Recent advances in serum-free microcarrier expansion of mesenchymal stromal cells: Parameters to be optimized.

Mesenchymal stromal cells (MSCs) are being investigated for a variety of therapeutic indications. However, current 2D planar technology cannot meet the anticipated demand and a shift to serum-free microcarrier cultures is needed in order to meet the quality and quantity of cells required. Here we summarize several recent attempts to grow cells in such conditions, and identify several variables that affect cell expansion, including tissue source, serum-free medium formulation, microcarrier type and matrix, and agitation regime (continuous versus intermittent). Optimization of these culture conditions will be necessary to ensure success in bioreactor-scale production of MSCs for cell therapies.