Fig. 3

A Macroscopic representation of wounds among different experimental groups. Sham group (wounded and non-diabetic group): on the 3rd day of healing appeared as continuous filling of the wound periphery with healthy stable granulation tissue which then rapidly infiltrated all the wound surface and hastily covered by epithelium to decrease the wound surface area, at the end of the study the wound appeared nearly completely healed. Diabetic group: filling with granulation tissue was developed slowly, the formed tissue was unstable easily ulcerated, the epithelium was also poorly established, and the wound failed to be healed by the end of the study with persistent cardinal signs of inflammation. PRP-treated group: although granulation tissue gradually filled the wound, about 15% of the wound surface was still unhealed by the end of the study. Stem cell-treated group: showed continuous filling of the wound surface with healthy granulation tissue that rapidly covered by epithelium to decrease the wound surface area, but about 10% of wound surface was still unhealed by the end of the study. Stem cells + PRP-treated group: healing characteristics and wound development were closely resembling that in the sham group and by the end of the study, the wound appeared nearly completely healed. B Photograph represents wound area percentage. n= 7 per group. Data are expressed as mean±SE. **Significant compared to the control group at p<0.01, ^$$significant compared to the Sham group at p<0.01, ^##significant compared to the diabetic group at p<0.01, ^££significant compared to groups IV and V at p<0.01, and ~~significant compared to group IV at p<0.01