Construction of polysulfone membrane bioreactor experimental system and its effects on plasma of patients with severe hepatitis / 中国组织工程研究

ABSTRACT

BACKGROUND: Property of artificial liver reactor is generally evaluated by using an enclosed experimental device, which is constructed through simulating bioartificial liver supporting system. Moreover, the enclosed experimental device is also comprehensively evaluated biological function of hepatocytes and biological response efficiency. In addition, it is significance for primarily evaluating the properties of polysulfone membrane hollow fiber reactor to optimize bioartificial liver supporting system. OBJECTIVE: To construct polysulfone membrane bioreactor experimental system, understand the effects on plasma of patients with severe hepatitis, and observe the feasibility of hollow fiber reactor regarded as bioartificial liver reactor. DESIGN: Repeated measurement.SETTING: General Infectious Disease Institute, Southwest Hospital, the Third Military Medical University of Chinese PLA. MATERIALS: Seven Chinese mini-pigs with 1-7 days old and of either gender were provided by Experimental Animal Center, the Third Military Medical University (certification: F99017). The animal disposal accorded to the ethical standard. Tumor necrosis factor-α (TNF-α) and transforming growth factor-β1 (TGF-β1) kits were purchased from Jingmei Bioengineering Company, China; polysulfone membrane hollow fiber reactor by Shanghai Dehong Biomaterial Institute, China; Cellco culture-circular artificial capillary culture system by Spectrum Company, USA; seven plasma exponents were taken from admission patients with chronic severe hepatitis during plasma exchange. All patients provided the informed consent, and the animal experiment was conducted with confirmed consent by the local ethics committee.METHODS: This study was performed at the General Infectious Disease Institute, Southwest Hospital, the Third Military Medical University of Chinese PLA from January 2004 to July 2005. ① Experimental procedure: The experimental pigs underwent ablactation at 12 hours before experiment, and then hepatocytes were separated after cleaning their fur. An enclosed system was composed of polysulfone membrane hollow fiber reactor and Cellco culture-circular artificial capillary culture system, which were connected with oxygen-carbon dioxide diffusion tube and media holding pond. Interface of external cavity was blocked with clean rubber tampon. The separated hepatocytes underwent spheroid culture by using magnetic stirring method, and then they were inoculated in the external cavity of polysulfone membrane hollow fiber reactor. Next, 200 mL plasma from severe hepatitis patients was added in media holding pond and circled from internal cavity of reactor to media holding pond at the speed of 80 mL/min. ② Experimental evaluation: 2 mL liquid circulation separately collected from internal cavity of reactor at 0, 2, 4 and 6 hours after circulation was used to measure level of ammonia in supernatant by using glutamic dehydrogenase-violet method. In addition, content of total bilirubin was detected by using automatic biochemistry analyzer, prothrombin time by using automatic blood coagulometer, and TNF-α and TGF-β1 were detected according to the kits. MAIN OUTCOME MEASURES: Effects of polysulfone membrane bioreactor on ammonia, bilirubin, prothrombin time, TNF-α and TGF-β1 in plasma of patients with severe hepatitis.RESULTS: ① Measurement of ammonia, total bilirubin and prothrombin time in patients with severe hepatitis: Level of ammonia decreased persistently, in particularly, the decrease was obvious from 0 to 2 hours, and then, it was decreased slowly. While, level of total bilirubin was also decreased persistently, and it was significantly lower at 6 hours than that at 0 hour (P < 0.05). Moreover, prothrombin time was decreased persistently, and it was significantly lower at 6 hours than that at 0 hour (P < 0.05). ② Measurement of TNF-α and TGF-β1 in patients with severe hepatitis: Contents of both TNF-α and TGF-β1 decreased persistently, and they were significantly lower at 6 hours than those at 0 hour (P < 0.05). CONCLUSION:Polysulfone membrane bioreactor experimental system can clear noxious substance of small molecules in plasma of patients with severe hepatitis, supply beneficial components, and decrease levels of cytokines. Therefore, it can be regarded as the bioartificial liver reactor.