AIM: To evaluate the efficacy and safety of a hybrid bioartificial liver (HBAL) system in the treatment of acute liver failure. METHODS: Canine models with acute liver failure were introduced with intravenous administration of D-galactosamine. The animals were divided into: the HBAL treatment group (n = 8), in which the canines received a 3-h treatment of HBAL; the bioartificial liver (BAL) treatment group (n = 8), in which the canines received a 3-h treatment of BAL; the non-bioartificial liver (NBAL) treatment group (n = 8), in which the canines received a 3-h treatment of NBAL; the control group (n = 8), in which the canines received no additional treatment. Biochemical parameters and survival time were determined. Levels of xenoantibodies, RNA of porcine endogenous retrovirus (PERV) and reverse transcriptase (RT) activity in the plasma were detected. RESULTS: Biochemical parameters were significantly decreased in all treatment groups. The TBIL level in the HBAL group was lower than that in other groups (2.19 ± 0.55 mmol/L vs 24.2 ± 6.45 mmol/L, 12.47 ± 3.62 mmol/L, 3.77 ± 1.83 mmol/L, P < 0.05). The prothrombin time (PT) in the BAL and HBAL groups was significantly shorter than the NBAL and control groups (18.47 ± 4.41 s, 15.5 ± 1.56 s vs 28.67 ± 5.71 s, 21.71 ± 3.4 s, P < 0.05), and the PT in the HBAL group was shortest of all the groups. The albumin in the BAL and HBAL groups significantly increased and a significantly higher level was observed in the HBAL group compared with the BAL group (27.7 ± 1.7 g/L vs 25.24 ± 1.93 g/L). In the HBAL group, the ammonia levels significantly decreased from 54.37 ± 6.86 to 37.75 ± 6.09 after treatment (P < 0.05); there were significant difference in ammonia levels between other the groups (P < 0.05). The levels of antibodies were similar before and after treatment. The PERV RNA and the RT activity in the canine plasma were all negative. CONCLUSION: The HBAL showed great efficiency and safety in the treatment of acute liver failure. AIM: To evaluate the efficacy and safety of a hybrid bioartificial liver (HBAL) system in the treatment of acute liver failure. METHODS: Canine models with acute liver failure were introduced with intravenous administration of D-galactosamine. The animals were divided into: the The bioartificial liver (BAL) treatment group (n = 8), in which the canines received a 3-h treatment of BAL; the HBAL treatment group (n = 8), in which the canines received a 3-h treatment of HBAL; The control group (n = 8), in which the canines received no additional treatment. Biochemical parameters and survival (n = 8), in which the canines received a 3-h treatment of NBAL; Levels of xenoantibodies, RNA of porcine endogenous retrovirus (PERV) and reverse transcriptase (RT) activity in the plasma were detected. RESULTS: Biochemical parameters were significantly less in all treatment groups. The TBIL level in the HBAL group was lower than that in other groups (2.19 ± 0.55 mmol / L vs. 24.2 ± 6.45 mmol / L, 12.47 ± 3.62 mmol / L, 3.77 ± 1.83 mmol / L, P <0.05). The prothrombin time was significantly shorter than the NBAL and control groups (18.47 ± 4.41 s, 15.5 ± 1.56 s vs 28.67 ± 5.71 s, 21.71 ± 3.4 s, P <0.05), and the PT in the HBAL group was shortest of all the groups. The albumin in the BAL and HBAL groups were significantly increased and a significantly higher level was observed in the HBAL group compared with the BAL group (27.7 ± 1.7 g / L vs. 25.24 ± 1.93 g / L). In the HBAL group, the ammonia levels significantly decreased from 54.37 ± 6.86 to 37.75 ± 6.09 after treatment (P <0.05); there were significant differences in ammonia levels between the other groups (P <0.05). The levels of antibodies were similar before and after treatment. The PERV RNA and the RT activity in the canine plasma were all negative. CONCLUSION: The HBAL showed great efficiency and safety in the treatment of a cute liver failure