Polydopamine and gelatin coating for rapid endothelialization of vascular scaffolds

Rapid endothelialization helps overcome the limitations of small-diameter vascular grafts. To develop biomimetic nonthrombogenic coatings supporting endothelialization, medical-grade polyurethane (PU) nanofibrous mats and tubular scaffolds with a diameter below 6 mm prepared by solution blow spinning were coated with polydopamine (PDA), or PDA and gelatin (PDA/Gel). The scaffolds were characterized by scanning electron microscopy, porosity measurement, tensile testing, wettability, Fourier Transform Infrared spectroscopy, and termogravimetric analysis, followed by the measurement of coating stability on the tubular scaffolds. The effect of coating on scaffold endothelialization and hemocompatibility was evaluated using human umbilical vein endothelial cells (HUVECs) and human platelets, showing low numbers of adhering platelets and significantly higher numbers of HUVECs on PDA-and PDA/Gel-coated mats compared to control samples. Tubular PU scaffolds and commercial ePTFE prostheses coated with PDA or PDA/Gel were colonized with HUVECs using radial magnetic cell seeding. PDA/Gel-coated samples achieved full endothelial coverage within 1???3 days post-endothelialization. Altogether, PDA and PDA/Gel coating significantly enhance the endothelialization on the flat surfaces, tubular small-diameter scaffolds, and commercial vascular prostheses. The presented approach constitutes a fast and efficient method of improving scaffold colonization with endothelial cells, expected to work equally well upon implantation.

Automated summary

Rapid endothelialization is crucial for overcoming the limitations of small-diameter vascular grafts. In this study, biomimetic coatings were developed using medical-grade polyurethane nanofibrous mats and tubular scaffolds. The coatings, consisting of polydopamine and gelatin, significantly enhanced endothelialization on both flat surfaces and small-diameter tubular scaffolds, as well as commercial vascular prostheses.