An Experimental Study On Construction Of Hemodialysis Hybrid Bioartificial Liver Support System

BackgroundlAims Fulminant hepatic failure (FHF) is one of the most challenging problems in clinic. Its mortality is more than 80%. Orthotopic liver transplantation (OLT) has greatly improved outcome, but limited organ availability enables only a small number of FHF patients to undergo transplantation. On the other hand, FHF is recognized as a potentially reversible clinical condition in which the framework of the liver remains intact facilitating organ regeneration and the restoration of normal hepatic functions. Hybrid bioartificial liver support system can stabilize patients and bridge Fl-IF patients to OLT or make patients recover themselves. Our objective is to establish a new hemodialysis hybrid bioartificial liver support system (hemodialysis HBLS) on the basis of previous work and evaluat this new system in the FHF dog model, which we report first. The study is supposed to demonstrate that the systems have multifarious hepatic biological functions, prolong life in animal models of FHF and prevent death from FHF. 1. Large-scale cultivation of porcine bepatocytes (I) Objective: To ameliorate and optimize the method for cultivation of porcine hepatocytes on microcarriers. To increase adhesive rate of hepatocyts. Methods: To utilize 1-L magnetic suspension culture vessel for hepatocytes formation of litter spheroids, then added microcarriers cytodex-3. Under the magnetic force, porcine hepatocytes became easier to adhere to the microcarriers at the low rotational speed. Results: The adhesive rate of the new method was significantly higher (90.3% .73, CV is 8.56%) than cultivate hepatocytes through stirring with hands (69.5 18.33, CV is 26.37%). The hepatocytes, which were cultivate through stirring with magnetic force, had the significantly higher function of synthesize albumin than hepatocytes cultivated with hands in two weeks(P<0.05). Conclusions: This method has good repetition and stabilization, reduce the chance to stain the culturing hepatocytes and is more easy to operate. (2) Objective: To establish a method of cultivation large-scale liver parenchyma and noparenchyma cells and to form the porcine hepatocyte spheroids. Methods: We performed spheroid in 1-L magnetic culture vessels. Results: To obtained approximately 2 ~ 5 X 1010 hepatocyte spheroids one time. We could observe the hepatic special structure of hepatocyte spheroids in a electric microscope. The hepatocyte spheroids expressed better function than conventional monolayers. Conclusion: The method of cultivating large-scale liver parenchyma and noparenchyma cells of hepatocyte spheroids can provide enough hepatocyts one time for bioartificial liver support systems. 2. Preparation the FHF dog model Objective: To establish a kind of big animal FHF model and provide a proper evaluation model for hybrid bioartificial liver support system. Methods: To unite acetaminophen and tetrachlormethane to induce the model of FHF in dogs. Results: Model dogs displayed hepatic encephalopathy and the special pathological changes of massive hepatocyte necrosis. Mortality rate of the model was 90%. Models expressed different phases: anesthesia, vivification, slightly coma and deep coma. We had enough time to treat them and they had chance to recover from coma. Conclusion: We first report this method; it is simply and conducted at low cost. We have enough time to support FHF dogs with our hybrid bioartificial liver support syst...