Abstract
Blood clotting (formation of thrombus) plays a critical role in the evolution of a number of cardiovascular diseases. Targeted delivery of thrombolytic agents reduces the risks of hemorrhage and toxicity associated with systemic drug administration, thus offering a promising, minimally invasive approach to controlling and treating thrombosis. Platelets play a major role in the progression of thrombosis on vascular injury. Platelet integrin αIIbβ3 (GP IIb/IIIa) serves as a receptor for various proteins such as fibrinogen, vWF, fibronectin and vitronectin, as well as contributing to the adhesion and aggregation of platelets in a variety of conditions. These receptor-based targeted therapies are currently under clinical studies. Integrins and RGD-based ligands for integrins are currently being investigated in imaging and drug delivery related areas of research. RGD-targeted drugs and imaging agents have been developed either by direct conjugation of the homing peptide to the drug or by conjugation of the RGD-peptide to a carrier device containing drug molecules. This review describes the role of integrin receptors in the pathophysiology of thrombosis and its use in the targeted delivery of thrombolytic agents.