Hyakutake Toru, Kishimoto Takumi
Faculty of Engineering, Yokohama National University, 79-5, Hodogaya, Yokohama, 240-8501, Japan.
Graduate School of Engineering, Yokohama National University, 79-5, Hodogaya, Yokohama, 240-8501, Japan.
J Artif Organs. 2017 Dec;20(4):341-349. doi: 10.1007/s10047-017-0974-5. Epub 2017 Jul 28.
The small size of hemoglobin-based oxygen carriers (HBOCs) may expand the realm of new treatment possibilities for various circulatory diseases. The parametric evaluation of HBOC performance for oxygen transport within tissue is essential for effectively characterizing its performance for each circulatory disease assessed. Thus, the overarching objective of this present study was to numerically investigate the reaction-diffusion phenomenon of oxygenated HBOCs and oxygen on tissues through microvessels. We considered dissociation rate coefficients, oxygen affinity, and diffusion coefficients due to Brownian motion as the biophysical parameters for estimating HBOC performance for oxygen transport. A two-dimensional computational domain, including vessel and tissue regions, was, therefore, accordingly assumed. It was observed that HBOC flows in a microvessel with a diameter of 25 μm and a length of 1 mm, and that the dissociated oxygen diffuses to the tissue region. The results indicated that oxyhemoglobin saturation and partial oxygen tension in a downstream region changed according to each biophysical parameter of HBOC. Moreover, the change in oxygen consumption rate in the tissue region had considerable influence on the oxyhemoglobin saturation level within the vessel. Comparison between simulation results and existing in vitro experimental data of actual HBOCs and RBC showed qualitatively good agreement. These results provide important information for the effective design of robust HBOCs in future.
基于血红蛋白的氧载体（HBOCs）的小尺寸可能会拓展各种循环系统疾病新治疗可能性的领域。对HBOC在组织内进行氧运输的性能进行参数评估，对于有效表征其在每种评估的循环系统疾病中的性能至关重要。因此，本研究的总体目标是通过微血管对氧合HBOCs与组织上的氧之间的反应扩散现象进行数值研究。我们将解离速率系数、氧亲和力以及由于布朗运动产生的扩散系数视为估算HBOC氧运输性能的生物物理参数。因此，相应地假定了一个包括血管和组织区域的二维计算域。观察到HBOC在直径为25μm、长度为1mm的微血管中流动，并且解离的氧扩散到组织区域。结果表明，下游区域的氧合血红蛋白饱和度和氧分压根据HBOC的每个生物物理参数而变化。此外，组织区域氧消耗率的变化对血管内的氧合血红蛋白饱和度水平有相当大的影响。模拟结果与实际HBOCs和红细胞的现有体外实验数据之间的比较在定性上显示出良好的一致性。这些结果为未来有效设计强大的HBOCs提供了重要信息。
