Desenvolvimento de membranas de polihidroxibutirato com hidroxiapatita para utilização em odontologia.

Abstract

The advancement of biomaterials technology allows to develop materials that aid in the reconstructive processes of body parts and increase treatments and improve the quality of life of human beings. Polyhydroxybutyrate (PHB) is a biocompatible, biodegradable polymer, widely studied for applications as biomaterial because of its properties, these may still be suitable for various applications with the incorporation of inorganic fillers, such as hydroxyapatite (HA) that is biocompatible and bioactive , Present in bone tissues. Thus, this work aimed to obtain PHB and HA biocomposites for use in guided bone tissue regeneration. The membranes were obtained using the solubilization method (solvent evaporation) and by melting (extrusion). Unfilled membranes were obtained in two concentrations of PHB (5 g / L and 10 g / L). The biocomposites were obtained with the addition of different concentrations of HA in the 10 g / L solution. Extrusion membranes were obtained without and at concentrations of HA (1%, 2% and 3%) relative to PHB using a monosulfate extruder. All the membranes were characterized by Optical Microscopy (OM), Scanning Electron Microscopy (SEM) / X-ray Dispersive Energy (EDS) Spectroscopy, X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy Thermogravimetry (TGA), Mechanical Traction Test, Wettability, In Vitro Biodegradation and Cytotoxicity. By means of the MO and MEV techniques, it was possible to observe uniform distribution of the charge with the presence of agglomerates and difference of gray shade, indicating the crystalline and amorphous regions in the extruded membranes. The XRD technique showed that the incorporation of HA decreased the semicrystalline profile of the biocomposites. With the FTIR technique, it was not possible to verify the interaction between the constituents, since the attenuated total reflection infrared (ATR) analysis is a method of surface analysis, possibly because the HA particles have been covered by the PHB matrix. The chemical elements present in the PHB and HA as well as the biocomposites were detected by the EDS technique. The mechanical tensile test presented a decrease of the elastic modulus and increase in the deformation with the addition of HA. TGA indicated mass loss in a single step, increasing the maximum degradation temperature with the addition of higher amounts of HA. Wettability analysis indicated hydrophilicity and decreased when HA was added. The biodegradation assay demonstrated that the presence of HA increased biodegradation. The Cytotoxicity assay indicated the biocompatibility of the material. It is concluded that it is possible to obtain PHB / HA biocomposites and it has potential to be used as biomaterial. The solvent evaporation biocomposite WBes1HA3 is the best to be used in in vivo tests for guided tissue regeneration and guided bone, due to its homogeneous surface, to be flexible and to be biodegradable.