Corrosion prevention on vascular stents
So far, there have been few magnesium alloy stent systems that achieved sufficient support time by using biodegradable coating. In a new paper, a dual strengthened biodegradable coating on a AZ31b magnesium alloy stent was suggested to achieve stronger adhesion and lower water permeability. The composite coating consisted of a magnesium hydrate – magnesium fluoride (Mg(OH)2-MgF2) inorganic base layer constructed by a simple two-step solution immersion and a graphene oxide – poly(trimethylene carbonate) outer layer prepared by ultrasonic spraying.
Reduced corrosion rate
The biodegradable composite coating modified magnesium alloy exhibited an extremely low corrosion current density of 4.3 × 10−10 A·cm−2, which is five orders of magnitude lower than the unmodified magnesium alloy. In vitro immersion tests revealed that the modification can effectively reduce the corrosion rate of the magnesium alloy stent, and the modified magnesium alloy stent can support at least 8 weeks. Furthermore, in vitro biological experiment revealed the modification of the composite coating improved the biocompatibility and ensured good microenvironment for vascular repair. These results suggest that the biodegradable composite coating has great potential for application in vascular stent.
The study has been published in Progress in Organic Coatings, Volume 174, January 2023.