Novel Biomimetic Coating for Circulatory Devices

描述（由申请人提供）：异物表面激活凝血和激活炎症反应是限制循环支持器械和其他直接接触血液的器械（如心脏瓣膜、膜式氧合器插管和心室辅助器械）长期使用的主要问题。大量研究表明，表面改性可显著降低异物表面的血栓形成特性。一种非常有前途的新技术是由Marchant等人提出的仿生表面活性剂聚合物涂层。该涂层在石墨基底上表现出优异的非血栓形成性能，但仅在低剪切应力环境下进行了研究。在第一阶段，我们证明了这种新型涂层用于体外血泵的可行性，这为涂层提供了高剪切环境。我们将表面活性剂聚合物涂层应用于血泵材料的样品基底上，其中一些材料涂覆有类金刚石膜。为了评估我们的涂层在血泵操作条件下的稳定性，我们在旋转圆盘装置中使测试样品经受高剪切应力。发现该涂层即使在暴露于530达因/cm 2的剪切应力4小时后仍保持其表面性质，从而证明了表面活性剂聚合物涂层用于血泵和其他循环装置的可行性。第二阶段研究的目的是涂覆现有的商业血泵，并通过使用人血的体外研究和动物体内研究来验证涂层的生物相容性。在第二阶段之后，我们将准备开始人体临床试验，并完成商业化过程。

DESCRIPTION (provided by applicant): The activation of blood coagulation and the activation of inflammatory response by foreign surfaces are leading issues limiting long-term use of circulatory support devices and other devices having direct contact with blood, such as heart valves, cannulae for membrane oxygenators, and ventricular assist devices. Numerous studies indicate that thrombogenic properties of a foreign surface can be significantly reduced by surface modifications. One very promising new technology is a biomimetic surfactant polymer coating, proposed by Marchant et. al. This coating had demonstrated excellent non-thrombogenic properties on graphite substrates but had been only investigated under low shear stress environments. In Phase I, we demonstrated the feasibility of this novel coating for use in an extracorporeal blood pump, which presents a high-shear environment for coatings. We applied the surfactant polymer coating to sample substrates of materials used in blood pumps, some coated with diamond-like carbon film. To evaluate the stability of our coating under the operating conditions of blood pumps, we subjected test samples to high shear stress in a rotating disk apparatus. The coating was found to maintain its surface properties even after four hours of exposure to a shear stress of 530 dynes/cm2, thus demonstrating the feasibility of surfactant polymer coatings for blood pumps and other circulatory devices. The aim of the Phase II research is to coat existing commercial blood pumps and to validate the biocompatiblity of the coatings through in-vitro studies using human blood and through in-vivo studies in animals. After Phase II, we will be prepared to start human clinical trials and to finish the commercialization process.