NOVEL INHIBITORS OF THROMBIN

使用一种名为“适配子”的新型体外选择/扩增技术 技术“，我们已经确定了一类新的凝血酶抑制物 关于单链DNA(SsDNA)寡核苷酸(Bock等人自然355， 564-6,1992)。一种寡核苷酸GGTTGGTGTGGGGTTGG(凝血酶适配子)， 在体外和体内均显示出较强的抗凝血活性。药理作用 对食蟹猴的研究表明，凝血酶适配子具有快速的 起效时间短，体内半衰期短。短暂的体内半衰期 体外血液滤过允许的局部抗凝治疗 绵羊的循环和犬的成功抗凝 体外循环模型。该项目的具体目标是：1) 凝血酶适配子作为犬抗凝剂的疗效评价 和灵长类体外循环模型，这将避免使用 并可能减少血液制品的使用；2)检测 凝血酶适配子作为非人类局部抗凝剂的疗效 灵长类血液透析可将与以下疾病相关的出血风险降至最低 全身性抗凝；3)开发成本效益高、规模大的 凝血酶适配子的制造工艺。我们的最终目标是 新型单链DNA凝血酶适配子抗凝血剂的研制 在体外循环和血液透析中的应用优于肝素 第三阶段临床试验。

Using a novel in vitro selection/amplification technique termed "aptamer technology", we have identified a new class of thrombin inhibitors based on single-stranded DNA (ssDNA) oligonucleotides (Bock et al. Nature 355, 564-6, 1992). One oligonucleotide GGTTGGTGTGGTTGG (thrombin aptamer), showed potent anticoagulant activity in vitro and in vivo. Pharmacological studies in cynomolgus monkeys showed the thrombin aptamer to have a rapid onset of action and short half-life in vivo. The short in vivo half-life permitted regional anticoagulation of an extracorporaal hemofiltration circuit in sheep, and successful anticoagulation in a canine cardiopulmonary bypass model. The specific aims of this project are: 1) To assess the efficacy of the thrombin aptamer as an anticoagulant in canine and primate models of cardiopulmonary bypass which will obviate the use of protamine sulfate and may reduce the use of blood products; 2) To test the efficacy of the thrombin aptamer as a regional anticoagulant in non-human primate hemodialysis which may minimize the bleeding risks associated with systemic anticoagulation; 3) To develop a cost efficient, large scale manufacturing process for the thrombin aptamer. Our ultimate goal is to develop this novel ssDNA based thrombin aptamer as an anticoagulant superior to heparin for use in cardiopulmonary bypass and hemodialysis in Phase III clinical trials.