Development of a Bioactive Polymeric Drug Eluting Coronary Stent Coating Using Electrospraying

Drug-eluting stents are now routinely used in the treatment of acute coronary syndromes caused by coronary artery disease. Whilst the sustained release of anti-proliferative drugs from these devices has greatly reduced the need for repeat revascularisation procedures, this approach is not suitable for all patients and appears to delay regrowth of the endothelium, necessitating the use of prolonged dual anti-platelet therapy. Although the development of more advanced stent platforms and drug coatings has produced modest improvements in performance, these devices have not fully addressed the limitations experienced with their first-generation counterparts. In the present study, we developed a novel stent coating that provides controlled sirolimus release from a bioactive polymer (accelerate™ AT) that has previously been shown to support endothelial cell growth in vitro. A bespoke electrospray deposition process provided control over the coating thickness, surface roughness, drug load, and release kinetics. The resultant optimised coating combines rapid release of an anti-proliferative agent from a bioactive polymer coating that promotes re-endothelialisation, thereby offering potential protection against in-stent restenosis and thrombosis. This novel, dual-action coating therefore has significant therapeutic potential, with the enhanced control of drug load and release kinetics offered by electrospray deposition also opening up opportunities for more personalised treatment approaches. Further development and evaluation of these technologies in vitro and in vivo is therefore warranted.