神经肽在血管神经化组织工程骨中的分布

目的 观察在组织工程骨内植入血管、神经束对大段组织工程骨成骨的]响,并探讨神经肽类物质在其中的分布.方法 36只新西兰大白兔,随机分为3组:A组,单纯组织工程骨组;B组,血管束植入组(股血管束);C组,感觉神经束植入组(隐神经柬).每只兔均在右侧股骨制造长1.5 cm的段缺性骨与骨膜缺损,钢板固定后植入3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,神经肽Y(NPY)及降钙素基因相关肽(CGRP)的免疫组织化学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血管、神经后,比单纯组织工程骨的修复效果有提高,术后12周新生骨小梁占骨缺损面积的平均百分数分别为(48.67±4.21)%、(75.13±5.75)%、(73.44±2.99)%.对新生骨的组织学染色半定量分析显示3组间差异有统计学意义(F=105.735,P＜0.01),免疫组织化学染色显示神经肽类物质NPY、CGRP在B组与C组中的表达高于A组,差异有统计学意义(F=30.509及16.475,P＜0.01).结论 在组织工程骨内植人血管、神经束在早期可促进成骨,其机制可能是植入的血管、神经束在组织工程骨内发芽并分泌神经肽所致.

Distribution of neuropeptide on the vascularization or neurotization of large tissue-engineered bone

Objective To investigate the osteogenesis effects in vivo on the construction of vascularization and neurotization of large tissue-engineered bone and approach the distribution of neuropeptide initially. Methods Thirty-six New Zeland rabbits were divided into 3 groups randomly and equally: tissueengineering group ( A), vascular bundle group ( B, femoral vascular bundle), sensory nerve tract group ( C, saphenous nerves). A segmental bone defects of 1.5 cm long were made at the right femur in each animal. After plate fixation, the defect was implanted respectively with the engineered bone prepared by the 3methods mentioned above. Four, 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 neuropeptide Y (NPY) and calcitonin gene related peptide (CGRP) in the new bone was detected by immunohistochemistryand analyzed semiquantitativly. Results After implantation of vascular bundle and sensory nerve into the tissue-engineered bone, the reparative effect was obviously better than the control group. New bone formation was gradually increased ( F = 105. 735, P ＜0. 01 ). The percentage of newly formed trabeculae in bone defect area at the 12th week was (48.67 ±4.21 ) %, (75.13 ± 5.75 ) %, (73.44 ± 2. 99) % in groups A, B and C, respectively. The effect of sensory nerve tract or vascular bundle implantation in osteogenesis have statistical significance ( F = 290. 008,P＜0. 01 ). The factorial design ANOVA showed time, sensory nerve tract and vascular bundle implantation had interaction (F=3. 177, P ＜ 0. 05 ). The formation of new bone in group B was increased as compared with that in group A and group C at the 4th week, that in group C was increased as compared with that in group A, and that in group B and group C was increased as compared with that in group A at 8th and 12th week. No obvious difference was found between group C and group B at the 8th and 12th week,The expression levels of NPY and CGRP in group B and group C were obviously higher than in group A at the three time points ( F = 30. 509 and 16. 475, P ＜ 0. 01 ). Conclusion Implantation of sensory nerve tract or vascular bundle into tissue-engineered bone can improve osteogenesis. Sprouting and secretion of neuropeptide by the implanted sensory nerve or vascular bundle may be the two possible mechanisms.