Development, characterization and in vivo performance analysis of doped beta- tricalcium phosphate ceramics

Abstract

β-Tri calcium phosphate ceramics play a significant role in several biomedical application for their marked resorbability and bioactivity. One of them is in bone grafting, where it is used for treating bone defects caused by wounds or osteoporosis. In the present work an in-depth and systematic study of pure and different doped variants (Zinc, Magnesium and Titanium) of β-Tri calcium phosphate was done. We have prepared pure β-Tri calcium phosphate and its different dopants of different composition. All together seven different composition were studied. We have tried to investigate some important features which are the prerequisite for their application. These include Green density, Sintered density, lattice parameter study, mechanical properties, contacts behaviour with SBF, haemolytic characteristics, and its cytotoxic nature. The capability of new apatite development on the surface of pure and doped β-TCP samples were also considered and compared by using Simulated Body Fluid (SBF) to observe their interaction with human body fluid. A comparative analysis was also made based on pure beta TCP and among its dopants.The focus of our work is to understand the combined influence of dopants and the effect of dynamic loading (in the form of axial oscillatory vibration) on bone regeneration performance of different doped β-tri-calcium phosphate ceramics. The pure and doped samples were implanted in femoral bone defect model (rabbit) to assess bone regeneration under dynamic loading. Bone regeneration was assessed after 1 and 2 month post-implantation on the basis of clinical radiological, histological, fluorochrome labelling, micro computed tomography (μ-CT) and scanning electron microscopy (SEM).Radiological and fluorochrome labelling study showed reduced size of 5% Ti-β-TCP implant vis-à-vis more new bone formation as compared to other groups. Micro-CT of the implanted bone sample showed a significant amount of newly formed bony tissue surrounding the Ti-β-TCP implant as compared to other samples. Similar findings of less interfacial gap between the implant and bone were also observed in SEM study. However, all the doped materials are suitable as bone grafting material and have potential for application in bone tissue engineering. It may be concluded that external loading in the form of low frequency intermittent axial vibration with porous beta tri calcium phosphate (both pure and doped) based implants stimulates prompt new bone formation and presents an exciting possibility for orthopedic reconstructive procedures.