A Study on Effects of EGCG and Design Parameter for Drug-Eluting Biodegradable Polymer Stents

Finite element analysis(FEA) has been extensively applied in the analyses of biomechanical propertiesof stents. Geometrically, a closed-cell stent is an assembly of a number of repeated unit cells and exhibits periodicityin both longitudinal and circumferential directions. This study concentrates on various parameters of the FEA modelsfor the analysis of drug-eluting biodegradable polymeric stents for application to the treatment of coronary arterydisease. In order to determine the mechanical characteristics of biodegradable polymeric stents, FEA was used tomodel two different types of stents: tubular stents(TS) and helicoidal stents(HS). For this modeling, epigallocatechin-3-O-gallate (EGCG)-eluting poly[(L-lactide-co-e-caprolactone), PLCL] (E-PLCL) was chosen as drug-eluting stentmaterials. E-PLCL was prepared by blending PLCL with 5% EGCG as previously described. In addition, the effectsof EGCG blending on the mechanical properties of PLCL were investigated for both types of stent models. EGCGdid not affect tensile strength at break, but significantly increased elastic modulus of PLCL. It is suggested that FEAis a cost-effective method to improve the design of drug-eluting biodegradable polymeric stents. Key words: poly(L-lactide-co-e-caprolactone), epigallocatechin-3-O-gallate, finite element analysis, bio-degradable polymer stent, coronary artery disease