E7-modified gelatin microcarriers for efficient expansion and stemness preservation of mesenchymal stem cells

Mesenchymal stem cells (MSCs) possess self-renewal ability, multi-differentiation potential and low immunogenicity, thus serving as an ideal choice for cell therapies. Ex-vivo expansion systems that have been developed to meet clinical demands are faced with two crucial barriers, limited quantity and stemness loss of expanded cells. Hence, it is crucial and feasible to construct microcarriers that can show high and specific affinity to MSCs, and support highly efficient cell expansion with minimal stemness loss. In this study, EPLQLKM (E7) peptides were modified onto gelatin microcarriers by poly (ethylene glycol) (PEG) linkers, which showed great antifouling ability against xenogenic components. The rat bone marrow-derived mesenchymal stem cells (rBMSCs) harvested from the E7-modified gelatin microcarriers achieved better cell attachment, stemness maintenance, viability, and multilineage differentiation potentials, especially those with a higher E7 density. Attributing to the promotion for cell adhesion, E7 functionalization increased the expansion efficiency of rBMSCs with improved quantity and quality simultaneously, thereby providing a novel strategy for scalable expansion to optimize the clinical performance of MSCs.