Application of omentum as an in vivo bioreactor for regeneration of decellularized human internal mammary artery.

This study investigates the extent of cell seeding as well as lumen patency in acellular Internal mammary artery (IMA) scaffolds that have been re-cellularized by omentum as a natural bioreactor. Sixteen Virgin female Wistar rats were selected for implantation of acellular scaffold in omentum. Following laparotomy omentum was retracted to the outside of the abdomen and the more vascularized portion of it was selected for the experiment. The scaffold was wrapped by omentum and placed between two layers of rectus muscles that have been previously dissected. Samples were taken from scaffolds at 2 and 3 months for histopathological evaluation. All the grafts were explanted at 2 and 3 months and the lumens were completely patent compared to the native scaffold. The histology of implanted IMA after 2 and 3 months showed progressive recellularization especially by smooth muscle cells over the media layer. CD 34 staining was positive adjacent to the grafts which showed well angiogenesis. Trichrome and Movat's Pentachrome staining showed normal collagen formation in the inner media layer. Promising results obtained from the introduced protocol for in vivo recellularization, including patent lumen and proper cell seeding, encourages application of the mentioned technique for experimental vascular graft application. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2685-2693, 2017.