模拟微重力环境对人牙髓干细胞体内增殖能力的影响

目的：研究模拟微重力环境对聚乳酸-羟基乙酸（PLGA）支架上人牙髓干细胞（hDPSCs）体内增殖能力的影响。方法：分离、培养hDPSCs并进行鉴定。以PLGA作为支架材料培养人牙髓干细胞,将hDPSCs-PLGA复合物分别在模拟微重力环境和普通重力环境下培养72h,然后移植到裸鼠背部皮下。植入4周后取出组织块,分别进行HE染色、Masson染色、Ki67和I型胶原免疫组化检测。结果：模拟微重力环境下细胞密度、胶原生成量、I型胶原表达量和Ki67阳性细胞数量明显高于普通环境（P〈0.01）。结论：模拟微重力环境培养的hDPSCs的体内增殖能力高于普通重力组。

In Vivo Study on Proliferation Ability of Human Dental Pulp Stem Cells on PLGA Scaffolds in Simulated Mierogravity Environments.

Objective： To investigate the effect of simulated microgravity enviroments on proliferation ability of human dental pulp stem cells （hDPSCs） on PLGA （Poly lactic acid glycolic acid） scaffolds in vivo. Methods： hDPSCs were seeded on PLGA scaffolds, and were cultured both on the conditions of conventional environment and simulated microgravity for 72 hours. Then, the hDPSCs--PLGA compounds were transplanted subcutaneously into immunodeficiency mice. After 4 weeks of transplantation, hematoxylin--eosin staining, Masson staining, immunohisto- chemical detection for type I collagen and Ki67 were conducted on hDPSCs--PLGA compounds. Results： In the experimental group, it displayed a higher density of cells and more collagen formation than control. In the meanwhile, it showed more collagen I expression and more positive cells of Ki67 in experimental group than that in the control group. Conclusion： In vivo, the proliferation ability of hDPSCs cultured in simulated microgravity conditions is significantly higher than that in the conventional environment.