Bioengineering Design of Artificial Blood

在第一阶段，本BRP的工作表明，MP4(聚乙二醇化血红蛋白)克服了大多数 发展改良的基于血红蛋白的血液替代品的重大障碍，即 血管收缩。MP4通过结合氧气运输和维持来促进组织氧合 功能性毛细血管密度，尽管它有违反直觉的特性，包括增加氧气亲和力， 粘度和肿胀压力。MP4优于血液，因为它能够使动物从严重的， 失控出血，在人类临床试验中已被证明是安全的。在此时此刻 应用我们将检验MP4是血红素配体O2、碳的有效载体的假设 一氧化碳(CO)和一氧化氮(NO)，并将进行相关的生理研究，以便 了解其作为血液替代品的有效性，并确定其新的临床应用。我们会 测试这一假设，即聚乙二醇-血红蛋白制剂是血管扩张剂，它以不同的方式与循环相互作用 与HB清除NO有关。我们认为，MP4的S性质部分是由于增加了亚硝酸盐 还原酶活性和NO转运。我们将开发一个使用MP4传递CO和利用的程序 这种CO-MP4非常稳定，即使在高温下也是如此，这使得它在现场使用时具有很高的价值 精神创伤。项目1有一个GMP设施，提供质量和属性一致的MP4。它会发展成 并生产新的聚乙二醇-血红蛋白化合物，目标是在不增加胶体的情况下优化浓度 渗透压和增加氧气输送能力，以增加MP4的适用性 临床应用范围广泛。将通过生化分析、数学建模和 大鼠系统实验包括对心肌梗死的影响。项目2将研究聚乙二醇HBS 对糖萼完整性的影响，聚乙二醇HBS的存在如何影响活性氧物种(ROS)，以及将 探讨聚乙二醇化血红蛋白与提高血浆粘度的联合作用。将使用MP4作为递送 CO在缺血和出血期间提供细胞保护的载体。微循环研究将使用 清醒仓鼠窗室模型，直接测量O2和NO水平，流量和 血管内径和功能性毛细血管密度。这项研究结合了生理学分析 输血，工程运输过程的基本原理和机械转导 两个合作超过12年的实验室。有效的血液替代品将显著 提高民用和军用输血的安全性和有效性，精简和简化 输血医学。将开发一种新型血液替代品的应用，这种替代品提供一种 完全不同的缺血治疗，基于微血管血流的增强，心脏和 肾功能、内皮修复和血红素配基(O2、NO和CO)的传递。

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).