Effects of bone marrow derived-mesenchymal stem cells (BMSCs), platelet-rich plasma (PRP), BMSCs + PRP, or standard treatment (PIS) on (A and B) burn area, (C) rate of burn contraction (%), and (D) period of epithelization (days) in a full-thickness skin burns in rats. The results are presented as mean ± SD values (n = 7). The letters (a and b) indicate statistical differences at P < 0.05 in comparison with the control and the model groups, correspondingly.