Arcabouços à base de colágeno de pele de Tilápia (Oreochromis niloticus) incorporados de apatitas para aplicações biomédicas

Abstract

This work aims to develop hydrogels from collagen extracted from the skin of Nile Tilapia (Oreochromis niloticus) with synthetic calcium and strontium apatites to produce a potential scaffold cross-linked with curcumin. The extraction of collagen was perfomed in chemical pathway, the synthesis of apatites were by coprecipitation associated to hydrothermal and the hydrogels were obtained by a in situ process. The raw materials and hydrogels were characterized by Fourier-transform infrared spectroscopy (FTIR), swelling, x-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and energy-dispersive spectroscopy (SEM/EDS). The FTIR showed that the apatites are close to the biological due to the presence of HPO42-, collagen presented the typical bands and it’s structural integrity, the hydrogels suffered broadening caused by the crosslinking mechanism. The swelling of the hydrogels in medium similar to the physiological promoted the release of curcumin. The XRD confirmed the hexagonal phase and well-crystallinity of the apatites and a crystalline phase of curcumin. The SEM showed the formation of grains in apatites, fibrous structure and smooth surface of collagen, increase in superface area in hydrogels with curcumin and crystal deposited on the surface of those with apatite. TGA and DSC showed the physic-chemical instability of the hydrogels, supposedly due to the competition of the hydrogen bond sites intra and inter collagenous chains with the solution and curcumin. EDS confirmed the non-stoichiometry of the apatite and the purity of collagen. The hydrogels showed potential as scaffolds with a novel underexplored biocompatible and bioactive crosslinker, with it’s release