Metal Surface Coating Using Electrospray of Biodegradable Polymers and alpha-Lipoic Acid Release Behavior for Drug-Eluting Stents

Abstract

Medical metal stents inserted to patients with a cardiovascular disease associated with coronary artery system have relatively increased the survival rate. The development of new stems is, however, urgently required due to restenosis and late thrombosis generated in metal stents. To solve these problems. the biodegradable polymers such as poly(lactide-co-glycolide) (PLGA), poly (L lactide) (PLLA), and poly (epsilon-caprolactone) (PCL) were mixed with alpha lipoic acid (ALA). which is well known to inhibit the proliferation of neointimal hyperplasia. Subsequently. the ALA loaded polymers were coated on stainless steel by electrospray. The drug-eluting behaviors from the coated polymers were investigated according to kinds and concentrations of polymers. spray rates, and kinds of solvents. The drug eluting rate from PCL with the lowest glass transition temperature was the fastest among three polymers and followed by PLGA and PLLA. The surface roughness increased as the spray rate was increased and also the drug eluting rate was affected by kinds of solvents with different boiling point. it is expected that drug eluting stem (DES) coated with ALA loaded polymers can be applied practically for clinical applications by controlling the behavior of drug release.