Development and utilization of model erythrocyte and primary study of artifical erythrocyte

我们开发了一种天然聚合物凝胶的微小颗粒作为人体红细胞（RBC）的模型，并在水和生理盐溶液中制作了这些颗粒的高浓度悬浮液作为人体血液的现实模型。模型红细胞（MRBC）由褐藻酸钙凝胶制成，呈球形，非常柔软和有弹性。它的平均直径约为10 μm，与人类红细胞非常相似，尽管它的形状不是所谓的双凹形。结果表明，在37℃温度下，具有45%红细胞比容（体积浓度）的人血与具有45%红细胞比容（体积浓度）的MRBC模型血在15℃温度下，剪切速率dγ/dt与剪切应力τ之间的关系在Casson图上非常吻合，即dγ/dt与√τ的平方根。在几种不同浓度和温度的情况下，由上图计算的黏度系数显示出明显的剪切变薄，与人体血液的黏度系数非常吻合。利用倒置显微镜、锥板粘度计和高速摄像机组成的流变仪系统，观察各MRBC在不同剪切速率范围内的运动。因此，在剪切速率低于约100/sec的低区域，MRBC会形成聚集体，这与真实RBC在剪切速率低于约100/sec时形成rouleaux的现象非常相似。使用显微操作器对MRBC的弹性进行可视化和测量。当ν= 0.5和0时，MRBC的总杨氏模量为0.075MPa。ν= 0的lOMPa，其中ν是泊松比。这些数值与明胶的数值几乎相同。

We have developed a tiny particle of natural polymeric gel as a model of human red blood cell (RBC), and have made a high concentration suspension of these particles in water and physiological salt solution as a realistic model of human blood. The model RBC (MRBC) was made of alginic acid calcium gel, and was of a spherical shape and very soft and elastic. Its average diameter was about 10 μm, which was very similar to human RBC, although its shape was not so-called biconcave. It was shown that the relationships between shear rate dγ/dt and shear stress τ for the human blood with 45% hematocrit (volumetric concentration) of the RBC at the temperature of 37℃ and for the model blood with 45% hematocrit of the MRBC at the temperature of 15℃ agreed with each other very well on the Casson's diagram, i.e. the square root of dγ/dt versus √τ. The coefficients of viscosity calculated from the above diagram in the case of several different concentrations and temperatures showed clear shear thinning, and agreed very well with that of the human blood. The motion of each MRBC in the various range of shear rate was observed using a rheoscope system consisted of an inverted microscope, a cone-plate viscometer, and a high-speed video camera. As a result, in the region of low shear rate less than about 100/sec, MRBC was seen to form aggregates, which was a very similar phenomenon as real RBC forms a rouleaux when shear rate is lower than about 100/sec. The elasticity of the MRBC was also visualized and measured using a micromanipulator. The relationship between the deformation of the spherical MRBC and the force applied on it obeyed the Hertz's contact theory, and the total Young's modulus of the MRBC was 0.075MPa for ν= 0.5 and 0.lOMPa for ν= O, where ν is the Poisson's ratio. These numerical values were almost same as those of gelatin.