PDF(Pubmed)
Abstract：
Haemorrhagic shock is a leading cause of death worldwide. Blood transfusions can be used to treat patients suffering severe blood loss but donated red blood cells (RBCs) have several limitations that limit their availability and use. To solve the problems associated with donated RBCs, several acellular haemoglobin-based oxygen carriers (HBOCs) have been developed to restore the most important function of blood: oxygen transport. One promising HBOC is the naturally extracellular haemoglobin (i.e. erythrocruorin) of Lumbricus terrestris (LtEc). The goal of this study was to maximise the portability of LtEc by lyophilising it and then testing its stability at elevated temperatures. To prevent oxidation, several cryoprotectants were screened to determine the optimum formulation for lyophilisation that could minimise oxidation of the haem iron and maximise recovery. Furthermore, samples were also deoxygenated prior to storage to decrease auto-oxidation, while resuspension in a solution containing ascorbic acid was shown to partially reduce LtEc that had oxidised during storage (e.g. from 42% Fe3+ to 11% Fe3+). Analysis of the oxygen equilibria and size of the resuspended LtEc showed that the lyophilisation, storage, and resuspension processes did not affect the oxygen transport properties or the structure of the LtEc, even after 6 months of storage at 40 °C. Altogether, these efforts have yielded a shelf-stable LtEc powder that can be stored for long periods at high temperatures, but future animal studies will be necessary to prove that the resuspended product is a safe and effective oxygen transporter in vivo.
摘要：
出血性休克是世界范围内死亡的主要原因。输血可用于治疗严重失血的患者，但捐献的红细胞（RBC）有一些限制，限制了其可用性和使用。为了解决与捐赠的红细胞相关的问题，已经开发了几种基于血红蛋白的无细胞氧载体(HBOC)来恢复血液最重要的功能:氧转运。一种有前途的HBOC是天麻（LtEc）的天然细胞外血红蛋白（即赤霉素）。这项研究的目的是通过冻干LtEc，然后在高温下测试其稳定性，从而最大程度地提高LtEc的便携性。为了防止氧化，筛选了几种冷冻保护剂，以确定冻干的最佳配方，该配方可以最大程度地减少血红素铁的氧化并最大程度地提高回收率。此外，样品在储存前也脱氧以减少自动氧化，而在含有抗坏血酸的溶液中的再悬浮显示部分还原在储存期间已氧化的LtEc(例如从42%Fe3+至11%Fe3+)。对重新悬浮的LtEc的氧平衡和大小的分析表明，storage,和再悬浮过程不影响氧传输性质或LtEc的结构，甚至在40℃下储存6个月后。总之,这些努力产生了一种货架稳定的LtEc粉末，可以在高温下长时间储存，但是，未来的动物研究将有必要证明重新悬浮的产品是体内安全有效的氧转运蛋白。
