In vitro peptide release from e-polycaprolactone and blends of e-polycaprolactone

Abstract

Coronary stent is designed to increase the lumen of blood vessel and provide scaffold against coronary stenosis. However, there was a high tendency of in stent restenosis (ISR) after the angioplasty procedure. Recent invention of drug-eluting stent (DES) has been successful to prevent ISR but signify a long term thrombosis effect. C-type-Dendroapsis Natriuretic Peptide (CD-NP) is particularly attractive to overcome this shortcoming since it is able to inhibit smooth muscle cells proliferation without delaying re-endothelialization. As peptide carrier, ɛ -polycaprolactone (PCL) and its blends are considered viable choices due to their biodegradable property. This project aims to study and understand CD-NP release profiles of PCL and blends of PCL (i.e. PCL/5%PEG, PCL/10%PEG, PCL/5%PCL-b-PEG, and PCL/10%PCL-b-PEG). Films were fabricated by polymer solution casting to the thickness of 40 μm with 3 wt% CD-NP loading. The study was conducted by immersing film samples in phosphate buffer solution (37°C, pH 7.4). Drug release was analyzed using Bichinconinic Acid Assay(BCA) and UV-Vis spectrometry. Degradation study comprised of weight loss tabulations, Gel Permeation Chromatography (GPC) for molecular mass profile, Differential Scanning Calorimeter (DSC) to determine thermal traces, and Scanning Electron Microscopy(SEM) to analyze surface morphology.