| In this study,porous ammonium hydroxyapatite and strontium-doped hydroxyapatite material(strontium-doped content of 5wt%)were prepared by spark plasma sintering without using ammonium bicarbonate as pore-forming agent without using binder.The XRD patterns show that the strontium doped hydroxyapatite is a crystal with the same structure as the hydroxyapatite.The incorporation of strontium does not produce other heterogeneous phases.Scanning electron microscopy shows that the material has a pore size of about 200 nm in the sintering process.The porosity is about 40%,and the holes and holes are interpenetrated to provide sufficient space for bone tissue and blood vessels.The mechanical properties of the two materials show that the compressive strength of the two materials is above 3MPa,close to the compressive strength of human cancellous bone.In addition,the incorporation of strontium improves the mechanical properties of hydroxyapatite.LDH activity tests show no cytotoxicity in both materials.Rabbit P3 generation of bone marrow mesenchymal stem cells co-culture experiments show that hydroxyapatite incorporation of strontium can help promote bone marrow mesenchymal stem cell proliferation,osteogenic differentiation and adhesion.Osteoblast MG-63 co-culture experiments show that hydroxyapatite incorporation of strontium could promote the proliferation,differentiation,adhesion and migration of osteoblasts.The results show that strontium-doped hydroxyapatite had good bone repair ability.After 8 weeks of implantation,the material was integrated with the bone of the host bone.A large amount of braided bone was formed on the surface of the material.After 16 weeks,the material was degraded.Shaping,bone remodeling basically completed.In vitro and in vivo experiments show that porous strontium hydroxyapatite material has no cytotoxicity,good bone conduction and biodegradability,is an ideal bone repair materials. |
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