Bioactivation of free-fat transfers: a potential new approach to improving graft survival.

A new approach to free-fat autotransplantation resorption was evaluated experimentally in a rat animal model. Bioactive fat grafts were created by the addition of basic fibroblast growth factor delivered by dextran beads to the grafts and compared with free fat alone, free fat plus beads, and free fat plus beads and a control solution in the same animal. The grafts were assessed by weight and histology at 1 and 12 months postoperatively in 40 animals. A graded response in weight retention was observed at 1 and 12 months, with the growth factor-treated grafts exhibiting near complete weight maintenance after 1 year. All other bead-containing grafts had an intermediate response, with free fat alone averaging more than one-half graft weight loss after 1 year. Histologically, the bead-containing grafts had good fibroblastic ingrowth, but extensive intercellular collagen formation and the occurrence of small-sized adipocytes among the larger adipocytes were seen only in the growth factor-treated grafts. These findings indicate that graft manipulations that affect the preadipocyte cells of the graft or fibroblastic components of the recipient site, either through polypeptide stimulation or surface charge attraction, may offer a viable approach to postoperative fat-graft volume maintenance.