3D printed degradable stents with controlled drug delivery capabilities

Atherosclerosis describes a diseased narrowing of an artery lumen, which untreated can ultimately lead to cardiac arrest and infarcts, yet difficult to combat. Especially severe stages are treated regularly using bare-metal and non- bioresorbable drug-eluting stents. However, incidence of stent failure is often associated with restenosis and thrombosis, which is due to their non-degradable nature. Hence, cardiovascular research shifts their attention towards degradable stents. Additive manufacturing attracts increasingly recognition as manufacturing technique for medical implants and devices. This work presents 3D printing as promising manufacturing technique for fabrication of biodegradable and drug-eluting stents. Three well-established configurations of stents were recreated, and printing protocols established. The anti-proliferative agent paclitaxel was incorporated onto the host polymer poly(ε-caprolactone) (PCL) to address current stent issues such as in-stent restenosis. Mechanical properties tests were carried out to investigate the influence of the drug-loading. In vitro release studies were undertaken to evaluate the drug-elution behaviour of paclitaxel-PCL-stents, presenting a sustained linear release profile of the drug over 21 days. Together the results demonstrated in this work indicate that additive manufacturing has a significant place in the future manufacture of stents.