Introduction and Objectives
A variety of tissue engineering techniques for bladder augmentation are currently under development or investigation, but thus far, no one approach is clearly superior. The aim of the study is to compare the suitability for cystoplasty augmentation in rats of in vivo implanted bladder acellular matrices previously seeded with hair follicle stem cells and of matrices implanted without cells (BAM, bladder acellular matrix).
Material and Methods
The rat hair follicle stem cell line was used. Cells were positive for CD34, p63 and Ki-67. 1×106 cells from 34–40 passages were seeded on 9 BAM scaffolds and cultured for a week. Nine scaffolds were left unseeded. Scaffolds were grafted into a surgically created defect within the anterior bladder wall. 9 rats were grafted with acellular matrices and 9 with cell seeded BAM. Rats were observed 6 months and sacrificed in monthly intervals. Gross examination, X-ray cystography, H&E, CK-7, CK-20, myoglobin and desmin staining of the excised bladders were performed.
Minimal adhesions were observed. Urinary leakage was observed in one case. Two animals died in acellular group. Rats developed stone disease in bladders reconstructed with acellular BAM. Bladders’ capacity was comparable but the shape was regular and characteristically oval only in bladders grafted with cell seeded BAM. Muscle layers in apical parts of the reconstructed bladder walls were extremely thin in the cases of acellular grafts and were thicker in bladders reconstructed with cell seeded grafts. Muscle layer regeneration was better in the cell-seeded group. Urothelium regenerated in all animals.
We present for the first time that hair follicle stem cells can improve regeneration of the rat bladder wall. The differentaion of hair follicle stem cells has to be studied.
© 2009 European Association of Urology. Published by Elsevier Inc. All rights reserved.