Microbiological safety of a novel bio-artificial liver support system based on porcine hepatocytes: a experimental study.
BACKGROUND
Our institute has developed a novel bio-artificial liver (BAL) support system, based on a multi-layer radial-flow bioreactor carrying porcine hepatocytes and mesenchymal stem cells. It has been shown that porcine hepatocytes are capable of carrying infectious porcine endogenous retroviruses (PERVs) into human cells, thus the microbiological safety of any such system must be confirmed before clinical trials can be performed. In this study, we focused on assessing the status of PERV infection in beagles treated with the novel BAL.


METHODS
Five normal beagles were treated with the novel BAL for 6 hours. The study was conducted for 6 months, during which plasma was collected from the BAL and whole blood from the beagles at regular intervals. DNA and RNA in both the collected peripheral blood mononuclear cells (PBMCs) and plasma samples were extracted for conventional PCR and reverse transcriptase (RT)-PCR with PERV-specific primers and the porcine-specific primer Sus scrofa cytochrome B. Meanwhile, the RT activity and the in vitro infectivity of the plasma were measured.


RESULTS
Positive PERV RNA and RT activity were detected only in the plasma samples taken from the third circuit of the BAL system. All other samples including PBMCs and other plasma samples were negative for PERV RNA, PERV DNA, and RT activity. In the in vitro infection experiment, no infection was found in HEK293 cells treated with plasma.


CONCLUSIONS
No infective PERV was detected in the experimental animals, thus the novel BAL had a reliable microbiological safety profile.
Department of Hepatobiliary Surgery, the Affiliated DrumTower Hospital of Nanjing University Medical School, Number 321 Zhongshan Road, Nanjing 210008, China.
Bing
B
Han
Xiao-Lei
XL
Shi
Yue
Y
Zhang
Xue-Hui
XH
Chu
Jin-Yang
JY
Gu
Jiang-Qiang
JQ
Xiao
Hao-Zhen
HZ
Ren
Jia-Jun
JJ
Tan
Zhong-Ze
ZZ
Gu
Yi-Tao
YT
Ding
D000818:Animals; D002986:Clinical Trials as Topic; D018920:Coculture Techniques; D004285:Dogs; D020077:Endogenous Retroviruses / Q000302:isolation & purification / Q000472:pathogenicity; D057809:HEK293 Cells; D022781:Hepatocytes / Q000821:virology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology*; D019164:Liver, Artificial / Q000821:virology*; D059630:Mesenchymal Stem Cells; D012190:Retroviridae / Q000472:pathogenicity; D012449:Safety; D013552:Swine