Bioengineering Design of Artificial Blood

在第一阶段，该BRP中的工作表明，MP4（PEG修饰的血红蛋白）克服了大多数 开发改良血红蛋白血液替代品的重大障碍，即 血管收缩MP4通过O2运输和维持的组合促进组织氧合 功能性毛细血管密度，尽管其违反直觉的性质，包括增加O2亲和力， 粘度和启动压力。MP4在使动物从严重， 不受控制的出血，并且在人类临床试验中已被证明是安全的。在目前 应用，我们将测试的假设，即MP4是一个有效的载体血红素配体O2，碳 一氧化碳（CO）和一氧化氮（NO），并将进行相关的生理研究，以 了解其作为血液替代品的有效性，并确定其使用的新临床应用。我们将 测试PEG-Hb制剂是血管扩张剂的假设，其与循环相互作用的方式不 与Hb清除NO有关。我们认为MP4的特性部分是由于亚硝酸盐的增加 还原酶活性和NO转运。我们将开发一个程序，使用MP4提供CO和利用 CO-MP4即使在高温下也非常稳定，这使得它在现场使用中具有价值， 外伤项目1有一个GMP设施，提供一致的质量和性能的MP4。经济社会发展呈现 并生产新的PEG-Hb化合物，目标是优化浓度而不增加胶体 渗透压和增加O2输送能力，以增加MP4的适用性，以更广泛的 临床应用范围。将通过生化分析、数学建模和 大鼠全身实验，包括对心肌梗死的影响。项目2将检查PEG-Hbs的 对糖萼完整性的影响，PEG-Hbs的存在如何影响活性氧（ROS），并将 研究PEG-Hb和增强的血浆粘度的联合作用。MP4将被用作交付 在缺血和出血期间，CO的载体提供细胞保护。微循环研究将使用 清醒的仓鼠窗口室模型，直接测量O2和NO水平，流量和 血管直径和功能性毛细血管密度。这项研究结合了生理分析， 输血，工程运输过程和机械转导的基础知识， 两个实验室合作超过12年。有效的血液替代品将大大 提高民用和军事环境中输血的安全性和有效性， 输血医学将开发一种新型血液替代品的应用， 缺血的根本不同的治疗，基于微血管流动的增强，心脏和 肾功能、内皮修复和血红素配体（O2、NO和CO）的递送。

In the first period, work in this BRP demonstrated that MP4 (PEG-modified hemoglobin) overcomes the most significant hurdle to the development of modified hemoglobin-based blood substitutes, namely vasoconstriction. MP4 promotes tissue oxygenation through a combination of O2 transport and maintenance of functional capillary density in spite of its counterintuitive properties, including increased O2 affinity, viscosity and oncotic pressure. MP4 is superior to blood in its ability to resuscitate animals from severe, uncontrolled hemorrhage, and it has been shown to be safe in human clinical trials. In this present application we will test the hypothesis that MP4 is an effective carrier of the heme ligands O2, carbon monoxide (CO)and nitric oxide (NO), and will carry out the related physiological studies in order to understand its effectiveness as a blood substitute and identify new clinical applications for its use. We will test the hypothesis that PEG-Hb formulations are vasodilators which interact with the circulation in ways not related to NO scavenging by Hb. We propose that MP4's properties are in part due to an increased nitrite reductase activity and NO transport. We will develop a procedure for using MP4 to deliver CO and exploit that CO-MP4 is exceptionally stable, even at elevated temperatures, making it valuable in field use for trauma. Project 1 has a GMP facility that provides MP4 of consistent quality and properties. It will develop and produce new PEG-Hb compounds with goals to optimize concentration without increasing colloid osmotic pressure and augment O2 delivery capacity so as to increase the applicability of MP4 to a wider range of clinical uses. Properties will be screened via biochemical analysis, mathematical modeling, and systemic experiments in rats including the effect on myocardial infarction. Project 2 will examine PEG-Hbs' effects on the glycocalyx integrity, how PEG-Hbs' presence influences reactive O2 species (ROS), and will investigate the combined effect of PEG-Hb and enhanced plasma viscosity. MP4 will be used as a delivery vehicle for CO to provide cellular protection during ischemia & hemorrhage. Microcirculation studies will use the awake hamster window chamber model, with direct measurements of O2 and NO levels, flow and diameter in blood vessels and functional capillary density. This research combines physiological analysis of transfusion, fundamentals of engineering transport processes and mechanotransduction with the expertise of two laboratories with more than 12 years of collaboration. Effective blood substitutes will significantly increase the safety and efficacy of blood transfusions in civilian and military settings, streamline and simplify transfusion medicine. Applications for a new type of blood substitute will be developed, one that provides a fundamentally different treatment of ischemia, based on enhancement of microvascular flow, cardiac and renal functions, repair of the endothelium and delivery of heme ligands (O2, NO and CO).