A novel paclitaxel eluting bioresorbable vascular stent with a super flexible stent structure and round cross section...

Bioresorbable stents (BRS) have emerged as a groundbreaking development in the field of percutaneous coronary intervention (PCI) as they address the long-standing concerns of metallic stents. Nevertheless, the observed higher thrombosis rates in the first generation BRS, i.e. ABSORB^®, might be attributed to their thicker struts, slower degradation rate and structural dismantling of partially endothelialized stents. In this study, measures have been taken to overcome these limitations include reducing strut thickness, modifying the structural design to maintain radial strength with thinner round cross section struts and using a new material poly(L-lactide-co-ɛ-caprolactone) (PLCL 95/5) that is tougher and degrade faster than poly(L-lactic acid) (PLLA).Given the excellent biocompatibility of PLCL materials, the US FDA has approved their use in clinical applications. PLCL stents can be used to treat diseases such as tracheal stenosis and tracheoesophageal fistula, and can also be applied in the construction of other tissue engineering stents, such as nerve conduitsand fat filling stents. The newly designed coronary stents were fabricated using a 3D printing technology with a rotating platform, coated with a paclitaxel coating and comprehensive in vitro research was conducted. It was the first to undergo tests in animals. Results showed the novel paclitaxel eluting PLCL stents had super-flexible structure, thinner round cross-sectional struts, a faster degradation profile and satisfactory hemocompatibility. With a paclitaxel dose of 0.57 μg/mm², the drug eluting stents showed very low degree of stenosis within 6 months of implantation in a porcine model. Overall, the results showed that the novel 3D printed PLCL drug eluting stent is a very promising candidate for next generation bioresorbable coronary stent.