Thromboresistant and endothelialization effects of dopamine-mediated heparin coating on a stent material surface

Abstract

Heparinization of surfaces has proven a successful strategy to prevent thrombus formation. Inspired by the composition of adhesive proteins in mussels, the authors used dopamine to immobilize heparin on a stent surface. This study aimed to assess the thromboresistant and endothelialization effects of dopamine-mediated heparin (HPM) coating on a stent material surface. The HPM was synthesized by bonding dopamine and heparin chemically. Cobalt-chromium (Co-Cr) alloy disks were first placed in the HPM solution and applied to surface stability then underwent thromboresistant tests and human umbilical vein endothelial cells (HUVEC) cytotoxicity assays. The results showed not only thromboresistant activity and a stable state of heparin on the surfaces after investigation with toluidine blue and thrombin activation assay but also proliferation of HUVEC in vitro. Studies on animals showed that the HPM-coated stent has no obvious inflammation response and increasing of restenosis rate compared to the bare metal stent (BMS) indicating good biocompatibility as well as safety in its in vivo application. Moreover, improving the endothelial cell (EC) proliferation resulted in a higher strut-covering rate (i.e., endothelialization) with shuttle-shaped EC in the HPM-coated stent group compared to that of the BMS group. These results suggest that this facile coating approach could significantly promote endothelialization and offer greater safety than the BMS for its much improved thromboresistant property. Moreover, it may offer a platform for conjugating secondary drugs such as anti-proliferative drugs.

Multifunctional MgF2/Polydopamine Coating on Mg Alloy for Vascular Stent Application

“…As a simple, versatile, and effective strategy to promote cell adhesion onto substrates with various material type and shape under solvent-free and non-toxic condition, polydopamine (PDA) films has attracted much attention in the field of biomaterials surface modification since Lee et al reported it in 2007 [41] . In the field of vascular biomaterials, PDA coating has been used as an immobilization layer for vascular endothelial growth factor (VEGF) [42,43] , heparin [44,45] , etc., and has also been used to control cell behaviors directly on the surface, which demonstrated that human umbilical vein endothelial cells (HUVECs) could adhere well and spread with a high viability on PDA coating [46][47][48] ; moreover, it showed that PDA coating on 316L stainless steel stent decreased adhesion and proliferation [48] .…”

Preclinical Evaluation of the Thrombogenicity and Endothelialization of Bare Metal and Surface-Coated Neurovascular Stents

“…8,[18][19][20][21] In our in vitro study, endothelial cell adhesion was shown on the surface of the bare metal and albumin-coated stents, whereas the heparin coating seems not to promote cell adhesion. Compared with the in vivo situation, our endothelialization experiments were performed in an isolated system containing endothelial cells and cell culture media with 2% fetal calf serum.…”

Mechanical and Histopathological Comparison between Commercialized and Newly Designed Coronary Bare Metal Stents in a Porcine Coronary Restenosis Model

“…The previous study used dopamine to immobilized heparin on a stent surface showed thromboresistant and endothelialization effects in rabbit iliac artery restenosis model 26. And a TiO 2 and nitrogen doped-TiO 2 thin film was deposited by plasma enhanced chemical vapor deposition (PECVD) process and its applicability as a drug coating matrix was demonstrated in promising alternatives to polymer for the preparation of drug-eluting stents 27,28.…”