Thrombin-inhibiting nanoparticles rapidly constitute versatile and detectable anticlotting surfaces.
Thrombin-inhibiting nanoparticles rapidly constitute versatile and detectable anticlotting surfaces.
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DOI：
10.1088/0957-4484/25/39/395101
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发表时间：
2014-10-03
期刊：
影响因子：
3.5
通讯作者：
Wickline S
中科院分区：
文献类型：
--
作者：
Myerson JW;He L;Allen JS;Williams T;Lanza G;Tollefsen D;Caruthers S;Wickline S
恢复抗血栓表面以抑制持续的血栓形成是治疗动脉粥样硬化斑块侵蚀等急性心血管疾病的一种有吸引力的策略。抗血栓表面将成为全身抗凝的替代方案，但会带来出血风险。我们设计了靶向凝血酶的纳米粒子，它与活跃凝血部位结合，消除局部凝血酶活性并抑制血小板沉积，同时仅表现出短暂的全身抗凝作用。通过将超过 15,000 个抑制剂共价连接到每个 PFC NP，将全氟化碳纳米颗粒 (PFC NP) 用凝血酶抑制剂（PPACK 或比伐卢定）进行功能化。纤维蛋白肽 A ELISA 证明，凝血酶抑制 NP 可防止游离凝血酶和凝块结合凝血酶对纤维蛋白原的裂解。磁共振成像证实，一层抑制凝血酶的纳米粒子可以在体外阻止血栓的生长。对受到颈动脉激光损伤的 C57BL6 小鼠体内施用凝血酶抑制 NP。 NP 显着延迟了动脉的血栓闭塞，而等量的游离抑制剂则无效。对于凝血酶抑制 NP，尽管具有较长的血栓抑制作用，但仅观察到对出血时间的短暂（约 10 分钟）全身影响。通过 PFC NP 的磁共振成像 (MRI) 证明了体内抗血栓 NP 层的成像和定量。 19F MRI 证实了颗粒与动脉血栓的共定位，定量 19F 光谱证明了凝血酶抑制纳米粒子在受损动脉中的特异性结合和保留。在急性血管综合征中快速形成新的抗血栓表面并成像，同时最大限度地降低出血风险的能力将允许比目前的全身抗凝方案更安全的钝化活动性病变的方法。
Restoring an antithrombotic surface to suppress ongoing thrombosis is an appealing strategy for treatment of acute cardiovascular disorders such as erosion of atherosclerotic plaque. An antithrombotic surface would present an alternative to systemic anticoagulation with attendant risks of bleeding. We have designed thrombin-targeted nanoparticles that bind to sites of active clotting to extinguish local thrombin activity and inhibit platelet deposition while exhibiting only transient systemic anticoagulant effects. Perfluorocarbon nanoparticles (PFC NP) were functionalized with thrombin inhibitors (either PPACK or bivalirudin) by covalent attachment of more than 15,000 inhibitors to each PFC NP. Fibrinopeptide A ELISA demonstrated that thrombin-inhibiting NPs prevented cleavage of fibrinogen by both free and clot-bound thrombin. Magnetic resonance imaging confirmed that a layer of thrombin-inhibiting NPs prevented growth of clots in vitro. Thrombin-inhibiting NPs were administered in vivo to C57BL6 mice subjected to laser injury of the carotid artery. NPs significantly delayed thrombotic occlusion of the artery, whereas an equivalent bolus of free inhibitor was ineffective. For thrombin-inhibiting NPs, only a short-lived (~10 minutes) systemic effect on bleeding time was observed, despite prolonged clot inhibition. Imaging and quantification of in vivo antithrombotic NP layers was demonstrated by magnetic resonance imaging (MRI) of the PFC NP. 19F MRI confirmed colocalization of particles with arterial thrombi, and quantitative 19F spectroscopy demonstrated specific binding and retention of thrombin-inhibiting NPs in injured arteries. The ability to rapidly form and image a new antithrombotic surface in acute vascular syndromes while minimizing risks of bleeding would permit a safer method of passivating active lesions than current systemic anticoagulant regimes.