The angiogenic and adipogenic modes of adipose tissue after free fat grafting

The major drawback of adipose grafting is its clinical unpredictability, which leads to surgeon and patient dissatisfaction. The mechanisms underlying angiogenesis and regeneration of the graft tissue are still unclear.

Mouse adipose tissue was processed using two different methods (fragmental and integral) and was used to identify the mode of angiogenesis of the graft. Cross-grafting of tissue from normal mice and transgenic mice expressing green fluorescent protein was used to observe the origin of cells during the adipose regeneration.

Almost all the CD31 endothelial cells of the new vessels were derived from the recipient. The new vessels in the graft were mainly formed through recipient vessels growing into the graft rather than the reassembly of donor endothelial cells or the reconnection of recipient and donor vessels. Angiogenesis depends largely on recipient-site environment. The retention of donor-derived tissue dropped to only 10 percent 8 weeks after grafting, and the majority of the key regeneration cells, the CD34 cells, came from the recipient during adipogenesis (p < 0.05). In total, the retention of the recipient-derived tissue was up to 73 percent in the fragmental group and 47.5 percent in the integral group.

The angiogenesis of the graft occurs by the classic "vessel branching" mode, in which the recipient plays a dominant role. The mode of graft tissue retention primarily involves CD34 adipose precursor cells derived from the recipient.