Microstructural-Mechanical Interactions of Drug Coated Balloons

Peripheral Artery Disease (PAD) is a common subset of atherosclerosis characterized by plaque build-up in the arteries of the lower extremities. Drug coated balloons (DCBs) are a promising new therapy for PAD and are made up of angioplasty balloons coated in an antiproliferative drug, usually paclitaxel, and are inserted into the artery via a guide wire. The balloon inflates at the target site, mechanically compressing the plaque and delivering antiproliferative drug into the arterial wall which can prevent restenosis up to 14.5 months after treatment. Previous studies within our lab show that the excipient microstructure of the DCB can modulate the amount of drug transferred into the arterial wall. We hypothesized that the dehydration temperature of urea (excipient) and paclitaxel (drug) solution on Nylon-12 sheets at temperatures of 4℃, 23℃, and 37℃ would affect the rate and size of crystal formation thereby altering drug transfer. We also hypothesized that the substrate hydrophobicity would impact drug delivery. To alter substrate hydrophobicity, we pre-treated the Nylon-12 sheet with UV/Ozone for 20m and 40m before coating application and dehydration at 23℃. We characterized surface coatings and drug delivery to a porcine artery using SEM, uniaxial mechanical testing, and HPLC. There was no significant difference between dehydration temperature and drug delivery (p = 0.12), however, pre-treating the Nylon-12 surface with UV/Ozone dramatically increased drug delivery (p = 0.00016). Future studies will optimize UV/Ozone treatment for drug delivery and quantify the size and number of urea crystals in SEM images