Decellularized extracellular matrix gelloids support mesenchymal stem cell growth and function in vitro.

Volumetric muscle loss (VML) injuries are irrecoverable due to a significant loss of regenerative elements, persistent inflammation, extensive fibrosis, and functional impairment. When used in isolation, previous stem cell and biomaterial-based therapies have failed to regenerate skeletal muscle at clinically relevant levels. The extracellular matrix (ECM) microenvironment is crucial for the viability, stemness, and differentiation of stem cells. Decellularized-ECM (D-ECM) scaffolds are at the forefront of ongoing research to develop a viable therapy for VML. Due to the retention of key ECM components, D-ECM scaffolds provide an excellent substrate for the adhesion and migration of several cell types. Mesenchymal stem cells (MSCs) possess regenerative and immunomodulatory properties and are currently under investigation in clinical trials for a wide range of medical conditions. However, a major limitation to the use of MSCs in clinical applications is their poor viability at the site of transplantation. In this study, we have fabricated spherical scaffolds composed of gelatin and skeletal muscle D-ECM for the adhesion and delivery of MSCs to the site of VML injury. These spherical scaffolds termed "gelloids" supported MSC survival, expansion, trophic factor secretion, immunomodulation, and myogenic protein expression in vitro. Future studies would determine the therapeutic efficacy of this approach in a murine model of VML injury.