title: Treatment of fulminant liver failure by transplantation of microencapsulated primary or immortalized xenogeneic hepatocytes.
abstract: BACKGROUND
  The aim of this study was to evaluate the in vitro and in vivo function of hepatocytes after immortalization, cryopreservation, encapsulation, and xenotransplantation into mice with fulminant liver failure (FLF).
  
  
  METHODS
  Rat and human hepatocytes were isolated by collagenase digestion. Human hepatocytes were immortalized using lentiviral vectors. Rat and immortalized human hepatocytes (IHH) were encapsulated in 400 microm of alginate-poly-L-lysine (PLL; Sigma, Buchs, Switzerland)-alginate membranes and cryopreserved using a computerized device. In vitro, encapsulated hepatocytes (cryopreserved or noncryopreserved) were cultured; albumin secretion was measured by enzyme-linked immunosorbent assay. Microencapsulated (cryopreserved or noncryopreserved) hepatocytes were transplanted intraperitoneally to mice with FLF: group 1 (n = 10) transplantation of empty capsules; group 2 (n = 12) transplantation of free primary rat hepatocytes; group 3 (n = 12) transplantation of cryopreserved encapsulated rat hepatocytes; group 4 (n = 10) transplantation of encapsulated rat hepatocytes; group 5 (n = 9) transplantation of cryopreserved encapsulated IHH; group 6 (n = 10) transplantation of encapsulated IHH.
  
  
  RESULTS
  Compared with free primary hepatocytes, cryopreserved or noncryopreserved encapsulated rodent hepatocytes showed similar levels of continuous in vitro albumin secretion over 1 week. Cryopreserved or noncryopreserved encapsulated IHH showed minimal albumin secretion compared with free primary human hepatocytes. Fulminant liver failure, produced by a combination of acetaminophen and 30% hepatectomy, resulted in a 20% to 30% host survival. In groups 1 and 2, survival was unmodified, compared with untreated mice. For groups 3 and 4, transplantation of cryopreserved or noncryopreserved encapsulated rat hepatocytes significantly increased survival rates to 66% and 80%, respectively (P < .01). For groups 5 and 6, transplantation of cryopreserved or noncryopreserved encapsulated IHH improved host survival to 50% and 55%, respectively (P < .05).
  
  
  CONCLUSIONS
  Primary rodent hepatocytes maintained synthetic functions after encapsulation and cryopreservation. Immortalized human hepatocytes showed minimal albumin secretion in the absence of encapsulation and cryopreservation, suggesting that hepatocytes lose some specific functions after immortalization. After induction of FLF in mice, intraperitoneal transplantation of encapsulated (primary or immortalized, cryopreserved or noncryopreserved) xenogeneic hepatocytes significantly improved survival. These results indicate that naive and genetically modified hepatocytes can be successfully encapsulated, stored by cryopreservation, and transplanted into xenogeneic recipients with FLF to sustain liver metabolic functions.
authors.affiliation: Department of Surgery, Surgical Research Unit, University Hospital Geneva, Geneva, Switzerland. maigang68@hotmail.com
authors.forename: G
authors.initials: G
authors.lastname: Mai
authors.forename: N T
authors.initials: NT
authors.lastname: Huy
authors.forename: P
authors.initials: P
authors.lastname: Morel
authors.forename: J
authors.initials: J
authors.lastname: Mei
authors.forename: D
authors.initials: D
authors.lastname: Bosco
authors.forename: T
authors.initials: T
authors.lastname: Berney
authors.forename: P
authors.initials: P
authors.lastname: Majno
authors.forename: G
authors.initials: G
authors.lastname: Mentha
authors.forename: D
authors.initials: D
authors.lastname: Trono
authors.forename: L H
authors.initials: LH
authors.lastname: Buhler
mesh_terms: D000818:Animals; D002214:Capsules; D015925:Cryopreservation; D006085:Graft Survival; D022781:Hepatocytes / Q000637:transplantation*; D006801:Humans; D017114:Liver Failure, Acute / Q000628:therapy*; D051379:Mice; D051381:Rats; D017207:Rats, Sprague-Dawley; D014183:Transplantation, Heterologous / Q000379:methods*
chemical_list: D002214:Capsules