Primitive Study On Bone Formation And Osteoinductive Activity Of Chitosan-nanohydroxyapatite Composite Materials Repair Rabbits Tibial Bone Defect

ObjectiveAmong procedure of tooth implant,The tooth implant operation can't extensivly develop always because of lack Sufficient quantity of bone.Purpose of this study is that explore the effect of bone formation,speed of absorption and osteoinductive activity of chitosan-nanohydroxyapatite(CTS-nHA) composite materials during rabbits Tibial bone defect is repaired.The mainly purpose of this experiment was to give a preliminary experimental evidence and to prove the novel composites as potential bone substitutions or bone tissue engineering scaffold.Methods1 Preparation of materials In this experiment,the CTS-nHA composite materials is synthesize by myself.After it was synthesize,the synthetic materials was used scanning electron microscope for crystal size, shape and porous nature should be observed.2 Animal experiments 18 adult New Zealand rabbits were randomly divided into 3 groups,CTS-nHA group;nHA group;control group.Rabbits were operated with 5mm osteomoty at two tibial bone,The materials was embeded into the defect position respectively,after 2,4,6 and 10 weeks post-operation,the samples were harvested and observed with roughly observer and pathogical and immunohistochemistry technical.ResultsAll the animals can tolerate anesthesia and surgery,mild swelling and ecchymosis of the incision area of early postoperative,About 1 week swelling and ecchymosis was gradually faded away,after surgery the cuts we re good healing and no significant inflammatory response.New bone formation of composite group and material absorption were faster.Up to 10 weeks was replaced by new bone organization,in nHA group and control group new bone organizations were more slowly,up to 10 weeks,there was large bone defect.Histological studies has shown,there was the most abundant new bonematrix migrating into CTS-nHA group than other two groups at each weeks we have observed(p<0.05),at the same time,more abundant new bonematrix migrating into the nHA group than control group(P<0.05).At the tenth week,in CTS-nHA group,the new bone matrix has formed lamellar bone.But in the control group there was more bone matrix.The speed of material of CTS-nHA group absorded was faster than material of nHA group,but the speed of material of CTS-nHA group absorbed was also faster than the speed of new bonematrix migrating.We have observed there was plenty BMP-2 expression on the surface of CTS-nHA,farthermore,the BMP-2 expression in CTS-nHA group was more abundant than nHA group and control group at the early time.Conclusion1 CTS-nHA composite materials is Strong osteogenic activity,bone formation is faster and the absorption rate is quick.The novel composites as potential bone substitutions or bone tissue engineering scaffold has a good outlook.2 We have observed there was plenty BMP-2 expression on the surface of CTS-nHA,around CTS-nHA,in new bonematrix,bone growth factor expressed earlier peak.This illustrate the CTS-nHA can absorb BMP-2 and then it has good osteogenic activity.Its good osteogenic active is relevant to it is good osteoinductive activity.