Biological vascularized matrix for bladder tissue engineering: matrix preparation, reseeding technique and short-term implantation in a porcine model.
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.
Schultheiss
Dirk
D
Departments of Urology and Pediatric Urology, Hannover Medical School, Cark-Neuberg-Strasse 1, D-30625 Hannover, Germany. schultheiss.dirk@mh-hannover.de
Gabouev
Alexander I
AI
Cebotari
Serghei
S
Tudorache
Igor
I
Walles
Thorsten
T
Schlote
Norbert
N
Wefer
Jörg
J
Kaufmann
P Matthias
PM
Haverich
Axel
A
Jonas
Udo
U
Stief
Christian G
CG
Mertsching
Heike
H
D000818:Animals; D021522:Bioartificial Organs; D009130:Muscle, Smooth / Q000166:cytology; D023822:Tissue Engineering; D001743:Urinary Bladder; D019459:Urothelium / Q000166:cytology; D014654:Vascular Patency