Regenerating new tissue using
cell transplantation has relied on successful cell engraftment in the host; however, cell engraftment into the diabetic skin
wound is not as successful as in many other tissues. We used a biodegradable and biocompatible triblock co-
polymer poly(
ethylene glycol-b-[DL-
lactic acid-co-
glycolic acid]-b-
ethylene glycol) (
PEG-PLGA-PEG), which forms a thermosensitive
hydrogel, as a
wound dressing and scaffold. We found that the thermosensitive
hydrogel increased the engraftment of muscle-derived stem cells (MDSCs) by 20- to 30-fold until day 20, when the
wound was completely closed in a db/db genetically diabetic mouse model. At day 9, 30% of the transplanted MDSCs were found to remain, and 15% remained at day 20 after
transplantation. The increased engraftment resulted in enhanced wound healing, as indicated by the
wound closure rate, epithelium migration, and
collagen deposition. Using MDSCs stably expressing beta-gal and immunofluorescence, we found that 25% of MDSCs differentiated into fibroblasts, 10% into myofibroblasts, and 10% into endothelial cells. We conclude that using the thermosensitive
hydrogel as a scaffold increased the engraftment of MDSCs, which leads to improved diabetic wound healing, possibly by retaining the cells at the
wound site for longer.