Research Of Sr²⁺ And Ag⁺ Ions Doped On ?-TCP Porous Bionic Bone Materials

Bioceramic beta tricalcium phosphate is an ideal material for repairing bone defect,which has excellent biocompatibility and biodegradability,can be combined with human bone after implantation.However,beta tricalcium phosphate's mechanical property is poor.Metal ions can be doped into calcium phosphate materials to enhance the mechanical property and biological property of the materials.Silver ion has no toxic on human body.Strontium is a key component of natural bone,which can promote bone development,accelerate the formation of bone.The purpose of this study is to develop a new type of beta tricalcium phosphate porous ceramic material with good mechanical properties and good antibacterial property by doping strontium ion and silver ion.According to the ratio of?Ca+Sr/Ag?/ P=1.50,prepared beta tricalcium phosphate powders contain 1%,7%,13% Sr²⁺ and 0.05%,0.8%,3% Ag⁺ by sol gel method.Prepared tricalcium phosphate bioceramic with carbon powder as porogen and polyvinyl solution as binder.Study on the microstructure,mechanical properties,antibacterial properties,biodegradability,friction and wear properties.Sr²⁺and Ag⁺ions can replace the Ca²⁺of beta tricalcium phosphate,the Sr²⁺and Ag⁺metal ions modified beta tricalcium phosphate powders have good crystallinity and purity,the particle size is small and the distribution is uniform,which all below 50?m.In the process of sintering,the carbon powders and PVA solution were completely decomposed,there was no residue in the tricalcium phosphate ceramics.Prepared beta tricalcium phosphate porous ceramic with 20wt% carbon powder and 6wt% PVA solution is good to the aperture state and mechanical property of materials,the compressive strength of Sr1%-Ag0.8%-beta tricalcium phosphate porous ceramic is 18.91 MPa,the pore porosity is69.64%,particle size is about 200³00?m,the water absorption rate is more than 60%.Doped Sr²⁺into calcium phosphate ceramics is beneficial to mechanical strength.Due tothe introduction of Ag⁺,Ag-beta tricalcium phosphate materials have antibacterial properties.In vitro degradation experiment,beta tricalcium phosphate materials degradated and formed apatite layer,the deposition rate is greater than the degradation rate.Sr²⁺promoted the deposition of hydroxyapatite on beta tricalcium phosphate ceramic,improved the compressive strength and degradation performance.The friction coefficient between Sr-beta tricalcium phosphate and ultra-high molecular polyethylene increased due to the introduction of strontium ion.The friction coefficient of Sr²⁺ and Ag⁺ modified tricalcium phosphate ceramics decreased in SBF solution and saline solution.