It was previously shown that polycaprolactone (PCL)-based electrospun-produced paclitaxel (PTX)-enriched matrices exhibit long-term drug release kinetics and can be used as coatings for drug-eluting stents (DES). The installation of vascular stents involves a twofold increase in stent diameter and, therefore, an elongation of the matrices covering the stents, as well as the arterial wall in a stented area. We studied the influence of matrix elongation on its structure and PTX release using three different electrospun-produced matrices. The data obtained demonstrate that matrix elongation during stent installation does not lead to fiber breaks and does not interfere with the kinetics of PTX release. To study PTX diffusion through the expanded artery wall, stents coated with 5%PCL/10%HSA/3%DMSO/PTX and containing tritium-labeled PTX were installed into the freshly obtained iliac artery of a rabbit. The PTX passing through the artery wall was quantified using a scintillator β-counter. The artery retained the PTX and decreased its release from the coating. The retention of PTX by the arterial wall was more efficient when incubated in blood plasma in comparison with PBS. The retention/accumulation of PTX by the arterial wall provides a prolonged drug release and allows for the reduction in the dose of the drugs in electrospun-produced stent coatings.
Keywords: drug-eluting stents; electrospinning; paclitaxel; polycaprolactone.