Ramasubramanian Anusuya, Muckom Riya, Sugnaux Caroline, Fuentes Christina, Ekerdt Barbara L, Clark Douglas S, Healy Kevin E, Schaffer David V
Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States.
Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94720, United States.
ACS Biomater Sci Eng. 2021 Apr 12;7(4):1344-1360. doi: 10.1021/acsbiomaterials.0c01462. Epub 2021 Mar 22.
Human pluripotent stem cells harbor an unlimited capacity to generate therapeutically relevant cells for applications in regenerative medicine. However, to utilize these cells in the clinic, scalable culture systems that activate defined receptors and signaling pathways to sustain stem cell self-renewal are required; and synthetic materials offer considerable promise to meet these needs. development of materials that target novel pathways has been stymied by a limited understanding of critical receptor interactions maintaining pluripotency. Here, we identify peptide agonists for the human pluripotent stem cell (hPSC) laminin receptor and pluripotency regulator, α-integrin, through unbiased, library-based panning strategies. Biophysical characterization of adhesion suggests that identified peptides bind hPSCs through α-integrin with sub-μM dissociation constants similar to laminin. By harnessing a high-throughput microculture platform, we developed predictive guidelines for presenting these integrin-targeting peptides alongside canonical binding motifs at optimal stoichiometries to generate nascent culture surfaces. Finally, when presented as self-assembled monolayers, predicted peptide combinations supported hPSC expansion, highlighting how unbiased screens can accelerate the discovery of targeted biomaterials.
人类多能干细胞具有无限的能力来生成与治疗相关的细胞,用于再生医学。然而,要在临床上利用这些细胞,就需要可扩展的培养系统,该系统能激活特定的受体和信号通路以维持干细胞的自我更新;而合成材料有望满足这些需求。对维持多能性的关键受体相互作用的了解有限,阻碍了针对新途径的材料的开发。在这里,我们通过基于文库的无偏淘选策略,鉴定出了人类多能干细胞(hPSC)层粘连蛋白受体和多能性调节因子α-整合素的肽激动剂。黏附的生物物理特征表明,鉴定出的肽通过α-整合素与hPSC结合,其解离常数低于微摩尔,与层粘连蛋白相似。通过利用高通量微培养平台,我们制定了预测指南,以便以最佳化学计量比将这些靶向整合素的肽与典型结合基序一起呈现,从而生成新生的培养表面。最后,当以自组装单层形式呈现时,预测的肽组合支持hPSC的扩增,突出了无偏筛选如何能够加速靶向生物材料的发现。