Produção e caracterização de mantas de nanofibras poliméricas eletrofiadas contendo proantocianidinas e sua potencial aplicação no tratamento de lesões cutâneas

Abstract

The development of novel biodegradable and biocompatible nanofibrous membranes are highly desirable for biomedical applications, including drug delivery and wound dressing. Thus, the present thesis focused on the development using electrospinning technique of biodegradable and biocompatible nanofibrous membranes with antioxidant properties through the encapsulation of natural antioxidants. The membranes were obtained using the polylactic acid (PLA), polyethylene oxide (PEO) and Aloe Vera extract (ALOE) as a matrix, with the addition of grape seed extract (GSE), which is a rich source of natural antioxidants. The membranes compositions and morphological characteristics were optimized to obtain homogeneous nanofibers displaying hydrophilicity. Specifically, nanofibers mats of PLA, PLA/PEO e PLA/ALOE without and with GSE (10% and 20%) were characterized in terms of composition, morphology and biocompatibility, which presented uniform morphology, random orientation and diameters in the range 149 - 306 nm. The PLA/PEO nanofibers presented hydrophilic feature, while the other nanofiber mats presented hydrophobic feature. The PLA, PLA/PEO and PLA/ALOE nanofibers showed high encapsulation efficiency, with a percentage close to 90%. The antioxidant action of GSE was also determined confirming the high antioxidant capacity of GSE even after the electrospinning process. Experimental data obtained by the in vitro release studies showed that GSE is released by diffusional transport, corresponding satisfactorily to the Korsmeyer-Pepas model. In addition, a more controlled release of GSE was observed for the PLA/PEO/GSE and PLA/ALOE/GSE membrane. The viability of human fibroblast growth (HFF1) was also evaluated, confirming the biocompatibility of all the obtained membranes, especially the PLA/PEO membrane with GSE, which presented better cell attachment and proliferation when compared to PLA/GSE and PLA/ALOE/GSE membranes. Thus, the results indicate the high potential of membranes loaded with GSE for topical drug-delivery system as wound dressing.