Regeneration study of skin burn in rat using adipose-derived mesenchymal stem cells (ADSCs) seeded into two noval scaffolds

Abstract

In the past 30 years, researchers have focused on skin regeneration, by using tissue engineering methods. Decellularized ECM-based scaffolds and bioprintring technique have been recently used as structures for repairing tissue defects, especially skin grafts for burns and cosmetic surgeries. Investigations have been mainly focused on the decellularized porcine SIS; however, there has not been any report on ovine SIS (OSIS) layer. The present study is a skin tissue engineering using decellular sheep small intestinal sub-mucosal layer and 3D- derived bioprinter scaffolds with adipose-derived stem cell transplanted in full-thickness rat skin burn to investigate capacity of regeneration of burn wound. Methods and Materials: In the present study, OSIS was decellularized using two phase (physical and chemical) and 3D scaffold was derived of an extrusion bioprinter, and their biomechanical and histological and biocompatibility properties were evaluated. At the second part of study, applications derived of in vitro phase were investigated in in vivo. In this phase, the effectiveness of the decellularized OSIS (DOSIS) and 3D scaffolds, with or without adipose mesenchymal stem cells (ADSCs) in full thickness burn wound were experimentally studied in a rat model. The experimental groups included; group I (untreated wound), group II (DOSIS scaffold), group III (3D scaffold), group IV (ADSCs seeded on DOSIS) and group V (ADSCs seeded on 3D scaffold). Results: Results revealed satisfactory decellularization of OSIS which could be due to its thin thickness. Mechanical properties, structural form and glycosaminoglycan contents were preserved in the decellularized groups. In decellularized groups, further cells and DNA residues were removed compared to the control groups. No toxicity was observed in all treatments and viability, expansion and cell proliferation were supported. At the second part of study, wound healing of all groups was examined and compared clinically, histopathologically and immunohistologically on days 5, 14 and 21 post-operations. Our results represented ADSCs-seeded on DOSIS and 3D scaffolds accelerated wound contraction and healing compared to the other groups. Epithelization was close to completion 21 days’ post-operation in both treatment groups. Despite, in this study, we used allo and xeno origin of mesenchymal stem cells and scaffold, no signs of inflammation, necrosis or rejection were observed in the experimental groups.