Human Urine-derived Stem Cells Seeded Surface Modified Composite Scaffold Grafts for Bladder Reconstruction in a Rat Model

We conducted this study to investigate the synergistic effect of human urine-derived stem cells (USCs) and surface modified composite scaffold for bladder reconstruction in a rat model. The composite scaffold (Polycaprolactone/Pluronic F127/3 wt% bladder submucosa matrix) was fabricated using an immersion precipitation method, and heparin was immobilized on the surface via covalent conjugation. Basic fibroblast growth factor (bFGF) was loaded onto the heparin-immobilized scaffold by a simple dipping method. In maximal bladder capacity and compliance analysis at 8 weeks post operation, the USCs-scaffold(heparin-bFGF) group showed significant functional improvement (2.34 ± 0.25 mL and 55.09 ± 11.81 microL/cm H2O) compared to the other groups (2.60 ± 0.23 mL and 56.14 ± 9.00 microL/cm H2O for the control group, 1.46 ± 0.18 mL and 34.27 ± 4.42 microL/cm H2O for the partial cystectomy group, 1.76 ± 0.22 mL and 35.62 ± 6.69 microL/cm H2O for the scaffold group, and 1.92 ± 0.29 mL and 40.74 ± 7.88 microL/cm H2O for the scaffold(heparin-bFGF) group, respectively). In histological and immunohistochemical analysis, the USC-scaffold(heparin-bFGF) group showed pronounced, well-differentiated, and organized smooth muscle bundle formation, a multi-layered and pan-cytokeratin-positive urothelium, and high condensation of submucosal area. The USCs seeded scaffold(heparin-bFGF) exhibits significantly increased bladder capacity, compliance, regeneration of smooth muscle tissue, multi-layered urothelium, and condensed submucosa layers at the in vivo study.

Advance in Small-intestinal Submucosa for Bladder Augmentation (review) / 中国康复理论与实践

@#The need to find an alternative to the use of bowel for urinary reconstruction has renewed research interests involving bladder regeneration. Small intestinal submucosa (SIS) is an acellular, nonimmunogenic, biodegradable, xenogeneic, collagen-based material that is derived from the submucosa layer of porcine small intestine. SIS has demonstrated regenerative capacities in multiple organ systems, including the aorta, vena cava, ligaments, tendons, abdominal wall, and skin. This article reviewed the history of the development of the bladder regeneration and the studies involving the use of SIS for bladder augmentation.

Bladder Regeneration by Small Intestinal Submucosa with Release of Exogenous Growth Factors / 中国康复理论与实践

@#ObjectiveTo explore the release of exogenous growth factors from small intestinal submucosa (SIS) in bladder regeneration. MethodsThe release of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) from SIS in vitro were evaluated by ELISA and MTT method. The defected bladder walls of rats in experimental group were repaired with porcine small intestinal submuscosa. Partial bladder mucosa and smooth muscle of the rats in control groups were destroyed. At regular intervals, the VEGF and bFGF expression were observed by histological and immunohistochemical methods. ResultsThe concentration of bFGF and VEGF released in vitro from SIS in PBS solution were (121.8±2.683) ng/L and (93.8±3.033) ng/L respectively, and showed proliferation of vascular endothelial cell. In the SIS framework, the capillary and smooth muscle were observed followed histological evaluation. The weak expression of VEGF and bFGF in both experimental and control groups were found in the first week. Since the second week the VEGF and bFGF expression in experimental group began to increase with a peak in the 6th week, and began to decrease after 8 weeks. In the control group, the weak VEGF and bFGF expression were shown during the observation. ConclusionSIS functions as a carrier for exogenous growth factors release in rat bladder regeneration.

Bladder Regeneration by Small Intestinal Submucosa with Release of Exogenous Growth Factors / 中国康复理论与实践

@#ObjectiveTo explore the release of exogenous growth factors from small intestinal submucosa (SIS) in bladder regeneration. MethodsThe release of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) from SIS in vitro were evaluated by ELISA and MTT method. The defected bladder walls of rats in experimental group were repaired with porcine small intestinal submuscosa. Partial bladder mucosa and smooth muscle of the rats in control groups were destroyed. At regular intervals, the VEGF and bFGF expression were observed by histological and immunohistochemical methods. ResultsThe concentration of bFGF and VEGF released in vitro from SIS in PBS solution were (121.8±2.683) ng/L and (93.8±3.033) ng/L respectively, and showed proliferation of vascular endothelial cell. In the SIS framework, the capillary and smooth muscle were observed followed histological evaluation. The weak expression of VEGF and bFGF in both experimental and control groups were found in the first week. Since the second week the VEGF and bFGF expression in experimental group began to increase with a peak in the 6th week, and began to decrease after 8 weeks. In the control group, the weak VEGF and bFGF expression were shown during the observation. ConclusionSIS functions as a carrier for exogenous growth factors release in rat bladder regeneration.

Bladder Cellular Regeneration after Augmentation Cystoplasty with Human Dura Mater (Tutoplast(R)) in Rat / 대한비뇨기과학회지

PURPOSE: To study the cellular events occuring during bladder development and regeneration, we used the human Dura mater (Tutoplast(R)) for augmenting the rat bladder. We compared their intravesical threshold pressure and volume, and observed the regenerative capacity of urothelium and smooth muscle cell within Tutoplast(R). MATERIALS AND METHODS: Among a total of 67 rats, 11 normal rats were checked their intravesical threshold pressure and volume(Group 1). 9 rats underwent only vesicotomy(Sham operation) and were checked their threshold pressure and volume at 2 months and 3 months postoperatively(Group 2). 47 rats underwent augmentation cystoplasty with Tutoplast(R) after partial cystectomy, which were checked pressure and volume at 1 day, 3-7 days, 2-4 weeks, 2-6 months postoperatively(Group 3). Specimens were examined histologically to assess the regeneration of urothelium and smooth muscle cell on the graft. RESULTS: There was a significant increase in intravesical volume of group 3 compared with group 1 and 2. There was a significant decrease in intravesical pressure of group 3 compared with group 2, but there was no significant difference between group 1 and 3. The specimens of 1 day postopratively showed inflammatory findings. Epithelialization on the graft margin was noted at 3 days postoperatively. At 7 days postoperatively, there was epithelial hyperplasia on the graft site. At 2 weeks postoperatively, there was a partial absorption of Tutoplast(R) as well as favorable progression of epithelialization. Smooth muscle regeneration and complete epithelialization were shown at 3 months postoperatively and absorption of Tutoplast(R) was completed thereafter. CONCLUSIONS: The regeneration of bladder cellular constituents within Tutoplast(R) will be valuable for further understanding the mechanism controlling bladder development and regeneration. Further studies will be necessary for using this method as an alternative strategy to the classical bladder augmentation.

An Experimental Study on Bladder Regeneration / 대한비뇨기과학회지

Mechanism and process of bladder regeneration were experimentally observed in this study, using 3S Korean mongrel dogs weighing 15~25kg. The animals were divided into two experimental groups. In the first group (A) of 27 dogs subtotal cystectomy and urinary diversion were underwent to study the influence of urine on the bladder regeneration and the second group (B) of 8 dogs in which only subtotal cystectomy was performed was investigated for the process of regeneration. In the group A the dogs were sacrificed every week in the first one month, every 2 weeks in the following 5 months and every 4 weeks thereafter. The bladder was examined morphologically and histologically and no remarkable regenerative process was observed. In the group B 8 dogs were sacrificed at intervals of 2 or 4 weeks after 6 months of initial operation. The distinct regenerated bladder was noticed and its completion took place in 36 weeks. The area of regeneration showed a definite thick walled pouch with normal uroepithelium and normal color. From these observations it is postulated that urine might have played a role in regeneration of the bladder. possibly by mechanical stimulation and a further study will be necessary to investigate a possible chemical factor.

An Experimental Study on Bladder Regeneration / 대한비뇨기과학회지

One hundred and ten rats weighing 100 gm. or more were used. These animals were divided into two study groups. The first consisted of 80 rats and this groupwas used to follow up the process of bladder regeneration. The second consisted of 30 rats and in this group polyethylene tube (I.D. .023" X O.D. .038") was placed in the space after subtotal cystectomy through the urethra, and the tube was sutured to the urethra with 4-0 silk to investigate whether the urinary retention is necessary for the bladder regeneration. Anesthesia was accomplished by intraperitoneal and through a subumbilical median incision the bladder was exposed transperitoneally and subtotal cystectomy was done saving the trigone andureteral orifices. To prevent the urinary leakage the edge of remnant bladder wasclosed with 4-0 chromic catgut. In the first group, 10 rats each were sacrificed at intervals of one week after initial operation for 8 weeks. There was complete restoration of what appeared to be normal bladder capacity at the end of 8 weeks. The regenerated bladder was a definite thick-walled pouch lined with normal epithelium and many capillaries. In the second group, 30 rats were sacrificed after the initial operation: 6 each at the 4th, 5th, 6th, 7th and 8th week. At the end of 8 weeks regeneration of the bladder was markedly inhibited as compared with the first group. It is felt that the mechanical stretch of the bladder is the main factor by which the bladder grows. The urine pooling in the pouch serves not only to preserve and enlarge the pouch but also to develop the elements of new bladder wall by intermittent filling and emptying. The most inhibitory factorin bladder regeneration is the wound infection.