Extracellular matrix protein gelatin provides higher expansion, reduces size heterogeneity, and maintains cell stiffness in a long-term culture of mesenchymal stem cells.

Extracellular matrices (ECM) present in our tissues play a significant role in maintaining tissue homeostasis through various physical and chemical cues such as topology, stiffness, and secretion of biochemicals. They are known to influence the behavior of resident stem cells. It is also known that ECM type and coating density on cell culture plates strongly influence in vitro cellular behavior. However, the influence of ECM protein coating on long-term mesenchymal stem cell expansion has not been studied yet. To address this gap, we cultured bone-marrow derived hMSCs for multiple passages on the tissue culture plastic plates coated with 25 μg/ml of various ECM proteins. We found that cells on plates coated with ECM proteins had much higher proliferation compared to the regular tissue culture plates. Further, gelatin-coated plates helped the cells to grow faster compared to collagen, fibronectin, and laminin coated plates. Additionally, the use of gelatin showed less size heterogeneity among the cells when expanded from passages 3 to 9 (P3 to P9). Gelatin also helped in maintaining cellular stiffness which was not observed across other ECM proteins. In summary, in this research, we have shown that gelatin which is the least expensive compared to other ECM proteins, provides a better platform for mesenchymal stem cell expansion.