bFGF and Poly‐RGD Cooperatively Establish Biointerface for Stem Cell Adhesion, Proliferation, and Differentiation

Biointerface design is widely used to functionalize biomaterials with controllable physicochemical properties. Functionalized biointerface provides a versatile platform to connect biological entities and nonbiogenic materials. Existing nanofabrication approaches to create such a nanostructured biointerface involve in low stability of the functionalized nanolayer and simple functionalities that limit its applicability. Here, a stable nanolayered synthetic polypeptide (poly[LA-co-(Glc-alt-Lys)] and modified with arginine-glycine-aspartic acid, PRGD)/basic fibroblast growth factor (bFGF) biointerface is created via structural matching, charge interaction, and hydrogen bonding. The cooperative effect of the PRGD/bFGF biointerface shows multiple functionalities in promoting stem cell adhesion by 33% increase in cell adhesion to poly(d,l-lactic acid) substrate as compared to experiments on bare substrate as a control. Moreover, the biointerface enhances proliferation by 40% in cell density, potential differentiation by 62%, and gene expression by 40 and 80% respectively as compared to the control samples. The fabricated biointerface may have applications in nerve regeneration, tissue repair, and stem cell-based therapy.