Tissue Regeneration of a Hybrid Vascular Graft Composed of Biodegradable Layers and Non-Biodegradable Layer by Static and Pulsatile Flows

Abstract

Clinical applications of expanded polytetrafluoroethylene (ePTFE) as a small diameter graft have been limited due to its limited patency rates, even though its demands are high. After fabricating the biodegradable PLGA layers on both the inside and outside of ePTFE, long-term in vitro smooth muscle cell culture was performed on the luminal scaffold surface. The fabricated hybrid ePTFE scaffolds were designed to have three distinctive layers and porous structures in the biodegradable layers generated by gas-foaming of the ammonium bicarbonate porogens, i.e. two layers of poly(lactide-co-glycolide) (PLGA) as biodegradable layers for tissue engineering and an ePTFE layer in the middle as a non-biodegradable layer. We evaluated the regenerated vascular tissues after applying either static or pulstile flow on a smooth muscle cells-seeded hybrid scaffold. Analysis of the engineered tissues was performed with SEM for morphological observation and H&E staining for observation of tissue development dependent upon a mode of culture system, flow patterns and scaffold species.