Ultrasound enhanced platelet-like particle therapy for accelerated wound repair

超声增强血小板样粒子治疗加速伤口修复

• 批准号: 9387659
• 负责人: Ashley Carson Brown
• 金额: $ 18.49万
• 依托单位: NORTH CAROLINA STATE UNIVERSITY RALEIGH
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-17 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9387659
• 关键词: Actins; Adhesions; Affect; Affinity; Aging; Antibodies; Atomic Force Microscopy; Beds; Binding; Biological; Biological Assay; Blood Platelets; Blood flow; Cells; Chronic; Clot retraction; Coagulation Process; Contracts; Coupled; Cues; Cytoskeleton; Development; Diabetes Mellitus; Diabetic mouse; Ensure; Event; Extracellular Matrix; Fiber; Fibrin; Fibrinolysis; Fibroblasts; Health Care Costs; Healthcare; Hemorrhage; Hour; In Vitro; Injury; Kinetics; Mechanical Stimulation; Mechanics; Mediating; Microscopic; Movement; Nature; Obesity; Outcome; Pathway interactions; Patients; Polymers; Production; Public Health; Publishing; Research Project Grants; Risk; Scanning Electron Microscopy; Science; Signal Transduction; Specificity; Technology; Testing; Thrombus; Time; Tissues; Transforming Growth Factor beta; Ultrasonic Therapy; Ultrasonography; United States; Work; Wound Healing; aging population; cell behavior; chronic wound; design; effective therapy; healing; in vivo; innovation; migration; mouse model; non-healing wounds; particle; particle therapy; poly-N-isopropylacrylamide; prevent; response to injury; rho GTP-Binding Proteins; simulation; success; tissue phantom; wound; wound closure

PROJECT SUMMARY Chronic wounds affect over 6.5 million patients in the United States alone and result in health costs of more than $25 billion annually. Proper wound healing is the result of a large number of interrelated biological events, which are orchestrated temporally in response to the injury microenvironment. Immediately following injury, a clot is produced which involves the formation of a platelet plug embedded within a fibrin mesh. Platelets bind multiple fibrin fibers and overtime, platelets contract this fibrin mesh through actin driven mechanisms, which contributes to subsequent wound healing by stabilizing the fibrin network, further preventing blood loss, and restoring blood flow past the otherwise obstructive thrombi. Platelet-mediated clot retraction, significantly decreases clot size, alters clot organization, and increases clot stiffness. Increased matrix stiffness has been implicated in activation of important mechanically sensitive pathways involved in wound healing, including Rho GTPase signaling, actin cytoskeleton engagement and mechanical activation of transforming growth factor beta (TGFβ), which in turn promote fibroblast migration into the wound bed and extracellular matrix (ECM) production. Importantly, chronic non-healing wounds are characterized by significantly decreased activation of these cellular events. The long-term objective of this proposal is to utilize recently develop platelet-like- particles (PLPs) that mimic this clot retraction feature of native platelets to promote healing in chronic non- healing wounds. PLP-mediated clot retraction occurs via a collective Brownian wrench mechanism to collapse the local fibrin matrix, inducing both global and cell-scale deformations, which ultimately leads to global clot collapse. Particle deformability and high fibrin affinity are critical to achieving PLP-mediated clot retraction. However, the dynamics of PLP-mediated clot retraction are much slower (days) than that of natural platelets (hours). To obtain the benefits of clot retraction in wound repair, it is critical to increase the rate of PLP-mediated clot retraction, to more closely recapitulate the time scale of natural platelets. Therefore, the overarching objective of this proposal is to utilize ultrasound (US) stimulation of PLPs to increase the deformation of PLPs within the fibrin network in order to increase the rate of clot retraction in a finely controlled manner. Our central hypothesis is that 1) US stimulation will increase PLP deformations within the fibrin network, thereby increasing interactions with the fibrin network and the rate and degree of PLP-mediated clot retraction; and 2) enhanced clot retraction will increase clot stiffness, promote fibroblast migration into the wound bed through activation of Rho GTPase signaling, increase ECM production, and increase wound closure rates in vitro and in vivo. We will explore this hypothesis in the following aims: 1) Determine the optimal US sequence to maximize PLP deformation and increase kinetics of PLP-mediated clot retraction. 2) Characterize the effect of PLP-US therapy on wound healing outcomes in vitro and in vivo. The significance of our proposed work is the development of a simple and translatable technology enabling the effective treatment of non-healing wounds.

项目摘要 仅在美国，慢性伤口就会影响超过650万患者，导致健康成本超过 每年250亿美元。适当的伤口愈合是大量相互关联的生物事件的结果， 根据伤害微环境暂时精心策划。受伤后立即，一个凝块是 产生的，涉及形成纤维蛋白网中的血小板塞的形成。血小板结合多个 纤维蛋白纤维和加班，血小板通过肌动蛋白驱动机制收缩此纤维蛋白网状，该机制是 通过稳定纤维蛋白网络，进一步防止失血和 恢复血液经过原本阻塞性血栓。血小板介导的克隆回缩，显着 矩阵刚度的增加已经 在激活伤口愈合中涉及的重要机械敏感途径的激活中实施，包括Rho GTPase信号传导，肌动蛋白细胞骨架参与度和转化生长因子β的机械激活 （TGFβ），进而促进成纤维细胞迁移到伤口床和细胞外基质（ECM） 生产。重要的是，慢性非治疗伤口的特征是显着改善 这些细胞事件。该提议的长期目标是利用最近开发的类似血小板的样子 颗粒（PLP）模仿天然血小板的这种克隆缩回特征，以促进慢性非 - 治愈伤口。 PLP介导的克隆缩回是通过集体的布朗扳手机制倒塌的 局部纤维蛋白基质诱导全球和细胞尺度变形，最终导致全局克隆 坍塌。颗粒的变形性和高纤维蛋白亲和力对于实现PLP介导的克隆回收至关重要。 但是，PLP介导的克隆回收的动力学比天然血小板慢得多（天） （小时）。为了获得凝块缩回在伤口修复中的益处，提高PLP介导的速率至关重要 凝块回缩，以更紧密地概括天然血小板的时间尺度。因此，总体 该建议的目的是利用PLP的超声模拟（US）来增加PLP的变形 在纤维蛋白网络中，以以精细控制的方式提高凝块回收速率。我们的 中心假设是1）美国刺激将增加纤维蛋白网络内的PLP变形， 从而增加与纤维蛋白网络的相互作用以及PLP介导的克隆的速率和程度 撤回； 2）增强的凝块回缩将增加凝块刚度，促进成纤维细胞迁移到 通过激活Rho GTPase信号传导，增加ECM产生并增加伤口闭合，伤口床 体外和体内的比率。我们将在以下目的中探讨这一假设：1）确定最佳 美国序列以最大化PLP变形并增加PLP介导的克隆的动力学 撤回。 2）表征PLP-US治疗对体外伤口愈合结果的影响 体内。我们提出的工作的意义是开发简单且可翻译的技术 实现非治疗收益的有效治疗。