Surface Modification of Absorbable Magnesium Stents by Reactive Ion Etching

The surface texture and chemistry of WE43 absorbable magnesium stents (AMS) and tube specimens processed by chemical and reactive ion etching (RIE) were investigated. Tube specimens were produced in three different conditions, namely as-received, chemically etched and plasma etched. The results of scanning electron microscopy, atomic force microscopy and energy dispersive X-ray spectroscopy studies showed that plasma etching and cleaning reduced surface roughness by 10 % compared to chemical etching alone, and completely removed surface deposits remaining from the chemical etch process. The same combination of chemical and plasma etching processes was employed to produce AMS. Expansion tests demonstrated uniform stent expansion characteristics and confirmed the viability of the device. The results of this study show that RIE is an effective surface modification technique for absorbable magnesium devices.