Isolation, purification and preservation of adipose-derived stem cells: Research progress and future development

BACKGROUND: In 2001, Zuk et al found adipose-derived stem cells (ASCs) from the aspirate of liposuction for the first time, which launched a new era of stem cell research. In recent years, stem cells have been proved to widely exist in many tissues and organs. ASCs are always in the spotlight of plastic and reconstructive surgery, tissue engineering and regenerative medicine because of extensive sources and simple isolation. OBJECTIVE: To review the fat tissue harvesting and ASCs isolation, purification, expansion, and cryopreservation, to discuss the main factors which influence the yield, proliferation capacity and differentiation potential of ASCs, and to predict the future research interests based on current issues. METHODS: On September 10^th, 2015, relevant articles were searched in PubMed using the following format: (adipose stem cells[Title]) OR (adipose-derived stem cells[Title]) OR (adipose-derived mesenchymal stem cells[Title]) and in SinoMed using the following format in Chinese: (“adipose-derived stem cells” [Title])or(“adipose-derived mesenchymal stem cells”[Title]). Finally, 81 representative articles were included according to their titles and abstracts. In this review, we also introduced relevant experience about the aforementioned procedures from the Department of Plastic Surgery and Tissue Regeneration and Molecular Cell Engineering Lab of University of Texas, MD Anderson Cancer Center, USA. RESULTS AND CONCLUSION: The widely dispersed fat tissues potentially provide abundant stem cells for tissue engineering and regenerative medicine. Liposuction is a mini-invasive approach for harvesting fat tissues. Collagenase digestion is the major method for ASCs isolation due to its simplicity and high yield in basic research. However, clinical fat transplantation without ASCs isolation or non-collagenase isolation of stromal vascular fraction or ASCs is preferred. The phenotype, proliferation and differentiation capacity of ASCs may be affected by several factors during the fat tissue harvesting and ASCs isolation. Therefore, a standard protocol for ASCs isolation is needed.