Delivery of Anti-thrombotic Drugs by Blood Cells

描述（由申请人提供）：血栓形成在许多病理条件下导致发病率和死亡率。抗凝剂和抗血小板剂的预防和纤溶纤溶酶原激活剂的治疗性溶栓，PA的疗效有限，并受到出血和脑损伤的影响。我们的团队：i）提出与载体红细胞（RBC）的偶联将改善纤溶PA的药代动力学，允许其预防效用; ii）证明了通过在动物中再输注RBC/tPA偶联物实现有效和安全血栓预防的原理证明（Nature Biotech 2003）; iii）设计了体内抗RBC/tPA偶联物对循环RBC的安全加载。为了将这种有前途的原型转化为具有临床可接受的效用、安全性和特异性的临床可应用的血栓预防，我们现在设计了一系列由凝血酶活化的抗RBC scFv/PA融合前药。为了测试用于递送装载在RBC载体上的抗血栓形成剂的该平台，我们将表征：i）抗RBC scFv/PA前药的活性、药代动力学和凝血酶调节（目的1）; ii）它们在静脉和动脉血栓形成的小鼠模型中的功效（目的2）;和iii）安全性：对RBC的潜在损害、出血、全身作用和CNS中的不良作用（目的3）。这项资助的实施将为将这种潜在的革命性的安全有效的血栓预防新方法转化为临床领域提供基础。我们设计了一种新的预防血栓形成的策略，该策略基于安全结合载体红细胞（RBC）的纤溶前药重组融合结构的偶联。我们将在小鼠血栓形成模型中表征药物的活性和药代动力学调节、有效性和安全性。这项翻译补助金的实施将为这种潜在革命性的血栓预防新方法的临床开发提供坚实的基础。

DESCRIPTION (provided by applicant): Thrombosis causes morbidity and mortality in many pathological conditions. Prevention by anticoagulants and anti-platelet agents and therapeutic thrombolysis by fibrinolytic plasminogen activators, PA have limited efficacy and marred by bleeding and brain injury. Our team: i) proposed that coupling to carrier red blood cells (RBC) will improve pharmacokinetics of fibrinolytic PA, permitting their preventive utility; ii) demonstrated a proof of principle for effective and safe thromboprophylaxis attained by re-infusion of RBC/tPA conjugates in animals (Nature Biotech 2003); and, iii) designed safe loading of circulating RBC by anti-RBC/tPA conjugates in vivo. In order to translate this promising prototype into clinically applicable thromboprophylaxis with clinically acceptable utility, safety and specificity, we now designed a series of anti-RBC scFv/PA fusion pro-drugs activated by thrombin. To test this platform for delivery of anti-thrombotic agents loaded on RBC carriers, we shall characterize: i) activities, pharmacokinetics and thrombin regulation of the anti-RBC scFv/PA pro-drugs (Aim 1); ii) their efficacy in mouse models of venous and arterial thrombosis (Aim 2); and, iii) safety: potential harm to RBC, bleeding, systemic effects and adverse effects in the CNS (Aim 3). Implementation of this grant will provide a basis for translation into the clinical domain of this potentially revolutionizing novel approach for safe and effective thromboprophylaxis. PUBLIC HEALTH RELEVANCE we have designed a new strategy for prophylaxis of thrombosis based on coupling of fibrinolytic pro-drug recombinant fusion constructs that safely bind to carrier red blood cells (RBC). We shall characterize activities and pharmacokinetics regulation of the drugs, efficacy and safety in mouse models of thrombosis. Implementation of this translational grant will provide a solid basis for clinical development of this potentially revolutionizing novel approach for thromboprophylaxis.