Surface modification of polyethylene balloon catheters for local drug delivery

Local drug delivery is an attractive approach to the associated problems of percutaneous transluminal coronary angioplasty (PTCA), including arterial injury. The objective of the present research was to deliver a high concent ration of a potent anti-thrombin agent, argatroban (ARG), to the vessel wal l in order to reduce arterial injury. Local delivery was accomplished by th e ionic attachment of drug particles to a modified balloon surface. Surface graft polymerization of ionic monomers to a high-density poly(ethylene) (P E) substrate was performed utilizing ultra-violet (UV) methods. Acrylic aci d (AAc) and 2(dimethylamino) ethyl methacrylate (DMAEMA) were successfully grafted onto PE surfaces. Surface grafting was verified by contact angle, X -ray photoelectron spectroscopy, and zeta potential measurements. The amount of ARG adsorbed onto the modified PE surface was highly dependen t on the pH of the drug media for both anionic and cationic grafted monomer s. The efficacy of local drug delivery to the arterial wall was analyzed us ing drug-immobilized PE balloon catheters in the rabbit common carotid arte ry model. High concentrations of ARG (280 nmol/g tissue) were found within the ballooned arterial segment immediately after angioplasty, followed by a decrease after blood flow was restored. (C) 2000 Elsevier Science Ltd. All rights reserved.