[Cellular therapy and urinary incontinence]

Two phase I/II clinical trials for the treatment of urinary incontinence with autologous mesenchymal stem cells

We evaluated the safety and feasibility of adipose‐derived mesenchymal stem cells to treat endoscopically urinary incontinence after radical prostatectomy in men or female stress urinary. We designed two prospective, nonrandomized phase I‐IIa clinical trials of urinary incontinence involving 9 men (8 treated) and 10 women to test the feasibility and safety of autologous mesenchymal stem cells for this use. Cells were obtained from liposuction containing 150 to 200 g of fat performed on every patient. After 4 to 6 weeks and under sedation, endoscopic intraurethral injection of the cells was performed. On each visit (baseline, 1, 3, 6, and 12 months), clinical parameters were measured, and blood samples, urine culture, and uroflowmetry were performed. Every patient underwent an urethrocystoscopy and urodynamic studies on the first and last visit. Data from pad test, quality‐of‐life and incontinence questionnaires, and pads used per day were collected at every visit. Statistical analysis was done by Wilcoxon signed‐rank test. No adverse effects were observed. Three men (37.5%) and five women (50%) showed an objective improvement of >50% (P < .05) and a subjective improvement of 70% to 80% from baseline. In conclusion, intraurethral application of stem cells derived from adipose tissue is a safe and feasible procedure to treat urinary incontinence after radical prostatectomy or in female stress urinary incontinence. A statistically significant difference was obtained for pad‐test improvement in 3/8 men and 5/10 women. Our results encourage studies to confirm safety and to analyze efficacy.

Histological and Urodynamic Effects of Autologous Stromal Vascular Fraction Extracted from Fat Tissue with Minimal Ex Vivo Manipulation in a Porcine Model of Intrinsic Sphincter Deficiency

PURPOSE

To evaluate the healing abilities of autologous stem cell therapy (stromal vascular fraction) prepared from adipose tissue we used an automated system without an ex vivo culture phase in a pig model of intrinsic sphincteric deficiency.

MATERIALS AND METHODS

A total of 15 pigs underwent endoscopic section of the urethral sphincter. Animals were then randomly assigned to 3 groups, including 1) controls without stromal vascular fraction injection, 2) early injection with stromal vascular fraction 2 to 3 days after section and 3) late stromal vascular fraction injection delivery 30 days after injury. Extraction and stromal vascular fraction injection were performed as a single procedure. The stromal vascular fraction was characterized by flow cytometry. Mesenchymal stem cell-like cells were enumerated by clonogenicity (cfu fibroblast) assay. Study end points included histological assessment of the urethral injury surface and urodynamics to determine maximum urethral pressure.

RESULTS

Flow cytometry analysis revealed a mesenchymal stem cell-like phenotype in a mean ± SD of 47.3% ± 11.8% of stromal vascular fraction cells. The cfu fibroblast frequency was 1.3 to 6.6/100 stromal vascular fraction cells (1.3% to 6.6%). Stromal vascular fraction injection was associated with a reduction of the urethral injury surface in the early and late injection groups compared with the respective controls (7% vs 17% and 1% vs 13%, p = 0.050 and 0.029, respectively). On day 30 after injection maximum urethral pressure was significantly higher in the injected groups than in the control group, that is 64% vs 50% of maximum urethral pressure on day 0 (p = 0.04).

CONCLUSIONS

These data demonstrate the ability of an autologous stromal vascular fraction to improve the urethral healing process in a large animal model of intrinsic sphincteric deficiency.

Stem Cell Therapy for Treatment of Stress Urinary Incontinence: The Current Status and Challenges

Stress urinary incontinence (SUI) is a common urinary system disease that mostly affects women. Current treatments still do not solve the critical problem of urethral sphincter dysfunction. In recent years, there have been major developments in techniques to obtain, culture, and characterize autologous stem cells as well as many studies describing their applications for the treatment of SUI. In this paper, we review recent publications and clinical trials investigating the applications of several stem cell types as potential treatments for SUI and the underlying challenges of such therapy.

Virus integration and genome influence in approaches to stem cell based therapy for andro-urology

Despite the potential of stem cells in cell-based therapy, major limitations such as cell retention, ingrowth, and trans-differentiation after implantation remain. One technique for genetic modification of cells for tissue repair is the introduction of specific genes using molecular biology techniques, such as virus integration, to provide a gene that adds new functions to enhance cellular function, and to secrete trophic factors for recruiting resident cells to participate in tissue repair. Stem cells can be labeled to track cell survival, migration, and lineage. Increasing evidence demonstrates that cell therapy and gene therapy in combination remarkably improve differentiation of implanted mesenchymal stromal cells (MSCs), revascularization, and innervation in genitourinary tissues, especially to treat urinary incontinence, erectile dysfunction, lower urinary tract reconstruction, and renal failure. This review discusses the benefits, safety, side effects, and alternatives for using genetically modified MSCs in tissue regeneration in andro-urology.

The dose-effect safety profile of skeletal muscle precursor cell therapy in a dog model of intrinsic urinary sphincter deficiency

Locally injected skeletal muscle precursor cells (skMPCs) integrate into and restore the muscle layers, innervation, vasculature, and function of the sphincter complex in animal models of intrinsic urinary sphincter deficiency (ISD). The goal of the present study was to test the dose-effect safety profile of skMPC therapy in a dog model of ISD. Sphincter deficiency was created in 20 adult female dogs by surgically removing the skeletal muscle layer of the urinary sphincter complex. skMPCs isolated from the hind leg were expanded in culture and injected 4 weeks later into the sphincter complex at a dose of 25 million cells (n = 5), 50 million cells (n = 5), or 100 million cells (n = 5) per milliliter in a 2-ml volume. Five dogs received no sphincter injection. The measures of maximal sphincter pressure, complete blood count, and blood chemistry were performed monthly until their sacrifice at 9 months. At that point, full necropsy was performed to assess the safety of the skMPC injections. Injection of different doses of cells had no effects on the body weight, blood cell count, or kidney or liver function test results (p > .05 among the skMPC doses). Some incidental pathologic features were found in the lower urinary tract in all groups and were most likely associated with repeat catheterization. The maximal urinary sphincter pressure was higher in the 50 million cells per milliliter treatment group than in the other experimental groups (p < .05). The findings of the present study have confirmed that urinary sphincter injection of skMPCs results in no significant local or systemic pathologic features within the dose range that improves sphincter pressures.

Skeletal myogenic differentiation of urine-derived stem cells and angiogenesis using microbeads loaded with growth factors

To provide site-specific delivery and targeted release of growth factors to implanted urine-derived stem cells (USCs), we prepared microbeads of alginate containing growth factors. The growth factors included VEGF, IGF-1, FGF-1, PDGF, HGF and NGF. Radiolabeled growth factors were loaded separately and used to access the in vitro release from the microbeads with a gamma counter over 4 weeks. In vitro endothelial differentiation of USCs by the released VEGF from the microbeads in a separate experiment confirmed that the released growth factors from the microbeads were bioactive. USCs and microbeads were mixed with the collagen gel type 1 (2 mg/ml) and used for in vivo studies through subcutaneous injection into nude mice. Four weeks after subcutaneous injection, we found that grafted cell survival was improved and more cells expressed myogenic and endothelial cell transcripts and markers compared to controls. More vessel formation and innervations were observed in USCs combined with six growth factors cocktail incorporated in microbeads compared to controls. In conclusion, a combination of growth factors released locally from the alginate microbeads induced USCs to differentiate into a myogenic lineage, enhanced revascularization and innervation, and stimulated resident cell growth in vivo. This approach could potentially be used for cell therapy in the treatment of stress urinary incontinence.