RESUMO
Intranasal (i.n.) vaccination with adjuvant-free plasmid DNA encoding the leishmanial antigen LACK (LACK DNA) has shown to induce protective immunity against both cutaneous and visceral leishmaniasis in rodents. In the present work, we sought to evaluate the safety and effectiveness of d,l-glyceraldehyde cross-linked chitosan microparticles (CCM) as a LACK DNA non-intumescent mucoadhesive delivery system. CCM with 5 µm of diameter was prepared and adsorbed with a maximum of 2.4 % (w/w) of DNA with no volume alteration. Histological analysis of mouse nostrils instilled with LACK DNA / CCM showed microparticles to be not only mucoadherent but also mucopenetrant, inducing no local inflammation. Systemic safeness was confirmed by the observation that two nasal instillations one week apart did not alter the numbers of bronchoalveolar cells or blood eosinophils; did not alter ALT, AST and creatinine serum levels; and did not induce cutaneous hypersensitivity. When challenged in the footpad with Leishmania amazonensis, mice developed significantly lower parasite loads as compared with animals given naked LACK DNA or CCM alone. That was accompanied by increased stimulation of Th1-biased responses, as seen by the higher T-bet / GATA-3 ratio and IFN-γ levels. Together, these results demonstrate that CCM is a safe and effective mucopenetrating carrier that can increase the efficacy of i.n. LACK DNA vaccination against cutaneous leishmaniasis.
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Organogel (OG) is a semi-solid material composed of gelling molecules organized in the presence of an appropriate organic solvent, through physical or chemical interactions, in a continuous net. This investigation aimed at preparing and characterizing an organogel from acai oil with hyaluronic acid (HA) structured by 12-hydroxystearic acid (12-HSA), aiming at topical anti-aging application. Organogels containing or not containing HA were analyzed by Fourier-transform Infrared Spectroscopy, polarized light optical microscopy, thermal analysis, texture analysis, rheology, HA quantification and oxidative stability. The organogel containing hyaluronic acid (OG + HA) has a spherulitic texture morphology with a net-like structure and absorption bands that evidenced the presence of HA in the three-dimensional net of organogel. The thermal analysis confirmed the gelation and the insertion of HA, as well as a good thermal stability, which is also confirmed by the study of oxidative stability carried out under different temperature conditions for 90 days. The texture and rheology studies indicated a viscoelastic behavior. HA quantification shows the efficiency of the HA cross-linking process in the three-dimensional net of organogel with 11.22 µg/mL for cross-linked HA. Thus, it is concluded that OG + HA shows potentially promising physicochemical characteristics for the development of a cosmetic system.
RESUMO
Current chemotherapy of cutaneous leishmaniasis (CL) is based on repeated systemic or intralesional administration of drugs that often cause severe toxicity. Previously, we demonstrated the therapeutic potential of biodegradable poly(lactic-co-glycolic acid) (PLGA) microparticles (MPs) loaded with 8% of the nitrochalcone CH8 (CH8/PLGA) prepared by a conventional bench method. Aiming at an industrially scalable process and increased drug loading, new MPs were prepared by spray drying: CH8/PDE with PLGA matrix and CH8/PVDE with PLGA + polyvinylpyrrolidone (PVP) matrix, both with narrower size distribution and higher drug loading (18%) than CH8/PLGA. Animal studies were conducted to evaluate their clinical feasibility. Both MP types induced transient local swelling and inflammation, peaking at 1−2 days, following a single intralesional injection. Different from CH8/PDE that released 90% of the drug in the ear tissue in 60 days, CH8/PVDE achieved that in 30 days. The therapeutic efficacy of a single intralesional injection was evaluated in BALB/c mice infected with Leishmania (Leishmania) amazonensis and golden hamsters infected with L. (Viannia) braziliensis. CH8/PVDE promoted greater reduction in parasite burden than CH8/PDE or CH8/PLGA, measured at one month and two months after the treatment. Thus, addition of PVP to PLGA MP matrix accelerates drug release in vivo and increases its therapeutic effect against CL.
RESUMO
The development of an effective amphotericin B (AmB) topical formulation to replace the systemically toxic injections currently used in cutaneous leishmaniasis (CL) treatment is challenging due to poor absorption through the skin. Aiming at an effective local chemotherapy, we designed PLGA (poly(lactide-co-glycolide acid) microparticles loaded with deoxycholate amphotericin B (d-AmB) for both macrophage intracellular targeting and sustained extracellular release. For that, d-AmB/PLGA microparticles with sizes ranging from 0.5⯵m to 20⯵m were synthesized and tested both in vitro and in vivo. In vitro, d-AmB/PLGA was more selectively active against intracellular amastigotes of Leishmania amazonensis than free d-AmB (selectivity indexâ¯=â¯50 and 25, respectively). In vivo, the efficacy of a single intralesional (i.l) injection with d-AmB/PLGA was determined in early and established BALB/c mouse ear lesions. In early lesions, a single injection given on day 10 of infection was more effective in controlling parasite growth than eight i.l. injections with free d-AmB, as measured on day 120. Such d-AmB/PLGA injection was also effective in established lesions (day 30), leading to 97% parasite burden reduction, as compared with d-AmB or liposomal AmB (Ambisome®) i.l. injection containing the same AmB dose. Pharmacokinetic studies showed that following d-AmB/PLGA injection, AmB leaked slower from non-infected than infected ears, yet remaining in the ear tissue for as long as 30 days. Of interest, AmB was not detectable in the circulating plasma for at least two weeks of d-AmB/PLGA injection, contrasting with the rapid and durable (2 days) detection after free d-AmB injection. Despite the transient ear swelling and local cell infiltration, no alterations in AST, ALT and creatinine serum levels was induced by d-AmB/PLGA. For its approved components, local efficacy, and single-dose applicability, this novel and safe AmB microparticle depot formulation has strong potential as a new therapy for human CL.
Assuntos
Anfotericina B/administração & dosagem , Antiprotozoários/administração & dosagem , Ácido Desoxicólico/administração & dosagem , Leishmaniose Cutânea/tratamento farmacológico , Nanopartículas/química , Anfotericina B/farmacocinética , Animais , Antiprotozoários/farmacocinética , Ácido Desoxicólico/farmacocinética , Combinação de Medicamentos , Sistemas de Liberação de Medicamentos , Orelha , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Poliglactina 910/químicaRESUMO
Current chemotherapy of cutaneous leishmaniasis (CL), even the mildest forms, encompasses multiple and painful injections with toxic drugs that cause systemic adverse effects. Recently, we showed the promising use of poly(lactic-co-glycolic acid) (PLGA) microparticles loaded with an antileishmanial nitrosylated chalcone (CH8) for effective, safe, local, and single-dose treatment of CL. Here, we proposed to optimize the delivery system by increasing the CH8 loading in PLGA-microparticles using spray drying instead of emulsification-solvent evaporation. The effect of solvent composition and polymeric matrix changes on thermal properties, loading efficiency, particle size, morphology, and spatial drug distribution of the CH8-loaded microparticles was evaluated. The results showed that spray drying allowed a higher CH8 content (18% w/w), as contrasting with the previous solvent evaporation technique that maximally incorporated 7.8% of CH8. In vitro studies on 96-hour incubation with L. amazonensis-infected macrophages showed that entrapment in spray-dried PLGA microparticles rendered CH8 safer, preserved its antileishmanial activity, and did not affect its antioxidant properties.
Assuntos
Chalconas/química , Chalconas/farmacologia , Leishmaniose Cutânea/tratamento farmacológico , Portadores de Fármacos/química , Composição de Medicamentos/métodos , Ácido Láctico/química , Microesferas , Tamanho da Partícula , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Polímeros/química , Solventes/químicaRESUMO
Conventional chemotherapy of cutaneous leishmaniasis (CL) is based on multiple parenteral or intralesional injections with systemically toxic drugs. Aiming at a single-dose localized therapy, biodegradable poly(lactic-co-glycolic acid) (PLGA) microparticles loaded with 7.8% of an antileishmanial nitrochalcone named CH8 (CH8/PLGA) were constructed to promote sustained subcutaneous release. In vitro, murine macrophages avidly phagocytosed CH8/PLGA smaller than 6 µm without triggering oxidative mechanisms. Upon 48 h of incubation, both CH8 and CH8/PLGA were 40 times more toxic to intracellular Leishmania amazonensis than to macrophages. In vivo, BALB/c were given one or three subcutaneous injections in the infected ear with 1.2 mg/kg of CH8 in free or CH8/PLGA forms, whereas controls received three CH8-equivalent doses of naked PLGA microparticles or meglumine antimoniate (Glucantime; Sanofi-Aventis). Although a single injection with CH8/PLGA reduced the parasite loads by 91%, triple injections with free CH8 or CH8/PLGA caused 80 and 97% reductions, respectively, in relation to saline controls. Meglumine antimoniate treatment was the least effective (only 36% reduction) and the most toxic, as indicated by elevated alanine aminotransferase serum levels. Together, these findings show that CH8/PLGA microparticles can be effectively and safely used for single-dose treatment of CL.
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Antiprotozoários/uso terapêutico , Chalconas/química , Leishmaniose Cutânea/tratamento farmacológico , Microesferas , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Animais , Antiprotozoários/química , Feminino , Leishmaniose Cutânea/metabolismo , Macrófagos Peritoneais/metabolismo , Macrófagos Peritoneais/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Poly(N-vinylcaprolactam) (PNVCL) and poly(N-vinylcaprolactam-co-acrylic acid) (poly(NVCL-co-AA)) were synthesized by solution-free radical polymerization and displayed thermo-responsive behavior, with lower critical solution temperatures (LCSTs) of 35 °C and 39 °C, respectively. The incorporation of AA unities made the poly(NVCL-co-AA) sensitive to both pH and temperature. They were exploited in this work in preparing microparticles loaded with ketoprofen via spray-drying to modulate the drug release rate by changing pH or temperature. The interaction between polymer and drug was studied using X-ray diffractometry, Raman spectrometry and scanning electron microscopy (SEM). The biocompatibility of pure polymers, free ketoprofen as well as the spray-dried particles was demonstrated in vitro by low cytotoxicity and a lack of nitric oxide production in macrophages at concentrations as high as 100 µg/ml. The release profile of ketoprofen was evaluated by in vitro assays at different temperatures and pH values. Drug diffusion out of PNVCL's hydrated polymer network is increased at temperatures below the LCST. However, when poly(NVCL-co-AA) was used as the matrix, the release of ketoprofen was primarily controlled by the pH of the medium. These results indicated that PNVCL and the novel poly(NVCL-co-AA) could be promising candidates for pH and temperature-responsive drug delivery systems.
Assuntos
Acrilatos/química , Caprolactama/análogos & derivados , Cetoprofeno/síntese química , Polímeros/síntese química , Caprolactama/síntese química , Caprolactama/química , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/química , Sistemas de Liberação de Medicamentos , Concentração de Íons de Hidrogênio , Cetoprofeno/química , Tamanho da Partícula , Polímeros/química , TemperaturaRESUMO
Chloroaluminum phthalocyanine (ClAlPc) is a promising sensitizer molecule for photodynamic therapy, but its hydrophobicity makes it difficult to formulate. In this study, we have efficiently encapsulated ClAlPc into gelled soybean oil particles dispersed in water. 12-Hydroxystearic acid (HSA) and polyethyleneimine (PEI) were the gelling and stabilizing agents, respectively. The preparation process involved hot emulsification above the gelation temperature (Tgel), followed by cooling to room temperature, which gave a colloidal dispersion of gelled particles of oil in aqueous medium. The gelled particles containing ClAlPc had a medium diameter of 280 nm, homogeneous size distribution (polydispersity index ≈0.3) and large positive zeta potential (about +50 mV) and showed a spherical morphology. The gelled oil particle formulations exhibited good physical stability over a 6-month period. ClAlPc interfered with the HSA self-assembly only slightly, and decreased the gelation temperature to a small extent; however it did not affect gelation process of the oil droplets. The amounts of PEI and HSA employed during the preparation allowed us to control particle size and the dispersion stability, a phenomenon that results from complex electrostatic interactions between the positively charged PEI and the negatively charged HSA fibers present on the gelled particles surface. In summary, by using the right ClAlPc, HSA, and PEI proportions, we prepared very stable dispersions of gelled soybean oil particles with excellent ClAlPc encapsulation efficiency. The obtained colloidal formulation of gelled oil particles loaded with ClAlPc shall be very useful for photodynamic therapy protocols.
Assuntos
Indóis/química , Compostos Organometálicos/química , Óleo de Soja/química , Interações Hidrofóbicas e Hidrofílicas , Estrutura Molecular , Tamanho da Partícula , Polietilenoimina/química , Ácidos Esteáricos/química , Propriedades de Superfície , TemperaturaRESUMO
OBJETIVO: Avaliar, por métodos in vitro e in vivo, a biodisponibilidade de uma nova forma de sulfato ferroso microencapsulado (genericamente denominado Ferlim), desenvolvido para a fortificação de alimentos, comparando-a com a de ferro eletrolítico (Fe0). MÉTODOS: A avaliação da dialisabilidade in vitro utilizou como matriz leite em pó reconstituído. A avaliação in vivo, utilizando o método de recuperação de hemoglobina em leitões anêmicos, teve duração de 13 dias e os animais (n=23) foram agrupados de acordo com o produto do peso (kg) x hemoglobina (g/dL). Como controle foi utilizado FeSO4.7H2O. RESULTADOS: As porcentagens médias de ferro dialisado foram 2,2 (desvio-padrão=0,1) por cento, 3,4 (desvio-padrão=0,1) por cento e 3,6 (desvio-padrão=0,0) por cento para FeSO4.7H2O, Ferlim e Fe0, respectivamente (p<0,05). A absorção de ferro foi de 16,0 (desvio-padrão=3,1) por cento para o grupo controle, de 15,1 (desvio-padrão=3,8) por cento para o grupo Ferlim e de 12,8 (desvio-padrão=4,3) por cento para o grupo Fe0, não sendo significantemente diferentes (p>0,05). As porcentagens de absorção do valor biológico relativo do FeSO4.7H2O foram de 94,2 (desvio-padrão=23,8) por cento para o grupo Ferlim e de 79,7 (desvio-padrão=26,6) por cento para o grupo Fe0, sem diferenças significantes (p>0,05). Em valores numéricos (p>0,05), o grupo Fe0 apresentou menor média de absorção ( por cento) valor biológico relativo de concentração de ferro total, de ferro heme e não-heme no fígado. CONCLUSÃO: A microencapsulação do sulfato ferroso com alginato mantém sua biodisponibilidade, caracterizando-se como boa alternativa para a fortificação de misturas sólidas.
OBJECTIVE: To evaluate, by in vitro and in vivo methods, the bioavailability of a new microencapsulated ferrous sulfate (Ferlim) developed for food fortification, and compare it with electrolytic iron (Fe0). METHODS: In vitro dialyzability assessment used reconstituted milk powder as matrix. In vivo assessment using the hemoglobin regeneration method in anemic piglets lasted for 13 days and the animals (n=23) were grouped according to the product of weight (kg) x hemoglobin (g/dL). FeSO4.7H2O was used as control. RESULTS: The percentages of dialyzed iron were 2.2 (standard deviation=0.1) percent, 3.4 (standard deviation=0.1) percent and 3.6 (standard deviation=0.0) percent for FeSO4.7H2O, Ferlim and Fe0 respectively (p<0.05). Iron absorption was 16.0 (standard deviation=3.1) percent for the control group, 15.1 (standard deviation=3.8) percent for the Ferlim group and 12.8 (standard deviation=4.3) percent for the Fe0 group; the differences were not significant (p>0.05). The absorption percentages of the relative biological value of FeSO4.7H2O were 94.2 (standard deviation=23.8) percent for the Ferlim group and 79.7 (standard deviation=26.6) percent for the Fe0 group; the differences were not significant (p>0.05). In numerical values (p>0.05), the Fe0 group presented the lowest mean relative biological value absorption ( percent) and concentration of total iron, heme iron and non-heme iron in the liver. CONCLUSION: Microencapsulation of ferrous sulfate with alginate retains its bioavailability therefore it is a good alternative for the fortification of solid mixtures.
Assuntos
Animais , Masculino , Feminino , Disponibilidade Biológica , Sulfato Ferroso , Cápsulas , SuínosRESUMO
Pantoprazole is a prodrug used in the treatment of acid related disorders and Helicobacter pylori infections. It is activated inside gastric parietal cells binding irreversibly to the H(+)/K(+)-ATPase. In this way, pantoprazole must be absorbed intact in the intestinal tract, which indicates that enteric drug delivery systems are required for its oral administration. The purpose of this study was to investigate the physical characteristics of enteric pantoprazole-loaded microparticles prepared by spray drying using a blend of Eudragit S100 and HPMC. The microparticles were produced in different spray dryers and operational conditions at laboratory and pilot scales. Microparticles produced with two fluid nozzle atomizer and air pressure of 196 kPa presented satisfactory encapsulation efficiency and gastro-resistance. Microparticles produced with the same atomizer but using 49 kPa of air pressure presented strings in the powder. The microparticles produced in mixed flow presented very high polydispersity and the ones produced with rotating disc atomizer presented drug crystals adsorbed on the particle surfaces. The microparticles produced with two fluid nozzle atomizer and 196 kPa were prepared in three consecutive days for the process validation. The powders showed reproducible diameter, polydispersity, densities, encapsulation efficiency and gastro-resistance profile.