The factors influencing the transfer of porcine endogenous retroviruses across the membrane in bioartificial livers / 中华肝胆外科杂志

ObjectiveTo identify the factors influencing the transfer of porcine endogenous retroviruses across the membrane of a new bioartificial liver (BAL),which is a necessary caution to consider for BALs carrying porcine hepatocytes.MethodsA novel porcine BAL composed of two circuits was constructed using a plasma filter with membrane pore size of 500 nm and a plasma component separator with membrane pore sizes 10 nm,20 nm,30 nm,and 35 nm.Co-cultured cells of porcine hepatocytes and mesenchymal stem cells or single porcine hepatocytes were incubated in the bioreactors.The BAL was continuously worked for 72 hours during which the supernatant was collected from the internal and external circuits every 12 hours.PERV RNA,reverse transcriptase (RT) activity,and in vitro infectivity from the supernatant were detected.ResultsIn the plasma filter group,the PERV RNAlevels were the same in both circuits,suggesting little to no effect of the plasma filter on the PERV RNA's crossing.With plasma component separators,PERV RNA was found in the external circuits at different times without positive RT activity and HEK293 cell infection,but its level was reduced significantly.The larger the membrane pore size was,the earlier and the more RNA was detected.ConclusionsThe membrane pore size,the treatment time and the viral level in the internal circuit are contributing factors influencing the transfer of PERV RNA across the membrane in a BAL.

An experimental study on the effects of membrane molecular weight cut off on a novel bioartificial liver system / 中华肝胆外科杂志

ObjectiveTo study the effects of membrane molecular weight cut off on a novel bioartificial liver(BAL) system.MethodsHealthy beagles underwent 6-hour treatment with a BAL containing membrane with 200 kDa retention rating or 1200 kDa retention rating.The functional changes and cell viability were characterized.ResultsHepatocyte performance levels such as albumin secretion,urea synthesis and viability were significantly higher in the 200 kDa retention rating group when compared with the 1200 kDa retention rating group (P＜0.05).Significant levels of canine proteins were detected in the BAL medium from the 1200 kDa retention rating group.Fluorescence microscopy further verified that heavy deposition of canine IgG,IgM and complement (C3) on co-culture cells were obtained after BAL treatment in the 1200 kDa retention rating group.ConclusionsSmall membrane molecular weight cut off of BAL could reduce the transfer of xenoreactive antibodies into the BAL medium and improved the performance of the BAL.