Development of a Scaffold with Optimal Structure and Application to a Hybrid Artificial Liver for Chronic Liver Failure Patients

1.椭圆形中空纤维作为一种新型的类器官形成支架的研制我们利用具有组织样结构的肝细胞类器官，研制了一种杂交型人工肝。类有机物培养的一个主要问题是类有机物核心的氧气消耗。这种有机物的存活厚度受到氧气供应的限制，因为氧气是通过扩散从有机物表面输送的。类有机物厚度的最佳范围约为100-150μm，因此我们正在尝试开发一种支架来将类有机物的厚度控制在合适的值内。我们用一种简单的退火法设计了小直径小于150μm的椭圆形HF。所有肝细胞均供氧，并在中空纤维内形成无死亡细胞层的类器官。在培养过程中，椭圆形中空纤维中的类肝细胞器官保持了比原始中空纤维高一倍的氨氮去除活性。椭圆形中空纤维中类有机物的白蛋白分泌活性也保持了至少一个月，与活体肝脏的白蛋白分泌活性相同。这些结果表明，利用椭圆形中空纤维进行类器官培养是开发混合型人工肝的一种有前途的技术。2.椭圆中空纤维杂交型人工肝模块的研制我们设计了一种椭圆形中空纤维杂交型人工肝模块。该模块的总体积为4.3 cm^3，固定的中空纤维数量为336个。肝细胞固定在中空纤维腔内。随后，在灌流培养中对该模块进行评估。这个新的模块在至少一个月的培养中保持了高水平的肝脏特异性功能。综上所述，利用椭圆形氢氟酸进行的有机培养和组件似乎是开发混合型人工肝的一种很有前途的技术。

1.Development of an elliptic hollow fiber as a novel scaffold for organoid formationWe have been developed a hybrid artificial liver by using a hepatocyte organoid, which has a tissue-like structure. One major problem in organoid culture is the depletion of oxygen at the core of an organoid. The survival thickness of such an organoid is limited by oxygen supply, because oxygen is transported by diffusion from the surface of an organoid. The optimum range of the thickness of an organoid is about 100 - 150μm. So we are trying to develop a scaffold to control the thickness of the organoid within suitable value. We designed an elliptic HF having less than 150μm minor diameter by using a simple annealing method. All hepatocytes were supplied with oxygen and formed an organoid without a dead cell layer in this hollow fiber. A hepatocyte organoid in an elliptic hollow fiber maintained ammonia removal activity twice as high as in the original hollow fiber for at least one month during culture. Albumin secretion activity of an organoid in an elliptic hollow fiber was also maintained for at least one month and was the same level as that of liver in a living body. These results indicate that an organoid culture by using an elliptic hollow fiber seems to be a promising technique to develop a hybrid artificial liver.2.Development of a hybrid artificial liver module with elliptic hollow fibersWe designed a hybrid artificial liver module with elliptic hollow fibers. Total volume of this module was 4.3 cm^3, and number of hollow fiber immobilized in the module was 336. Hepatocytes were immobilized in lumen of hollow fibers. Following this, the module was evaluated in perfusion culture. This novel module was maintained liver specific functions at high level for at least one month of culture. In conclusion, these organoid culture and module by using an elliptic HF seems to be a promising technique to develop a hybrid artificial liver.