Background aims: Studies of mesenchymal stromal cells (MSC) from BM and adipose tissue have demonstrated similar differentiation potentials along the adipo-, osteo- and chondrogenic lineages. While most clinical trials have been performed using BM-derived MSC, the focus is shifting toward the use of stem cells derived from fat tissue. The aim of the current investigation was to define optimal culture conditions that would facilitate clinical use of adipose-derived stem cells (ASC).
Methods: Different types and concentrations of serum replacers and basal media were tested with respect to the optimal expansion and subsequent differentiation of primary human ASC. The effect of initial seeding density on the growth of ASC was also determined.
Results: While several of the serum replacements proved to be clearly inferior to fetal calf serum (FCS) in promoting ASC growth, the knockout serum replacement (KOSR) had expansion properties similar to those of FCS. However, with respect to the capacity to support adipo-, osteo- and chondrogenic differentiation, KOSR proved to be less consistent than FCS. Among the media formulations, modified Eagle medium alpha supported a significantly faster cell expansion than the other basal media while still maintaining the full differentiation potential of ASC. Regarding the plating density most favorable for rapid expansion, we found that initial plating densities ranging from 100 to 200 cell/cm(2) resulted in significantly shorter doubling times than plating densities both below and above that range.
Conclusions: Identification of the optimal basal medium and serum replacer, together with the most favorable plating density, will facilitate cell-based and tissue-engineering applications employing ASC in pre-clinical and clinical settings.