Study Of Property Improvement On Calcium Phosphate System Containing Strontium Ions For Bone Prosthesis

As a new type self-setting non-ceramic hydroxypatite artificial bone material, calcium phosphate cement has plenty excellent property, among which are, fine biocompatibility, property of self-setting and shaping, degenerating activity in corresponding with ossification, being able to be used for release-carrier of drug and bioactive factor, and so on. However, it still has some demerits, such as, long time of setting, poor adhesion property, deficiency of strength, slowness of degradation, and being prone to breakdown in contact with liquid at original setting stage. The application of calcium phosphate cement was thus restricted to certain degree.The aim of this research is to consummate the property of calcium phosphate cement through property improving.The experiment used SrCO₃ and phosphorylated starch to improve the properties of α -TCP cement system. The hydrating process and the final product were analyzed by X-ray diffraction , infrored spectum and electronmicroscope. The results show: Strontium carbonate and phosphorylated starch had* no interference with α -TCP cement's hydrating process , setting time and strength. The hydrating product was Calcium deficiency hydroxyapatite containing strontium ions and phosphorylated starch. The dissolubility in vitro and biological reactivityincreased.Replacing bFGF by bovine's albumin, the study observe the affranchise dynamics of the composite of a -TCP cement and albumin through estimating the protein in solutions. The result show: The Liberation of protein from compound material coincidents with Higuchi equation. The Liberation of protein and square root of time (hours) had a relationship of linear correlation. The bone cement system can be used as slowly releasing carrier of activity substance.To study the biocompatibility of the composite, the experiment culture a -TCP cement material and osteoblasts together, analysed by MTT\ ALP activity and secretion of Collagen I . The result show: The composite has good biocompatibility and can be a good carrier of biocompatibility material.