Biodegradable Polymer-Coated Surgical Sutures for Controlled and Sustained Release of Sirolimus, Tacrolimus, and Paclitaxel

Biodegradable polymer-coated surgical sutures represent a promising strategy for localized drug delivery to prevent post-surgical complications, such as restenosis, inflammation, and excessive tissue proliferation. In this study, bioactive coatings based on poly(L-lactic acid) (PLA), polycaprolactone (PCL), chitosan, and their binary blends were developed and applied to PLA-based surgical sutures for controlled release of sirolimus, tacrolimus, and paclitaxel. A total of 36 coated suture formulations were prepared using solvent-based deposition techniques and systematically evaluated. In vitro drug release studies conducted under physiological conditions (PBS, 37 °C) over a 12-week period demonstrated sustained and formulation-dependent release profiles. Cumulative drug release varied significantly depending on polymer composition, ranging from 17.53% to 90.93% for sirolimus, 70.93% to 98.50% for tacrolimus, and 34.62% to 67.65% for paclitaxel. PLA-based coatings generally exhibited faster release kinetics, whereas PCL-containing formulations showed slower, more sustained release. Binary polymer blends enabled fine-tuning of release profiles, demonstrating tunable drug delivery performance. All coatings maintained structural integrity during handling and simulated suturing conditions. These findings confirm that polymer composition plays a critical role in controlling drug release kinetics and demonstrate the feasibility of biodegradable polymer-coated sutures as a versatile platform for sustained, localized drug delivery in surgical and vascular applications.