A promoting nitric oxide‐releasing coating containing copper ion on ZE21B alloy for potential vascular stent application
Qianying Jia, Qinggong Jia, Shijie Zhu, Yufeng Zheng, Yoji Mine, Kazuki Takashima, Shaokang Guan
Abstract
Magnesium-based biodegradable metals as cardiovascular stents have shown a lot of excellent performance, which have been used to treat coronary artery diseases. However, the excessive degradation rate, imperfect biocompatibility and delayed re-endothelialization still lead to a considerable challenge for its application. In this work, to overcome these shortcomings, a compound of catalyzing nitric oxide (NO) generation containing copper ions (Cu2+) and hyaluronic acid (HA), an important component of the extracellular matrix, were covalently immobilized on a hydrofluoric acid (HF)-pretreated ZE21B alloy via amination layer for improving its corrosion resistance and endothelialization. Specifically, the Cu2+chelated firmly with a cyclen 1,4,7,10-tetraazacyclododecane-N, N′, N″, N″′- tetraacetic acid (DOTA) could form a stability of hybrid coating, avoiding the explosion of Cu2+. The chelated Cu2+enabled the catalytic generation of NO and promoted the adhesion and proliferation of endothelial cells (ECs) in vascular micro-environment. In this case, the synergistic effect of NO-generation and endothelial glycocalyx molecules of HA lead to efficient ECs promotion and smooth muscle cells (SMCs) inhibition. Meanwhile, the blood compatibility also had achieved a marked improvement. Moreover, the standard electrochemical measurements indicated that the functionalized ZE21B alloy had better anti-corrosion ability. In a conclusion, the dual-functional coating displays a great potential in the field of biodegradable magnesium-based implantable cardiovascular stents.