Desenvolvimento de arcabouços biodegradáveis para regeneração de tecidos cartilaginosos.

Abstract

Tissue Engineering was created by the needed for researchers to turn to multidisciplinary approaches in search specific solutions to issues in medicine. In this field of research are employed methods which cells can proliferate and organize their extracellular matrix (ECM) in scaffolds, constituted of a biomaterial. Recently, has been an introduction of concepts of tissue engineering in the repair of articular cartilage. The cartilage, once damaged, has little or no regenerative capacity and certain lesions may progress, cause degeneration and very severe changes in articulation. In this context, studies showed the biopolymer chitosan as favorable candidate for use as a porous support, mainly, for low cost and availability for obtaining, and their biodegradability. Thus, this dissertation purposed to develop and characterize biodegradable scaffolds of Chitosan and Chitosan-Genipina for regeneration of cartilaginous tissue using the technique of freeze drying. Genipin, natural crosslinking agent, was chosen for presenting efficiency in several studies. The scaffolds were produced at varying concentrations and different freezing rates and were submitted to physico-chemical characterization by Spectroscopy in the Region of Fourier Transform Infrared (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Optical microscopy (OM) and test the degree of swelling (Gl), and biological assays for the Assessment of Cell Viability of macrophages (MTT) and Determination of the Production of Nitric Oxide (NO). The FTIR analysis revealed all characteristic bands of a polysaccharide for all concentrations, and the effectiveness of the crosslinking. XRD analysis showed typical pattern of chitosan, amorphous with the less with increasing concentration of the solution and the crosslinking agent. Analysis by SEM showed the influence of high freezing rate of the solutions and the introduction of Genipin, with formation of different pore size and morphology for each variable. Analysis by MO indicated the effectiveness of the crosslinking Genipin and, by Gl, the influence of the rate of freezing of the solution and the concentration of chitosan and crosslinking on the swelling capacity of the scaffolds. The biological tests have shown, under the conditions studied, the biocompatibility of scaffolds. The scaffolds were produced and evaluated, showed promising results for the preparation of biomaterial to be used in the regeneration of cartilaginous tissues.