Evaluation of drug-eluting nanoparticle coating on magnesium alloy for development of next generation bioabsorbable cardiovascular stents.

Abstract

Since the introduction of bioabsorbable magnesium alloys into cardiovascular stent technology, many researches have been conducted to improve these metallic scaffolds. Various coatings and different coating techniques, super plastic deformation techniques and synthesizing different Mg-based alloy are examples of such efforts. In this study, a magnesium based alloy (WE43) was coated with dexamethasone loaded polymeric nanoparticles via electrospraying method. Drug release behavior, drug inhibitory effects, surface properties and cell responses to the surface were evaluated. Drug release profile was investigated and compared to drug-loaded nanoparticle on stainless steel as a control. The inhibitory effects of the drug-loaded nanoparticle coatings on smooth muscle cells was evaluated via MTT assay. Endothelial cells response to the surface was investigated by SEM. The results showed that contact angle and roughness of the surface were 131° and 600-800nm, respectively. Drug release studies showed a burst release less than 30% after 24h which followed by nearly zero order release kinetic. MTT assay showed that SMCs viability decreased to 60% and 25% after 24 and 72h, respectively. SEM images indicated proper adhesion and proliferation of endothelial cells on the surface. The findings suggest that nanoparticle-coated surfaces could effectively inhibit SMC proliferation meanwhile provide desirable surface features for adhesion and proliferation of endothelial cell on magnesium alloy based stents.