Polyurethane/polyurethane nanoparticle‐modified expanded poly(tetrafluoroethylene) vascular patches promote endothelialization

Abstract

Expanded poly(tetrafluoroethylene) (ePTFE) has been widely used as a vascular graft material due to the fact that it is durable, porous, flexible, and inert. However, ePTFE grafts easily induce thrombosis, calcification and neointimal hyperplasia in small-diameter (<6 mm) graft bypass surgeries and thus cause surgical failure. Therefore, it is necessary to improve the in vitro and in vivo performances of ePTFE grafts. In this work, we first prepared a polyurethane/polyurethane nanoparticles (PU/PU-NPs) composite film by a simple cosedimentation method. Compared with the pure PU film, the blood compatibility and the cell compatibility of the PU/PU-NPs composite film were significantly improved. Then, we constructed a PU/PU-NPs/ePTFE vascular patch (PPVP) by coating PU and PU-NPs onto the surface of an ePTFE graft. PU-NP modification endowed the ePTFE graft with the nanopatterned surface similar to the luminal surface of a blood vessel. PU NPs and the structural likeness of the surface synergistically optimized the overall performance, and thus improved the blood and cell compatibilities, effectively inhibited platelet adhesion, enhanced cell attachment and proliferation, and facilitated the formation of endothelial tissue-endothelialization. The abdominal artery patched with PPVP was not blocked and the endothelialization was achieved 30 days after the implantation. All the results taken together indicate that PPVP may be a promising alternative for a vascular patch. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2131-2140, 2018.

Surface modification of polyvinyl alcohol (PVA)/polyacrylamide (PAAm) hydrogels with polydopamine and REDV for improved applicability

“…PVA/PAAm hydrogels were immersed into a dopamine solution with a concentration of 2 mg/mL in Tris buffer (pH = 8.5) at room temperature under shaking for 24 h . Afterward, the hydrogels were washed with distilled water thrice to remove the unbound molecules, and the PDA‐coated hydrogel (H‐PDA) was ready for use after drying.…”

“…Coating the hydrogels with PDA and REDV PVA/PAAm hydrogels were immersed into a dopamine solution with a concentration of 2 mg/mL in Tris buffer (pH = 8.5) at room temperature under shaking for 24 h. 16 Afterward, the hydrogels were washed with distilled water thrice to remove the unbound molecules, and the PDA-coated hydrogel (H-PDA) was ready for use after drying. The PDA-coated hydrogel was immersed in a REDV solution with a concentration of 0.1 mg/mL in Tris buffer at 4 C under shaking for 24 h to further label the hydrogel with REDV and obtain the H-PDA-REDV hydrogel ( Fig.…”

“…Small‐diameter vascular grafts based on PET and ePTFE tend to induce a series of complications, such as thrombosis and intimal hyperplasia, because of hemodynamic differences between large and small blood vessels . One of the effective approaches to prevent thrombosis and maintain a high patency is to quickly regenerate an endothelium on the inner surface of the vascular prosthesis in vivo in a manner similar to that of native blood vessels . The main cause of intimal hyperplasia is the low compliance of such grafts, leading to compliance mismatch with native blood vessels …”

“…14 One of the effective approaches to prevent thrombosis and maintain a high patency is to quickly regenerate an endothelium on the inner surface of the vascular prosthesis in vivo in a manner similar to that of native blood vessels. 15,16 The main cause of intimal hyperplasia is the low compliance of such grafts, leading to compliance mismatch with native blood vessels. 15,17 Studies on small-diameter vascular grafts with a satisfactory comprehensive performance, especially cells adhesion, cells proliferation, and high compliance, have been performed.…”

“…Numerous strategies have been developed to improve cells adhesion and proliferation performance, resulting in endothelialization in vitro and in vivo. 12,[14][15][16][17][18][19][20][21][22][23][24][25][26] Shin 27 et al enhanced the endothelialization of poly(L-lactide-co-ε-caprolactone) vascular grafts through polydopamine coating and the immobilization of vascular endothelial growth factors. Inseong 28 et al utilized PDA as an adaptor to graft heparin onto polyurethane substrates, leading to the enhancement of blood compatibility.…”