고려대학교

초록/요약

Understanding of relationship between pore properties and tissue regeneration of expanded polytetrafluoroethylene(ePTFE) is important in design of vascular tissue engineering. Tissue regeneration into a micron scalepore of the ePTFE wall was investigated by employing techniques of superficial surface modification of ePTFE, fabricationof the hybrid scaffold composed of biodegradable poly (lactide-co-glycolide) (PLGA) and ePTFE, and seedingof vascular cells on its lumen surface. The ePTFE was in advance transformed into a hybrid scaffold bysequential four steps of treatments such as chemical modification of ePTFE surfaces, impregnation of biodegradablePLGA polymer into its wall pores, and coatings of both PLGA polymer on the ePTFE lumen surface and collagenson the PLGA-coated lumen surface. The hybrid scaffold was in advance in vitro tissue-cultured with vascularsmooth muscle for 12 weeks and stem cells for another 2 weeks on its collagen-coated lumen surface, thus obtainingan in vitro tissue-cultured scaffold. This in vitro tissue-cultured hybrid scaffold was implanted in a carotid artery ofmongrel dog for 4 weeks. The morphologies of the hybrid grafts explanted from the artery were analyzed by lightmicroscopy, scanning electron microscopy and transmission electron microscopy (TEM), focusing on tissue regenerationin the modified pores of ePTFE wall. They demonstrated migration of smooth muscle cells into the PLGAimpregnated/surface-modified pores of ePTFE wall along biodegradation of impregnated PLGA polymer, leadingto tissue regeneration in its surface-modified pores. TEM results of the patent hybrid grafts showed both cellorganelles and extracellular matrix of the regenerated media tissues in the pore channels of ePTFE wall with 20-30 μm inter-nodal distances. Key words: Hybrid scaffold, ePTFE, Vascular graft, TEM