Estudo do biopolímero poli (B-hidroxibutirato) para aplicação na fixação e regeneração de tecido ósseo.

Abstract

This thesis aims to propose the use of a biodegradable polymeric material PHB (poly (p-hydroxybutyrate)) for osteosynthesis and bone tissue regeneration. For this, we carried out an investigative study about performance of PHB, analyzing factors such as bioactivity, biodegradability, biocompatibility, mechanical and thermal properties. To evaluate the bioactivity of PHB, it has been subjected to a contact with an environment mimicking the biological environment, the SBF solution, determining the morphology, chemical composition and hydrophilicity of these plates PHB after interacting with these medium. For the biodegradation study, the PHB was subjected to a contact with a buffer solution (PBS) and lysozyme. The evaluation of mechanical properties was performed before and after that the plates were immersed in the buffer solution with lysozyme. The biocompatibility was determined by the cell viability test using the MTT method and nitric oxide (NO) production. The PHB samples were characterized structurally and morphologically through the analysis of XRD, FTIR, SEM, EDS, OM, AFM, contact angle, TG / DTG, DSC, TMA and tensile and bending trials. After the evaluation of the results obtained in vitro, it is concluded that: PHB even being a hydrophobic polymer, showed that after the attack with hydrogen peroxide, became more receptive, acquiring a bioactive behavior, has presented slight surface degradation without structural compromising and remained mechanical properties near the original PHB in the end of the period of 180 days of exposure to biodegradable ambient. Finally, it was proved that PHB is a biocompatible polymer, because by determining the percentage of cell viability and determination of nitric oxide (NO), had a score of 87,22% and 3.5 respectively, very close to the mean of the control groups performed.