Research On Laser Sintering Mechanism And Technology Of Calcium Phosphate Ceramic Bone Scaffold

Abstract:It had become one of the hot topics in the field of biological manufacturing research on the preparation of bone scaffold with suitable mechanical properties and excellent biological properties. Owing to their inorganic composition and crystal structure similar to natural bone, calcium phosphate bioceramics have good biocompatible, could combine with bone and induce bone tissue regeneration. However, the application of calcium phosphate bioceramics is restricted in bone tissue engineering due to the brittleness, low toughness and uncontrollable degradation rate. In this thesis, reinforces phase was used to improve the properties of calcium phosphate bioceramics bone scaffolds. It focused on the the influencing rule and mechanism of reinforces phase on the mechanical properties and biological properties of bone scaffold. The main research work and innovative results are as follows:1. The dynamic loading of a moving laser heat source with a Gaussian distribution was realized with ANSYS Parameter Design Language (APDL). The change rules of three-dimensional transient temperature field with the different speeds of the moving laser heat source were analyzed. The obtained ideal laser scanning speed was50-250mm/min after optimization.2. Three-dimensional porous β-TCP scaffold was fabricated using SLS. The association regularity of the average grain size with mechanical properties of the prepared scaffold under different laser scanning speed was studied. The effect of grain size on the cell adhesion and proliferation ability of the scaffold was studied. MG63osteoblast-like cells and human bone marrow mesenchymal stem cells could attach and grow on the prepared scaffolds. Moreover, the smaller the grain size is, the better the cell biocompatibility is. The porous scaffold was immersed in a simulated body fluid (SBF) to assess study the bioactivity, the prepared scaffold exhibited good biological activity in SBF.3. The scaffold was added with ZnO to improve the properties. The influence of doped ZnO on the microstructure, phase composition, and mechanical properties was studied. It was found that the addition of ZnO can improve the mechanical properties of scaffold, and the optimal proportion was2.5%.4. The influence of doped ZnO on the cell ashesion and degradation properties of the bone scaffold was studied. The scaffold exhibited increasing better ability to support MG63cell attachment and proliferation. The degradation rate of the scaffolds slowed down with the increase of ZnO content, and improved the bioactive of porous bone scaffold. Figures:45, Tables:7, References:86...