title: Human embryoid body-derived stem cells in bladder regeneration using rodent model.
abstract: OBJECTIVE
  To evaluate the capability of a human embryonic germ (hEG) cell-derived cell line (SDEC), previously characterized in our laboratory, seeded on porcine small intestinal submucosa (SIS) to regenerate the injured rat bladder.
  
  
  METHODS
  Fluorescent-labeled SDEC cells seeded on SIS for 8 days in vitro were used as bladder grafts in rats. A total of 30 congenitally athymic rats (six groups of 5 rats each), underwent partial cystectomy and replacement with plain SIS (groups 1 to 3) or cell-seeded SIS (groups 4 to 6). The rats were sacrificed after 7 (groups 1 and 4), 14 (groups 2 and 5), and 28 (groups 3 and 6) days. The bladders were analyzed by histopathologic examination and fluorescence microscopy.
  
  
  RESULTS
  No graft rejection or diminution in bladder capacity occurred. Plain SIS implants had multiple calcareous deposits, not seen with the cell-seeded implants. Macroscopically, at 7 days, the grafts were healed with a cellular lining on the luminal aspect in groups 4 to 6. Microscopically, the rat bladder was completely regenerated 28 days after stem cell-seeded SIS implantation. Labeled stem cells were identified throughout the graft and contributed significantly to bladder regeneration.
  
  
  CONCLUSIONS
  The results of this study have demonstrated the successful replacement of a bladder defect in a rat model using hEG cell-derived cells seeded on SIS grafts. Longer term analysis of these bladder grafts will allow evaluation of function, cell migration, and differentiation processes of human stem cells.
authors.affiliation: Division of Pediatric Urology, Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA.
authors.forename: Dominic
authors.initials: D
authors.lastname: Frimberger
authors.forename: Nelly
authors.initials: N
authors.lastname: Morales
authors.forename: Michael
authors.initials: M
authors.lastname: Shamblott
authors.forename: John D
authors.initials: JD
authors.lastname: Gearhart
authors.forename: John P
authors.initials: JP
authors.lastname: Gearhart
authors.forename: Yegappan
authors.initials: Y
authors.lastname: Lakshmanan
mesh_terms: D000818:Animals; D002460:Cell Line; D023421:Models, Animal; D051381:Rats; D011923:Rats, Nude; D012038:Regeneration; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000502:physiology*; D046509:Tissue Culture Techniques; D001743:Urinary Bladder / Q000502:physiology*