Rapid isolation of adipose tissue-derived stem cells by the storage of lipoaspirates

This study examined a rapid isolation method decreasing the time and cost of the clinical application of adipose tissue-derived stem cells (ASCs). Aliquots (10 g) of the lipoaspirates were stored at 4°C without supplying oxygen or nutrients. At the indicated time points, the yield of mononuclear cells was evaluated and the stem cell population was counted by colony forming unit-fibroblast assays. Cell surface markers, stem cell-related transcription factors, and differentiation potentials of ASCs were analyzed. When the lipoaspirates were stored at 4°C, the total yield of mononuclear cells decreased, but the stem cell population was enriched. These ASCs expressed CD44, CD73, CD90, CD105, and HLA-ABC but not CD14, CD31, CD34, CD45, CD117, CD133, and HLA-DR. The number of ASCs increased 1×10(14) fold for 120 days. ASCs differentiated into osteoblasts, adipocytes, muscle cells, or neuronal cells. ASCs isolated from lipoaspirates and stored for 24 hours at 4°C have similar properties to ASCs isolated from fresh lipoaspirates. Our results suggest that ASCs can be isolated with high frequency by optimal storage at 4°C for 24 hours, and those ASCs are highly proliferative and multipotent, similar to ASCs isolated from fresh lipoaspirates. These ASCs can be useful for clinical application because they are time- and cost-efficient, and these cells maintain their stemness for a long time, like ASCs isolated from fresh lipoaspirates.