Heteromultivalent Peptide-Lipid Nanoconstructs as Artificial Platelet Analogs

作为人工血小板类似物的异多价肽-脂质纳米结构

• 批准号: 8803679
• 负责人: Anirban Sen Gupta
• 金额: $ 38.14万
• 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 2019-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8803679
• 关键词: Acute; Adhesions; Adverse effects; Allogenic; Animal Model; Binding; Biological; Biological Assay; Bleeding time procedure; Blood Coagulation Factor; Blood Platelet Disorders; Blood Platelets; Chronic; Clinic; Clinical; Coagulants; Coagulation Process; Collagen; Complication; Ensure; Evaluation; Exhibits; FDA approved; Familial disease; Fibrillar Collagen; Fibrin; Fibrinogen; Fluorescence Microscopy; Future; Generations; Goals; Health; Hemorrhage; Hemostatic Agents; Hemostatic function; In Vitro; Injection of therapeutic agent; Injury; Integrins; Intravenous; Knowledge; Lead; Life; Lipids; Measures; Mediating; Membrane; Modality; Modeling; Molecular; Monitor; Mus; Operative Surgical Procedures; Pathologic; Patients; Peptides; Plasma; Platelet Activation; Platelet Count measurement; Platelet Transfusion; Platelet aggregation; Process; Radiation therapy; Research; Risk; Saline; Site; Surface; Tail; Techniques; Technology; Testing; Therapeutic; Thrombin; Thrombocytopenia; Transfusion; Trauma; Treatment Efficacy; Vision; Wit; analog; base; clinically relevant; clinically significant; cost; design; design and construction; glycocalicin; high risk; in vivo; in vivo Model; innovation; insight; interest; large scale production; mimetics; pathogen; surface coating; von Willebrand Factor

DESCRIPTION (provided by applicant): Allogeneic natural platelet transfusions are clinically routinely required in hemostatic therapy of a variety of bleeding complications. However, natural platelets suffer from (i) limited supply, (ii pathogenic contamination risks resulting in short shelf-life (~3-5 days), and (iii) risks of multipe biological side-effects. Current photochemical pathogen reduction techniques extend the shelf-life of natural platelet products only to ~7 days. Consequently, there is a substantial clinical interest in artificial platelet analogs that can mimic platelet's hemostatic actions, while allowin large-scale production, longer shelf-life and safer in vivo applications. To this end, past approaches in artificial platelets have shown very limited efficacy, possibly because of a major design drawback: platelet's natural hemostatic action requires injury site-specific platelet adhesion and site- selective platelet aggregation to act in tandem, but none of the past approaches have integrated these two capabilities effectively on a single platform. Our research is the first to have successfully integrated these two key hemostatic functions via heteromultivalent vesicular assembly of adhesion-promoting and aggregation- promoting peptide-lipid conjugates. Our artificial platelet construct is simultaneously surface-decorated wit VWF-binding peptides (VBP) for shear-responsive VWF adhesion, collagen-binding peptides (CBP) for shear- independent collagen adhesion and fibrinogen-mimetic peptides (FMP) for enhancing the aggregation of active platelets onto the adhered constructs. This innovative artificial platelet design has exhibited superior hemostatic activity both in vitro and in vivo, an we hypothesize that this superior hemostatic efficacy is due to a combined effect of both primary hemostasis and secondary hemostasis mechanisms induced by our constructs. Our overall goal is to corroborate this hypothesis using three specific aims: In Aim 1 we will establish a mechanistic model of the primary hemostatic action of our nanoconstructs, by first elucidating the domain-specific molecular mechanism of shear-responsive VBP interactions with VWF, and then combining this insight with the already established knowledge of shear-independent helicogenic interaction of CBP with fibrillar collagen and platelet activation-selective interactio of FMP with platelet integrin GPIIb-IIIa. In Aim 2 we will investigate whether the construct-mediated direct enhancement of primary hemostasis, can also in effect enhance secondary hemostasis (coagulation) at the site of construct-induced platelet aggregation, due to pro- coagulant ability of the active platelet membrane. Thus, Aims 1 and 2 will help synergistically corroborate the mechanistic components of our hypothesis. Hence in Aim 3, we will determine whether these construct- induced mechanisms lead to superior hemostatic efficacy in a tail transection bleeding model in thrombocytopenic mice, compared to current clinical hemostat NovoSeven(R). Establishing the construct- induced hemostatic mechanisms in vitro and demonstrating its resultant superior therapeutic efficacy in the thrombocytopenia model in vivo, will lead to detailed evaluation in acute and chronic bleeding models in future.

描述（由申请人提供）： 临床上常规止血治疗需要同种异体天然血小板输注 各种出血并发症。然而，天然血小板面临以下问题：(i) 供应有限，(ii 导致保质期短（约 3-5 天）的病原体污染风险，以及 (iii) 多种生物副作用的风险。目前的光化学病原体减少技术延长了天然血小板产品的保质期仅为约7天，因此，人工血小板类似物具有很大的临床意义，它可以模拟血小板的止血作用，同时允许大规模生产、更长的保质期和更安全的体内应用。为此，过去的方法人工血小板的功效非常有限，可能是因为一个主要的设计缺陷：血小板的自然止血作用需要损伤部位特异性血小板粘附和部位选择性血小板聚集协同作用，但过去的方法都没有有效地整合这两种能力我们的研究首次通过促进粘附和促进聚集的肽-脂质缀合物的异多价囊泡组装成功地整合了这两种关键的止血功能。我们的人工血小板结构同时表面装饰有用于剪切响应性 VWF 粘附的 VWF 结合肽 (VBP)、用于非剪切性胶原粘附的胶原蛋白结合肽 (CBP) 和用于增强纤维蛋白原模拟肽 (FMP) 聚集的纤维蛋白原模拟肽 (FMP)。将活性血小板附着到粘附的结构上。这种创新的人工血小板设计在体外和体内均表现出优异的止血活性，我们假设这种优异的止血功效是由于我们的构建体诱导的初级止血和次级止血机制的综合作用。我们的总体目标是通过三个具体目标来证实这一假设：在目标 1 中，我们将通过首先阐明剪切响应 VBP 与 VWF 相互作用的特定领域分子机制，建立纳米结构主要止血作用的机制模型，以及然后将这一见解与已经建立的知识相结合，即 CBP 与纤维状胶原的剪切独立螺旋相互作用以及 FMP 与血小板整合素的血小板活化选择性相互作用GPIIb-IIIa。在目标 2 中，我们将研究由于活性血小板膜的促凝能力，构建体介导的初次止血的直接增强是否也可以有效地增强构建体诱导的血小板聚集部位的二次止血（凝血）。因此，目标 1 和 2 将有助于协同证实我们假设的机制组成部分。因此，在目标 3 中，我们将确定与目前的临床止血剂 NovoSeven(R) 相比，这些构建体诱导的机制是否会在血小板减少小鼠的尾部横断出血模型中产生优异的止血效果。在体外建立构建体诱导的止血机制并在体内血小板减少模型中证明其优越的治疗效果，将导致未来对急性和慢性出血模型的详细评估。