Victor Nurcombe, Simon M. Cool, Andre J. van Wijnen, Michael Raghunath, Rebekah M. Samsonraj, James H. Hui
Mesenchymal stem cells (MSC) hold great potential for regenerative medicine because of their ability for self-renewal and differentiation into tissue-specific cells such as osteoblasts, chondrocytes, and adipocytes. MSCs orchestrate tissue development, maintenance and repair, and are useful for musculoskeletal regenerative therapies to treat age-related orthopedic degenerative diseases and other clinical conditions. Importantly, MSCs produce secretory factors that play critical roles in tissue repair that support both engraftment and trophic functions (autocrine and paracrine). The development of uniform protocols for both preparation and characterization of MSCs, including standardized functional assays for evaluation of their biological potential, are critical factors contributing to their clinical utility. Quality control and release criteria for MSCs should include cell surface markers, differentiation potential, and other essential cell parameters. For example, cell surface marker profiles (surfactome), bone-forming capacities in ectopic and orthotopic models, as well as cell size and granularity, telomere length, senescence status, trophic factor secretion (secretome), and immunomodulation, should be thoroughly assessed to predict MSC utility for regenerative medicine. We propose that these and other functionalities of MSCs should be characterized prior to use in clinical applications as part of comprehensive and uniform guidelines and release criteria for their clinical-grade production to achieve predictably favorable treatment outcomes for stem cell therapy. Stem Cells Translational Medicine 2017
Adopting a multifaceted approach for characterizing mesenchymal stem cells (MSCs) is critical for the selection of best-in-class cells for therapeutic use. Assaying for surfactome, secretome, self-renewal, colony formation, trophic factor secretion, and multilineage differentiation, all form part of an assessment of cellular naivety or “stemness.” When this status is combined with functional assays such as immunomodulation, and other key parameters of cellular health that include telomere length, they collectively help provide a robust assessment of characteristics that are increasingly becoming important indicators of clinical efficacy.