New type of artificial liver support system (ALSS) using the photocatalytic effect of titanium oxide

Although various types of artificial liver support systems (ALSSs) including a hybrid type have been made, few are practical ALSSs for treatment of acute and/or chronic hepatic failure. Titanium oxide (TiO2), a stable material, dismantles various materials using a photocatalytic action under ultraviolet irradiation. The aim of this study was to assess the effect of a new ALSS using TiO2. Hepatic failure plasma obtained from patients undergoing plasma exchange therapy due to acute liver failure was used in these experiments. The plasma was perfused using a closed circuit model with a column filled with TiO2. The plasma concentrations of total bilirubin, albumin, fibrinogen, interleukin (IL)-6, IL-8, and IL-10 were serially measured. We evaluated the photocatalytic effect of TiO2 irradiated with ultraviolet light. The effect of initial perfusion with fresh-frozen plasma (FFP) was also investigated, focusing on the decrease in fibrinogen during perfusion. Levels of total bilirubin decreased after perfusion using the column filled with TiO2, compared with no UV irradiation. The levels of IL-6, IL-8, and IL-10 decreased after perfusion using the TiO2 device. The albumin level was maintained at the initial level, however, the fibrinogen level decreased within 4 hr. Initial perfusion of the circuit with FFP improved the decrease in fibrinogen for up to 8 hr. Our new perfusion device using the photocatalytic action of TiO2 may be a promising ALSS.