人多能干细胞是组织工程、细胞治疗等理想的种子细胞来源。其临床应用的关键问题之一，是如何在成分明确条件下获得大量符合要求的人多能干细胞。成分明确、经济、效果良好的多肽修饰表面，被认为是体外大规模培养人多能干细胞的理想选择。然而，在细胞贴壁和干性维持方面，多肽修饰表面仍与Matrigel对照有一定的差距，且缺乏多肽氨基酸序列与其支持人多能干细胞生长性能间关系的研究。本课题针对介导细胞贴壁主要的信号通路，即整合素蛋白和RGD序列，合成并研究多种含RGD多肽支持人多能干细胞贴壁和干性维持的性能。同时，利用分子动力学模拟、石英晶体微天平、等温滴定量热法和生物素标记等技术，研究含RGD多肽与整合素受体间的相互作用。最终，总结含RGD多肽氨基酸变化影响多肽与整合素受体结合，及多肽支持人多能干细胞生长性能的规律，设计性能更好的含RGD多肽序列，促进多肽修饰表面在人多能干细胞体外培养中的应用。

Human pluripotent stem cells (hPSCs) exhibit great promise to provide seed cells for fields such as tissue engineering and cell therapy. Obtaining a large number of hPSCs under chemically defined conditions plays a key role in clinical application of hPSCs. Economical, stable, and effective synthetic peptide decorating surfaces are considered to be the perfect constitute for chemically defined in vitro culture microenvironments of hPSCs. However, peptide presenting surface was worse than Matrigel control in adhesion and pluripotency maintenance of hPSCs. Moreover, the correlations between amino acid sequences and abilities in supporting hPSCs survive has never been investigated. In this study, we will focus on “Arg-Gly-Asp (RGD) sequence and integrin receptor proteins that constitute the major recognition system for cell adhesion. Then, a series of new RGD containing peptide sequences will be designed and synthetized, and their abilities in supporting adhesion and pluripotency maintenance of hPSCs will be investigated. Simultaneously, methods such as molecular dynamics simulation, quartz crystal microbalance, isothermal titration calorimetry and biotin labeling will be applied to study the interaction between RGD peptides and corresponding integrin receptors. With those results, the mechanisms behind changing amino acid sequence of RGD containing peptides affecting the interaction between peptides and corresponding integrin receptors, as well as the performance of peptides in sustaining hPSCs survival will be revealed. Finally, better RGD peptide sequences will be designed for the culture of hPSCs, which exhibit promise to promote the application of peptide presenting surfaces in in vitro culture of hPSCs.