An Innovative Solvent-Responsive Coiling-Expanding Stent.

Coronary artery disease is the "first killer" in the world, while the classical treatment for this disease is to implant stent. An ideal vascular stent should be nontoxic with self-expanding characteristics, quick expanding speed, and appropriate mechanical supporting property. However, no existing vascular stent covers all properties. Herein, a two-way shape-memory cellulose vascular stent, which can realize shape adjustments by mild solutions such as water and alcohol, is constructed. The shape-memory characteristics, mechanical properties, cell toxicity, and biocompatibility, are systemically investigated by ex vivo experiment as well as molecule simulation and theoretical modeling, revealing that the achieved bilayer two-way shape-memory films (BSMFs) can be used as an artificial vascular stent. In particular, this vascular stent made from BSMFs shows superb biocompatibility according to live/dead cell viability assays. Ex vivo experiments reveal that the novel vascular stent can support arteria coronaria sinistra, or the left main coronary artery, at the opening state while the cross-section of the vessel becomes two times larger than that of the initial state after implantation. Thus, it is believed that effective and scalable BSMFs can make meritorious fundamental contributions to biomaterials science and practical applications such as vascular stents.