks, and a longer soft hydrophobic PnBA block (163 or 223 units) were synthesized by atom transfer radical polymerisation (ATRP) of n-butyl acrylate and tert-butyl acrylate (tBA), followed by selective hydrolysis of the PtBA blocks. These terpolymers are not directly soluble in water but form defined spherical micelles by employing the dialysis method as confirmed by dynamic light scattering (DLS) and cryogenic transmission microscopy (cryo-TEM). Based on terpolymer architecture and composition, a three-layered micellar structure comprising a PnBA core, a PEO/PAA middle layer, and a PEO outer layer is suggested. The micelles do not dissociate to very low concentrations and, therefore, are promising candidates for long-circulating drug delivery systems. Further, as evidenced by high-performance liquid chromatography (HPLC), the micelles can load and release, without burst effect, the hydrophobic drug paclitaxel.
Revista:
REV ESP MED NUCL IMAGEN MOL
ISSN:
2253-654X
Año:
2013
Vol.:
32
N°:
2
Págs.:
92 - 97
Purpose: To optimize radiolabeling with (99m)Tc of mannosylated Gantrez(®) nanoparticles loaded with the Brucella Ovis antigen (Man-NP-HS) and to carry out biodistribution studies in mice after ocular administration of the nanoparticles.
Material and methods: Man-NP-HS nanoparticles were prepared by the solvent displacement method. They were purified, lyophilized and characterized. Following this, they were radiolabeled with 74 MBq of (99m)TcO4(-) previously reduced with an acidic stannous chloride solution, working in absence of oxygen and at a final pH of 4. Radiolabeling yield was evaluated by TLC. Biodistribution studies were carried out in mice after ocular administration of the formulation and control of free (99m)TcO4(-). To do so, the animals were humanely killed at 2 and 24hours after the ocular administration and activity in organs was measured in a Gamma counter.
Results: Radiolabeling yield obtained was greater than 90%. Biodistribution studies of (99m)Tc-Man-NP-HS showed radioactivity accumulated at 2 and 24hours in nasal and ocular mucosa and gastrointestinal tract, in contrast to biodistribution of free (99m)TcO4(-) that remained concentrated in the skin around the eye and gastrointestinal tract.
Conclusion: Biodistribution studies of (99m)Tc-Man-NP-HS after ocular instillation have made it possible to demonstrate its biodistribution in nasal mucosa and gastrointestinal tract. This characteristic is essential as an antigenic delivery system throughout the ocular mucosa. This, together with its elevated immune response, effective protection and intrinsic avirulence make them a suitable anti-Brucella vaccine candidate.
Revista:
EXPERT REVIEW OF VACCINES
ISSN:
1476-0584
Año:
2013
Vol.:
12
N°:
1
Págs.:
43 - 55
The burden of dysentery due to shigellosis among children in the developing world is still a major concern. A safe and efficacious vaccine against this disease is a priority, since no licensed vaccine is available. This review provides an update of vaccine achievements focusing on subunit vaccine strategies and the forthcoming strategies surrounding this approach. In particular, this review explores several aspects of the pathogenesis of shigellosis and the elicited immune response as being the basis of vaccine requirements. The use of appropriate Shigella antigens, together with the right adjuvants, may offer safety, efficacy and more convenient delivery methods for massive worldwide vaccination campaigns.
Autores:
Fernandes-Silva, M.; Winkler-Hechenleitner, A. A.; Gómez-Pineda, E. A.; et al.
Revista:
PAKISTAN JOURNAL OF MEDICAL SCIENCES
ISSN:
1682-024X
Año:
2013
Vol.:
1
N°:
2
Págs.:
30 - 31
Revista:
METHODS
ISSN:
1046-2023
Año:
2013
Vol.:
60
N°:
3
Págs.:
264 - 268
Shigellosis is one of the leading causes of diarrhea worldwide with more than 165 million cases annually. Hence, a vaccine against this disease is a priority, but no licensed vaccine is still available. Considering target population as well as intrinsic risks of live attenuated vaccines, non-living strategies appear as the most promising candidates. Remarkably, the preservation of antigenic properties is a major concern since inactivation methods of bacteria affect these qualities. We previously reported the use of a subcellular antigen complex for vaccination against shigellosis, based on outer membrane vesicles (OMVs) released from Shigella flexneri. Now, we describe in more detail the employment of binary ethylenimine (BEI) for inactivation of Shigella and its subsequent effect on the antigenic conservation of the vaccinal product. Results demonstrate the effectiveness of BEI treatment to completely inactivate Shigella cells without disturbing the antigenicity and immunogenicity of the OMVs. Thus, OMVs harvested after BEI inactivation were able to protect mice against an experimental infection with S. flexneri.
Revista:
JOURNAL OF CONTROLLED RELEASE
ISSN:
0168-3659
Año:
2012
Vol.:
162
N°:
3
Págs.:
553 - 560
The use of sub-unit vaccines can solve some drawbacks associated with traditional attenuated or inactivated ones. However, in order to improve their immunogenicity, these vaccines needs to be associated to an appropriate adjuvant which, adequately selected, may also offer an alternative pathway for administration. The aim of this work was to evaluate the protection offered by the hot saline complex extracted from Brucella ovis (HS) encapsulated in mannosylated nanoparticles (MAN-NP-HS) when instilled conjunctivally in mice. Nanoparticles displayed a size of 300 nm and the antigen loading was close to 30 mu g per mg nanoparticle. Importantly, encapsulated HS maintained its protein profile, structural integrity and antigenicity during and after the preparative process of nanoparticles. The ocular immunization was performed on BALB/c mice. Eight weeks after vaccination animals were challenged with B. ovis, and 3 weeks later, were slaughtered for bacteriological examinations. Animals immunized with MAN-NP-HS displayed a 3-log reduction in spleen CFU compared with unvaccinated animals. This degree of protection was significantly higher than that observed for the commercial vaccine (Rev1) subcutaneously administered. Interestingly, the mucosal IgA response induced by MAN-NP-HS was found to be much more intense than that offered by Rev1 and prolonged in time. Furthermore, the elicited IL-2, IL-4 and.-IFN levels showed good correlation with the degree of protection. On the other hand, biodistribution studies in animals were performed with nanoparticles labelled with either (99m)technetium or rhodamine B isothiocyanate. The biodistribution revealed that, after instillation, MAN-NP-HS moved from the palpebral area to the nasal region and, the gastrointestinal tract. This profile of distribution was different to that observed for free (TcO4)-Tc-99m-colloids, which remained for at least 24 h in the site of administration. In summary, mannosylated nanoparticles appear to be a safe and suitable adjuvant for conjunctival vaccination. (C) 2012 Elsevier B. V. All rights reserved.
Revista:
Journal of investigational allergology & clinical immunology
ISSN:
1018-9068
Año:
2012
Vol.:
22
N°:
Suppl 1
Págs.:
7 - 15
Revista:
EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS
ISSN:
0939-6411
Año:
2012
Vol.:
82
N°:
2
Págs.:
241-249
Allergen-specific immunotherapy is based on the administration of allergens with the main disadvantage of inducing an allergic reaction. Within this context, we report the generation of an adjuvant and allergen-delivery system for peanut allergen immunotherapy with reduced IgE induction. Therefore, we prepared and characterized poly(anhydride) nanoparticles loaded with peanut proteins using the solvent displacement method, with some modifications in the manufacturing process. The precipitation of polymer was performed with either a mixture of ethanol and water or water. The resultant nanoparticles were dried by either freeze-drying or spray-drying, respectively. Poly(anhydride) nanoparticles loaded with peanut proteins were successfully developed, achieving both high encapsulation efficiency (70-80%) and manufacturing yield (60-80%). After intradermal immunization of mice (C57Bl/6) with peanut proteins incorporated into poly(anhydride) nanoparticles, a strong mixed T(H)1/T(H)2-type immune response was observed. Furthermore, we also provide, to our knowledge for the first time, clear evidence of the influence of formulation design on the immunostimulatory properties of nanoparticles. Taken together, our findings indicate that poly(anhydride) nanoparticles are efficient stimulators of immune responses and promising adjuvants and allergen-delivery systems applied for immunotherapy. (C) 2012 Elsevier B.V. All rights reserved.
Autores:
Prieto, E.; Puente, B.; Uixera, A.; et al.
Revista:
OPHTHALMIC RESEARCH
ISSN:
0030-3747
Año:
2012
Vol.:
48
N°:
3
Págs.:
109-117
Aim: To prepare and evaluate the in vitro release of memantine-loaded poly(anhydride) (Gantrez (R)) nanoparticles (NPs). The clinical safety and retinal toxicity caused by unloaded NPs after sub-Tenon and intravitreal ocular injections were also evaluated. Methods: Preparation and characterization of this type of NP as well as the in vitro release study are described. Twenty-three healthy New Zealand rabbits were used for clinical and histological assessment after sub-Tenon and intravitreal ocular injections of unloaded NPs. Results: The amount of drug associated with NPs was 55 mu g of memantine/mg of NP. The release profile of memantine from this type of NPs was characterized by an initial burst effect, followed by continuous release of the drug for at least 15 days. No relevant complications were found during the clinical follow-up. The histological evaluation suggested that Gantrez NPs are well tolerated after sub-Tenon ocular injection and that signs of inflammation during the first days after intravitreal ocular injections can be considered a normal reaction of the eye's defence mechanism. Copyright (C) 2012 S. Karger AG, Basel
Revista:
JOURNAL OF BIOMEDICINE AND BIOTECHNOLOGY
ISSN:
1110-7243
Revista:
ANALES DEL SISTEMA SANITARIO DE NAVARRA
ISSN:
1137-6627
Año:
2012
Vol.:
35
N°:
1
Págs.:
41 - 51
La inmunoterapia para el tratamiento de enfermedades alérgicas implica ciertas desventajas, que pueden ser reducidas si se emplean adyuvantes adecuados, que sean capaces de amplificar la respuesta inmune con un efecto alergénico mínimo. En ese contexto, las formas farmacéuticas más prometedoras para aumentar la eficacia y seguridad de la inmunoterapia, parecen ser las micro y nanopartículas, de polímeros biodegradables y liposomas. En esta revisión describimos estudios previos de nuestro grupo en los que empleamos como adyuvante nanopartículas Gantrez® AN y demostramos su capacidad de estimular el sistema inmune. Empleamos dos tipos de nanopartículas, con y sin lipopolisacárido de Brucella ovis como inmunomodulador en un modelo de ratón alérgico a L. perenne. Encontramos que los ratones sensiblizados a Phleum cuando recibían inmunoterapia con nanopartículas Lolium-Gantrez® estaban protegidos de la anafilaxia inducida por el alérgeno tanto en las tasas de mortalidad como en los niveles de MCP-1. Probamos asimismo estas formulaciones por vía oral en un modelo animal sensibilizado a ovoalbúmina y comprobamos que les protegía también del shock anafiláctico.
Autores:
Zabaleta, V.; Ponchel, G.; Salman, H.; et al.
Revista:
EUROPEAN JOURNAL OF PHARMACEUTICS AND BIOPHARMACEUTICS
ISSN:
0939-6411
Año:
2012
Vol.:
81
N°:
3
Págs.:
514 - 523
The aim of this work was to study the potential of pegylated poly(anhydride) nanoparticles as carriers for the oral delivery of paclitaxel (PTX). Paclitaxel is an anticancer drug, ascribed to the class IV of the Biopharmaceutical Classification system, characterised for its low aqueous solubility and to act as a substrate of the P-glycoprotein and cytochrome P450. For the pegylation of nanoparticles, three different poly(ethylene glycol) (PEG) were used: PEG 2000 (PTX-NP2), PEG 6000 (PTX-NP6) and PEG 10,000 (PTX-NP10). The transport and permeability of paclitaxel through the jejunum mucosa of rats was determined in Ussing chambers, whereas its oral bioavailability was studied in rats. The loading of PTX in pegylated nanoparticles increased between 3 and 7 times the intestinal permeability of paclitaxel through the jejunum compared with the commercial formulation Taxol. Interestingly, the permeability of PTX was significantly higher for PTX-NP2 and PTX-NP6 than for PTX-NP10. In the in vivo studies, similar results were obtained. When PTX-NP2 and PTX-NP6 were administered to rats by the oral route, sustained and therapeutic plasma levels of paclitaxel for at least 48 h were observed. The relative oral bioavailability of paclitaxel delivered in nanoparticles was calculated to be 70% for PTX-NP2, 40% for PTX-NP6 and 16% in case of PTX-NP10. All of these observations would be related with both the bioadhesive properties of these carriers and the inhibitory effect of PEG on the activity of both P-gp and P450 cytochrome.
Revista:
PHARMACEUTICAL RESEARCH
ISSN:
0724-8741
Año:
2012
Vol.:
29
N°:
9
Págs.:
2615 - 2627
To evaluate the acute and subacute toxicity of poly(anhydride) nanoparticles as carriers for oral drug/antigen delivery.
Three types of poly(anhydride) nanoparticles were assayed: conventional (NP), nanoparticles containing 2-hydroxypropyl-beta-cyclodextrin (NP-HPCD) and nanoparticles coated with poly(ethylene glycol) 6000 (PEG-NP). Nanoparticles were prepared by a desolvation method and characterized in terms of size, zeta potential and morphology. For in vivo oral studies, acute and sub-acute toxicity studies were performed in rats in accordance to the OECD 425 and 407 guidelines respectively. Finally, biodistribution studies were carried out after radiolabelling nanoparticles with (99m)technetium.
Nanoparticle formulations displayed a homogeneous size of about 180 nm and a negative zeta potential. The LD50 for all the nanoparticles tested was established to be higher than 2000 mg/kg bw. In the sub-chronic oral toxicity studies at two different doses (30 and 300 mg/kg bw), no evident signs of toxicity were found. Lastly, biodistribution studies demonstrated that these carriers remained in the gut with no evidences of particle translocation or distribution to other organs.
Poly(anhydride) nanoparticles (either conventional or modified with HPCD or PEG6000) showed no toxic effects, indicating that these carriers might be a safe strategy for oral delivery of therapeutics.
Revista:
Molecular Imaging and Biology
ISSN:
1536-1632
Año:
2011
Vol.:
13
N°:
6
Págs.:
1215 - 1223
Purpose: Study by molecular imaging the biodistribution of poly(anhydride) nanoparticles after oral administration.
Procedures: Poly (anhydride) nanoparticles (NP) and cyclodextrin-tagged nanoparticles (CD-NP) were radiolabelled with Tc-99m. Radiochemical purity was measured with a double-solvent chromatography system and the absence of undesirable components was confirmed by size and polydispersion measurement of the technetium-labelled nanoparticles by photon correlation spectroscopy. Single photon emission computed tomography (SPECT) fused computed tomography (CT) in vivo molecular imaging was used for biodistribution studies in small animals.
Results: SPECT-CT images revealed activity only in the gastrointestinal tract. Thirteen percent of the given dose of CD-NP and 3% of the given dose of conventional NP were found in the stomach at 8 h.
Conclusion: No evidence of translocation or distribution out of gastrointestinal tract was found. CD-NP moved significantly more slowly inside the gut than conventional NP, probably due to their physico-chemical structure that allows stronger interactions with the gut mucosa.
Revista:
Vaccine
ISSN:
0264-410X
Año:
2011
Vol.:
29
N°:
46
Págs.:
8222 - 8229
Revista:
VETERINARY PARASITOLOGY
ISSN:
0304-4017
Año:
2011
Vol.:
180
N°:
1-2
Págs.:
47 - 71
Nanomedicine can be defined as the application of nanotechnology to the prevention and treatment of diseases as well as for diagnosis purposes. In this context, the development of various types of drug-carrier nanodevices offers new strategies for targeted drug delivery, minimising the secondary effects and the toxicity associated to drug widespread to healthy organs or cells. This review is divided in two different parts. The first one summarizes the main types of nanomedicines developed in the past few decades, including drug nanocrystals, polymer therapeutics, lipid-nanosized and polymeric-nanosized drug delivery systems. The second part of our review is devoted, more specifically, to the presentation of polymeric nanoparticles. Here, we discuss various aspects of nanoparticle formulation, characterization, behaviour in the body and some of their potential applications. More particularly we present some approaches for the treatment of cancer, treatment of infectious diseases and the potential of these nanoparticles as adjuvants for vaccination purposes.
Revista:
Vaccine
ISSN:
0264-410X
Año:
2011
Vol.:
41
N°:
29
Págs.:
7130 - 7135
Revista:
DRUG DEV IND PHARM
ISSN:
0363-9045
Año:
2010
Vol.:
36
N°:
6
Págs.:
676 - 690
Revista:
Vaccine
ISSN:
0264-410X
Año:
2010
Vol.:
28
N°:
17
Págs.:
3038 - 3046
Revista:
Journal of Controlled Release
ISSN:
0168-3659
Año:
2010
Vol.:
145
N°:
1
Págs.:
2 - 8
Revista:
International Journal of Pharmaceutics
ISSN:
0378-5173
Año:
2010
Vol.:
390
N°:
1
Págs.:
37 - 44
Revista:
Journal of Microencapsulation
ISSN:
0265-2048
Año:
2010
Vol.:
27
N°:
5
Págs.:
460 - 469
A commercially available chitosan with a degree of deacetylation (DD) of 85% and a molecular weight (Mw) of 400 kDa was modified by acetylation with acetic anhydride to obtain a chitosan with a DD of 75%. Both polysaccharides were used to prepare DNA-chitosan nanoparticles by charge interactions with pDNA (coacervation process). Both resulting nanoparticles showed an almost total DNA loading efficiency (96%) and displayed similar physico-chemical properties with a size of similar to 200 nm and a zeta potential close to +20 mV. In order to study the effect of the DD on the properties of DNA-chitosan nanoparticles as gene delivery systems, the hydrodynamics-based procedure was used. The transgene expression was observed using either the green fluorescent protein (GFP) or the luciferase (Luc) as reporter genes. After the hydrodynamic injection, the DNA-chitosan nanoparticles were accumulated in the liver, where the transgene expression was mostly localized. Interestingly, the decrease of the DD affected the transgene expression, improving the initial burst effect and accelerating the DNA release. Both combined effects led to an increase in the transgene expression levels. In addition, the emitted bioluminescence could be detected over 105 days for all the formulations injected. The calculation of the kinetic parameters (C(max), AUC, Ke, t(1/2) Ke and MET) gave some interesting information regarding the abilities to control the DNA release of the two DNA-chitosan formulations tested and allowed narrower comparisons.
Revista:
CLINICAL AND VACCINE IMMUNOLOGY
ISSN:
1556-6811
Año:
2010
Vol.:
17
N°:
9
Págs.:
1356 - 1362
The mechanisms that underlie the potent Th1-adjuvant capacity of poly(methyl vinyl ether-co-maleic anhydride) nanoparticles (NPs) were investigated. Traditionally, polymer NPs have been considered delivery systems that promote a closer interaction between antigen and antigen-presenting cells (APCs). Our results revealed that poly(anhydride) NPs also act as agonists of various Toll-like receptors (TLRs) (TLR2, -4, and -5), triggering a Th1-profile cytokine release (gamma interferon [IFN-gamma], 478 pg/ml versus 39.6 pg/ml from negative control; interleukin-12 [IL-12], 40 pg/ml versus 7.2 pg/ml from negative control) and, after incubation with dendritic cells, inducing a 2.5- to 3.5-fold increase of CD54 and CD86 costimulatory molecule expression. Furthermore, in vivo studies suggest that NPs actively elicit a CD8(+) T-cell response. Immunization with empty NPs resulted in a significant delay in the mean survival date (from day 7 until day 23 postchallenge) and a protection level of 30% after challenge against a lethal dose of Salmonella enterica serovar Enteritidis. Taken together, our results provide a better understanding of how NPs act as active Th1 adjuvants in immunoprophylaxis and immunotherapy through TLR exploitation.
Revista:
FRONTIERS IN BIOSCIENCE (SCHOLAR EDITION)
ISSN:
1945-0516
Año:
2010
Vol.:
2
Págs.:
876 - 890
In the last years, many efforts have been directed toward the enhancement of vaccine delivery by using polymeric nanoparticles as adjuvants for mucosal immunization. However, conventional nanoparticles usually display a low capability to target specific sites within the gut and, thus, the elicited immune responses are not as high as necessary to offer the adequate protection to the host. To overcome these drawbacks, one possible strategy can be the association of nanoparticles with compounds involved in the colonization process of microorganisms. In this biomimetic context, two different examples are shown. In both cases, poly(anhydride) nanoparticles were coated with either flagellin from Salmonella Enteritidis or mannosamine. When administered by the oral route both types of ligand-coated nanoparticles induced stronger and more balanced serum titers of IgG2a and IgG1 than control nanoparticles which induced a typical Th2 response. This Th1 response enhancement may be related to the high tropism of both flagellin- and mannosylated-nanoparticles to the ileum and uptake by Peyer's patches rich in antigen presenting cells.
Revista:
JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
ISSN:
1773-2247
Año:
2010
Vol.:
20
N°:
5
Págs.:
353 - 359
