Avaliação da adição de colágeno tipo I e nanopartículas de vidro bioativo a hidrogéis termossensíveis de quitosana para uso na engenharia de tecido

Abstract

Recently, hydrogels have gained notoriety in tissue engineering because they can be applied as injectable scaffolds. These systems, which present in situ gelation, have advantages over preformed scaffolds, such as the possibility of minimally invasive implantation, ability to fill the damaged cavity and easy incorporation of therapeutic agents. Due to the potential of these systems, this study aimed at prepare and characterize thermosensitive hydrogels of chitosan and evaluate the effects of collagen addition and bioactive glass nanoparticles, in different proportions. Before the preparation of hydrogels, the raw materials were characterized by thermal analysis (TGA and DSC), scanning electron microscopy (SEM), infrared spectroscopy (FTIR), X-ray diffraction (XRD) to assess its properties and purity. After several adjustments of the formula, it was possible to obtain hydrogels with gelation temperature of approximately 37°C. The samples characterization was performed by SEM, FTIR and rheological tests. SEM micrographs show that the hydrogels have a porous structure and the addition of collagen causes an increase in pore size. FTIR spectra showed characteristic bands of each component of the system with the absence of new bands. Rheological measurements allowed the assessment of the viscoelastic behavior of the hydrogels against temperature increase and determine the gelation time at 37°C. The results showed that the addition of collagen and bioactive glass cause an increase in stiffness after gelation of the hydrogel and that all proposed formulations undergo gelation in a relatively short period of time, approximately 3 minutes.