development of model erythrocyte and creation of artificial erythrocyte by using an electro-hydrodynamic spraying operating in cone-jet mode

为了开发模型红细胞和制造人工红细胞，我们制造了海藻酸凝胶的微小、柔软和有弹性的颗粒，其直径在1到10微米之间。为此，我们开发了一种双喷法，将海藻酸的稀溶液通过加压喷涂或电液喷涂的方法制成微小的液滴，然后这些液滴与氯化钙液滴直接接触发生化学反应。这种球状的、柔软的、有弹性的颗粒，其大小比人的红细胞还小，因此可以顺利地通过人的毛细血管。为了评估聚合物凝胶颗粒的弹性，我们观察了其在水中的表面结构，并利用原子力显微镜（AFM）计算了其局部杨氏模量值。结果表明，其表面由直径在100 ~ 2 ~ 00 nm之间的微小卵石状颗粒聚集而成，其局部杨氏模量为2.6 ~ 3.7 MPa，远高于人红细胞。由凝胶颗粒的整体变形得到的总杨氏模量约为0.5 mpa。我们试图制造一种微型的凝胶颗粒，里面有一个气泡。这种粒子作为超声造影剂是非常有用的。我们已经成功地制造出这样的粒子，它的内部结构是一层聚合物凝胶薄膜包裹在一个微米大小的气泡上。我们尝试开发含有磁性流体的海藻酸凝胶颗粒作为一种新的给药系统。三种不同的凝胶颗粒生产方法，即碰撞三流体喷雾法、EHD喷雾法和双重喷雾法。结果表明，三种方法均可制得均匀分散、平均粒径小于10 μ m且含有磁流体的海藻酸凝胶颗粒。特别是用EHD喷射法制备了直径为几微米的球形凝胶颗粒。少

In order to develop model erythrocyte (red blood cell) and to create artificial erythrocyte, we have created tiny, soft and elastic particles of alginic acid gel, of which diameter ranges from about 1 to 10 micrometers. lb do so, we have developed a double spraying method, in which a dilute solution of alginic acid has been made into tiny droplet by a pressurized spraying or an electro-hydrodynamic spraying method, and then these droplets have been chemically reacted with a droplet of calcium chloride by direct contact. This spherical shaped, soft and elastic particle has a size smaller than human erythrocyte, and so can pass smoothly through human blood capillaries.1.In order to evaluate the elasticity of the polymeric gel particle, we have observed its surface structure in water and have evaluated the local value of Young's modulus by using an atomic force microscope (AFM). As a result, it is observed that its surface is composed of aggregated tiny pebble-like particles from 100 to 2 … More 00 nm in diameter, and that its local Young's modulus is 2.6 to 3.7 MPa, which is much higher than that of human erythrocyte. The overall Young's modulus which have been obtained from the overall deformation of the gel particle is about 0.O5MPa.2.We have tried to create a micro-sized gel particle containing a bubble inside it. This type of particle will be very useful as an ultrasound contrast agent. We have succeeded in creating such particles, which have an inner structure that a thin membrane of polymeric gel coat a single micron-sized bubble.3.We have tried to develop alginic acid gel particles containing magnetic fluid as a new drug delivery system (DDS). Three different kinds of gel particle production methods, that is, an impinging 3-fluid spray method, an EHD spray method and a double spray method. As a result, uniformly dispersed aliginic acid gel particles less than 10 μ m in mean diameter, which are containing magnetic fluid, were produced by all the methods. Especially, spherical gel particles of several microns in diameter were produced by the EHD spraying method. Less