“Hot-dog-string” drug-eluting degradable stents for treating stenosis in tortuous arteries

Despite advances in cardiovascular technology, treating stenosis in tortuous arteries with balloon-expandable stents, typically deployed in a straight orientation, remains a challenge. This study developed novel balloon-expandable “hot-dog-string” (HDS) drug-eluting poly(ϵ-caprolactone) (PCL) nanofibrous stents using solvent casting and coaxial electrospinning techniques. A unique HDS geometry was designed for the PCL stent backbone, while aspirin and sirolimus were loaded into the core-sheath structured poly(lactic-co-glycolic acid) (PLGA) nanofibers, which were then wrapped around the degradable stent. In vitro characterization of the biodegradable HDS stent and drug-eluting nanofibers was conducted. The results indicate that the biodegradable HDS stents exhibited excellent mechanical properties and superior flexibility, allowing them to navigate curved sections of a simulated in vitro vessel model more effectively than metallic stents. The core-sheath structure of the nanofibers enabled sustained release of high concentrations of aspirin and sirolimus over 14 and 23 days, respectively, with sirolimus effectively inhibiting smooth muscle cell proliferation. Moreover, in vivo animal tests showed that the rabbits remained in good health with excellent vessel patency following stent placement. By implementing the innovative design and techniques proposed in this study, we anticipate fabricating biodegradable drug-eluting HDS stents of various sizes for diverse cardiovascular applications at curved lesions.