Abstract
In this research work, a novel biodegradable shape memory dual drug-eluting stent (SMDES) is developed by cross-linked PEG-PCL copolymer (cPEG-PCL). The stent is able to perform shape memory effect with a transition temperature close to body temperature by BPO cross-linking strategy. The stent incorporates with controlled drug release system to prevent the in-stent restenosis of the vessel in two stages, anti-platelet adhesion initially followed by long-term inhibition of smooth muscle cells hyperproliferation.. From the results, 1H-NMR and GPC indicated that compositions of PEG-PCL block copolymers were highly close to the feed ratios of PEG/ε-CL. cPEG-PCL stent was demonstrated to recover to its permanent spiral shape from temporary linear shape with excellent fixing ratio (>99%), recovery ratio (>87.5%) and recovery time (<10s) by photographing and video recording. DSC data revealed the transition temperature was around body temperature (40oC). Cytotoxicity tests proved cPEG-PCL_6040 stent possessed good biocompatibility. In vitro degradation test showed cPEG-PCL_6040 stent decreased 47% of weight after 60 days incubation under flow condition. The inhibition of platelets adhesion and smooth muscle cells proliferation were significantly achieved after cell co-cultured with mitomycin C/curcumin-eluting stents. After 60 days incubation in bioreactor, stent remained intact and showed no signs of recoiling or collapse. Key words: Poly(ε-caprolactone), Polyethylene glycol, Cross-linking, Shape memory polymer, Drug-eluting stent