Site-specific thrombolytic and anticoagulant biomaterials

Abstract

Thrombolytic drugs are used in medicine to dissolve blood clots in a procedure termed thrombolysis. To prevent occlusion, patients are treated with an antiplatelet or antithrombotic drug, or a combination of both. However, the traditional thrombolytic therapies have often been associated with the risk of severe bleeding. We have incorporated low molecular weight heparin (LMWH) and/or streptokinase to biodegradable polyvinyl alcohol (PVA) and gelatine biomaterials in a form of films. These biomaterials will be used to decorate inner surfaces of experimental vascular grafts to evaluate the potential of enhancing their thromboresistance by controlled release of one or both the active compounds. Solvent casting method was used to produce the PVA and crosslinked gelatine films. High initial burst release of LMWH has been observed during our in vitro experiments, followed by a slow stable release during subsequent hours. Biomaterials with LMWH incorporated in the vascular graft luminal surface can be used to prevent thrombus formation shortly after the surgery graft implantation and decrease it in the following hours. Slow stable streptokinase release can be used to attenuate excessive fibrin deposition inside the graft.