Biomechanical Response of Platelets to Superhydrophobic Surface in Mechanical Heart Valves and Other Blood-Contacting Medical Devices

机械心脏瓣膜和其他血液接触医疗器械中血小板对超疏水表面的生物力学反应

• 批准号: 9231050
• 负责人: David Bark
• 金额: $ 3.44万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-10 至 2018-09-09
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9231050
• 关键词: Biomechanical; Response; Platelets; Superhydrophobic; Surface

 DESCRIPTION (provided by applicant): As the leading cause of death in industrialized nations and as an increasing problem in developing countries, the treatment for cardiovascular disease can impact a very large population. Interventions common to cardiovascular disease involve blood-contacting medical devices that are at-risk for thrombosis (blood clots). Since thrombosis on these devices can lead to ischemia in vital organs and possible death, it is critical to mitigate the risk. Therefore, patients are commonly placed on antiplatelet and anticoagulant drug regimens. Unfortunately, these therapies can create additional bleeding risks and do not completely prevent the risk for thrombosis. Therefore, many material scientists have been investigating alternative non-thrombogenic materials to those currently used in order to minimize the need for drug therapeutics. Superhydrophobic surfaces are one of the surface treatments that has exhibited excellent results in static conditions at mitigating processes involved in thrombus growth. However, the response of blood to superhydrophobic materials remains ill-defined in a flow environment more relevant to cardiovascular devices. This environment consists of spatially changing shear, which has been shown to have a very large impact on platelet aggregation. Therefore the ultimate goal of the proposed work is to assess superhydrophobic materials in this environment to determine if these materials should be investigated further for devices such as prosthetic heart valves or stents. For this investigation we have 2 aims: Specific Aim 1) Prepare and characterize superhydrophobic surfaces in microfluidic channels involving large changes in shear rate. A series of surface treatments of varying texture and surface energy will be characterized by evaluating contact angles, surface structure, and flow over the surfaces. These treatments will be applied to microfluidic channels involving flow constrictions to assess material durability in a shear environment and to determine if air pockets exist along the superhydrophobic surface, which is common to surfaces with texture and low surface energy. Specific Aim 2) Analyze the impact of spatially varying hemodynamic shear forces on blood cell dynamics and the role for chemical activators using a novel Lab-on-Chip approach. We will be testing the ability for superhydrophobic surfaces to prevent platelet aggregation in a shear gradient. To test this, a series of microfluidic devices wil be developed for high throughput evaluation of material thrombogencity in a flow environment pertinent to medical devices. These tools will be combined with imaging techniques to evaluate different shear environments to guide future cardiovascular device designs and to determine the role for soluble agonist platelet activation in the aggregation process for superhydrophobic surfaces.

 描述（由适用提供）：作为工业化国家死亡的主要原因，作为发展中国家的越来越多的问题，对心血管疾病的治疗可能会影响很大的人口。心血管疾病常见的干预措施涉及血栓形成危险的血液接触医疗设备（血凝块）。由于这些设备上的血栓形成会导致重要器官缺血和死亡，因此至关重要 减轻风险。因此，患者通常将患者放在抗血小板和抗凝药物方案上。不幸的是，这些疗法会产生额外的出血风险，并不能完全阻止血栓形成的风险。因此，许多物质科学家一直在调查目前用于最大程度地减少药物治疗需求的替代性非养育材料。超疏水表面是在静态条件下在减轻参与血栓生长的过程中暴露出极好结果的表面处理之一。但是，血液对超疏水材料的反应在与心血管设备更相关的流动环境中仍然不明显。该环境由空间变化的剪切组成，已显示出对血小板聚集的影响很大。因此，拟议工作的最终目标是评估在这种环境中的超疏水材料，以确定是否应该进一步研究这些材料，例如假肢心脏瓣膜或支架。对于这项投资，我们有2个目标：特定目标1）在微流体通道中准备和表征超疏水表面，涉及剪切速率发生巨大变化。一系列对各种质地和表面能量的表面处理将以评估表面上的接触角，表面结构和流动来进行特征。这些处理将应用于涉及流动收缩的微流体通道，以评估剪切环境中的材料耐用性，并确定沿超疏水表面的空气口袋是否存在，这对于具有质地和低表面能的表面通常。具体目的2）分析使用新型实验室芯片方法分析空间变化的血液动力学剪切力对化学激活剂的作用。我们将测试超疏水表面防止剪切梯度中血小板聚集的能力。为了测试这一点，将开发一系列的微流体设备，以高吞吐量评估与医疗设备有关的流动环境中。这些工具将与成像技术结合使用，以评估不同的剪切环境，以指导未来的心血管装置设计，并确定固体激动剂血小板激活在超疏水表面的聚合过程中的作用。