Poly(hydroxybutyrate-co-hydroxyvalerate) microspheres loaded with atrazine herbicide: screening of conditions for preparation, physico-chemical characterization, and in vitro release studies

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

IL-12 and neutralization of endogenous IL-10 revert the in vitro antigen-specific cellular immunosuppression of paracoccidioidomycosis patients

Treatment of patients with paracoccidioidomycosis is still a challenge. Patients present defective lymphoproliferation and IFN-γ responses to the main Paracoccidioides brasiliensis antigen (gp43), which correlates with disease severity. Here, we demonstrated that the patients show also a defective synthesis of interleukin (IL)-12. Therefore, we attempted to revert this immune disfunction by adding IL-12 and neutralizing anti-IL-10 antibody to gp-43-stimulated peripheral blood mononuclear cell cultures. Both treatments increased IFN-γ secretion to levels observed with healthy sensitized individuals, but affected proliferation only modestly. When combined, the treatments further increased IFN-γ synthesis and cell proliferation. The addition of suboptimal concentrations of IL-2 also further increased the IL-12-mediated secretion of IFN-γ. Interestingly, the immune modulation was mostly antigen-specific, since the responses to Candida albicans' antigen were not affected. These results suggest that appropriate immune intervention with cytokines and/or anti-cytokines may help in the treatment of PCM. © 2002 Elsevier Science Ltd. All rights reserved.

Anti-inflammatory mechanisms of the annexin A1 protein and its mimetic peptide Ac2-26 in models of ocular inflammation in vivo and in vitro

Annexin A1 (AnxA1) is a protein that displays potent anti-inflammatory properties, but its expression in eye tissue and its role in ocular inflammatory diseases have not been well studied. We investigated the mechanism of action and potential uses of AnxA1 and its mimetic peptide (Ac2-26) in the endotoxin-induced uveitis (EIU) rodent model and in human ARPE-19 cells activated by LPS. In rats, analysis of untreated EIU after 24 and 48 h or EIU treated with topical applications or with a single s.c. injection of Ac2-26 revealed the anti-inflammatory actions of Ac2-26 on leukocyte infiltration and on the release of inflammatory mediators; the systemic administration of Boc2, a formylated peptide receptor (fpr) antagonist, abrogated the peptide's protective effects. Moreover, AnxA1-/- mice exhibited exacerbated EIU compared with wild-type animals. Immunohistochemical studies of ocular tissue showed a specific AnxA1 posttranslational modification in EIU and indicated that the fpr2 receptor mediated the anti-inflammatory actions of AnxA1. In vitro studies confirmed the roles of AnxA1 and fpr2 and the protective effects of Ac2-26 on the release of chemical mediators in ARPE-19 cells. Molecular analysis of NF-κB translocation and IL-6, IL-8, and cyclooxygenase-2 gene expression indicated that the protective effects of AnxA1 occur independently of the NF-κB signaling pathway and possibly in a posttranscriptional manner. Together, our data highlight the role of AnxA1 in ocular inflammation, especially uveitis, and suggest the use of AnxA1 or its mimetic peptide Ac2-26 as a therapeutic approach. Copyright © 2013 by The American Association of Immunologists, Inc.

Obtenção, caracterização e estudo de liberação in vitro e permeação in vivo de sistemas microestruturados contendo cafeína

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da estabilidade química, física e liberação in vitro da eritromicina veiculada em sistemas líquido-cristalinos para tratamento da Acne Vulgaris

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Investigação das propriedades citotóxicas e imunológicas de complexos de paládio(II) in vitro utilizando o modelo experimental de Ehrlich

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Farmacomagnetografia colônia: estudo in vitro da desintegração de comprimidos magnéticos revestidos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microemulsões biocompatíveis de anfotericina B para administração oral: estudo estrutural, liberação in vitro e farmacocinética pré-clínica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estabilidade, polimorfismo, dissolução e correlação in vivo-in vitro de Darunavir comprimidos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desenvolvimento e caracterização de sistemas líquido-cristalinos para aplicação tópica de metotrexato: estudos de liberação, retenção e permeação in vitro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Mesenchymal stem cells modulate release of matrix proteins from tendon surfaces in vitro: a potential beneficial therapeutic effect

Aim: Injury of tendons contained within a synovial environment, such as joint, bursa or tendon sheath, frequently fails to heal and releases matrix proteins into the synovial fluid, driving inflammation. This study investigated the effectiveness of cells to seal tendon surfaces and provoke matrix synthesis as a possible effective injectable therapy. Materials & methods: Equine flexor tendon explants were cultured overnight in suspensions of bone marrow and synovium-derived mesenchymal stems cells and, as controls, two sources of fibroblasts, derived from tendon and skin, which adhered to the explants. Release of the most abundant tendon extracellular matrix proteins into the media was assayed, along with specific matrix proteins synthesis by real-time PCR. Results: Release of extracellular matrix proteins was influenced by the coating cell type. Fibroblasts from skin and tendon appeared less capable of preventing the release of matrix proteins than mesenchymal stems cells. Conclusion: The source of cell is an important consideration for cell therapy.

Pluronics F-127/L-81 Binary Hydrogels as Drug-Delivery Systems: Influence of Physicochemical Aspects on Release Kinetics and Cytotoxicity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nanostructured Lipid Carriers as a Strategy to Improve the In Vitro Schistosomiasis Activity of Praziquantel

Praziquantel (PZQ) is a pyrazinoisoquinoline anthelmintic that was discovered in 1972 by Bayer Germany. Currently, due to its efficacy, PZQ is the drug of choice against all species of Schistosoma. Although widely used, PZQ exhibits low and erratic bioavailability because of its poor water solubility. Nanostructured lipid carriers (NLC), second-generation solid lipid nanoparticles, were developed in the 1990s to improve the bioavailability of poorly water soluble drugs. The aim of this study was to investigate nanostructured lipid carriers as a strategy to improve the efficacy. of PZQ in S. mansoni treatment. We prepared NLC2 and NLC4 by adding seventy percent glycerol monostearate (GMS) as the solid lipid, 30% oleic acid (OA) as the liquid lipid and two surfactant systems containing either soybean phosphatidylcholine/poloxamer (PC/P-407) or phosphatidylcholine/Tween 60 (PC/T60), respectively. The carriers were characterized by nuclear magnetic resonance, differential scanning calorimetry, thermogravimetric analysis and Fourier transform-infrared spectroscopy. The safety profile was evaluated using red cell hemolysis and in vitro cytotoxicity assays. The results showed that the encapsulation of PZQ in NLC2 or NLC4 improved the safety profile of the drug. Treatment efficacy was evaluated on the S. mansoni BH strain. PZQ-NLC2 and PZQ-NLC4 demonstrated an improved efficacy in comparison with free PZQ. The results showed that the intestinal transport of free PZQ and PZQ-NLC2 was similar. However, we observed that the concentration of PZQ absorbed was smaller when PZQ was loaded in NLC4. The difference between the amounts of absorbed PZQ could indicate that the presence of T60 in the nanoparticles (NLC4) increased the rigid lipid matrix, prolonging release of the drug. Both systems showed considerable in vitro activity against S. mansoni, suggesting that these systems may be a promising platform for the administration of PZQ for treating schistosomiasis.

Study of quercetin-loaded liposomes as potential drug carriers: in vitro evaluation of human complement activation

Liposomes have been employed as potential drug carriers. However, after their in vivo administration, they can be destabilized by proteins of complement system, contributing to the clearance of vesicles from blood circulation. Antioxidant flavonoids such as quercetin have been reported to be beneficial to human health, but their low water solubility and bioavailability limit their enteric administration. Therefore, the development of appropriate flavonoid-carriers could be of great importance to drug therapy. The aim of the present study was to evaluate the activation of human complement system proteins by liposomes composed of soya phosphatidylcholine (SPC) and cholesterol (CHOL) or cholesteryl ethyl ether (CHOL-OET) loaded with quercetin or not. The consumption of complement, via classical (CP) and alternative (AP) pathways, by different vesicles was evaluated using a hemolytic assay and quantitative determination of iC3b and natural antibodies deposited on empty liposomal surfaces by ELISA. The main results showed that empty liposomes composed of large amounts of CHOL consumed more complement components than the others for both CP and AP. Furthermore, replacement of CHOL with CHOL-OET reduced complement consumption via both CP and AP. Incorporation of quercetin did not change CP and AP consumption. Deposition of iC3b, IgG and IgM in vesicles composed of SPC: CHOL-OET at a molar ratio of 1.5:1 was lower compared to the others. Taken together, these observations suggest that liposomes composed of SPC: CHOL-OET at a molar ratio of 1.5:1 are the most appropriate among the vesicles studied herein to be used as a drug carrier system in further investigations.