title: Biological vascularized matrix for bladder tissue engineering: matrix preparation, reseeding technique and short-term implantation in a porcine model.
abstract: OBJECTIVE
  We generated a vascularized, autologous, reseeded bladder substitute and evaluated immediate vascularization and perfusion of the graft after implantation to the recipient organism in a porcine model.
  
  
  METHODS
  Acellular matrix was processed from porcine small bowel segments by subsequent mechanical, chemical and enzymatic decellularization, preserving the jejunal arteriovenous pedicles. In 2 separate steps the matrix was reseeded with primary bladder smooth muscle cells (SMCs) and urothelial cells (UCs), and its vascular structures were resurfaced with endothelial progenitor cells (EPCs). To evaluate graft perfusion short-term implantation was performed.
  
  
  RESULTS
  The acellular scaffold was successfully repopulated with multilayers of ingrowing SMCs and superficial UCs. After reseeding the jejunal arteriovenous pedicles with EPCs and cultivation for 3 weeks the larger vessels as well as the intramural scaffold capillary network were repopulated with cell monolayers expressing endothelial specific proteins. Perfusion stagnation and implant thrombosis occurred within 30 minutes after the implantation of acellular scaffolds not reseeded with EPCs. In the EPC reseeded group the vascular system revealed intact perfusion and no relevant thrombus formation was observed after 1 or 3 hours.
  
  
  CONCLUSIONS
  The current study of successful SMC and UC reseeding, vessel resurfacing with EPCs and short-term vascular patency represents the promising in vitro and in vivo basis for further evaluation of this biological vascularized matrix in chronic long-term large animal implantation experiments.
authors.affiliation: Departments of Urology and Pediatric Urology, Hannover Medical School, Cark-Neuberg-Strasse 1, D-30625 Hannover, Germany. schultheiss.dirk@mh-hannover.de
authors.forename: Dirk
authors.initials: D
authors.lastname: Schultheiss
authors.forename: Alexander I
authors.initials: AI
authors.lastname: Gabouev
authors.forename: Serghei
authors.initials: S
authors.lastname: Cebotari
authors.forename: Igor
authors.initials: I
authors.lastname: Tudorache
authors.forename: Thorsten
authors.initials: T
authors.lastname: Walles
authors.forename: Norbert
authors.initials: N
authors.lastname: Schlote
authors.forename: Jörg
authors.initials: J
authors.lastname: Wefer
authors.forename: P Matthias
authors.initials: PM
authors.lastname: Kaufmann
authors.forename: Axel
authors.initials: A
authors.lastname: Haverich
authors.forename: Udo
authors.initials: U
authors.lastname: Jonas
authors.forename: Christian G
authors.initials: CG
authors.lastname: Stief
authors.forename: Heike
authors.initials: H
authors.lastname: Mertsching
mesh_terms: D000818:Animals; D021522:Bioartificial Organs; D009130:Muscle, Smooth / Q000166:cytology; D023822:Tissue Engineering; D001743:Urinary Bladder; D019459:Urothelium / Q000166:cytology; D014654:Vascular Patency