Abstract
Mesenchymal stromal cells (MSCs) have been one of the most widely studied cell types in preclinical and clinical trials, due to their self-renewing, multipotent capacity, immunomodulatory properties and relative ease of isolation from multiple tissues. Despite limitations and safety concerns, fetal bovine serum (FBS) is still predominantly used for MSC expansion in clinical protocols. In addition, the undefined nature of serum composition and lot-to-lot variability have been linked to reduced reproducibility and efficiency of MSC bioprocessing. Moreover, use of animal serum in human cell culture increases the risk of contamination with adventitious pathogenic microorganisms, such as viruses, prions and bacteria. Hence, a defined serum-free formulation can provide increased safety, better control over physiological responsiveness, consistent performance and reproducible results. Here we present preliminary data on a prototype serum-free medium optimized for in vitro tenogenic differentiation of human bone marrow-derived MSCs. This serum-free formulation is capable of generating tenocyte-like cells in vitro expressing tenogenic markers such as Scx, Tnmd, TnC, Collagen I and Collagen III, whilst repressing expression of specific markers of other mesenchymal lineages.
