3D printed personalized, heparinized and biodegradable coronary artery stents for rabbit abdominal aorta implantation

Biodegradable stents have become the focus of attention in the field of interventional medicine. Compared to non-biodegradable stents, these stents are designed to degrade, leaving behind regenerating healthy arteries. In addition to biodegradability, customizability and anticoagulation are also important for stent treatments. The combination of magnetic resonance angiography (MRA) and 3D printing can customize coronary stents according to different vascular geometries of patients. Therefore, this work focused on the rapid fabrication of stents composed of polycaprolactone (PCL) by 3D printing and then functionalized the stents with heparin via covalent grafting. The 3D printed stents were implanted into the abdominal aorta of rabbits to evaluate the feasibility of implantation and biocompatibility. Mechanical tests showed that 3D printed stents have good mechanical properties. In vitro data demonstrated that the stents had excellent blood compatibility and cytocompatibility. The heparinized PCL(PCL-NH2-Hep) stent can promote the adhesion, spreading and proliferation of human umbilical vein endothelial cells (HUVECs) and inhibit the excessive proliferation of smooth muscle cells (SMCs). Presently, there is insufficient study about 3D printed stent implantation in rabbit arteries. Hence, personalized stents were prepared via MRA and 3D printing, which tailored to the patient's unique anatomy. A 3D printed stent-balloon delivery system was employed to deliver stents to the abdominal aorta. At 3-month follow-up, the PCL-NH2-Hep stent maintained good vascular patency. Moreover, the heparinized stents showed rapid endothelialization and prevention of neointimal restenosis in vivo. This study demonstrated that personalized PCL-NH2-Hep stent may have the potential in the field of biodegradable coronary artery stents.