Preparation And Study On Porous β-TCP/Gel Scaffold

The research on bone tissue replacement materials is one of the most attractive aspects of biomedical engineering. Materials for defect replacement and repairing process special functional requirements for mechanical properties for bone bearing, biocompatibility, osteoconductivity and osteoinductivity. Therefore, the exploration of the bone replacement materials based on tissue engineering technology has become a heated topic in this field. Traditional bioceramic such asβ-tricalcium phosphate (β-TCP) has a component simulated with bone minerals, and possesses a good biocompatibility. However,β-TCP has disadvantages like big brittleness, poor toughness and high elastic modulus, which limits it application in clinic. To satisfy the demand for mechanical and biological properties of bone replacement materials, composite materials ofβ-TCP have been studied.Fist of all, Ca(OH)2/H3PO4 processes of preparingβ-TCP powders at the Ultrasonic field were studied. Secondly, the technique of production of porousβ-TCP scaffold formation, a new technique called porogen enwrap method was set forward. The homogenous mixture of porogen andβ-TCP powders were formed, and interconnected porousβ-TCP scaffold, an additive(K2HPO4)was chosen to improve sintering process, and the effect of the additive concentration on strength was studied. We used SiO2 to improve scaffold bioactivity. In order to make a kind of porousβ-TCP/Gel composite scaffold which composition and structure just like bone. The method of freeze-drying was used. The composition and structure ofβ-TCP/Gel composite scaffold just like bone.The characters ofβ-TCP/Gel composite scaffold, such as composition, granularity, microstructure, porosity, water absorption and so on were analyzed with IR, XRD, SEM and some chemistry methods.The results show that:β-TCP powder could be abstained by subsection liquid phase reaction at the ultrasonic field, and the chemical ingredient of scaffold wasβ-TCP, The K2HPO4 can improve compressive of porousβ-TCP scaffold, and the bioactive material of SiO2 can improve compressive of porousβ-TCP scaffold. The pores were interconnected and distributed homogenously, average big pore size was 688.88±46.39μm ,the diameter of the channel between pores was 160.59±39.46μm,and the porosity, water absorption, compressive strength of scaffold respectively 68.01%±4.42 %, 48.34%±6.23%, 2.60±0.84MP. The composite samples were immersed in stimulated body fluid(SBF) at 37℃,Mechanical strengths and microstructure changes were measured, and the samples were characterized by IR and SEM. The results showed that bone-like apatite was formed on the surface of composites, and the mechanical strengths continuously descend with the time of degradation.