Development of a Hybrid Artificial Liver for Treatment of Acute and Chronic Liver Failure Patients

1.用于临床试验的混合型人工肝的研制我们研制了一种混合型人工肝（hybrid artificial liver，HAL），它由含有200 g原代猪肝细胞的多毛细管聚氨酯泡沫填充床肝细胞培养模块和体外循环管路组成。几乎所有的肝细胞在模块中形成球状体，他们保持至少2周的肝脏特异性功能。作为临床前研究，将HAL应用于约25 kg的热缺血性肝衰竭猪。在临床前研究中，我们证实了其有效性，如抑制血氨升高，维持血糖，稳定生命体征和尿排泄，延长生存时间。HAL除了支持各种肝功能外，还能有效稳定身体的一般状况。这些结果提示HAL有很强的可能用于治疗急性肝功能衰竭患者.利用肝细胞类器官培养开发新型混合型人工肝模块作为一种新型人工肝模块，我们开发了一种具有肝小叶状结构的中空纤维模块，其中代表血管的中空纤维通过间隔物以150 μm内的微规则排列排列。在纤维外间隙中接种的肝细胞通过加载适当的离心力在莲藕类器官中形成。与先前的中空纤维模块相比，新型模块实现了约4.0 × 10^7个细胞/ cm^3模块的高细胞密度，并维持了数月的更好的肝功能。这些结果表明，这种新型模块将成为一种新的HAL，用于治疗慢性和急性肝功能衰竭患者，并用于肝移植的长期桥梁使用。现在我们正在研究模块的优化和扩展。

1. Development of a hybrid artificial liver for clinical trialWe developed a hybrid artificial liver (HAL) which consists of a hepatocyte culture module with multi-capillary polyurethane foam packed-bed containing 200 g primary porcine hepatocytes and an extracorporeal circulation line. Almost all of the hepatocytes in the module formed spheroids, and they maintained the liver specific functions for at least 2 weeks. As preclinical study, the HAL was applied to about 25 kg warm ischemic liver failure pigs. In the preclinical study, we demonstrated its effectiveness such functions as suppression of increase of blood ammonia, maintenance of blood glucose, stabilization of vital sign and urinary excretion, extension of survival time. The HAL was effective to stabilize the general conditions of the body in addition to supporting various liver functions. These results suggest that the HAL has a strong possibility to be used in treating acute liver failure patients.2. Development of novel hybrid artificial liver module using hepatocyte organoid cultureAs a novel artificial liver module, we developed a hollow fiber module having a liver lobule-like structure, in which the hollow fibers representing blood vessels are arranged by spacers in a micro-regular arrangement within 150 μm. Inoculated hepatocytes in the extra-fiber space were formed in a lotus root-organoid by loading appropriate centrifugal force. The novel module achieved high cell density of about 4.0 x l0^7 cells / cm^3 - module and maintained better liver function compared to previous hollow fiber modules for several month. These results suggest that this novel module will be a new HAL for treatment of both chronic and acute liver failure patients, and for long-term bridge use for liver transplantation. Now we are investigating the optimization and scale up of the module.