Mesenchymal stem cells transduced by stromal cell-derived factor-1α augment ischemic free flaps' survival

Mesenchymal stem cells (MSCs) have the potential for differentiating into vascular endothelial cells. Stromal cell-derived factor-1α (SDF-1α) plays an important role in neovascularization of ischemic flaps. The authors evaluated the feasibility of applying MSCs transduced by SDF-1α gene to the treatment of early and partial ischemic free flaps survival. MSCs were isolated from Lewis rats and cultured in vitro. Recombinant adenovirus encoding SDF-1α gene (Ad-SDF-1α) was transduced into the MSCs. Lewis rats that underwent epigastric free flaps based on medial and lateral branches of superficial inferior epigastric vessels and femoral vessels were equally randomized into 4 groups, and injected with Ad-SDF-1α-transduced MSCs, MSCs, Ad-SDF-1α, and normal saline, respectively. Gene transduction, flaps survival, neovascularization, and expression level of SDF-1a protein were detected. The results showed that Ad-SDF-1α-transduced MSCs expressed higher SDF-1α both in vitro and in vivo, yielded more survival area, and resulted in higher neovascularization than any other groups. Interestingly, the necrotic sites of all free flaps were in the proximal end rather than in the distal end. In conclusion, Ad-SDF-1α-transduced MSCs can increase neovascularization of early and partial ischemic free flaps and augment the surviving areas.