Background: Decellularized xenogenic vascular tissue has potential applications in small-diameter tissue engineering vascular grafts. Decellularization removes most xenogenic antigen and leaves most of the extracellular matrix for cell adhesion, migration and proliferation. Recellularization is recognized as an important step to improve the endothelialization of decellularized vascular grafts in vivo and most studies used endothelial cells for recellularization. However, there have been no studies on applying undifferentiated adipose stem cells (ASCs) in recellularization.
Material and methods: In this study, we evaluated the feasibility of decellularized porcine coronary artery (DPCA) with ASC recellularization as tissue-engineered vascular grafts by in vitro cell biocompatibility and in vivo aorta repair tests. Porcine coronary artery was decellularized with the enzyme-detergent method and characterized by histology and biochemical methods. In vitro biocompatibility was tested by human and rat adipose stem cells (hASCs/rASCs). In vivo, potential for endothelialization of ASC-seeded DPCA scaffolds were evaluated by rat aorta patch repair model.
Results: In vitro, hASCs and rASCs could adhere and maintain cell viability on DPCA scaffold. In vivo, rat abdominal aorta repair model revealed that DPCA with rat ASC seeding had a 100% patency rate. Grossly, there was integration between host tissue and graft tissue, and no leakage or rupture was observed. Histologically, DPCA with rat ASC seeding displayed endothelialization on the luminal side. In addition, the layer structure was preserved with collagen deposition. However, intimal hyperplasia was noted.
Conclusion: This preliminary study indicates that DPCA with undifferentiated ASC seeding exhibited cell biocompatibility in vitro and endothelialization in vivo. DPCA with ASC recellularization has potential for use in the development of small-diameter tissue engineering vascular grafts.