Thermo-induced shape-memory PEG-PCL copolymer as a dual-drug-eluting biodegradable stent.

In this work, a thermo-induced shape-memory drug-eluting stent (SMDES) has been developed by cross-linking PEG-PCL copolymer (cPEG-PCL). The stent is able to perform the shape-memory effect from a temporary linear form to a permanent spiral shape with the transition temperature close to body temperature. The stent incorporates a controlled dual drug-release system for the purpose of preventing in-stent restenosis of the vessel for short- and long-term therapeutic effects. From the results, 1H NMR and GPC indicate that the compositions of PEG-PCL block copolymers are similar to the feed ratios of PEG/e-CL. A Young’s modulus of the cPEG-PCL stent can be achieved that ranges from tens to one hundred megapascals by modulation of the mixing ratio of PEG/PCL. The cPEG-PCL stent is demonstrated to recover to its permanent shape with a high fixing ratio (>99%), recovery ratio (>90%), and recovery time (<10 s). DSC data reveals that the transition temperature is around body temperature (40 °C). Cytotoxicity tests ...