Development of boron-doped bioceramic/PVDF-PCL composite scaffolds for bone tissue engineering and determination of In-Vitro efficacy

In the presented thesis study, membrane scaffolds with different properties by doping boron to synthesized calcium phosphate and calcium silicate-based bioceramic powders incorporating the powders into polyvinylidene fluoride and polycaprolactone were produced. The aim was to evaluate the bone tissue formation potential of alternative scaffolds that support bone regeneration produced using non-solvent induced phase separation and then freeze drying methods. For this purpose, in the first chapter of the thesis, boron doped biphasic calcium phosphate powders were synthesized by a sequential method including wet chemical technique and heat treatment processes. The morphology of the synthesized powders was examined by scanning electron microscope, the chemical structure was confirmed by X-ray diffraction analysis, particle size analysis and BET density measurements were performed. Composite scaffolds were produced by adding the synthesized boron doped biphasic calcium phosphate powders into polyvinylidene fluoride at different ratios, and structural, morphological, thermal, mechanical and biological characterizations of the scaffolds were performed. In the second chapter of the study, the effects of coagulation bath temperature, which is an important production parameter, on the morphology, crystallinity, β-phase formation, mechanical and biological properties of scaffolds containing boron-doped biphasic calcium phosphate and polyvinylidene fluoride produced by non-solvent induced phase separation method were investigated. In the third chapter of the study, boron-doped baghdadite powders were synthesized and characterized by a sequential method including sol-gel and heat treatment processes. The effects of the synthesized boron-doped baghdadite powders on polyvinylidene fluoride-polycaprolactone scaffolds produced by non-solvent induced phase separation method at the selected coagulation bath temperature were evaluated with various characterizations. The effects of boron-doped baghdadite powders on composites were also investigated with more detailed in vitro tests. Boron-doped bioceramic powders significantly affected the structural, morphological, thermal, mechanical and biological properties of composite scaffolds. The molecular interactions and chemical bonds between the synthesized powders and the polymer matrix were demonstrated. It was observed that the pore structures of all the produced composite scaffolds were within the observed limits. It was determined that the mechanical strength of the scaffolds was mechanically compatible with native bone. In addition, the incorporation of the synthesized powders into the composite scaffolds revealed that the in vitro bioactivity significantly supported the apatite growth ability of the composite scaffolds. It was shown that by further in vitro tests the composite scaffolds supported cell viability and proliferation without cytotoxicity, and that the cell adhesion affinity and biocompatibility were higher than those of pure polyvinylidene fluoride-based scaffolds. As a result, it was evaluated that the produced membrane form polyvinylidene fluoride-based composite scaffolds have a high potential to meet the expected properties of the scaffold material and can be used as an alternative structure for bone tissue engineering applications.