The treatment options for patients with a urethral defect are limited by the availability of autologous tissues. We hypothesized that transplantation of decellularized human amniotic scaffolds (dHAS) seeded with allogeneic bone marrow mesenchymal cells (BMSCs) and/or endothelial progenitor cells (EPCs) may serve as a promising repair strategy for long segment of circumferential urethral defect. To verify the hypothesis, with urinary catheterization, a 3-cm segment of whole urethra in 25 male mongrel dogs was excised and replaced by dHAS seeded with allogeneic BMSCs and/or EPCs. Postoperative observation and ascending urethrogram found that dHAS+BMSCs+EPCs and dHAS+EPCs groups demonstrated unhindered urination and capacious urethral caliber, which were similar to the normal group, while urethrostenosis was revealed in dHAS+BMSCs, dHAS, and sham-operated groups, with the shortest narrow section in dHAS+BMSCs group and the longest in sham-operated group. Urethral anatomy check and histological analyses showed that new urethral mucosa composed of stratified columnar epithelium completely covered on the inner surface of the graft site in dHAS+BMSCs+EPCs and dHAS+EPCs groups, but the middle epithelium was thin in dHAS+EPCs group, while incompletely covered in dHAS+BMSCs, dHAS, and sham-operated groups, and there were monolayer epithelial cells at the urethrostenosis in dHAS+BMSCs and dHAS groups. In addition, abundant new vessel and blood sinus showed at submucosa in dHAS+BMSCs+EPCs and dHAS+EPCs groups, instead of the scar tissue of collagen deposition and structural distortion at the urethrostenosis in dHAS+BMSCs, dHAS, and sham-operated groups. This study demonstrates that dHAS seeded with BMSCs+EPCs or EPCs can successfully repair a 3-cm circumferential urethral defect in model dogs, but the former works best. This technology may provide some references for human clinical trials on long segment of circumferential urethral defect repair.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1089/ten.TEA.2016.0518 | DOI Listing |
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!