Tailoring the everolimus immobilisation time on poly (L-Lactic Acid/ poly (D-Lactic Acid) scaffold for biodegradable stent coating development

Abstract

Biodegradable stents (BDS) are projected to be degraded while supporting the blood vessel lumen. Equipping BDS with coated drugs will enhance its biological properties. In this study, everolimus drug was coated on poly (L-lactic acid) (PLLA)/poly (D-lactic acid) (PDLA) scaffolds by utilising polydopamine (PDA) as an intermediate layer. The immobilisation time for the coating process was tailored at 12 and 24 hours. The effects of different immobilisation time of everolimus (12 and 24 hours) were characterised through an ATR-FTIR, SEM and water contact angle analyses to investigate the chemical functionalities, surface morphology and hydrophilicity properties, respectively. The ATR-FTIR results indicated the presence of chemical functionalities of the coating and the scaffolds. The scaffold surfaces were having a transition from smooth to irregular surfaces after the PDA grafting and the coating of everolimus. More homogeneous surface formation was observed and greater hydrophilicity was recorded on the PLLA/PDLA scaffolds coated with everolimus at 24 hours immobilisation compared to the 12 hours immobilisation. These findings are beneficial for the fabrication of BDS with the implementation of everolimus and PDA as coating materials.