Novel Biomimetic Coating for Circulatory Devices

说明(申请人提供)：血液凝固的激活和异物表面的炎症反应是限制循环支持装置和其他与血液直接接触的装置的长期使用的主要问题，例如心脏瓣膜、膜氧合器的套管和心室辅助装置。大量研究表明，通过表面修饰可以显著降低异物表面的血栓形成特性。Marchant等人提出的一种非常有前景的新技术是仿生表面活性剂聚合物涂层。艾尔这种涂层在石墨衬底上表现出了优异的非血栓形成性能，但仅在低剪应力环境下进行了研究。在第一阶段，我们论证了这种新型涂层用于体外血泵的可行性，这为涂层提供了一个高剪切环境。我们将表面活性聚合物涂层应用于血泵材料的基材样品，其中一些材料表面涂有类金刚石碳膜。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对测试样品进行了高剪切应力测试。发现该涂层即使在530dynes/cm2的剪切应力下暴露4小时后仍保持其表面性能，从而证明了表面活性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对现有的商用血泵进行涂层，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，并完成商业化进程。

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.