E7-Modified Substrates to Promote Adhesion and Maintain Stemness of Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) have drawn great attention in clinical applications due to the self-renewal ability, multi-differentiation potential, and low immunogenicity. However, there are challenges in the ex vivo expansion of MSCs, including low efficiency, stemness loss, and safety. Therefore, it is crucial to construct a substrate that can show an alterable affinity to MSCs, and induce efficient cell expansion with minimal stemness loss. In this study, EPLQLKM (E7)-modified substrates with tunable E7 densities are fabricated on PEGylated substrates. The PEG layer with an average thickness of 1.7 nm shows good antifouling ability. E7-modified substrates have an improving effect on adhesion and spreading of the rat bone marrow-derived mesenchymal stem cells (rBMSCs), along with the increase of E7 densities. rBMSCs on E7-modified substrates maintain the stem cell phenotypes, and shows robust proliferation and multilineage differentiation, especially on the substrates with high E7 densities. In summary, this study provides a novel strategy of E7 functionalization to promote adhesion and maintain stemness of MSCs, which holds great potentials in the functionalization of microcarriers for the expansion of MSCs.