The predictors of short and long term urinary continence recovery after laparoscopic radical prostatectomy: a single cancer center report in China.

PURPOSE: To evaluate the predictors for short and long term urinary continence (UC) recovery after laparoscopic radical prostatectomy (LRP) from clinical and oncological variables. METHODS: We retrospectively collected data from 142 prostate cancer patients who underwent LRP between September 2014 and June 2021 at a tumor specialist diagnosis and treatment center in China. The rate of post-prostatectomy incontinence (PPI) was evaluated from immediate and at 3, 6 and 12 mo after LRP, and UC was defined as the use of no or one safety pad. Sixteen clinical and oncological variables were analyzed by univariate and multivariate regression analysis to determine whether they were associated with short (3 mo) or long term (12 mo) UC recovery after LRP. RESULTS: After eliminating patients who were lost to follow-up, 129 patients were eventually included. The mean ± SD age was 68 ± 6.3 years. The UC rates of immediate, 3, 6 and 12 mo after the operation were 27.9%, 54.3%, 75.2% and 88.4%, respectively. Multivariate analyses revealed that membranous urethral length (MUL) was a protective predictor of UC after catheter extraction(P < 0.001), and at 3 mo (P < 0.001), 6 mo (P < 0.001) and 12 mo (P = 0.009) after surgery. CONCLUSION: MUL is a significant independent factor that can contribute to short and long term UC recovery post-LRP, which may assist clinicians and their patients in counseling of treatment.

Establishment and evaluation of ectopic and orthotopic prostate cancer models using cell sheet technology.

BACKGROUND: The traditional prostate cancer (PCa) model is established by injecting cell suspension and is associated with a low tumor formation rate. Cell sheet technology is one of the advancements in tissue engineering for 3D cell-based therapy. In this study, we established ectopic and orthotopic PCa models by cell sheet technology, and then compared the efficiency of tumor formation with cell suspension injection. METHODS: DU145 cells were seeded on 35 mm temperature-sensitive dishes to form PCa cell sheets, while the cell suspension with the same cell density was prepared. After transplanting into the nude mice, the tumor volumes were measured every 3 days and the tumor growth curves were conducted. At the time points of 2 weeks and 4 weeks after the transplantation, magnetic resonance imaging (MRI) was used to evaluate the transplanting site and distant metastasis. Finally, the mice were sacrificed, and the related tissues were harvested for the further histological evaluation. RESULTS: The orthotopic tumor formation rate of the cell sheet injection group was obviously better than that in cell suspension injection group (100% vs 67%). Compared with cell suspension injection, the tumors of DU145 cell sheet fragments injection had the higher density of micro-vessels, more collagen deposition, and lower apoptosis rate. There was no evidence of metastasis in forelimb, lung and liver was found by MRI and histological tests. CONCLUSION: We successfully cultured the DU145 cell sheet and can be used to establish ectopic and orthotopic PCa tumor-bearing models, which provide an application potential for preclinical drug development, drug-resistance mechanisms and patient individualized therapy.

Biobanked human foreskin epithelial cell sheets reduce inflammation and promote wound healing in a nude mouse model.

BACKGROUND: Human epithelial cell sheets (ECSs) are used to clinically treat epithelial conditions such as burns, corneal blindness, middle ear cholesteatoma and vitiligo. As a widely used material in clinic, there is little information on the biobanking of ECSs and its repair effect after storage. RESULTS: Two methods for biobanking foreskin ECSs were compared in a short term (7 days): 4-degree storage and programmed cryopreservation. Cell sheet integrity, viability, apoptosis, immunogenicity, mechanical properties and function were evaluated. In vivo, ECSs were directly transplanted to skin defect models and histological examination was performed at 1 week postoperatively. We successfully extracted human foreskin-derived primary epithelial cells and fabricated them into ECSs. Compared with 4-degree storage, programmed cryopreservation preserved the ECS structural integrity, enhanced the mechanical properties, decreased HLA-I expression, and increased cell viability and survival. An increased proportion of melanocytes with proliferative capacity remained in the cryopreserved sheets, and the undifferentiated epithelial cells were comparable to those of the fresh sheets. In vivo, cryopreserved ECSs could reduce inflammatory cell infiltration and promote connective tissue remodeling, epithelial cell proliferation and vascular regeneration. CONCLUSIONS: Programmed cryopreservation of ECSs was superior and more feasible than 4-degree storage and the cryopreserved ECSs achieved satisfying skin wound healing in vivo. We anticipate that the off-the-shelf ECSs could be quickly used, such as, to repair human epithelial defect in future.

Magnetic targeting of super-paramagnetic iron oxide nanoparticle labeled myogenic-induced adipose-derived stem cells in a rat model of stress urinary incontinence.

Cell-based injectable therapy utilizing stem cells is a promising approach for the treatment of stress urinary incontinence (SUI). Applying a magnetically controlled cell delivery approach has enormous potential to enhance cell retention capability within the specified site. To assess the therapeutic efficacy of cellular magnetic targeting, we applied an external magnetic force to target an adipose-derived stem cell based therapy in a rat model of SUI. The results revealed that magnetic attraction of transplanted cells under the magnetic field was generated by cell uptake of superparamagnetic iron oxide nanoparticles in vitro. More importantly, magnetic targeting improved the retention rate of transplanted cells and facilitated the restoration of sphincter structure and function in a rat SUI model according to the results of histological examination and urodynamic testing. Therefore, magnetically guided targeting strategy might be a potential therapy method for treatment of SUI.

The fabrication of 3D surface scaffold of collagen/poly (L-lactide-co-caprolactone) with dynamic liquid system and its application in urinary incontinence treatment as a tissue engineered sub-urethral sling: In vitro and in vivo study.

AIMS: To fabricate a novel nanoyarn biomaterial via a dynamic liquid electrospinning system, and to simultaneously evaluate whether nanoyarn is capable of being applied as a urinary sling for future clinical transfer. METHODS: Nanoyarn was cultured with adipose-derived stem cells (ADSCs). Cell morphology and function were observed on nanoyarn. Female rats that underwent vagina dilatation (VD) and bilateral ovarian resection (BOR) were used as the urinary incontinence model. After 2 weeks, the cells-sling was fixed to the suburethra. A commercial sling that tension-free vaginal tape-obturator (TVT-O) was used as a control. The urodynamic test for leak point pressure (LPP) and histological tests were used to evaluate the sling's performance in vivo. RESULTS: The nanoyarn possessed beneficial properties and the actin filament from ADSCs, which is very similar to muscle. Rats that underwent VD and BOR maintained a low LPP, whereas the LPP in rats with VD alone recovered to normal levels within 2 weeks. LPP in the nanoyarn group gradually decreased on the three urodynamic tests post-suburethral surgery, however, the cell-laden nanoyarn maintained LPP at normal levels for 8 weeks; the TVT-O group showed a significant increase in LPP at 8 weeks. Cell-laden nanoyarn was infiltrated with more cells, collagen, and vessels than the controls. CONCLUSIONS: The nanoyarn showed sufficient efficacy to maintain LPP in urinary incontinence rat model. In addition, it improved cell infiltration, collagen and muscle development compared to TVT-O. Thus, the combination of ADSCs and a nanoyarn scaffold could be a promising tissue-engineered sling for the treatment of urinary incontinence.

The Immediate Management of Pelvic Fracture Urethral Injury-Endoscopic Realignment or Cystostomy?

PURPOSE: We determined whether endoscopic realignment or cystostomy would provide the best immediate management of pelvic fracture urethral injury. MATERIALS AND METHODS: We retrospectively reviewed the records of 590 patients with pelvic fracture urethral injury. Of the patients 522 were included in analysis due to strict criteria, including 129 in the endoscopic realignment group and 393 in the cystostomy group. Data on stricture formation and length, intervention technique and long-term functional outcomes were analyzed. RESULTS: In the endoscopic realignment group stricture developed in 111 patients (83%) at a mean of 23.5 months, which is longer than the 7.6 months reported in the cystostomy group (p <0.05). Mean stricture length was 3.2 cm in the realignment group and 3.7 cm in the cystostomy group (p <0.05). Internal urethrotomy was performed in 21 patients (19%) treated with realignment vs 18 (5%) treated with cystostomy (p <0.05). Further repair was accomplished via simple perineal anastomosis in 57 patients (51%) with realignment and 138 (35%) with cystostomy (p <0.05). Ancillary procedures such as corporeal splitting, inferior pubectomy and crural rerouting were necessary in 14 (13%), 14 (13%) and 5 patients (4%) in the endoscopic realignment group, and in 94 (24%), 100 (25%) and 43 (11%), respectively, in the cystostomy group (all p <0.05). The rates of impotence and incontinence did not statistically differ between the endoscopy and cystostomy groups (14.3% vs 16.2% and 1.6% vs 2.1%, respectively, p >0.05). CONCLUSIONS: Endoscopic realignment may reduce stricture formation and length, and facilitate urethroplasty. However, endoscopic realignment is also associated with a prolonged clinical course for recurrence.

Etiology and Management of Male Iatrogenic Urethral Stricture: Retrospective Analysis of 172 Cases in a Single Medical Center.

PURPOSE: To investigate the etiology and management of male iatrogenic urethral stricture in China. METHODS: The data of 172 patients with iatrogenic urethral stricture who underwent treatment at a high volume reference center in China from January 2008 to February 2014 were analyzed retrospectively. Databases were analyzed to understand the impact of different types of iatrogenic injury on stricture location, length and treatment of urethral strictures, as well as success rates. RESULTS: The most common type of iatrogenic stricture was urethral instrumentations in 80 patients (46.51%). Mean stricture length was 3.3 ± 2.54 cm and the longest strictures were those caused by intravesical instillation. Substitution urethroplasty was the most common intervention and was performed in 60.47% (104/172) of patients. The overall success rate was 85.00% (136/160). Univariable analyses revealed that the type of iatrogenic injury was significantly related to restenosis (p = 0.036), and it is more apt to postoperative restenosis in the type of intravesical instillation than others. CONCLUSION: Our results showed that urethral instrumentation is the most common etiology of iatrogenic urethral stricture, and most iatrogenic urethral strictures involve the anterior urethra. The different etiologies are closely associated with stricture location, length and the overall prognosis of urethral strictures.

Current Stem Cell Biomarkers and Their Functional Mechanisms in Prostate Cancer.

Currently there is little effective treatment available for castration resistant prostate cancer, which is responsible for the majority of prostate cancer related deaths. Emerging evidence suggested that cancer stem cells might play an important role in resistance to traditional cancer therapies, and the studies of cancer stem cells (including specific isolation and targeting on those cells) might benefit the discovery of novel treatment of prostate cancer, especially castration resistant disease. In this review, we summarized major biomarkers for prostate cancer stem cells, as well as their functional mechanisms and potential application in clinical diagnosis and treatment of patients.

Evaluation of 18F-PSMA-1007 PET/CT in prostate cancer patients with biochemical recurrence after radical prostatectomy.

PURPOSE: Prostate-specific membrane antigen (PSMA) ligands targeting has shown promising results in staging of prostate cancer (PCa). The aim of present study was to evaluate the value of 18F-PSMA-1007 PET/CT in PCa patients with biochemical recurrence. METHODS: 71 patients with PCa after radical prostatectomy (RP) were included in the present study. Median prostate-specific antigen (PSA) level was 1.27 ng/mL (range 0.01-67.40 ng/mL, n = 69). All patients underwent whole-body PET/CT imaging after injection of 333±38 MBq 18F-PSMA-1007. The distribution of PSMA-positive lesions was assessed. The influence of PSA level, androgen deprivation therapy and primary Gleason score on PSMA-positive finding and uptake of 18F-PSMA-1007 were evaluated. RESULTS: 56 (79%) patients showed at least one pathological finding on 18F-PSMA-1007 PET/CT. The rates of positive scans were 50%, 80%, 100%, 100% among patients with PSA levels ≤0.5, 0.51-1.0, 1.1-2.0 and >2.0 ng/mL, respectively. The median Gleason score was 8 (range 7-10), and higher Gleason score (≤7 vs. ≥8) leads to higher detection rates (58.3% (14/24) vs. 88.9% (32/36), P = 0.006). The median SUVmax of positive findings in patients with PSA levels ≤0.5, 0.51-1.0, 1.1-2.0 and >2.0 ng/mL were 4.51, 4.27, 11.50 and 14.08, respectively. The median SUVmax in patients with PSA level >2.0 ng/mL was significantly higher than that in patients with PSA ≤2.0 ng/mL (14.08 vs. 6.13, P<0.001). CONCLUSION: 18F-PSMA-1007 PET/CT demonstrated a high detection rate for patients with a raised PSA level after radical prostatectomy even in patients with extremely low PSA level (eg. PSA level ≤0.5 ng/mL), which was essential for further clinical management for PCa patients.

Retroperitoneal laparoscopic partial nephrectomy for unilateral synchronous multifocal renal carcinoma with different pathological types: A case report.

BACKGROUND: The majority of renal cell carcinomas are single lesions; unilateral synchronous multifocal renal carcinoma (USMRC) is rarely reported and poses a treatment challenge for urological oncologists. CASE SUMMARY: A 56-year-old man was hospitalized for pain and discomfort in the right kidney area for 6 d. Contrast-enhanced computed tomography demonstrated cT1a renal tumors at the lower pole of the right kidney and a cT1b renal tumor at the middle dorsal portion of the right kidney. The patient underwent retroperitoneal laparoscopic partial nephrectomy (RLPN). There were no complications peri-operatively. Histopathology revealed a low-grade, pathologic stage T1a (pT1a), clear cell renal cell carcinoma at the lower pole of the right kidney and a pT1b, chromophobe renal cell carcinoma at the middle dorsal portion of the right kidney. No tumor bed recurrence or metastasis was observed on imaging and his renal function remained stable during the 12-mo follow-up period. CONCLUSION: RLPN is a safe, effective, and feasible for the management of USMRC, which can obtain equivalent oncological results with optimal renal function preservation.

Cryopreserved skin epithelial cell sheet combined with acellular amniotic membrane as an off-the-shelf scaffold for urethral regeneration.

BACKGROUND: Autologous tissue transplantation for urethral repair is often limited and causes donor site complications. Here, a cryopreserved rabbit skin epithelial cell sheet (SEC) combined with an acellular amniotic membrane (AM) was used to repair rabbit urethral defects. METHODS: Abdominal skin was collected from 4-week-old New Zealand rabbits, and primary epithelial cells were extracted and cultured to form a cell sheet. Fresh SEC-AMs were constructed and cryopreserved. A cryopreservation system including optimized medium, two-pump perfusion, a programmed freezer and liquid nitrogen storage was established. Cell viability, mechanical strength, electron microscopy, and histological staining were performed in vitro after 1 month. Next, the sheets were transplanted subcutaneously for 2 weeks, and the graft was used to repair the rabbit urethral defect. Urinary function was measured and samples were collected for histological staining after 1 month. RESULTS: We confirmed that cryopreservation damage of SECs was reduced by composition with acellular AMs in terms of high cell activity. The SEC mechanical strength was also enhanced by AMs, which was convenient for the operation. In in vivo experiments, we transplanted sheets into the groin area for two weeks and found that cryopreservation reduced inflammatory cell infiltration and significantly improved vascular density. In the urethral repair experiment, the near-normal passive urine flow rate, smooth mucosa of the gross specimen, intact epithelialization and abundant neovascularization were confirmed in the cryopreserved-SEC-AM group compared with the other groups. CONCLUSIONS: Cryopreserved SEC-AMs demonstrated similar outcomes of rabbit urethral defect repair as fresh SEC-AMs, showing good clinical application prospects.

Electrokinetic remediation of uranium(VI)-contaminated red soil using composite electrolyte of citric acid and ferric chloride.

In the process of electrokinetic (EK) remediation of uranium-contaminated soil, the existence form of uranium in soil pore fluid will affect on its migration behavior. In this paper, a novel type of electrolyte (citric acid + ferric chloride, CA+ FeCl3) has been investigated for the EK remediation of uranium-contaminated red soil. The effects of different electrolyte and the concentrations of FeCl3 on migration behavior of U(VI) and environmental risks were investigated after EK remediation. The result showed that the optimum concentration was 0.1 mol/L CA mixed with 0.03 mol/L FeCl3 in this study. At this time, the removal efficiency of uranium was about 61.55 ± 0.41%, and the cumulative energy consumption was 0.2559 kWh. Compared with deionized water and single CA, combined CA with FeCl3 has the advantages of high removal efficiency, low leaching toxicity, and less damage to the soil after the electrokinetic remediation treatment.

The Fabrication and Evaluation of a Potential Biomaterial Produced with Stem Cell Sheet Technology for Future Regenerative Medicine.

To date, the decellularized scaffold has been widely explored as a source of biological scaffolds for regenerative medicine. However, the acellular matrix derived from natural tissues and organs has a lot of defects, including the limited amount of autogenous tissue and surgical complication such as risk of blood loss, wound infection, pain, shock, and functional damage in the donor part of the body. In this study, we prepared acellular matrix using adipose-derived stem cell (ADSC) sheets and evaluate the cellular compatibility and immunoreactivity. The ADSC sheets were fabricated and subsequently decellularized using repeated freeze-thaw, Triton X-100 and SDS decellularization. Oral mucosal epithelial cells were seeded onto the decellularized ADSC sheets to evaluate the cell replantation ability, and silk fibroin was used as the control. Then, acellular matrix was transplanted onto subcutaneous tissue for 1 week or 3 weeks; H&E staining and immunohistochemical analysis of CD68 expression and quantitative real-time PCR (qPCR) were performed to evaluate the immunogenicity and biocompatibility. The ADSC sheet-derived ECM scaffolds preserved the three-dimensional architecture of ECM and retained the cytokines by Triton X-100 decellularization protocols. Compared with silk fibroin in vitro, the oral mucosal epithelial cells survived better on the decellularized ADSC sheets with an intact and consecutive epidermal cellular layer. Compared with porcine small intestinal submucosa (SIS) in vivo, the homogeneous decellularized ADSC sheets had less monocyte-macrophage infiltrating in vivo implantation. During 3 weeks after transplantation, the mRNA expression of cytokines, such as IL-4/IL-10, was obviously higher in decellularized ADSC sheets than that of porcine SIS. A Triton X-100 method can achieve effective cell removal, retain major ECM components, and preserve the ultrastructure of ADSC sheets. The decellularized ADSC sheets possess good recellularization capacity and excellent biocompatibility. This study demonstrated the potential suitability of utilizing acellular matrix from ADSC sheets for soft tissue regeneration and repair.

Use of bioactive extracellular matrix fragments as a urethral bulking agent to treat stress urinary incontinence.

Injection of urethral bulking agents is a low-risk, minimally invasive surgical procedure to treat stress urinary incontinence (SUI). In this study, we developed a promising injectable bulking agent comprising extracellular matrix fragments of adipose-derived stem cell sheets (ADSC ECM) and investigated its effectiveness in urethral bulking therapy. The structural integrity and proteins of ADSC sheet ECM were well retained in decellularized ADSC ECM fragments. To locate transplanted ADSC ECM fragments, they were labeled with ultrasmall super-paramagnetic iron oxide nanoparticles, which enabled in vivo monitoring after implantation in a SUI rat model for up to 4 weeks. When ADSC ECM fragments were injected into the rat urethra, they became fully integrated with the surrounding tissue within 1 week. Four weeks after transplantation, host cells had regenerated within the ADSC ECM fragment injection area. Moreover, new smooth muscle tissue had formed around the ADSC ECM fragments, as confirmed by positive staining of myosin. These results indicate that injection of ECM fragments may be a promising minimally invasive approach for treating SUI.

Let-7i-5p Regulation of Cell Morphology and Migration Through Distinct Signaling Pathways in Normal and Pathogenic Urethral Fibroblasts.

microRNAs regulate subcellular functions through distinct molecular mechanisms. In this study, we used normal and pathogenic fibroblasts in pelvic fracture urethral distraction defects (PFUDD) patients. PFUDD is a common disease that could severely affect patients' life quality, yet little is known about the molecular mechanism associated with pathogenic fibrosis in PFUDD. Our data showed that let-7i-5p performs a multi-functional role in distinct signaling transduction pathways involved in cell morphology and cell migration in both normal and pathogenic fibroblasts. By analyzing the molecular mechanism associated with its functions, we found that let-7i-5p regulates through its direct target genes involved in collagen metabolism, cell proliferation and differentiation, TGF-beta signaling, DNA repair and ubiquitination, gene silencing and oxygen homeostasis. We conclude that let-7i-5p plays an essential role in regulating cell shape and tissue elasticity, cell migration, cell morphology and cytoskeleton, and could serve as a potential target for clinical treatment of urethral stricture patients.

Preparation of aluminum sludge composite gel spheres and adsorption of U(IV) from aqueous solution.

A novel three-dimensional aluminum sludge/polyvinyl alcohol/sodium alginate(AS/PA/SA) gel spheres were designed and prepared for uranium(VI) adsorption, and it overcomes the shortcomings of poor recycling of powdery aluminum sludge adsorbent and poor stability of sodium alginate. Experiments show that the P-S-AS has a good pH range for removal of uranium (4-5). Fitting experimental data with pseudo-first-order kinetic model and pseudo-second-order kinetic model shows that the adsorption of U(VI) by P-S-AS is a chemical action. The fit of the Langmuir isotherm model and Freundlich isotherm model to the experimental data found that the P-S-AS adsorbed U(VI) to a single layer. Thermodynamic analysis shows that the adsorption occurs spontaneously, and an increase in temperature is favorable for the adsorption of uranium by the P-S-AS. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis of the P-S-AS before and after adsorption showed that the main adsorption mechanism was the complexation reaction between functional groups and U(VI), the bonding reaction between metal oxides and U(VI).

Bioengineered bladder patches constructed from multilayered adipose-derived stem cell sheets for bladder regeneration.

Cell-seeded scaffolds are a common route of cell transplantation for bladder repair and reconstruction. However, when cell suspensions are harvested, proteolytic enzymes often cause extracellular matrix damage and loss of intercellular junctions. To overcome this problem, we developed a bioengineered three-dimensional bladder patch comprising porous scaffolds and multilayered adipose-derived stem cell (ASC) sheets, and evaluated its feasibility for bladder regeneration in a rat model. Adipose-derived stem cells (ASCs) were labeled with ultrasmall super-paramagnetic iron oxide (USPIO) nanoparticles. ASC patches were constructed using multilayered USPIO-labeled ASC sheets and porous polyglycolic acid scaffolds. To monitor the distribution and localization of bioengineered bladder patches in live animals, magnetic resonance imaging (MRI) was performed 2 weeks, 4 weeks and 8 weeks after transplantation. The bladder regenerative potential of ASC patches was further evaluated by urodynamic and histological analysis. Scanning electron microscopy indicated that cell sheets adhered tightly to the scaffold. MRI showed hypointense signals that lasted up to 8 weeks at the site of USPIO-labeled ASC sheet transplants. Immunofluorescence demonstrated that these tissue-engineered bladder patches promoted regeneration of urothelium, smooth muscle, neural cells and blood vessels. Urodynamic testing revealed that the ASC patch restored bladder function with augmented capacity. The USPIO-labeled ASC patch provides a promising perspective on image-guided tissue engineering and holds great promise as a safe and effective therapeutic strategy for bladder regeneration. STATEMENT OF SIGNIFICANCE: Adipose-derived stem cell (ASC) sheets avoid enzymatic dissociation and preserve the cell-to-cell interactions and extracellular matrix (ECM) proteins, which exhibit great potential for tissue regeneration. In this study, we developed a bioengineered three-dimensional bladder patch comprising porous scaffolds and multilayered ASC sheets, and evaluated its feasibility for bladder regeneration in a rat model. Tissue-engineered bladder patches restored bladder function and promoted regeneration of urothelium, smooth muscle, neural cells and blood vessels. Moreover, ultrasmall super-paramagnetic iron oxide (USPIO)-labeled bladder patches can be dynamically monitored in vivo by noninvasive MRI for long periods of time. Therefore, The USPIO-labeled bladder patch provides a promising image-guided therapeutic strategy for bladder regeneration.

The enhanced angiogenesis effect of VEGF-silk fibroin nanospheres-BAMG scaffold composited with adipose derived stem cells in a rabbit model.

We report a study to determine whether a vascular endothelial growth factor (VEGF)-silk fibroin (SF) nanospheres-bladder acellular matrix graft (BAMG) scaffold composited with adipose derived stem cells (ADSCs) could enhance angiogenesis in bladder regeneration in rabbits. Rabbit ADSCs were isolated and identified by flow cytometry. The morphology and release behaviour of VEGF-SF nanospheres were detected. After the composite scaffolds were successfully used in bladder reconstruction, the bladder capacity, H&E staining and immunohistochemical staining were studied at different time points. ADSCs exerts high expression rates of CD29, CD90, and CD44, accompanied with low expression rates of CD34 and CD45. SF nanospheres with diameters of 200-1000 nm were prepared to load VEGF, and they contributed to maintain the release of VEGF. The reconstructed bladder with VEGF-SF nanospheres-BAMG plus ADSCs had more regular smooth muscle tissue and blood vessels. Moreover, instead of differentiating into epithelial or vascular endothelial cells, ADSCs may be more likely to provide additional cytokines to enhance angiogenesis in the bladder regeneration process. The tissue engineered bladder constructed by BAMG modified by VEGF-SF nanospheres possessed high bio-compatibility and an enhanced angiogenesis effect, and could be used as an ideal biological material to repair bladder defects after being composited with ADSCs.

Labeling adipose derived stem cell sheet by ultrasmall super-paramagnetic Fe3O4 nanoparticles and magnetic resonance tracking in vivo.

Cell sheet therapy has emerged as a potential therapeutic option for reparation and reconstruction of damaged tissues and organs. However, an effective means to assess the fate and distribution of transplanted cell sheets in a serial and noninvasive manner is still lacking. To investigate the feasibility of tracking Adipose derived stem cells (ADSCs) sheet in vivo using ultrasmall super-paramagnetic Fe3O4 nanoparticles (USPIO), canine ADSCs were cultured and incubated with USPIO and 0.75 µg/ml Poly-L-Lysine (PLL) for 12 h. Labeling efficiency, cell viability, apoptotic cell rate were assessed to screen the optimum concentrations of USPIO for best labeling ADSCs. The results showed ADSCs were labeled by USPIO at an iron dose of 50 µg/ml for a 12 h incubation time, which can most efficiently mark cells and did not impair the cell survival, self-renewal, and proliferation capacity. USPIO-labeled ADSCs sheets can be easily and clearly detected in vivo and have persisted for at least 12 weeks. Our experiment confirmed USPIO was feasible for in vivo labeling of the ADSCs sheets with the optimal concentration of 50 µg Fe/ml and the tracing time is no less than 12 weeks.

Fabrication of Tissue-Engineered Bionic Urethra Using Cell Sheet Technology and Labeling By Ultrasmall Superparamagnetic Iron Oxide for Full-Thickness Urethral Reconstruction.

Urethral strictures remain a reconstructive challenge, due to less than satisfactory outcomes and high incidence of stricture recurrence. An "ideal" urethral reconstruction should establish similar architecture and function as the original urethral wall. We fabricated a novel tissue-engineered bionic urethras using cell sheet technology and report their viability in a canine model. Small amounts of oral and adipose tissues were harvested, and adipose-derived stem cells, oral mucosal epithelial cells, and oral mucosal fibroblasts were isolated and used to prepare cell sheets. The cell sheets were hierarchically tubularized to form 3-layer tissue-engineered urethras and labeled by ultrasmall super-paramagnetic iron oxide (USPIO). The constructed tissue-engineered urethras were transplanted subcutaneously for 3 weeks to promote the revascularization and biomechanical strength of the implant. Then, 2 cm length of the tubularized penile urethra was replaced by tissue-engineered bionic urethra. At 3 months of urethral replacement, USPIO-labeled tissue-engineered bionic urethra can be effectively detected by MRI at the transplant site. Histologically, the retrieved bionic urethras still displayed 3 layers, including an epithelial layer, a fibrous layer, and a myoblast layer. Three weeks after subcutaneous transplantation, immunofluorescence analysis showed the density of blood vessels in bionic urethra was significantly increased following the initial establishment of the constructs and was further up-regulated at 3 months after urethral replacement and was close to normal level in urethral tissue. Our study is the first to experimentally demonstrate 3-layer tissue-engineered urethras can be established using cell sheet technology and can promote the regeneration of structural and functional urethras similar to normal urethra.