Engineering Time Release from Sirolimus-Eluting Stents

Restenosis often causes failure in percutaneous coronary intervention. Drug-eluting stents (DES) are effective in mitigating this issue. This study aimed to fabricate sirolimus (an antiproliferative drug)-eluting stents and investigate drug release from the stents. INA-Stents were coated with a combination of sirolimus and collagen (a biodegradable polymer) using three different forward speeds (7â-9 mm/s) of the ultrasonic airbrush spray. Alternate coatings of 10 layers of sirolimus and 11 layers of collagen were implemented in the DES to reduce post-implantation thrombosis and ensure controlled drug release, respectively. Among the fabricated DES, stents produced using the lowest forward speed (INA-Stent A) exhibited the thickest coating (around 317â-490 nm) and the most consistent sirolimus release. All three stents released the drug at the rates of approximately 0.60â-0.72 mg/day. These findings suggest that INA-stent A may be the most optimal design for the DES. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.