Study On Biocompatibility And Osteogenic Activity Of Porous SrO/nHA Bone Repair Materials Prepared By SPS In Non-human Primates

Objective:The biocompatibility and osteogenic activity of SrO/nHA composites which Sr with a mass ratio of 3%in non-human primates were studied.Method:1.Porous nHA materials and porous SrO/nHA composites were prepared by SPS sintering technology and NH₄HCO₃ as pore-forming agent,and their qualifications were tested.2.An animal model of repairing middle fibular bone defect of cynomolgus monkey was established by using SPS sintering technology,NH₄HCO₃ as pore-forming agent and porous SrO/nHA composite material.The model was divided into blank control group,nHA material group and SrO/nHA composite material group.The biocompatibility and osteogenic activity of SrO/nHA composites which Sr with a mass ratio of 3%in non-human primates were evaluated by routine feeding observation,blood routine,blood biochemical detection,X-ray detection,gross anatomical observation,micro-CT detection and histological examination?HE staining?.Result:1.Porous nHA material and porous SrO/nHA composite prepared by SPS sintering technology and NH₄HCO₃ as pore former.The main components of the two materials are still hydroxyapatite.The pore sizes of the materials are different,evenly distributed and interpenetrated.The pore size is in the range of 50⁵00?m,and the average size is 200?m,which can meet the needs of fiber tissue,bone cells and blood vessels,increase the contact area of tissue fluid and materials,promote metabolism,and provide necessary conditions for the survival of new bone.The compressive strength of the two materials is above 300MPa,which is higher than the compressive strength of normal human cancellous bone 4¹2MPa and the compressive strength of dense bone 130¹80MPa,which can meet the mechanical requirements of artificial bone repair materials.In subsequent animal experiments.2.Porous nHA materials and porous SrO/nHA composites prepared by SPS sintering technology and NH₄HCO₃ as pore-forming agent were implanted into non-human primates,and no obvious immune rejection was observed in all experimental animals.At the same time,the two materials did not cause adverse effects on the renal and liver functions of experimental animals.3.By analyzing the X-ray film,gross anatomical observation and micro-CT three-dimensional reconstruction of the blank control group,it was found that a small amount of callus was formed at the osteotomy end of the blank control group,and the surface healed,but the bone defect was not completed by self-repair.The reconstruction of the site still showed a large segmental bone defect,indicating that the skeletal segmental bone defect model of the cynomolgus monkey was successfully established,and the possibility of reconstructing the fibular defect site by self-repair in the experimental animals in this study was excluded.4.Porous nHA materials and porous SrO/nHA composites prepared by SPS sintering technology and NH₄HCO₃ as pore-forming agent were implanted into fibula defects of non-human primates.Compared with the blank control group,both materials can promote the repair of bone defect.After 24 weeks of implanting the material,the implant material was filled with a large number of new bone inside the porous nHA material group,and a large amount of material was not degraded.The porous SrO/nHA composite material group had basically formed a mesh-like trabecular structure,occasionally a small amount of material residues were observed,which could be considered as the basic completion of bone remodeling.Porous SrO/nHA composites are better than porous nHA materials in repairing fibular defect.Conclusion:SrO/nHA composites which Sr with a mass ratio of 3%have good biocompatibility and osteogenic activity in non-human primates.