Cell-Seeded Tubularized Scaffolds for Reconstruction of Long Urethral Defects: A Preclinical Study |
| |
Authors: | Hazem Orabi Tamer AbouShwareb Yuanyuan Zhang James J. Yoo Anthony Atala |
| |
Affiliation: | 1. Department of Urology and Institute for Regenerative Medicine, Wake Forest School of Medicine, Winston Salem, NC, USA;2. Urology Department, Assiut University, Egypt 71516 |
| |
Abstract: | BackgroundThe treatment options for patients requiring repair of a long segment of the urethra are limited by the availability of autologous tissues. We previously reported that acellular collagen-based tubularized constructs seeded with cells are able to repair small urethral defects in a rabbit model.ObjectiveWe explored the feasibility of engineering clinically relevant long urethras for surgical reconstruction in a canine preclinical model.Design, setting, and participantsAutologous bladder epithelial and smooth muscle cells from 15 male dogs were grown and seeded onto preconfigured collagen-based tubular matrices (6 cm in length). The perineal urethral segment was removed in 21 male dogs. Urethroplasties were performed with tubularized collagen scaffolds seeded with cells in 15 animals. Tubularized constructs without cells were implanted in six animals. Serial urethrography and three-dimensional computed tomography (CT) scans were performed pre- and postoperatively at 1, 3, 6, and 12 mo. The animals were euthanized at their predetermined time points (three animals at 1 mo, and four at 3, 6, and 12 mo) for analyses.Outcome measurements and statistical analysisStatistical analysis of CT imaging and histology was not needed.Results and limitationsCT urethrograms showed wide-caliber urethras without strictures in animals implanted with cell-seeded matrices. The urethral segments replaced with acellular scaffolds collapsed. Gross examination of the urethral implants seeded with cells showed normal-appearing tissue without evidence of fibrosis. Histologically, an epithelial cell layer surrounded by muscle fiber bundles was observed on the cell-seeded constructs, and cellular organization increased over time. The epithelial and smooth muscle phenotypes were confirmed using antibodies to pancytokeratins AE1/AE3 and smooth muscle–specific desmin. Formation of an epithelial cell layer occurred in the unseeded constructs, but few muscle fibers formed.ConclusionsCell-seeded tubularized collagen scaffolds can be used to repair long urethral defects, whereas scaffolds without cells lead to poor tissue development and strictures. This study demonstrates that long tissue-engineered tubularized urethral segments may be used for urethroplasty in patients. |
| |
Keywords: | Urethra Stricture repair Cell-seeded tubularized urethra reconstruction Tissue-engineered urethra |
本文献已被 ScienceDirect 等数据库收录! |
|