title: Fluidized-bed bioartificial liver assist devices (BLADs) based on microencapsulated primary porcine hepatocytes have risk of porcine endogenous retroviruses transmission.
abstract: OBJECTIVE
  Bioartificial liver assist devices (BLADs) are expected to bridge liver failure patients to liver transplantation, but porcine endogenous retroviruses (PERVs) still pose a potential risk in pig-to-human xenotransplantation and thereby limit the use of bioartificial liver therapy. In our lab, fluidized-bed BLADs based on microencapsulated primary porcine hepatocytes have been successfully used to treat liver failure pigs. We detected the risk of PERVs transmission of microencapsulated primary porcine hepatocytes-the key component of fluidized-bed BLADs, to evaluate the biosafety of this device for further clinical applications.
  
  
  METHODS
  Microencapsulated primary porcine hepatocytes (cell diameter = 300 μm) were cultured in Dulbecco's modified Eagles medium (DMEM). Microencapsulated cell culture supernatants were collected at 6, 12, 24 and 72 h. HEK-293 were cocultured with these supernatants, and the cocultured cells were harvested every 7 days. RT-PCR was used to detect PERVs transmission. RT-qPCR was used to get the number of virus copies. PK-15 was used as the positive control whereas HepG2 was used as the negative control.
  
  
  RESULTS
  PERV was detected in all supernatants, and the viral load of the supernatants increased with time. Moreover, cocultured 293 cells were positive for PERV-specific sequences.
  
  
  CONCLUSIONS
  The kind of fluidized-bed BLADs based on microencapsulated primary porcine hepatocytes have risk of PERVs transmission. Further extensive pre-clinical study focused on biosafety is warranted.
authors.affiliation: The First Affiliated Hospital, College of Medicine, Zhejiang University, No.79 Qingchun Road, Hangzhou, 310003 China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Yang
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
authors.forename: Xiao Ping
authors.initials: XP
authors.lastname: Pan
authors.forename: Guoliang
authors.initials: G
authors.lastname: Lv
authors.forename: Anye
authors.initials: A
authors.lastname: Zhang
authors.forename: Chen Bo
authors.initials: CB
authors.lastname: Yu
authors.forename: Lanjuan
authors.initials: L
authors.lastname: Li