Advances in coatings on magnesium alloys for cardiovascular stents – A review

Abstract

Magnesium (Mg) and its alloys, as potential biodegradable materials, have drawn wide attention in the cardiovascular stent field because of their appropriate mechanical properties and biocompatibility. Nevertheless, the occurrence of thrombosis, inflammation, and restenosis of implanted Mg alloy stents caused by their poor corrosion resistance and insufficient endothelialization restrains their anticipated clinical applications. Numerous surface treatment tactics have mainly striven to modify the Mg alloy for inhibiting its degradation rate and enduing it with biological functionality. This review focuses on highlighting and summarizing the latest research progress in functionalized coatings on Mg alloys for cardiovascular stents over the last decade, regarding preparation strategies for metal oxide, metal hydroxide, inorganic nonmetallic, polymer, and their composite coatings; and the performance of these strategies in regulating degradation behavior and biofunction. Potential research direction is also concisely discussed to help guide biological functionalized strategies and inspire further innovations. It is hoped that this review can give assistance to the surface modification of cardiovascular Mg-based stents and promote future advancements in this emerging research field.

Applications of Magnesium and Its Alloys: A Review

“…However, bare magnesium alloy stents are notorious for rapid corrosion or biodegradation, leading to devastating effects described in Section 4.3. Hence, as magnesium-based biodegradable coronary stent implantation is highly regarded as a potential therapeutic application to coronary heart disease, one of the leading causes of death globally [79][80][81], extensive ongoing investigations centered around strategies to control its degradation rate [82,83]. The strategies proposed are consistent with our earlier discussion in Section 4.3.…”

“…It includes improving the design of the alloy and modifying the surface with coating technologies. Thus far, the literature has suggested that incorporation of both strategies would work [82], although early in vivo trials have demonstrated mixed clinical outcomes [81]. Nonetheless, more research and advancements in this direction will likely persist in the coming years.…”

Biocompatibility pathways and mechanisms for bioactive materials: The bioactivity zone

“…Two principal implantable devices could be considered here, the vascular graft and the intravascular stent. However, this essay concentrates on the graft only; with stents, the situation is complicated by the use of drug elution methods, which have pharmacological activity [ 87 ] and by the use of biodegradable alloys, which operate by different mechanisms; these have been comprehensively reviewed in this journal very recently [ 88 ]. With respect to prosthetic vascular grafts, Zilla et al discussed the difficulties of encouraging graft endothelialization a number of years ago [ 89 ].…”

Sustainable Coatings on Metallic Alloys as a Nowadays Challenge

“…Creating surface coatings may help in overcoming this limitation. Moreover, functional coatings can further improve the biocompatibility of such alloys [113][114][115][116][117]. Several novels, multifunctional coatings are presented in Table 2, and some of these, along with others, are discussed in more detail below.…”