Development of a Novel Biodegradable Metallic Stent Based on Microgalvanic Effect

The implementation of biodegradable stents has the potential to revolutionize obstructive coronary artery disease treatment. Limitations still currently exist, however, that prevent biodegradable stents from replacing permanent metallic stents in the global market. The ideal combination of stent properties, including sufficient mechanical strength, controlled degradation, and biocompatibility, has yet to be realized. A novel manufacturing process is proposed that utilizes cold gas-dynamic spraying to fabricate a metal structure with significantly reduced grain size. Iron and stainless steel 316L are combined to form a novel amalgamate with enhanced mechanical strength and a controllable degradation rate, due to the resulting microgalvanic reaction. Flat specimens composed of iron and 316L are fabricated in various compositions, and mechanical and degradation tests were conducted. Femto laser techniques are utilized to produce stents composed of 80% Fe and 20% stainless steel 316L. The in vitro degradation behaviour of the stent is investigated using static and dynamic corrosion tests. It is shown that the corrosion rate can be adjusted to desired values, by varying the weight percentage of iron and stainless steel 316L within the amalgamate.