Heteromutivalent Peptide-Lipid Nanoconstructs as Artificial Platelet Analogues

作为人工血小板类似物的异多价肽-脂质纳米结构

• 批准号: 10579965
• 负责人: Anirban Sen Gupta
• 金额: $ 53.27万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-02-08 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10579965
• 关键词: Acute; Address; Adhesions; Alpha Granule; Alteplase; Attenuated; Award; Binding; Biocompatible Materials; Blood; Blood Coagulation Factor; Blood Platelets; Clinical; Coagulation Process; Collagen; Emergency Medicine; Encapsulated; Engineering; Enzymes; Exposure to; Fibrin; Fibrinogen; Generations; Goals; Hemorrhage; Hemostatic Agents; Hemostatic function; Hospitals; Hybrids; In Vitro; Injury; Integrins; Kinetics; Legal patent; Life; Lipids; Liposomes; Mediating; Military Personnel; Modeling; Morphology; Mus; N-formylmethionylphenylalanine; Patients; Peptides; Phosphatidylserines; Phospholipids; Plasma; Plasmin; Platelet Transfusion; Play; Polyphosphates; Research; Resources; Rodent; Role; Site; Stimulus; Surface; System; Tail; Technology; Testing; Thrombin; Transfusion; Trauma; Traumatic Hemorrhage; Vascular Endothelium; Whole Blood; analog; design; functional mimics; high risk; improved; in vivo; innovation; military trauma; mimetics; mimicry; mortality; nano; nanoparticle; peptidomimetics; portability; response; self assembly; trauma centers; von Willebrand Factor

Platelets play a central role in hemostasis via injury site-selective multi-step mechanisms of: (1) Adhesion to vWF and collagen, (2) Fibrinogen-mediated aggregation to form the primary hemostatic plug, (3) Biointerfacial presentation of anionic phosphatidylserine (PS) on the activated platelet surface for procoagulant amplification of thrombin (hence fibrin), and (4) clot-localized secretion of platelet granule contents (e.g. inorganic polyphosphate, PolyP) to locally enhance fibrin stability. These mechanisms are significantly compromised in non-compressible traumatic hemorrhage, which remains a major cause of mortality. The `gold standard' for treating such hemorrhage is massive transfusion of whole blood or components (platelets, plasma, RBC). Especially, platelet transfusion has shown tremendous clinical benefit in saving lives in trauma. However, platelets are rarely available in resource-limited hospitals and unavailable pre-hospital, due to challenges of storage, portability, high risk of bacterial contamination and very short shelf-life (~5 days). We aim at addressing this challenge by designing biomaterials-based `artificial platelet' nanoconstructs. To this end, utilizing a previous R01 award (HL121212) we developed self-assembled lipid-peptide nanoconstructs that mimic and integrate the platelet mechanisms of (1) and (2) stated above. This design showed hemostatic ability in vitro and in thrombocytopenic mouse tail-bleeding models, and modest efficacy in severe trauma models. Building on this, we now propose to mimic the mechanisms of (3) and (4) on a liposomal template by designing unique enzyme- responsive lipopeptides, that will subsequently allow integration of all four mechanisms onto a single nanoconstruct for a superior artificial platelet design. Our central hypothesis is `Modular amplification of hemostasis via mimicry of platelet's biointerfacial and secretory mechanisms within an artificial platelet construct can significantly attenuate hemorrhage and enhance survival in trauma'. To test this, our Specific Aims are to: (1) Evaluate stimuli (plasmin)-triggered exposure of PS on lipidic nanoconstructs for platelet-inspired amplification of thrombin (hence fibrin) site-specifically in trauma; (2) Evaluate stimuli (thrombin)-triggered release of inorganic polyphosphate (PolyP) as a payload from lipidic nanoconstructs for injury site-targeted stabilization of fibrin clot; and (3) Integrate these independent synergistic components in artificial platelet nanoconstructs to evaluate hemostatic efficacy and survival in rodent trauma model. The traumatic insult to vascular endothelium results in enhanced secretion of tissue plasminogen activator (hence plasmin) at the clot site, resulting in rapid fibrin degradation (hyperfibrinolysis) and compromising clot stability. Exploiting this plasmin to expose PS on `artificial platelet' surface will allow enhanced thrombin (and hence fibrin) generation to offset hyperfibrinolysis. This thrombin can then also act as a local trigger to destabilize the `artificial platelet' constructs and release encapsulated PolyP to enhance fibrin stability and augment hemostasis. Our principal innovation is in uniquely mimicking platelet's multi-step mechanisms of hemostasis on a single nanoconstruct.

血小板通过受伤现场选择性多步骤机制在止血中起着核心作用：（1）粘附于VWF 和胶原蛋白，（2）纤维蛋白原介导的聚集以形成主要的止血塞，（3）生化 激活血小板表面上的阴离子磷脂酰丝氨酸（PS）的呈现，以进行凝聚 凝血酶（因此纤维蛋白），（4）血小板颗粒含量的凝结凝结分泌（例如无机 多磷酸盐，息肉）以局部增强纤维蛋白的稳定性。这些机制在 不可压缩的创伤性出血，这仍然是死亡率的主要原因。用于的“黄金标准” 治疗这种出血是全血或成分（血小板，血浆，RBC）的大量输血。 特别是，血小板输血在挽救创伤中的生命方面表现出巨大的临床益处。然而， 由于挑战的挑战 存储，可移植性，细菌污染的高风险和非常短的保质期（约5天）。我们旨在解决 通过设计基于生物材料的“人造血小板”纳米结构的挑战。为此，利用一个 以前的R01奖（HL121212）我们开发了模仿和模仿的自组装脂质肽纳米结构 整合了上述（1）和（2）的血小板机制。该设计在体外显示出止血能力， 在血小板减少小鼠的尾流模型中，以及在严重创伤模型中适度的功效。在此基础上， 现在，我们建议通过设计独特的酶 - 在脂质体模板上模仿（3）和（4）的机制 响应型脂肽，随后将允许将所有四种机制整合到一个单一的机构上 纳米构造，用于卓越人造血小板设计。我们的中心假设是` 通过模仿血小板的生物学和分泌机制的止血 构造可以显着减轻出血并增强创伤的生存。为了测试这一点，我们的具体目标 为：（1）评估PS在脂质纳米结构上的刺激（纤溶酶）暴露于血小板启发的 凝血酶（因此纤维蛋白）在创伤中特异性位点的扩增； （2）评估刺激（凝血酶）触发的 从脂质纳米结构中释放无机多磷酸盐（Polyp）作为受伤部位目标的有效载荷 纤维蛋白凝块的稳定； （3）将这些独立的协同组件整合在人造血小板中 纳米结构以评估啮齿动物创伤模型中的止血功效和存活率。痛苦的侮辱 血管内皮导致在凝块处组织纤溶酶原激活剂（因此纤溶酶）的分泌增强 位点，导致快速纤维蛋白降解（高纤维蛋白溶解）和损害凝块稳定性。利用这个 纤溶酶在“人造血小板”表面暴露PS将允许增强的凝血酶（因此）生成 抵消高纤维蛋白溶解。然后，该凝血酶还可以充当局部触发因素，使“人造血小板”不稳定 构造和释放封装的息肉以增强纤维蛋白的稳定性和增强止血。我们的校长 创新是在单一纳米结构上独特地模仿血小板的多步肌的多步骤机制。