Síntese e caracterização de filmes a base de Poli (Álcool vinílico)/Tanfloc com potencial aplicação na área biomédica

Abstract

This study reports the synthesis and characterization of films based on polyvinyl alcohol (PVA) and tanfloc (TN), an amino-functionalized tannin derivative synthesized from condensed tannins. Films were obtained by “casting” method from PVA/TN polymer blends, using PVA solutions at 5.0 wt.% or 10% wt.% and Tanfloc (TN) solution at 5 wt.%. Polymeric blends were prepared in different PVA/TN weight ratios (100/0, 90/10, 80/20 and 50/50). Glutaraldehyde was used as a crosslinking agent to promote stability to the films, and its concentration (1,7 g L–1) was maintained constant in many assays. The materials were characterized through infrared spectroscopy with attenuated total reflectance (FTIR-ATR) mode, thermogravimetric analysis (TGA/DTG), X-ray photoelectron spectroscopy (XPS), contact angle measurements and scanning electron microscopy (SEM). More hydrophilic films were obtained using PVA at 10 wt.% to create PVA/TN blends. PVA/TN films presented excellent stability in PBS (pH 7.4) at least 14 days, making possible their application as scaffold matrices. All PVA/TN films had cytocompatibility on fibroblast cell lines (L929), epithelial cells (VERO) and macrophages (J774A1) cells and on bone mesenchymal stem cells (MSCs). In addition, some tests showed that PVA/TN films presented antimicrobial activity against Staphylococcus aureus and Pseudomonas aeruginosa, as well as antioxidant activity. These properties occurred due to the presence of TN in the films and also on the TN concentration in the final blend composition. The films were applied as scaffolds to promote adhesion and proliferation of MSCs. Fluorescence and SEM images revealed that the more hydrophilic film (PVA10/TN10) acted as a scaffold because in only 7 days of cell culture its matrix promoted fixation, proliferation, and spread of MSCs cells. In general, this more hydrophilic film showed great potential to be used as a scaffold because when compared to the biomedical activity of the titanium (one of the most important biomedical devices applied in implants), it was confirmed the effectiveness of the PVA/TN film to be used in tissue engineering arena.