A comparison of engineered urinary bladder and intestinal smooth muscle for urinary bladder wall replacement in a rabbit model.
OBJECTIVE
The small intestine is the most common resource for bladder augmentation. Little is known whether intestinal smooth muscle cells (SMCs) may be engineered into bladder tissue. We investigated the phenotypic and functional characteristics of engineered bladder and intestinal SMCs as bladder wall replacement in a rabbit model.


METHODS
One month after an initial 70% partial cystectomy, 3 autoaugmentation surgeries were performed, including traditional autoaugmentation (TA, n = 6), TA using engineered bladder SMCs (TA + B, n = 6), and TA using intestinal SMCs (TA + I, n = 6). All were followed up by bladder volume measurement and retrieved on the first, third, and sixth month. The grafts and the native bladder wall were evaluated with immunocytochemistry and electrical field stimulation (EFS). Statistical analysis was performed using analysis of variance.


RESULTS
Both the TA + I and TA + B groups showed significant and similar bladder capacity increment in all time points. The engineered muscle cells demonstrated the typical "contraction-relaxation" response to supramaximal EFS. There were no statistical differences in both the TA + I and TA + B groups in contractility force.


CONCLUSIONS
Engineered SMCs derived from urinary bladder and small intestine could retain their phenotype after implantation in vivo. Both exhibited a similar degree of contractility to EFS. These results suggest that there are no phenotypic or functional differences between muscle cells obtained from the 2 different organs. Both have the potential to be engineered into normal bladder tissues.
Lai
Jin-Yao
JY
Department of Pediatric Surgery, Chang-Gung Children's Hospital, School of Medicine, Chang-Gung University, Kweishan, Taoyuan 333, Taiwan. jylai@cgmh.org.tw
Chang
Pei-Yeh
PY
Lin
Jer-Nan
JN
D000818:Animals; D007421:Intestine, Small / Q000637:transplantation; D008297:Male; D023421:Models, Animal; D009130:Muscle, Smooth / Q000637:transplantation; D032389:Myocytes, Smooth Muscle; D011817:Rabbits; D023822:Tissue Engineering; D001743:Urinary Bladder