神经植入对大段组织工程骨成骨影响的早期实验研究

The early experimental study of the osteogenesis effects on nerves implantation in the large tissue engineered bone

目的研究在组织工程骨内植入神经束对大段组织工程骨成骨的影响以及初步探讨促进成骨的机制。方法48只新西兰大白兔，随机分为4组：A组，单纯组织工程骨组；B组，组织工程骨＋运动神经束植入组（股神经肌支）；C组，组织工程骨＋感觉神经束植入组（隐神经）；D组，组织工程骨＋感觉、运动神经束联合植入组。每只动物均在右侧股骨制备长1．5cm的节段性骨与骨膜缺损．钢板固定后在骨缺损处分别植入四种方法制备的组织工程骨。术后4、8、12周行大体观察、X线观察、新生骨组织定量观察成骨效果，降钙素基因相关肽（CGRP）及S-100蛋白的免疫组化染色观察其在组织工程骨内的分布，并行半定量分析。结果在组织工程骨内植入感觉神经后，比单纯组织工程骨和运动神经束植入的修复效果均有明显提高，而在组织工程骨中植入运动神经与单纯组织工程骨修复效果无明显差异．感觉神经植入与感觉、运动联合植入的成骨效果无明显差异。免疫组化染色显示神经肽类物质CGRP、S-100在C组与D组中的表达高于A组与B组，差异有统计学意义。结论在组织工程骨内植入感觉神经在早期可促进成骨，而植入运动神经未见促进作用，其机制可能是植入的感觉神经在组织工程骨内分泌神经肽所致。

Objective To investigate the osteogenesis effects in vivo on nerve-tract implant into large tissue engineered bone and innitialy explore the mechanism of osteogenesis. Methods 48 New Zeland rabbits were divided into 4 groups randomly and equally： tissue-engineering group （A）, motor nerve tract group （ B,muscular branches of femoral nerves）, sensory nerve tract group （C,saphenous nerves）, sensory and motor nerve tract group （D）. A segamental bone defect of 1.5 cm long was made at the right femur in each animal. After plate fixation, the defects were implanted respectively with the engineered bone prepared in the above-mentioned 4 ways. At 4,8 and 12 weeks postoperatively, gross observation ,X-ray observation and HE staining were adopted to evaluate the engineered bone and the new bone formation was measured by image analysis. The distribution of calcitonin gene related peptide （CGRP） and protein S-100 in the new bone were detected by immunohistochemistry and analysised semi-quantatively. Results After implantation of sensory nerve into the tissue-engineered bone, the reparative effect was obviously better than that in both group A and group B. No obvious osteogenetic difference was found between group A and group B. The expression of CGRP and S-100 in group C and group D were obvious higher than in group A and group B. Conclusion Implantation of sensory nerve tract into tissue-engineered bone can improve osteogenesis, but implantation of motor nerve tract can not achieve the similar efffect according to this experiment, secretion of neuropeptide by the implanted sensory nerve may be the possible mechanism.