Improved porosity promotes reendothelialization and smooth muscle remodeling in decellularized tissue-engineered vascular grafts

Decellularized tissue-engineered vascular grafts (dTEVGs) exhibit superior biocompatibility, anti-infection properties and repair potential, contributing to better patency and making them a more ideal choice for arteriovenous grafts (AVGs) in hemodialysis compared to chemically synthesized grafts. However, the unsatisfactory reendothelialization and smooth muscle remodeling of current dTEVGs limit their advantages. In this study, we investigated the use of elastase to improve the porosity of elastic fiber layers in dTEVGs, aiming to promote cell infiltration and achieve superior reendothelialization and smooth muscle remodeling. Our findings revealed that elastase treatment induced scattered cracks and holes in the elastic fiber layers of dTEVGs. Porous dTEVGs demonstrated increased cell infiltration in rat subcutaneous tissue. In the rat AVG models, mildly elastase-treated dTEVGs significantly improved cell infiltration and graft remodeling, including adequate smooth muscle cell (SMC) repopulation, impressive reendothelization and regeneration of the extracellular matrix, without stenosis, dilation or disintegration of the grafts. This study demonstrates that porous dTEVGs promote reendothelization, smooth muscle remodeling and extracellular matrix regeneration while retaining a stable graft structure, enhancing durability and puncture resistance in hemodialysis.