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The aim of the present study was to investigate the chitosan - nano-hydroxyapatite composite material (CTS-nHA) implanted in the animal body repair bone defects osteogenic effect, the the materials absorption rate, biocompatibility and osteoinductive activity for vivo bone graft material and tissue engineering bone scaffold to provide experimental evidence and theoretical basis. Method an experimental material to prepare nano-hydroxyapatite (nHA) in this experiment by Sichuan University, Key Laboratory of Oral Biomedical Engineering, the CTS-of nHA composite synthesized by the experiment. CTS-nHA crystal size, shape, and porosity were observed using scanning electron microscopy. 2 animal experiments 18 New Zealand white rabbits were randomly divided into: CTS-of nHA group, nHA group and blank group (not implanted any material), bilateral rabbit hind tibia manufacturing about 5mm in diameter size bone defects, on each side of the lower extremity make two bone defects, bone defects between distance of about 10mm, implantable material or blank, 2,4,6,10 weeks after to remove experimental bone specimens, the experimental area osteogenesis specimens, histological The observation of the growth factor BMP-2 expression and bone. Results All the animals were able to tolerate the anesthesia and surgical incision area early mild swelling bleeding subsides in about one week, the incision healed well, no significant inflammatory response, the CTS-of nHA group of new bone formation and materials absorption are faster to 10 weeks has basically been replaced by new bone tissue, bone tissue regeneration of nHA and blank groups slower, 10 weeks, there is a large bone defects. The histological observation results show that new bone matrix generation volume in each time period CTS-nHA group the nHA group was significantly higher than blank group (P lt; 0.05), which nHA group was higher than that in the blank group (P lt; 0.05). CTS-nHA group to 10 weeks more mature lamellar bone tissue has formed, and the the nHA group of mesh woven bone intermingled amount of callus matrix. However, CTS-nHA absorption rate in the body faster than nHA group, CTS-of nHA of absorption is slightly faster than the rate of new bone formation. Immunohistochemical staining showed that the direct observation of the surface of the CTS-nHA a strong expression of BMP-2, BMP-2 expression in the the CTS-of nHA group of new bone tissue than the the nHA group of peak advance. Positive cells in the expression level of the CTS-nHA group decreased to 10 weeks, the main bone cells, a small amount of osteoblasts, the callus matrix staining. nHA group and blank group is still more positive cells, osteoblasts, chondrocytes, callus stromal staining still deeper. Conclusion 1 CTS-nHA strong osteogenic activity in vivo, osteogenesis fast, faster absorption, showing good prospects as a graft material in the body and tissue engineering bone scaffold. 2 CTS-nHA implanted in the body, on its surface, a strong expression of BMP-2, peak around the new bone tissue, bone growth factor expression in advance prompted CTS-nHA osteoinductive activity in the body can adsorb growth factor, In vivo stronger osteogenic activity of bone inducing activity.
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