Delivery of Anti-thrombotic Drugs by Blood Cells

描述(由申请人提供)：血栓在许多病理情况下会导致发病率和死亡率。PA用抗凝剂和抗血小板药物预防，用纤溶型纤溶酶原激活剂治疗血栓，疗效有限，常伴有出血和脑损伤。我们的团队：i)提出与载体红细胞(RBC)偶联将改善纤溶PA的药代动力学，从而使其具有预防作用；ii)展示了通过在动物身上重新输注RBC/tPA结合物来实现有效和安全预防血栓的原理证明(Natural Biotech 2003)；以及iii)设计了通过体内抗RBC/tPA结合物安全加载循环RBC。为了将这一有希望的原型转化为具有临床可接受的实用性、安全性和特异性的血栓预防措施，我们现在设计了一系列凝血酶激活的抗RBC单链抗体/PA融合前药。为了测试该平台在RBC载体上的抗血栓药物输送，我们将分析：i)抗RBC scFv/PA前体药物的活性、药代动力学和凝血酶调节(目标1)；ii)它们在小鼠静脉和动脉血栓形成模型上的有效性(目标2)；iii)安全性：对红细胞的潜在损害、出血、全身反应和中枢神经系统的不良反应(目标3)。这笔赠款的实施将为这一安全有效的血栓预防的潜在革命性新方法进入临床领域提供基础。与公共卫生相关我们设计了一种新的预防血栓形成的策略，该策略基于与载体红细胞(RBC)安全结合的纤溶前药物重组融合构建物的偶联。我们将在小鼠血栓形成模型中表征这些药物的活性和药代动力学调节、有效性和安全性。这一翻译赠款的实施将为这一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.