Desenvolvimento de nanocompósitos poliméricos híbridos e biocompatíveis para aplicação na engenharia de tecidos

Abstract

Interest in PPy-based nanocomposites has been growing due to their biocompatibility and economic viability, which make them promising for biomedical applications. Biodegradable polymers have shown potential for use as temporary matrices in studies of tissue damage therapies. Therefore, this work aimed to study the incorporation of OGR and Ag nanostructures in PPy, via direct addition of OGR in polymerization of pyrrole and direct coating of Ag by using sputtering method after PPy synthesis process, as well as to characterize the nanostructures formed by FTIR, FESEM, TEM, XRD, electrical conductivity, and to evaluate in vitro the cytotoxicity. Also, polymeric PCL/PLGA films were prepared by solvent casting, using molds without and with standardized microtopography, were characterized by FESEM, AFM, contact angle, Young's Module, and on the viability, proliferation, and adhesion of different mammalian cell types. Nanocomposite films by the addition of PPy/OGR or PPy/Ag were also prepared by solvent casting and characterized. The best method for PPy/OGR was that with sonication treatment, which doubled the electrical conductivity of the product with 20% (w/w) OGR. TEM image results confirmed the deposition of Ag nanoparticles (<32 nm) on the PPy surface and the electrical conductivity was increased 102 times relative to pure PPy. In vitro cytotoxicity testing of nanocomposites (nanocharges) suggested cell viability until 200 μg/ mL. For polymeric films, the addition of 30% (w/w) of PLGA increased the biocompatibility and surface roughness of the PCL matrix. Films from the PCL/PLGA (70/30) blend when microstructured efficiently promoted the orientation of fibroblasts, as well as the oriented growth and proliferation of neural cells (DRG). The standardized channels in the nanocomposite films were maintained after the addition of the nanocharges, being an alternative interesting to enhance the matrix for cell orientation action.