Abstract Mo032: Biofabrication of Small Vascular Graft using Human Amniotic Membrane

Abstract

Vascular diseases encompass a spectrum of pathological conditions affecting blood vessels, including cerebrovascular disease, coronary heart disease, aneurysms, deep vein thrombosis, and peripheral arterial disease. In severe cases, surgical interventions such as bypass grafting or vascular replacement surgeries are necessary to restore blood flow by bypassing obstructed vessels with functional vascular substitutes. Autologous blood vessels harvested from patients are considered the gold standard for vascular surgeries. However, their availability is limited in patients with pre-existing chronic diseases or previous vessel harvest, and the associated morbidities of vessel harvesting and subsequent surgeries further restrict their therapeutic applicability. Synthetic grafts, including polytetrafluoroethylene (e-PTFE), polyethylene terephthalate (PET), and polyurethane (PU), have obtained FDA approval for clinical application and have shown satisfactory outcomes in large vessel surgeries (internal diameter > 6mm). However, clinical trials targeting medium (6-10 mm) to small (< 6mm) vessels often yield unsatisfactory results. This study aims to develop a small vascular graft using human amniotic membrane (HAM) that meets the structural, mechanical, and biological requirements for human vascular reconstructive surgeries. Fresh HAMs were decellularized with 1% Triton X-100 and 0.1% sodium dodecyl sulfate to prepare decellularized HAM (DAM). The DAM was trimmed into a rectangular shape and rolled around a catheter to prepare a tubular-shaped DAM vascular graft. After rolling, the DAM grafts were crosslinked with 1% genipin for 24 hours followed by thorough water washing. The final DAM vascular graft exhibited a multi-layered wall structure and comparable dimensions and mechanical properties to native arteries. The DAM vascular graft was further evaluated in vivo by replacing part of the rat abdominal aorta and part of the carotid artery in pigs. Both small and large animal studies demonstrated vascular patency with no neointimal hyperplasia (NIH), suggesting that the DAM graft holds significant promise as a small tissue-engineered vascular graft for future vascular reconstruction surgeries.