Low serum and serum-free culture of multipotential human adipose stem cells.

Abstract

Adipose tissue provides an easily accessible and abundant source of putative stem cells for translational clinical research. Currently prevalent culture techniques include the use of FBS, a highly variable and undefined component, which brings with it the potential for adverse patient reactions. In an effort to eliminate the use of animal products in human adipose stem cell (ASC) cultures, we have developed two new culture methods, a very low human serum expansion medium and a completely serum-free medium. Through serial testing, a highly enriched medium formulation was developed for use with and without the addition of 0.5% human serum, an amount easily obtainable from autologous blood draws. Very low-serum culture yielded population-doubling times averaging 1.86 days in early passage, while the serum-free formulation was associated with less robust cell growth, with doubling times averaging 5.79 days. ASC in both conditions maintained its ability to differentiate into adipo-, chondro- and osteogenic lineages in vitro, despite lower expression of CD34 in early passage. Expression of ALDH, HLA, CD133, CD184, and CD31 was comparable with that seen in cells cultured in 10% FBS. These newly developed culture conditions provide a unique environment within which to study ASCs without the interference of animal serum, and allow for the rapid expansion of autologous ASCs in culture in an animal product-free environment for use in human clinical trials.