In vivo injectable human adipose tissue regeneration by adipose-derived stem cells isolated from the fluid portion of liposuction aspirates.

Liposuction aspirates separate into fatty and fluid portions. Cells isolated from the fatty portion are termed processed lipoaspirate (PLA) cells and isolated from the fluid portion termed liposuction aspirate fluid (LAF) cells, both of which contain adipose-derived stromal cells (ASCs). Here, we examined the biological differences between PLA and LAF cells and then tested the differentiation capacity of LAF cells in vivo. The cell surface marker and the multiple differentiation ability of fresh isolated PLA and LAF cells and which from passaged 3-5 were examined in vitro. LAF cells were then incubated in adipogenic medium, stained with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine (DiI), mixed with fibrin glue then injected to nude mice; fibrin glue without cells was as a control. Three months later, the transplants were subjected to macroscopic observation and histological analysis. PLA and LAF cells were similar in growth kinetics, morphology, capacity for differentiation, and surface marker profiles. After plating, both PLA and LAF cells showed increased expression of CD29, CD44, CD133 and HLA DR and decreased expression of CD34. In vivo differentiation assay showed the mixture of LAF cells and fibrin glue formed adipose tissue which contained red fluorescent DiI-positive adipocytes. LAF cells can be harvested more easily than PLA cells. The in vivo adipogenic capacity suggested LAF cells would be useful and valuable for cell-based therapies and soft tissue reconstruction.