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.

项目概要 仅在美国，慢性伤口就影响了超过 650 万名患者，造成的健康成本超过 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， 是为了响应损伤微环境而临时编排的。受伤后立即出现凝块 其产生涉及嵌入纤维蛋白网内的血小板塞的形成。血小板结合多个 纤维蛋白纤维和超时，血小板通过肌动蛋白驱动机制收缩该纤维蛋白网，这 通过稳定纤维蛋白网络，进一步防止失血，有助于随后的伤口愈合，以及 恢复通过阻塞性血栓的血流。血小板介导的血块收缩，显着 减少血块尺寸，改变血块组织，并增加血块硬度。基体刚度增加 参与伤口愈合中重要机械敏感通路的激活，包括 Rho GTPase 信号传导、肌动蛋白细胞骨架接合和转化生长因子 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，慢性不愈合伤口的特点是激活显着减少。 这些细胞事件。该提案的长期目标是利用最近开发的血小板样- 颗粒（PLP）模仿天然血小板的凝块回缩特征，以促进慢性非 愈合伤口。 PLP 介导的凝块收缩通过集体布朗扳手机制发生塌陷 局部纤维蛋白基质，引起全局和细胞尺度的变形，最终导致全局凝块 坍塌。颗粒变形性和高纤维蛋白亲和力对于实现 PLP 介导的血栓回缩至关重要。 然而，PLP 介导的凝块收缩动力学比天然血小板慢得多（数天） （小时）。为了在伤口修复中获得凝块回缩的好处，提高 PLP 介导的凝块回缩率至关重要 凝块回缩，以更接近地再现天然血小板的时间尺度。因此，总体 该提案的目的是利用超声 (US) 刺激 PLP 来增加 PLP 的变形 在纤维蛋白网络内，以精细控制的方式增加凝块回缩率。我们的 中心假设是 1) US 刺激会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 介导的凝块的速率和程度 撤回； 2) 增强的凝块回缩会增加凝块硬度，促进成纤维细胞迁移到 通过激活 Rho GTPase 信号传导，增加 ECM 产生并促进伤口闭合 体外和体内的速率。我们将通过以下目标探索这一假设：1）确定最优 US 序列可最大化 PLP 变形并增加 PLP 介导的凝块动力学 撤回。 2) 表征 PLP-US 疗法对体外伤口愈合结果的影响 体内。我们提出的工作的意义在于开发一种简单且可转化的技术 能够有效治疗不愈合的伤口。