外伤等原因极易造成儿童牙齿全脱出，全脱出牙的牙周膜活性降低甚至发生坏死是导致其再植术失败的重要原因。因此，牙周膜再生对于条件不理想的全脱出牙再植具有重要意义。本研究组拟利用组织工程技术体外构建“人工牙周膜”系统，用于模拟全脱出牙再植术后理想的牙周膜愈合方式，以期提高全脱出牙再植的成功率。我们在纳米材料合成及组织再生应用研究的前期工作基础上，利用静电纺丝技术制备“三明治式”复合成纤维细胞生长因子-2质粒/骨形态发生蛋白-2质粒的聚乳酸-羟基乙酸共聚物纳米纤维支架材料（PLGA/pFGF-2/pBMP-2），探究其“程序性释放”质粒的规律；通过扫描电镜、MTT、RT-PCR等实验方法检测该“人工牙周膜”系统中牙周膜细胞的增殖和分化能力，分析其促进牙周膜再生的潜力；进一步通过犬全脱出牙再植实验动物模型评估其在体内再生牙周膜的能力，为其应用于临床，提高脱出牙再植术的成功率提供新的思路和有力依据。

Trauma can cause tooth avulsion of children frequently. The failure of avulsed tooth replantation is mainly caused by the low viability or necrosis of periodontal ligament. Hence, periodontal ligament regeneration is important to avulsed tooth with poor state replantation. Our research group will structure “artificial periodontal ligament” system by tissue engineering technology to simulate the ideal periodontal ligament healing pattern for enhancing success rates of avulsed tooth replantation. On the basis of preliminary work about the synthesis of nano materials and tissue regeneration applied research, we will synthesize poly (lactic -co-glycolic acid)/ fibroblast growth factor 2 plasmid /bone morphogenetic protein 2 plasmid “sandwich” nano-fibrous scaffold（PLGA/pFGF-2/pBMP-2） by electrospinning technology and explore its regularity of programmed plasmid release. The proliferation and differentiation of periodontal ligament cells in “artificial periodontal ligament” system were detected by scanning electron microscope, MTT, RT-PCR for analyzing its potential for periodontal ligament regeneration. Further, the capability of periodontal ligament regeneration in vivo is evaluated by dog avulsed tooth replantation experimental animal mode for offering new idea and powerful basis to clinical application and success rates of avulsed tooth replantation.