SBIR-STTR Award

Heparin, a parenterally administered thrombin inhibitor, is an effective coagulant, but its use can be limited by heparin-induced thrombocytopenia, a side-effect observed in about 5% of patients. In addition, heparin has limited efficacy in the prevention of deep-vein thrombosis in total hip replacement. We have described a novel approach for the isolation of an alternative thrombin inhibitor. The approach is based on a repetitive cycle of in vitro binding and PCR amplification which has yielded single-stranded DNA molecules with greatly enhanced affinity for thrombin compared to the unselected starting DNA. This DNA was cloned and isolates identified which inhibit thrombin activity. Inhibitory clones were sequenced and a highly conserved region, spanning about 15 bases, was identified. Our goal is to modify oligonucleotides to produce a therapeutic agent with potent anti-clotting activity.Awardee's statement of the potential commercial applications of the research:Acute vascular diseases constitute major health risks. Heparin has been widely used to treat conditions in which thrombin activity is responsible for the development or expansion of thrombus. However, heparin produces undesirable side-effects such as hemorrhaging or thrombocytopenia, and is ineffective at inhibiting clot bound thrombin. The present approach offers a promising avenue for the development of pharmacologically superior antithrombotic agents and has potential applications in other diseases as well.National Heart, Lung and Blood Institute (NHLBI)

Heparin, a parenterally administered thrombin inhibitor, is an effective anticoagulant, but its use can be limited by heparin-induced thrombocytopenia, a side-effect observed in about 5% of patients. In addition, heparin has limited efficacy in prevention of deep-vein thrombosis in total hip replacement. This proposal describes a novel approach for the isolation of an alternative thrombin inhibitor. The approach is based on a repetitive cycle of in vitro binding and PCR amplification which has yielded single-stranded DNA molecules with greatly enhanced affinity for thrombin compared to the unselected starting DNA. This DNA was cloned and isolates identified which inhibit thrombin activity. Inhibitory clones were sequenced and a highly conserved region, spanning 15 bases, was identified. Our goal is to modify oligonucleotides to produce a therapeutic agent with potent anti-clotting activity.Awardee's statement of the potential commercial applications of the research: The use of extracorporeal circuits in clinical medicine is widespread and growing (20 million annually U. S.-cardiopulmonary bypass, hemodialysis, plasma pheresis, photophoresis, respiratory failure). A need exists to improve upon the therapeutic profile of heparin as an anticoagulant in the setting of extracorporeal circulation. The discovery of a new class of antithrombin inhibitors based on ssDNA offers promise for the development of a pharmacologically superior anticoagulant agent for use in extracorporeal circuits.National Heart, Lung, and Blood Institute (NHLBI)