Gel Entrapped Hepatocytes For Investigation Of Drug Hepatotoxicity

During the drug development, early elimination of high toxic compounds can shorten the development phase and save the cost in animal and clinical trails. However, it is not yet possible to get an accurate extrapolation of in vitro to in vivo. Therefore, this paper employed a new model of gel entrapped hepatocytes in hollow fiber membrane microreactor especially for high throughput screening of drug hepatotoxicity. Rifampicin and isoniazid were chosen for the study on reactive metabolite induced hepatotoxicity; Tetracycline, amiodarone and salicylate were selected for the study on steatosis, phospholipidosis and mitochondria toxicity, respectively. And gel entrapped hepatocytes in hollow fiber membrane microreactor were used as the cell model, while hepatocytes in monolayer was set as a control.As results, the drug induced toxicity in rats could be reproduced in rat hepatocytes of gel entrapment but only some in hepatocyte monolayer. Furthermore, the detectable toxic concentrations of drugs in gel entrapped rat hepatocytes were very close to their toxic plasma concentrations in rats, while hepatocyte monolayer was insensitive to drug toxicity. In addition, we used rat and human hepatocytes in gel entrapment to study the species difference of rifampicin and isoniazid hepatotoxicity between human and rats. Our results also consisted with the observation in rats and clinic. Finally, the gel entrapped hepatocytes in hollow fiber membrane microreactor can be applied for the screening of antitoxicity compounds in Chinese herbal medicine. Glycyrrhizic acid and matrine/silibinin were discovered as antitoxicity compounds for reactive metabolite induced hepatotoxicity and amiodarone-induced phospholipidosis, respectively.Because of the high adsorption of drugs on hollow fiber membrane of polysulfone, polysulfone was grafted with polyethylene glycol before preparation of new hollow fiber membrane. The new hollow fiber membrane was founded with reduced drug adsorption and thus suggested to be applicable for gel entrapment culture of hepatocytes in the drug test.In conclusion, gel entrapped hepatocytes within hollow fiber membrane made of polyethylene glycol grafted polysulfone can be used as a model for screening of drug hepatotoxicity. According to the results from this model, the detectable toxic concentrations in vitro can be extrapolated to the toxic plasma concentrations in vivo. And the mechanism of toxicity in vitro consisted with the corresponding mechanism of drugs in vivo. Thus, it should be possible for comparison of drug toxicity in vitro and in vivo quantitatively and qualitatively. Overall, our hollow fiber membrane reactor with gel entrapped hepatocytes appears to be a relevant system for safety evaluation in drug development.