磷酸钙复合材料构建模式对颌骨缺损修复效率的影响

The effectiveness of scaffolds of calcium phosphate cement composites on jaw defect repair

目的:探讨神经多肽P物质(SP)及Ⅰ型胶原(Col-Ⅰ)复合自固化磷酸钙(CPC)构建模块化生物活性骨替代材料对其修复颌骨缺损效率的影响。方法:制备对照组单纯CPC以及试验组共价交联SP/Col-Ⅰ复合CPC、SP/Col-Ⅰ溶液混合CPC、SP溶液混合CPC再复合Col-Ⅰ海绵颗粒、SP溶液混合CPC、Col-Ⅰ溶液混合CPC材料试件,扫描电镜观察材料超微结构。将材料分别植入兔下颌骨缺损区(n=5),术后8周处死取材Micro-CT检查,观察各组材料降解及骨缺损重建情况。结果:扫描电镜检查显示Col-Ⅰ溶液混合CPC可改善材料微孔隙结构,Col-Ⅰ海绵颗粒则可于材料内部形成>300μm的大孔隙结构;术后8周Micro-CT及组织学检查示SP多肽和Col-Ⅰ均可改良CPC复合材料成骨活性,两者交联后活性显著减退;SP溶液混合CPC再复合Col-Ⅰ海绵颗粒材料诱导骨再生能力及生物降解速度显著优于其余5组材料(P<0.05)。结论:模块化设计骨替代材料利于移植应用,SP多肽、Ⅰ型胶原、CPC模块化复合材料构建模式对其生物活性有显著影响,SP释放及材料孔隙结构是决定其引导和诱导骨再生能力的关键因素。

Objective：To investigate the effectiveness of modular strategy for engineering bone scaffolds composed of synthetic neuropeptide substance P（SP）,collagen type Ⅰ（Col-I） and self-setting calcium phosphate cement（CPC）.Methods：6 groups of scaffolds were constructed,including CPC control,CPC mixed with SP crosslinked Col-I solution,CPC mixed with SP supplemented by Col-I solution,CPC mixed with SP solution and blended with Col-I sponge,CPC mixed with SP solution,CPC mixed with Col-I solution.The microstructure of the materials was observed by scanning electron microscope（SEM）.The scaffolds were respectively implanted into rabbit mandibular bone defects（n=5）.8 weeks after operation micro-CT and histological examination were performed to observe the transplants and bone defect repair.Results：SEM revealed that Col-I solution slightly improved the pore size of composite CPC.Col-I sponge created macro-pores（＆gt;300 μm）inside the materials.SP and Col-I showed additive effects on the osteogenic activities of CPC scaffolds.Crosslinking SP with Col-I resulted in reduced bio-activity.The most significant bone ingrowth and material degradation occurred in the macro-porous scaffold composed of CPC,SP and Col-I sponge（P〈0.05）.Conclusion：Modular design of bone substitutes might facilitate their in vivo translation.The combination patterns of SP,Col-I and CPC may affect the final composites bioactivity.The determining factors for scaffold＆#39;s osteo-inductivity/conductivity include controlled SP peptides＆#39; release and material＆#39;s pore structures.