Utilizing muscle-derived stem cells to enhance long-term retention and aesthetic outcome of autologous fat grafting: pilot study in mice.

Autologous fat grafting has been regarded as the ideal soft tissue filler for more than a century. Low long-term retention rate and unpredictability limit it from widespread clinical practice. Many theories for this have been proposed: lack of sufficient blood supply and subsequent necrosis is the most accepted. In this pilot study, we showed both macroscopically and microscopically the viability of muscle-derived stem cells (MDSCs) cotransplanted with fat placed intramuscularly for 3 months. MRI scanning showed a stronger fat signal in the MDSC-treated group than that of the control group. Moreover, histological evaluation exhibited well-preserved and intact fat cells in the MDSC-treated group. In contrast, the control group showed extensive fibrosis and fat graft loss. Furthermore, the MDSC-treated group possessed almost threefold greater capillary density than the control group. We conclude that cotransplantation of muscle-derived stem cells and autologous fat tissue improves the long-term survival of intramuscular fat transplants by promoting neovascularization.