新型糖酐交联血红蛋白降低氧化损伤的机制及其在急性大失血救治中的使用策略研究

HBOCs, the representative products of red blood cell (RBC) substitute, have the advantages of sufficient source, unnecessary cross match pre-transfusion, and no risk of pathogens infection. HBOCs have the potential to replace blood for acute massive hemorrhage and alleviate the shortage of blood. However, the autoxidation of HBOCs aggravates the secondary oxidative injury in the cure of acute massive hemorrhage. The technology of autoxidation regulation is thus the difficulty of HBOCs research. By combination of the sodium periodate oxidation of dextran and protection of Cys-93(β), we prepare a new dextran-hemoglobin conjugate (Dex-bHb) with low autoxidation and effective oxygen delivery, which has been demonstrated to efficiently protect organs in the treatment of acute massive hemorrhage. Via analyzing dextran, we hypothesize that the Dex-bHb with low autoxidation could alleviate the oxidative injury, which may due to the stable conformation. Therefore, we plan to study the effects of Dex-bHb on oxidative injury via cellular experiments. And we analyze the conformation of Dex-bHb to verify the mechanism of Dex-bHb with low autoxidation. The determination of the relationship among molecular properties, conformation of HBOCs and autoxidation will provide theoretical support for the autoxidation regulation in HBOCs research. Then the optimized strategy of Dex-bHb in treatment of acute massive hemorrhage wil be studied via animal experiment，which could improve the effect of Dex-bHb on oxidative injury.

血红蛋白氧载体（HBOCs）类红细胞代用品具有来源充足、无需配型、无病原体传播等优势，可弥补天然血液的不足，满足大失血的急救需求。但HBOCs的易氧化性会加重急救后继发的组织氧化损伤，其控制技术是研发的难点。项目组通过高碘酸钠氧化结合巯基保护技术，制备出了具有低自氧化速率及高携-放氧功能的新型糖酐交联血红蛋白（Dex-bHb），证实在大失血急救中有脏器保护作用。经过对糖酐分子特性的分析，项目组提出“新型交联工艺可能通过稳定分子构象降低Dex-bHb的自氧化速率，减轻组织氧化损伤”。因此，本课题拟在细胞水平验证Dex-bHb降低氧化损伤的能力；并进一步阐明Dex-bHb具有低自氧化速率的机制，明确“改构分子特性-HBOCs构象-自氧化速率”的相关性，为HBOCs研发中自氧化的控制提供理论支持；最后，通过动物实验明确Dex-bHb的最佳使用策略，更好地发挥其在大失血急救中降低氧化损伤的作用。

本项目致力于解决血红蛋白氧载体易加重大失血急救后继发的氧化应激损伤的瓶颈问题。依托于课题组研制的具有低自氧化速率的糖酐交联血红蛋白（Dex-bHb），验证了其在大失血急救中降低组织氧化损伤的能力；通过分子构象研究阐明Dex-bHb降低氧化损伤的机制，明确“改构分子特性-HBOCs构象-自氧化速率”的相关性，为HBOCs研发中氧化损伤的控制提供理论支持；进一步通过对动物大失血休克模型的复苏研究，明确Dex-bHb的最佳使用策略，更好地发挥其降低组织氧化损伤的作用，推动HBOCs在急性大失血救治中的应用。