Healing potential of injectable Aloe vera hydrogel loaded by adipose-derived stem cell in skin tissue-engineering in a rat burn wound model

Adipose stem cells (ASCs) are a great promise in wound healing due to their potential in differentiating into various cell lineages and secreting growth factors. The purpose of this study is to evaluate the in vivo effects of Aloe vera hydrogel loaded by allogeneic ASCs on a rat burn wound model. The ASCs were isolated, cultured and mixed with 50% Aloe vera hydrogel and injected intradermally around the wound. Demineralized bone matrix (DBM) was used as dressing in the experiment. The burn wound-healing properties of different experimental groups were investigated by histopathological, molecular, scanning electron microscopic and biochemical analysis at the 7th, 14th and 28th days post-wounding. The Aloe vera and DBM-Aloe vera groups showed almost similar healing properties, while treatment by DBM-Aloe vera/ASCs significantly enhanced wound healing. The levels of transforming growth factor-beta 1 (TGF-beta 1) and interleukin-1 beta markedly decreased at the 7th day post-injury, in the DBM-Aloe vera/ASC-treated group, suggesting that this treatment regime subsided the inflammatory responses. Angiogenesis, re-epithelialization and the level of TGF-beta 1 in the wounds treated with DBM-Aloe vera/ASCs were also remarkably higher than those of other groups, at the 14th day post-injury. Besides, scar formation significantly decreased in the DBM-Aloe vera/ASC-treated wounds when compared with other groups. Our biochemical results were in agreement with the molecular and histopathological findings and strongly demonstrated that a DBM-Aloe vera/ASC composite can stimulate burn wound healing. These results suggest that the DBM-Aloe vera/ASC composite can be considered as a promising therapeutic strategy in the treatment of burn wounds.