PhysiologixTM, a Potent Serum Replacement Supplement for Mesenchymal Stem Cells (MSCs) with a Higher Proliferation Rate and Preserved Stemness

This last decade was marked by exceptional advancements in the field of Cell and Gene Therapy. Cell culture, a technique formerly restricted to research purposes, is nowadays showing a huge potential for the treatment of acute leukemia, osteoporosis, and joint injuries; and opening new perspectives for the cure of deadly diseases, such as Parkinson's, Dementia, and Alzheimer. Thus, traditional cell culture media supplements, i.e., Fetal Bovine Serum (FBS), are no longer accepted, and a complete review of cell culture practices is currently in progress to make these therapies safe and reproducible. Cell culture media constitutes of cell microenvironment and new requirements are being applied to evaluate the quality of the media used to grow or maintain the cells. Supplements origin is becoming more and more critical and xeno-free, serum-free, and chemically-defined terms are currently used to categorize and qualify the media and its supplements. PhysiologixTM XF Human Growth Factor Concentrate (hGFC) is a cGMP, xeno-free media supplement made for stem cells and T cells that replaces standard serum supplements such as FBS or Human Serum. This study recapitulates best practices to increase Physiologix potency in MSCs and shows that higher cell count could be reached in fewer days using PhysiologixTM compared to FBS. To this end, different levels of Physiologix were tested and an evaluation of the impact of media change on cell proliferation was assessed. Our results confirm previous findings that using Physiologix at 2% show equivalent proliferation to 10% FBS, but most importantly it shows that using higher percentages (5%) is associated with increased cell proliferation rate at earlier time points, reaching 90% confluence at day 4 compared to 50% confluence in media supplemented with 10% FBS. Phenotype data shows that cell pluripotency is maintained through the evaluation of stemness surface markers such as CD90, CD73, and CD44. This data emphasizes the potency of PhysiologixTM in supporting MSCs proliferation, but also shows that confluency could be reached in 4 days using 5% PhysiologixTM compared to 6 days using 10% FBS. Supplementing cell culture media with Physiologix as a growth factor concentrate helps shorten the protocol by at least two days which, in a large-scale cell culture system (bioreactor), is expected be more impactful as it reduces labor and consumables cost, as well as energy consumption, and helps accelerate therapy delivery without affecting the quality of the cells.