Caracterização física, quimica e biologica de membranas de látex natural incorporadas com moxifloxacina para tratamento de feridas cutâneas
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Data
2017-05-05
Autores
Garms, Bruna Cambraia [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O látex natural (LN) é um polímero natural de grande interesse na área biomédica devido à capacidade de promover o aumento da vascularização e epitelização de tecidos. Considerando as propriedades físico, química e biológica do LN, bem como sua capacidade em atuar como dispositivo de liberação buscou-se, com o presente estudo, desenvolver membranas de LN associadas à moxifloxacina (MXF), antibiótico de amplo espectro de ação, com o intuito de tratar lesões infectadas de difícil cicatrização. A caracterização do material foi realizada por técnicas de microscopia eletrônica de varredura (MEV), espectroscopia no infravermelho por transformada de Fourier (FTIR) e ensaios mecânicos. Além disso, foi avaliado o potencial de liberação da MXF em diferentes pHs. Ensaios microbiológicos e de citotoxicidade foram realizados com as membranas carregadoras. A presença de cristais do fármaco na superfície e no interior do material foi observada por MEV de superfície e de corte transversal. Os espectros de FTIR identificaram as bandas de absorção características dos compostos, sugerindo que a integridade dos compostos foi mantida, o que evidencia a rápida liberação inicial do composto. Além disso, o módulo de elasticidade das membranas com e sem MXF foram similares (0,8 MPa), indicando que a elasticidade das membranas é suficiente para aplicações biomédicas. Os cristais da MXF visualizados nas micrografias da superfície da amostra, tendem a solubilizar rapidamente nas primeiras horas de liberação, promovendo o efeito denominado burst release. Em relação à posterior redução na velocidade de liberação, este comportamento deve-se aos cristais do fármaco alojados no interior da membrana, que foram liberados através da matriz de forma sustentada. O percentual de liberação de MXF em pH 7,4 foi de 65,44%, enquanto em pH 5,6, o percentual foi de 53,13% em 12 dias. Os ensaios de citotoxicidade mostraram alta viabilidade celular em linhagens de fibroblastos e queratinócitos inferindo a baixa toxicidade do material. Finalmente, ensaios de sensibilidade bacteriana comprovam a capacidade de liberação de MXF por meio da matriz de liberação utilizada sem que haja comprometimento da atividade do fármaco. Assim, os resultados apresentados demonstram que a membrana de LN+MXF representa um promissor biomaterial para o tratamento de lesões cutâneas.
The natural rubber latex (LN) is a natural polymer which has aroused large interest in the biomedical fields. Mostly, due its ability to promote vascularization increasing and tissue epithelization. Considering the physical, chemical and biological properties of LN, as well as its ability to act as a release device, the present study aimed to develop LN membranes associated with moxifloxacin (MXF), a wide-spectrum antibiotic, in order to treat infected wounds. The techniques performed in the biomaterial characterization were FTIR, mechanical tests and electronic microscopy. Moreover, the potential of MXF release was evaluated at different pHs. In addition, microbiological assays and cell viability were performed with carrier membranes. The presence of drug crystals on the surface and inside the material was observed by electronic microscopy. The FTIR spectra identified the characteristic absorption bands of the compounds, suggesting that their integrity was maintained, which resulted in rapid early release of the compound. Furthermore, the modulus of elasticity of the membranes with and without MXF were similar (0.80 MPa), indicating the membranes have sufficient elasticity for biomedical applications. The MXF crystals visualized by electronic microscopy on the surface of the material, tend to solubilize quickly during the first hours of release, which promote the burst release effect. Results showed that the MXF released after 295 hours, was 66.44% at pH 7.4, and 53.13% at acidic pH 5.6. Regarding to the subsequent decrease in release rate, this behavior is due to the drug crystals found inside the membrane, which were released through the matrix in a sustained manner. Cytotoxicity assays have shown high cell viability in fibroblast and keratinocyte lines, inferring the low toxicity of the material. Finally, bacterial sensitivity assays confirm the release capacity of MXF through the polymeric matrix without compromising the activity of the drug. Thus, the results presented in this study has shown that the LN+MXF membrane represents a promising biomaterial for the treatment of infected wounds.
The natural rubber latex (LN) is a natural polymer which has aroused large interest in the biomedical fields. Mostly, due its ability to promote vascularization increasing and tissue epithelization. Considering the physical, chemical and biological properties of LN, as well as its ability to act as a release device, the present study aimed to develop LN membranes associated with moxifloxacin (MXF), a wide-spectrum antibiotic, in order to treat infected wounds. The techniques performed in the biomaterial characterization were FTIR, mechanical tests and electronic microscopy. Moreover, the potential of MXF release was evaluated at different pHs. In addition, microbiological assays and cell viability were performed with carrier membranes. The presence of drug crystals on the surface and inside the material was observed by electronic microscopy. The FTIR spectra identified the characteristic absorption bands of the compounds, suggesting that their integrity was maintained, which resulted in rapid early release of the compound. Furthermore, the modulus of elasticity of the membranes with and without MXF were similar (0.80 MPa), indicating the membranes have sufficient elasticity for biomedical applications. The MXF crystals visualized by electronic microscopy on the surface of the material, tend to solubilize quickly during the first hours of release, which promote the burst release effect. Results showed that the MXF released after 295 hours, was 66.44% at pH 7.4, and 53.13% at acidic pH 5.6. Regarding to the subsequent decrease in release rate, this behavior is due to the drug crystals found inside the membrane, which were released through the matrix in a sustained manner. Cytotoxicity assays have shown high cell viability in fibroblast and keratinocyte lines, inferring the low toxicity of the material. Finally, bacterial sensitivity assays confirm the release capacity of MXF through the polymeric matrix without compromising the activity of the drug. Thus, the results presented in this study has shown that the LN+MXF membrane represents a promising biomaterial for the treatment of infected wounds.
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Palavras-chave
Látex natural, Moxifloxacina, Carreadores poliméricos