模拟微重力环境对人牙髓干细胞体外增殖能力的影响

目的：研究模拟微重力环境对人牙髓干细胞（human dental pulp stem cells,hDPSCs）在PLGA支架上体外增殖能力的影响。方法：将分离、鉴定后的人牙髓干细胞接种在PLGA支架上,采用MTT法检测普通环境和模拟微重力环境中培养24、48、72h的人牙髓干细胞在PLGA支架上的细胞活性。DAPI荧光染色和流式细胞术比较牙髓干细胞在两种环境培养3d的细胞数量以及细胞周期分布情况。结果：MTT显示模拟微重力组中各时间点的A值均高于普通环境培养组;DAPI荧光染色显示在模拟微重力下培养3d的人牙髓干细胞数量明显多于普通环境培养组;细胞周期分析结果表明模拟微重力组中S期细胞比例明显高于普通环境培养组（P〈0.05）。结论：接种在PLGA支架上的人牙髓干细胞在模拟微重力环境下较普通环境具有更高的体外增殖能力。

Influence of Simulated Microgravity on the Proliferation Ability of Human Dental Pulp Stem Cells on PLGA Scaffolds in Vitro

Objective：To study the effect of simulated microgravity on the proliferation of human dental pulp stem cells（hDPSCs）in the PLGA scaffolds in vitro.Methods：HDPSCs were seeded in the PLGA scaffolds,and divided into normal gravity（NG）and microgravity group（SMG）with rotary cell culture system.At 24h,48hand 72hof cell culture,MTT assay was carried out to detect the proliferation ability of human dental pulp stem cells.Cell number in PLGA scaffolds and cell cycle were observed using DAPI immunofluorescence staining and flow cytometry after 3dof cultivation.Results：After 24h,48hand 72hof cultivation,the optical density（OD）,as a measurement of cell viability,in the SMG group was significantly higher than that in the NG group.The number of hDPSCs in experimental group was increased compared with the control group（P〈0.05）,and more SMG-treated cells progressed into the S phase.Conclusion：The proliferation ability of hDPSCs in the PLGA scaffolds was enhanced in the simulated microgravity.