| Bone injuries are one of the main causes of people sickness. Nowadays the most common way to cure bone injuries is using implants to fix the broken bone and help bone tissue to grow. Titanium and its alloys has been widely used as human bone replacement implant for its excellent biocompatibility and mechanical properties. The traditional bone replacements are mainly dense metal and foam metal with many disadvantages. In recent years, with the development of metal fast prototyping technology, there are more and more researches on titanium scaffold with regular pores. Ti alloy scaffold provides mechanical environment and biological environment for cell growth in human body. The mechanical environment requires that the scaffold has a certain strength and elasticity modulus, the biological environment requires the scaffold has large pore size and high porosity. As a result, the higher the strength of scaffold,the better, under the condition that its porosity meets the demands.Designed 5 different unit cells using Unigraphics NX 7.5, repeat the unit cell in 3-dimentional directions to make porous scaffolds. 5 porous scaffolds are with the same pole section size and near porosity. Their physical models are made using the EBM technology. Observe their characterization under optical microscope, the results indicate that there is a certain error between actual and designed pole section size and pore size, but the error is controllable. The scaffolds’ porosity and strength are measured by experiments. The results indicate that scaffolds with near porosity but different unit cells may have great differences in strength.To explore the designed parameters’ effects on scaffold strength, for V-structure, designed a series of porous scaffolds. Their strengths are compared using finite element analysis. The results show that the pole intersection angle has the greatest effect on scaffold strength; the influence factors of pole section size and pole length are similar to each other. Pole section size has greater influence than pole length if putting manufacturing error and pore size into consideration.The application status of polymeric biomaterials is introduced. Use chitosan/silk fibroin/HAP to make a composite with β-TCP and porous Ti scaffold. Their characterizations are observed under SEM. The results show that the β-TCP-based three-layered composite has obvious three-layered structures, different layers are closely connected, the pore sizes are different in different layers. In the Ti composite, the scaffold is filled with porous biomaterials meaning that it can promote bone cell growth. Osteoblast is cultured on Ti alloy scaffold, the results show that Ti alloy scaffold has promotion for the growth of osteoblast... |
