IN VITRO FUNCTIONAL ASSESSMENT OF BAL USING IMMOBILIZED PIG HEPATOCYTES IN PLASMA

Abstract

A249 Aims: To treat fulminant hepatic failure (FHF) patients, various extracorporeal bioartificial liver (BAL) support systems have been developed. Hepatocyte spheroids are known to show enhanced liver functions via direct cell-to-cell contacts in culture medium. However, The maintenance of hepatocyte functions during plasma exposure are important for the clinical application of BAL system. In this study, we aimed to evaluate the usefulness of hepatocyte spheroids under the BAL circulation. Methods: We used small scale BAL with packed bed bioreactor. Hepatocytes were isolated from pig using two step collagenase method. Hepatocyte spheroids were made using 24 hours rotational culture. After immobilization with calcium alginate, we applied the beads into packed bed bioreactor. The pig plasma from hepatic failure pig was circulated continously during 11 hours. We compared the change of liver specific functions and viability between initial single hepatocytes and spheroids during plasma exposure. Results: The viability was maintained stably in both groups. However, the level of AST/ALT in initial single cells was higher than that in spheroids. The ammonia removal rates were 370 μg/dl/hr in initial single hepatocytes and 620μg/dl/hr in hepatocyte spheroids at fist hour of operation. The ammonia removal rates were 800 μg/dl/hr in initial single hepatocytes and 1100μg/dl/hr in hepatocyte spheroids at 5 hours. Hepatocyte spheroids showed in vivo structures after 11 hours operation. Conclusions: Hepatocytes spheroids are superior to the initial single cells in terms of liver specific functions under the toxic plasma condition.