Coatings for biodegradable magnesium-based supports for therapy of vascular disease: A general view

Metal stents are used as base material for fabrication of medical devices to support and improve the quality of life of patients with cardiovascular diseases such as arterial stenoses. Permanently present implants may induce responses that resemble adverse wound healing that compromise tissue function. A similar process namely restenosis, frequently may occur after the use of this kind of implants. However, the use of non-permanent, resorbable stents are a promising option to avoid this problem. The advantage of these implants is that they can degraded upon vascular repair. The most common metal used for this application, is magnesium (Mg) which is an interesting material due its biological properties and because it is an essential element for human life. However, Mg-based resorbable biomaterial have some restrictions in clinical applications because its corrosion resistance, and mechanical properties. As solutions of this problem, the material can be modified in its composition (Mg-based alloys) or by surface treatments. This review shows and discusses recent challenges in the improvement of Mg-based biomaterials to be used to treat vascular disease and novel approaches at design-based biomaterials engineering of the same. Design-based methodologies are introduced and discussed in the context of balancing multi-functional properties against adaptation to the complex extreme in vivo environment. Traditional alloying approaches of Mg-based biomaterials are also discussed in the context of corrosion resistance controlled by surface modification strategies including conversion techniques: physicochemical or electrochemical transformation such as anodization, plasma and electrophoretic deposition.