Epithelial-Differentiated Adipose-Derived Stem Cells Seeded Bladder Acellular Matrix Grafts for Urethral Reconstruction: An Animal Model

Abstract

The limited amount of available epithelial tissue is considered a main cause of the high rate of urethral reconstruction failures. The aim of this study was to investigate whether epithelial-differentiated rabbit adiposederived stem cells (Epith-rASCs) could play a role of epithelium in vivo functionally and be a potential substitute of urothelium. Substitution urethroplasty was performed to repair an anterior urethral defect in male New Zealand rabbits using Epith-rASCs seeded bladder acellular matrix grafts (BAMGs) after 5-bromo-2¢-deoxyuridine (BrdU) labeling, based on the in vitro epithelial induction system we previously described. Urethroplasty with cell-free BAMGs and with undifferentiated rASCs (Und-rASCs) seeded BAMGs were performed as controls. After surgery, a notable amelioration of graft contracture and recovery of urethral continuity were observed in the Epith-rASCs/BAMG group by retrograde urethrograms and macroscopic inspection. Immunofluorescence revealed that the BrdU-labeled Epith-rASCs/Und-rASCs colocalized with cytokeratin 13 or myosin. Consistent with the results of western blotting, at early postimplantation stage, the continuous epithelial layer with local multilayered structure was observed in the Epith-rASCs/BAMG group, whereas no significant growth and local monolayer growth profile of epithelial cells were observed in the BAMG and Und-rASCs/BAMG group, respectively. The results showed that Epith-rASCs could serve as a potential substitute of urothelium for urethral tissue engineering and be available to prevent lumen contracture and subsequent complications including recurrent stricture.

Urethral tissue regeneration using collagen scaffold modified with collagen binding VEGF in a beagle model

“…To date, many attempts have been made to determine appropriate substitutes for urethral reconstruction, and in general, it is believed that seeding cells is necessary for constructing an artificial biomaterial scaffold that is suitable for reconstruction of extensive urethral defects. Various types of cells have been adopted in animal and clinical experiments, such as bone marrow mesenchymal stem cells [19][20][21], urethral epithelial cells [22] and smooth muscle cells [6,7,[23][24][25], urine-derived stem cells [26], mesothelial cells [27], adipose-derived stem Cells [28,29], and oral keratinocytes [30], and other cell types.…”

Tissue-engineered tubular substitutions for urinary diversion in a rabbit model

“…25 Through follow-up study, scholars confirmed that epithelial-differentiated rabbit ADSCs can be used as potential substitute of urothelial cells for urethral tissue engineering. 26 In addition, Zhang et al 27 incubated ADSCs in a conditioned medium and in a Transwell co-culture system with an immortalized urothelial cell line in vitro; they confirmed that ADSCs can potentially be differentiated toward urothelium-like cell lines. Given the aforementioned striking features, in the present study, we selected ADSCs as the seeded cell source to accelerate the epithelialization of conduits.…”

Biomatrices in Urethral Reconstruction

“…The natural collagen based matrices were derived from decellularized heterogenic tissue, including small intestinal submucosa (SIS) [13][14][15], bladder accellular matrix (BAM) [16][17][18], accellular corpus spongiosum matrix (ACSM) [19] and accellular dermal matrix (ADM) [20]. Bhargava et al [20] firstly used ADM and oral cells to fabricate tissue engineered buccal mucosa to repair long complex urethral stricture in 5 patients, the urethra successfully regenerated in 3 of them and maintained functional at mean follow-up of 8 years, however, 2 of them resulted in complete or partial graft removal.…”