Preliminary results of myoblast injection into the urethra and bladder wall: a possible method for the treatment of stress urinary incontinence and impaired detrusor contractility

Cell Therapy in the Treatment of Female Stress Urinary Incontinence: Current Status and Future Proposals

BACKGROUND

Stress urinary incontinence (SUI) is a common condition with a significant impact on the quality of life of female patients. The limitations of current treatment strategies have prompted the exploration of new effective and minimally invasive alternative approaches, including cell therapy.

METHODS

A literature search was conducted to update the current clinical status of stem cell therapy in the management of female stress urinary incontinence.

RESULTS

Over thirty clinical studies have been designed to assess the feasibility, safety and efficacy of cell therapy for female SUI. Despite differences in cell types and protocols, the overall treatment procedures were similar. Standard subjective and objective assessment tools, and follow-up periods ranged from 6 weeks to 6 years have been used. Cell injection has shown to be a safe therapy in the treatment of female SUI. However, the results from more recent randomized trials have shown less promising results than expected in restoring continence. Heterogeneous research methodologies using different cell types and doses make it difficult to draw conclusions about effectiveness. Several key points remain that need to be further explored in future clinical trials.

CONCLUSION

To advance in the development of cell therapy, it is essential to know the mechanisms involved to be able to direct it properly, its efficacy and the durability of the injected cells. Rigorous and homogenized preclinical and clinical studies that demonstrate its scope and improve its application are necessary for validation in the treatment of female SUI.

Endoscopic implantation of autologous myoblasts for stress urinary incontinence and evaluation of its efficacy in sphincterotomized rabbits

INTRODUCTION

Stress urinary incontinence (SUI) is one of the health problems with more impact on patients' lives. The aim of the present work was to develop a therapy for SUI using tissue engineering by isolation and culture of autologous myoblasts (CAM) followed by endoscopic implantation. We also evaluated the efficacy of this therapy in a rabbit model of incontinence after sphincterotomy.

MATERIALS AND METHODS

We used healthy male New Zealand rabbits. The animals were first bled to obtain platelet-poor plasma (PPP) and biopsied for myoblast isolation. Post-sphincterotomy, they were divided into two groups: the treatment group (including animals that received CAM resuspended in PPP) and the control group (including animals receiving only PPP). The leak-point pressure (LPP) was used to measure continence in both groups at different time points. The results were evaluated with hierarchical linear regression models. Histological evaluation of the rabbits' sphincters was also performed at the end of follow-up.

RESULTS

No statistically significant differences were observed between the baseline LPP values of each group. The post-sphincterotomy values of both groups were below 50% of the baseline value, which was a mandatory condition for incontinence. The post-implantation values of the treatment group were higher than 50% of the baseline value, which led us to assume continence recovery. A statistically significant difference was observed in the LPP values between the two treatment groups (p=0.003). Histological study revealed interconnected islands formed by muscle fibers in the treatment group, and connective tissue surrounding the urethral lumen and inflammatory infiltrate in the control group.

DISCUSSION AND CONCLUSIONS

The implantation of CAM significantly improved LPP values in the treatment group, and the improvement remained throughout the evaluation period. It may be associated with the consistency of the implant and its stability at the injection site. Longer follow-up studies and human clinical investigations are required to consider CAM implantation as an alternative treatment for stress urinary incontinence.

Transurethral injection of autologous muscle precursor cells for treatment of female stress urinary incontinence: a prospective phase I clinical trial

INTRODUCTION AND HYPOTHESIS

The purpose was to investigate the safety and feasibility of transurethral injections of autologous muscle precursor cells (MPCs) into the external urinary sphincter (EUS) to treat stress urinary incontinence (SUI) in female patients.

METHODS

Prospective and randomised phase I clinical trial. Standardised 1-h pad test, International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI-SF), urodynamic study, and MRI of the pelvis were performed at baseline and 6 months after treatment. MPCs gained through open muscle biopsy were transported to a GMP facility for processing and cell expansion. The final product was injected into the EUS via a transurethral ultrasound-guided route. Primary outcomes were defined as any adverse events (AEs) during follow-up. Secondary outcomes were functional, questionnaire, and radiological results.

RESULTS

Ten female patients with SUI grades I-II were included in the study and 9 received treatment. Out of 8 AEs, 3 (37.5%) were potentially related to treatment and treated conservatively: 1 urinary tract infection healed with antibiotics treatment, 1 dysuria and 1 discomfort at biopsy site. Functional urethral length under stress was 25 mm at baseline compared with 30 mm at 6 months' follow-up (p=0.009). ICIQ-UI-SF scores improved from 7 points at baseline to 4 points at follow-up (p=0.035). MRI of the pelvis revealed no evidence of tumour or necrosis, whereas the diameter of the EUS muscle increased from 1.8 mm at baseline to 1.9 mm at follow-up (p=0.009).

CONCLUSION

Transurethral injections of autologous MPCs into the EUS for treatment of SUI in female patients can be regarded as safe and feasible. Only a minimal number of expected and easily treatable AEs were documented.

Differentiation of patient-specific void urine-derived human induced pluripotent stem cells to fibroblasts and skeletal muscle myocytes

Cell-based therapy is a major focus for treatment of stress urinary incontinence (SUI). However, derivation of primary cells requires tissue biopsies, which often have adverse effects on patients. A recent study used human induced pluripotent stem cells (iPSC)-derived smooth muscle myocytes for urethral sphincter regeneration in rats. Here, we establish a workflow using iPSC-derived fibroblasts and skeletal myocytes for urethral tissue regeneration: (1) Cells from voided urine of women were reprogrammed into iPSC. (2) The iPSC line U1 and hESC line H9 (control) were differentiated into fibroblasts expressing FSP1, TE7, vinculin, vimentin, αSMA, fibronectin and paxillin. (3) Myogenic differentiation of U1 and H9 was induced by small molecule CHIR99021 and confirmed by protein expression of myogenic factors PAX7, MYOD, MYOG, and MF20. Striated muscle cells enriched by FACS expressed NCAM1, TITIN, DESMIN, TNNT3. (4) Human iPSC-derived fibroblasts and myocytes were engrafted into the periurethral region of RNU rats. Injected cells were labelled with ferric nanoparticles and traced by Prussian Blue stain, human-specific nuclear protein KU80, and human anti-mitochondria antibody. This workflow allows the scalable derivation, culture, and in vivo tracing of patient-specific fibroblasts and myocytes, which can be assessed in rat SUI models to regenerate urethral damages and restore continence.

Exosome biopotentiated hydrogel restores damaged skeletal muscle in a porcine model of stress urinary incontinence

Urinary incontinence afflicts up to 40% of adult women in the United States. Stress urinary incontinence (SUI) accounts for approximately one-third of these cases, precipitating ~200,000 surgical procedures annually. Continence is maintained through the interplay of sub-urethral support and urethral sphincter coaptation, particularly during activities that increase intra-abdominal pressure. Currently, surgical correction of SUI focuses on the re-establishment of sub-urethral support. However, mesh-based repairs are associated with foreign body reactions and poor localized tissue healing, which leads to mesh exposure, prompting the pursuit of technologies that restore external urethral sphincter function and limit surgical risk. The present work utilizes a human platelet-derived CD41a and CD9 expressing extracellular vesicle product (PEP) enriched for NF-κB and PD-L1 and derived to ensure the preservation of lipid bilayer for enhanced stability and compatibility with hydrogel-based sustained delivery approaches. In vitro, the application of PEP to skeletal muscle satellite cells in vitro drove proliferation and differentiation in an NF-κB-dependent fashion, with full inhibition of impact on exposure to resveratrol. PEP biopotentiation of collagen-1 and fibrin glue hydrogel achieved sustained exosome release at 37 °C, creating an ultrastructural “bead on a string” pattern on scanning electron microscopy. Initial testing in a rodent model of latissimus dorsi injury documented activation of skeletal muscle proliferation of healing. In a porcine model of stress urinary incontinence, delivery of PEP-biopotentiated collagen-1 induced functional restoration of the external urethral sphincter. The histological evaluation found that sustained PEP release was associated with new skeletal muscle formation and polarization of local macrophages towards the regenerative M2 phenotype. The results provided herein serve as the first description of PEP-based biopotentiation of hydrogels implemented to restore skeletal muscle function and may serve as a promising approach for the nonsurgical management of SUI.

Long-term effects of muscle-derived stem cell therapy on the regeneration of the urethra of female rats

INTRODUCTION AND HYPOTHESIS

The aim was to analyze the long-term effects of muscle-derived stem cells (MDSCs) therapy in traumatized urethras of female rats regarding messenger ribonucleic acid (mRNA) expression of collagens 1 and 3, Ngf and Ki67; and the mRNA and protein expression of Myh11 and Myh2.

METHODS

Muscle-derived stem cells were injected into the tail vein of rats 3 days after trauma by vaginal distention. Urethras were analyzed from 30 animals divided into three groups: control without injury or treatment, trauma (30 days post-injury), and MDSC (30 days post-injury who received MDSC therapy). Real-time quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry were performed. The Kruskal-Wallis and ANOVA tests were used with p < 0.05 indicating significance.

RESULTS

We detected increased Myh11 and Myh2 mRNA expression in the trauma group compared with the control group (p = 0.03 and p = 0.04 respectively). Ki67 and Col1a1 genes were overexpressed in the MDSC group compared with both the trauma (p = 0.02 and p = 0.008 respectively) and the control group (p = 0.01 and p = 0.03 respectively). Col3a1 gene was upregulated in the MDSC compared with the control group (p = 0.03). Ngf mRNA level was lower in the MDSC group than in the trauma group (p = 0.002). Myh11, Myh2, and Desmin proteins were overexpressed in the MDSC compared with the trauma group (1.5-fold, p = 0.01; 1.5-fold, p = 0.04; 1.3-fold, p = 0.01 respectively).

CONCLUSIONS

Muscle-derived stem cell therapy may have had long-term structural and molecular effects on the injured urethra of female rats, particularly on markers of cell proliferation, neural growth factor, extracellular matrix, and muscle content. This study suggests that MDSC therapy acted mainly to produce urethral sphincter regeneration marked by increased immunohistochemical expression of the proteins desmin, smooth muscle Myh11, and skeletal muscle Myh2.

Efficacy evaluation of Lattice Carbon Dioxide Laser Therapy in the treatment of postmenopausal patients with mild to moderate stress urinary incontinence

Objectives

To investigate the efficacy and postoperative complications of lattice carbon dioxide laser in the treatment of postmenopausal patients with mild to moderate stress urinary incontinence.

Methods

A total of 30 postmenopausal female patients with mild to moderate stress urinary incontinence, recruited from the Affiliated Hospital of Hebei University from September to November 2019, were selected as the study subjects and treated with lattice carbon dioxide laser therapy. Treatment was given at intervals of one month. The degree of urinary incontinence, the urinary incontinence questionnaire (ICI-Q-SF) score, and the urinary incontinence quality of life scale (I-QOL)) Score, surgical satisfaction, one hour pad test and postoperative complications before treatment and after each treatment of all patients were respectively recorded and compared.

Results

Compared with those before treatment, the grade of urinary incontinence and ICI-Q-SF scores of these 30 patients after each treatment were lower, and their I-QOL scores were higher. The difference of one hour urine pad test was statistically significant (P<0.05), but the follow-up data of three months after the third treatment was close to that of one month after the first treatment. The satisfaction rate of these 30 patients was 76.67% (23/30). After treatment, only one patient presented vaginal itching discomfort on the first day after surgery and the symptoms disappeared three days later. No obvious complications occurred in the other 29 patients.

Conclusion

The treatment of mild and moderate postmenopausal patients with stress urinary incontinence with lattice carbon dioxide laser can effectively reduce the incidence of incontinence and improve the quality of life.

Treatment of Stress Urinary Incontinence with Muscle Stem Cells and Stem Cell Components: Chances, Challenges and Future Prospects

Urinary incontinence (UI) is a major problem in health care and more than 400 million people worldwide suffer from involuntary loss of urine. With an increase in the aging population, UI is likely to become even more prominent over the next decades and the economic burden is substantial. Among the different subtypes of UI, stress urinary incontinence (SUI) is the most prevalent and focus of this review. The main underlying causes for SUI are pregnancy and childbirth, accidents with direct trauma to the pelvis or medical treatments that affect the pelvic floor, such as surgery or irradiation. Conservative approaches for the treatment of SUI are pelvic physiotherapy, behavioral and lifestyle changes, and the use of pessaries. Current surgical treatment options include slings, colposuspensions, bulking agents and artificial urinary sphincters. These treatments have limitations with effectiveness and bear the risk of long-term side effects. Furthermore, surgical options do not treat the underlying pathophysiological causes of SUI. Thus, there is an urgent need for alternative treatments, which are effective, minimally invasive and have only a limited risk for adverse effects. Regenerative medicine is an emerging field, focusing on the repair, replacement or regeneration of human tissues and organs using precursor cells and their components. This article critically reviews recent advances in the therapeutic strategies for the management of SUI and outlines future possibilities and challenges.

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.

Generation of myogenic progenitor cell-derived smooth muscle cells for sphincter regeneration

BACKGROUND

Degeneration of smooth muscles in sphincters can cause debilitating diseases such as fecal incontinence. Skeletal muscle-derived cells have been effectively used in clinics for the regeneration of the skeletal muscle sphincters, such as the external anal or urinary sphincter. However, little is known about the in vitro smooth muscle differentiation potential and in vivo regenerative potential of skeletal muscle-derived cells.

METHODS

Myogenic progenitor cells (MPC) were isolated from the skeletal muscle and analyzed by flow cytometry and in vitro differentiation assays. The differentiation of MPC to smooth muscle cells (MPC-SMC) was evaluated by immunofluorescence, flow cytometry, patch-clamp, collagen contraction, and microarray gene expression analysis. In vivo engraftment of MPC-SMC was monitored by transplanting reporter protein-expressing cells into the pyloric sphincter of immunodeficient mice.

RESULTS

MPC derived from human skeletal muscle expressed mesenchymal surface markers and exhibit skeletal myogenic differentiation potential in vitro. In contrast, they lack hematopoietic surface marker, as well as adipogenic, osteogenic, and chondrogenic differentiation potential in vitro. Cultivation of MPC in smooth muscle differentiation medium significantly increases the fraction of alpha smooth muscle actin (aSMA) and smoothelin-positive cells, while leaving the number of desmin-positive cells unchanged. Smooth muscle-differentiated MPC (MPC-SMC) exhibit increased expression of smooth muscle-related genes, significantly enhanced numbers of CD146- and CD49a-positive cells, and in vitro contractility and express functional Cav and Kv channels. MPC to MPC-SMC differentiation was also accompanied by a reduction in their skeletal muscle differentiation potential. Upon removal of the smooth muscle differentiation medium, a major fraction of MPC-SMC remained positive for aSMA, suggesting the definitive acquisition of their phenotype. Transplantation of murine MPC-SMC into the mouse pyloric sphincter revealed engraftment of MPC-SMC based on aSMA protein expression within the host smooth muscle tissue.

CONCLUSIONS

Our work confirms the ability of MPC to give rise to smooth muscle cells (MPC-SMC) with a well-defined and stable phenotype. Moreover, the engraftment of in vitro-differentiated murine MPC-SMC into the pyloric sphincter in vivo underscores the potential of this cell population as a novel cell therapeutic treatment for smooth muscle regeneration of sphincters.

Stem cell applications in regenerative medicine for stress urinary incontinence: A review of effectiveness based on clinical trials

Objective

To evaluate the current state, therapeutic benefit and safety of urethral injection of autologous stem cells for the treatment stress urinary incontinence (SUI).

Materials and methods

A selective database search of PubMed, the Excerpta Medica dataBASE (EMBASE), Cochrane Library and Google Scholar was conducted to validate the effectiveness of stem cell-based therapy. The search included clinical trials published up until 4 January 2020, written in English, and included cohorts of women and men who had received stem cell-based therapy for SUI. The search used the following keywords in various combinations: ‘stem cell therapy’, ‘cell-based therapy for SUI’, ‘regenerative medicine for SUI’, and ‘tissue engineering’. The success rates were assessed according to cough test, urodynamics, pad tests, and International Consultation on Incontinence Questionnaire-Urinary Incontinence. The primary endpoint was continence rate to measure objectively the effect of the treatment.

Results

We identified four clinical trials using local injections of adipose-derived stem cells (ADSCs), 11 trails with muscle-derived stem cells (MDSCs), and two trails with human umbilical cord blood stem cells (HUCBs) and total nucleated cells (TNCs). The median improvement rate of intrinsic sphincter deficiency after ADSCs, MDSCs, TNCs, HUCBs injections were 88%, 77%, 89%, 36% (improvement rate: 1–2 pads) at a mean (range) follow-up of 6 (1–72) months. The cell sources, methods of cell processing, cell number, and implantation techniques differed considerably between studies. Most of the periurethral injections were at the 3, 5, 7, and 9 o’clock positions and for submucosa were at the 4, 6, and 8 o’clock positions. No significant postoperative complications were reported.

Conclusion

Despite many challenges in stem cell-based therapy for treating SUI, it appears to provide, in both male and female patients, acceptable functional results with minimal side-effects and complications. In the future, more clinical trials should be funded in order to optimise stem cell-based therapy and evaluate long-term outcomes.

Abbreviations

ADSC: adipose-derived stem cell; BMSCs: bone marrow-derived mesenchymal stem cell; CLPP: cough leak-point pressure; FPL: functional profile length; HUCB: human umbilical cord blood stem cell; ICIQ-(QOL)(SF)(UI): International Consultation on Incontinence Questionnaire (Quality of life) (-Urinary incontinence Short Form) (-Urinary Incontinence); IIQ-7: Incontinence Impact Questionnaire-short form; I-QOL: Incontinence quality of life questionnaire; ISD: intrinsic urinary sphincter deficiency; MDSC: muscle-derived stem cell; MUCP: maximum urethral closure pressure; NR: not reported; Pdet-max: maximum detrusor pressure; PVR: post-void residual urine volume; Q_max: maximum urinary flow; QOL: quality of life; RP: radical prostatectomy; TNC: total nucleated cell; (S)UI: (stress) urinary incontinence; UDSCs: urine-derived stem cells; UTUS: upper tract ultrasonography; VLPP: Valsalva leak-point pressure

Regenerative medicine and injection therapies in stress urinary incontinence

Stress urinary incontinence (SUI) is a common and bothersome condition. Anti-incontinence surgery has high cure rates, but concerns about mesh tapes have resulted in the resurgence of surgical procedures that involve increased abdominopelvic dissection and morbidity. Injection therapy with urethral bulking agents or stem cell formulations have been developed as minimally invasive alternatives. Many synthetic and biological bulking agents have been trialled, but several have been discontinued owing to safety concerns. The use of Macroplastique and Contigen has the largest evidence base, but, overall, success rates seem to be similar between the various agents and positive outcomes are poorly sustained for more than 6 months. Furthermore, subjective cure rates, although initially high, also deteriorate over time. The available data consistently demonstrate manifestly poorer outcomes for injection therapies than for surgery. Stem cell treatments are thought to functionally regenerate the urethral sphincter in patients with suspected intrinsic sphincter deficiency. Autologous adipose and muscle-derived stem cells seem to be the intuitive cell source, as they are comparatively abundant, can be harvested and cause minimal donor site morbidity. To date, only a few small clinical studies have been reported and most data are derived from animal models. The success rates of stem cell injection therapies seem to be comparable with those of bulking agents.

[Medical prevention and treatment of radiation-induced urological and nephrological complications]

Abdominal and pelvic irradiations play a major place in the management of patients with cancer and present a risk of acute and late side effects. Radiation-induced lesions can affect kidney or urological structures. These side effects can have an impact in the quality of life of patients. The aim of this article is to describe the physiopathology, the symptomatology, and the principles of management of radiation-induced nephropathy, uretheritis, cystitis, and urethritis.

Advances in stem cell therapy for male stress urinary incontinence

INTRODUCTION

Among the several options that have been proposed in recent years for the management of male stress urinary incontinence (SUI), stem cell therapy represents a new frontier in treatment. The aim of this paper is to update the current status of stem cell therapy in animal and human studies for the management of iatrogenic male SUI.

AREAS COVERED

A literature review was conducted based on MEDLINE/PubMed searches for English articles using a combination of the following keywords: stem cell therapy, urinary incontinence, prostatectomy, regenerative medicine, mesenchymal stem cells.

EXPERT OPINION

The few studies reported in the literature have demonstrated short-term safety and promising results of stem cell therapy in treating male SUI. However, many aspects need to be clarified before stem cell therapy can be introduced into daily urologic practice. In fact, important issues such as the limitations of these studies in terms of small sample sizes and short follow-ups, the incomplete knowledge of the mechanism of action of stem cells, the technical details regarding the delivery method and the best sources of stem cells, the safety risks regarding genomic or epigenetic changes and potential immune reactions in the longer term need to be identified in more stringent clinical trials.

Intraurethral co-transplantation of bone marrow mesenchymal stem cells and muscle-derived cells improves the urethral closure

Background

Cell therapy constitutes an attractive alternative to treat stress urinary incontinence. Although promising results have been demonstrated in this field, the procedure requires further optimization. The most commonly proposed cell types for intraurethral injections are muscle derived cells (MDCs) and mesenchymal stem/stromal cell (MSCs). The aim of this study was to evaluate the effects of MDC-MSC co-transplantation into the urethra.

Methods

Autologous transplantation of labeled MDCs, bone marrow MSCs or co-transplantation of MDC-MSC were performed in aged multiparous female goats (n = 6 in each group). The mean number of cells injected per animal was 29.6 × 10⁶(± 4.3 × 10⁶). PBS-injected animals constituted the control group (n = 5). Each animal underwent urethral pressure profile (UPP) measurements before and after the injection procedure. The maximal urethral closure pressure (MUCP) and functional area (FA) of UPPs were calculated. The urethras were collected at the 28th or the 84th day after transplantation. The marker fluorochrome (DID) was visualized and quantified using in vivo imaging system in whole explants. Myogenic differentiation of the graft was immunohistochemically evaluated.

Results

The grafted cells were identified in all urethras collected at day 28 regardless of injected cell type. At this time point the strongest DID-derived signal (normalized to the number of injected cells) was noted in the co-transplanted group. There was a distinct decline in signal intensity between day 28 and day 84 in all types of transplantation. Both MSCs and MDCs contributed to striated muscle formation if transplanted directly to the external urethral sphincter. In the MSC group those events were rare. If cells were injected into the submucosal region they remained undifferentiated usually packed in clearly distinguishable depots. The mean increase in MUCP after transplantation in comparison to the pre-transplantation state in the MDC, MSC and MDC-MSC groups was 12.3% (± 11.2%, not significant (ns)), 8.2% (± 9.6%, ns) and 24.1% (± 3.1%, p = 0.02), respectively. The mean increase in FA after transplantation in the MDC, MSC and MDC-MSC groups amounted to 17.8% (± 15.4%, ns), 15.2% (± 12.9%, ns) and 17.8% (± 2.5%, p = 0.04), respectively.

Conclusions

The results suggest that MDC-MSC co-transplantation provides a greater chance of improvement in urethral closure than transplantation of each population alone.

Cell therapy for stress urinary incontinence: Present-day frontiers

Stress urinary incontinence (SUI) significantly diminishes the quality of patients' lives. Currently available surgical and nonsurgical therapies remain far from ideal. At present, advances in cellular technologies have stirred growing interest in the use of autologous cell treatments aimed to regain urinary control. The objective was to conduct a review of the literature and analyse preclinical and clinical studies dedicated to various cell therapies for SUI, assessing their effectiveness, safety, and future prospects. A systematic literature search in PubMed was conducted using the following key terms: "stem," "cell," "stress," "urinary," and "incontinence." A total of 32 preclinical studies and 15 clinical studies published between 1946 and December 2014 were included in the review. Most preclinical trials have used muscle-derived stem cells and adipose-derived stem cells. However, at present, the application of other types of cells, such as human amniotic fluid stem muscle-derived progenitor cells and bone marrow mesenchymal stromal cells, is becoming more extensive. While the evidence shows that these therapies are effective and safe, further work is required to standardize surgical techniques, as well as to identify indications for their use, doses and number of doses. Future research will have to focus on clinical applications of cell therapies; namely, it will have to determine indications for their use, doses of cells, optimal surgical techniques and methods, attractive cell sources, as well as to develop clinically relevant animal models and make inroads into understanding the mechanisms of SUI improvement by cell therapies.

Injectable scaffold materials differ in their cell instructive effects on primary human myoblasts

Scaffolds are materials used for delivery of cells for regeneration of tissues. They support three-dimensional organization and improve cell survival. For the repair of small skeletal muscles, injections of small volumes of cells are attractive, and injectable scaffolds for delivery of cells offer a minimally invasive technique. In this study, we examined in vitro the cell instructive effects of three types of injectable scaffolds, fibrin, alginate, and poly(lactic-co-glycolic acid)-based microparticles on primary human myoblasts. The myoblast morphology and progression in the myogenic program differed, depending on the type of scaffold material. In alginate gel, the cells obtained a round morphology, they ceased to proliferate, and entered quiescence. In the fibrin gels, differentiation was promoted, and myotubes were observed within a few days in culture, while poly(lactic-co-glycolic acid)-based microparticles supported prolonged proliferation. Myoblasts released from the alginate and fibrin gels were studied, and cells released from these scaffolds had retained the ability to proliferate and differentiate. Thus, the study shows that human myogenic cells combined with injectable scaffold materials are guided into different states depending on the choice of scaffold. This opens for in vivo experiments, including testing of the significance of the cell state on regeneration potential of primary human myoblasts.

Myoblast Therapy: From Bench to Bedside

Myoblasts are defined as stem cells containing skeletal muscle cell precursors. A decade of experimental work has revealed many properties of myoblasts, including the stability of resulting hybrid myofibers without immune suppression, the persistence of transgene expression, and the lack of tumorigenicity. Early phase clinical trials also showed that myoblast-based therapy is a promising approach for many intractable clinical conditions, including both muscle-related and non-muscle-related diseases. The potential application of myoblast therapy may be in the treatment of genetic muscle diseases, cardiomyocyte damaged heart diseases, and urinary incontinence. This review will provide an overview of myoblast biology, along with discussion of the potential application in clinical medicine. In addition, problems in current myoblast therapy and possible future improvements will be addressed.

Stem Cell Therapy for Male Urinary Incontinence

INTRODUCTION

Among the medical and surgical options which have been proposed in the last years for the management of male stress urinary incontinence (SUI), stem cell therapy represents a new frontier treatment. The aim of this paper is to update the current status of stem cell therapy in animal and human studies for the management of iatrogenic male SUI.

MATERIAL AND METHODS

A PubMed review of the literature on stem cell therapy for the treatment of male SUI was performed.

RESULTS

Regarding animal studies, bone marrow-, muscle- and adipose-derived stem cells have been widely studied, showing regeneration of the urethral sphincter and recovery of the damaged pelvic nerves. With regard to human studies, only four papers are available in the literature using muscle- and adipose-derived stem cells which reported a significant improvement in sphincteric function and incontinence with no severe side effects.

CONCLUSIONS

In spite of these promising results, further studies are needed with longer follow-ups and larger numbers of patients in order to clarify the potential role of stem cell therapy for the treatment of male SUI.

Magnetization Transfer MR Imaging to Monitor Muscle Tissue Formation during Myogenic in Vivo Differentiation of Muscle Precursor Cells

Purpose To determine whether magnetization transfer (MT) magnetic resonance (MR) imaging may serve as a quantitative measure of the degree of fiber formation during differentiation of muscle precursor cells into engineered muscle tissue as a potential noninvasive monitoring tool in mice. Materials and Methods The study was approved by the local ethics committee (no. StV 01/2008) and the local Veterinary Office (license no. 99/2013). Human muscle progenitor cells (hMPCs) derived from rectus abdominis muscles were subcutaneously injected into CD-1 nude mice (CD-1 nude mice, Crl:CD1-Foxn1^nu; Charles River Laboratories, Wilmington, Mass) for development of muscle tissue. The mice underwent MR imaging examinations at 4.7 T at days 1, 3, 7, 14, 21, and 28 after cell transplantation by using a gradient-echo sequence with an MT prepulse and systematic variation of the off-resonance frequency (50-37 500 Hz) at an amplitude of 800°. Direct saturation was estimated from a Bloch equation simulation. The MT ratio (MTR) was correlated to immunohistochemistry findings, Western blot results, and results of myography. Data were analyzed by using one-way or two-way analysis of variance with the Sidak or Tukey multiple comparisons test. Results In the reference skeletal muscle, highest MT was found for 2500 Hz off-resonance frequency with an MTR ± standard deviation of 57.5% ± 3.5. The developing muscle tissue exhibited increasing MT values during the 28 days of myogenic in vivo differentiation and did not reach the values of native skeletal muscle. Mean values of MTR (2500 Hz) for hMPCs were 27.6% ± 6.3 (day 1), 24.7% ± 8.7 (day 3), 28.2% ± 5.7 (day 7), 35.9% ± 5.0 (day 14), 37.0% ± 7.9 (day 21), and 39.9% ± 8.1 (day 28). The results from MT MR imaging correlated qualitatively well with muscle tissue expression of specific skeletal markers, as well as muscle contractility. Conclusion MT MR imaging may be used to noninvasively monitor the process of myogenic in vivo differentiation of hMPCs as a biomarker of the quantity and quality of muscle fiber formation. ^© RSNA, 2016 Online supplemental material is available for this article.

Autologous skeletal-muscle-derived cell injection for anal incontinence due to obstetric trauma: a 5-year follow-up of an initial study of 10 patients

AIM

Our aim was to determine whether the benefits of autologous skeletal-muscle-derived cell injection to treat obstetric anal incontinence are sustained at 5 years.

METHOD

An observational study was performed of 10 women suffering from obstetric anal incontinence refractory to non-surgical therapy. Autologous skeletal-muscle-derived cells were injected into the external sphincter defect under ultrasound guidance. Incontinence diaries and quality of life questionnaires were obtained pre-implantation and annually after implantation for 5 years. Anal physiology testing was performed before implantation and at 1, 2 and 5 years after implantation. The end-points included were adverse events, Wexner incontinence scores, incontinence episodes, anal squeeze pressures and quality of life over 5 years. An independent statistician used multilevel linear regression to analyse changes in repeated measures over time. Any skewed distributions were log transformed prior to analysis.

RESULTS

No procedure-related adverse events occurred and haematological and biochemical parameters were normal during the 5-year period. There were sustained significant improvements in the Wexner incontinence score and reduced frequency of defaecation and number of incontinence episodes (all comparisons P < 0.001). Anal resting and squeeze pressures showed sustained improvement (all P < 0.001) and quality of life improved overall (P < 0.001), including all submeasures studied (P < 0.001).

CONCLUSION

Autologous skeletal-muscle-derived cells to treat obstetric anal incontinence resulted in sustained improvement in incontinence episodes, physiological measurements of anal function and quality of life at 5 years.

Prospects of stem cell treatment in benign urological diseases

Stem cells (SCs) are undifferentiated cells that are capable of self-renewal and differentiation and that therefore contribute to the renewal and repair of tissues. Their capacity for division, differentiation, and tissue regeneration is highly dependent on the surrounding environment. Several preclinical and clinical studies have utilized SCs in urological disorders. In this article, we review the current status of SC use in benign urological diseases (erectile dysfunction, Peyronie disease, infertility, and urinary incontinence), and we summarize the results of the preclinical and clinical trials that have been conducted.

Mesenchymal stromal cells for sphincter regeneration

Stress urinary incontinence (SUI), defined as the involuntary loss of considerable amounts of urine during increased abdominal pressure (exertion, effort, sneezing, coughing, etc.), is a severe problem to the individuals affected and a significant medical, social and economic challenge. SUI is associated with pelvic floor debility, absence of detrusor contraction, or a loss of control over the sphincter muscle apparatus. The pathology includes an increasing loss of muscle cells, replacement of muscular tissue with fibrous tissue, and general aging associated processes of the sphincter complex. When current therapies fail to cure or improve SUI, application of regeneration-competent cells may be an alternative therapeutic option. Here we discuss different aspects of the biology of mesenchymal stromal cells, which are relevant to their clinical applications and for regenerating the sphincter complex. However, there are reports in favor of and against cell-based therapies. We therefore summarize the potential and the risks of cell-based therapies for the treatment of SUI.

Slings for urinary incontinence and the application of cell-based therapy

The most commonly used technique for the treatment of stress urinary incontinence (SUI) in women is the suburethral polypropylene sling, using either a retropubic or transobturator tape approach This treatment results in a cure rate of over 80%, based on both subjective and objective evaluations. Biological slings have been largely abandoned due to lack of efficacy. Despite the high success rates, 10-20% of women remain incontinent. Cell-based therapy might offer solutions for the future both for the primary setting as for the treatment of failures. Preclinical studies suggest that stem cells (SC) can enhance the recovery of damaged tissue either by direct integration and replacement of damaged tissue (differentiation) or by secreting factors that influence host response mechanisms (paracrine effect). The clinical data to date do not allow strong efficacy conclusions, except that SC therapy seems to be safe in the short term. Most published studies use autologous cells. Allogeneic cell sources need to be investigated as well to allow ready-to-use solutions in the future. Most importantly, we need better insight into the mechanisms of action. We need more basic stem cell research, better acute and chronic animal models, better investigational tools and more efforts using tissue engineering approach.

Cell-Based Therapies in Lower Urinary Tract Disorders

Cell-based therapy for the bladder has its beginnings in the 1990s with the successful isolation and culture of bladder smooth muscle cells. Since then, several attempts have been made to artificially implant native cell types and stem cell-derived cells into damaged bladders in the form of single-cell injectables or as grafts seeded onto artificial extracellular matrix. We critically examined in the literature the types of cells and their probable role as an alternative to non-drug-based, non-bowel-based graft replacement therapy in disorders of the urinary bladder. The limitations and plausible improvements to these novel therapies have also been discussed, keeping in mind an ideal therapy that could suit most bladder abnormalities arising out of varied number of disorders. In conclusion, muscle-derived cell types have consistently proven to be a promising therapy to emerge in the coming decade. However, tissue-engineered constructs have yet to prove their success in preclinical and long-term clinical setting.

Effect of myogenic stem cells on the integrity and histomorphology of repaired transected external anal sphincter

INTRODUCTION AND HYPOTHESIS

The objective was to evaluate the effect of myogenic stem cells on histological properties and the volume of striated muscle of the external anal sphincter after transection and repair.

METHODS

Histological analysis was performed on the external anal sphincters of 40 young female rats euthanized at 7 or 90 days after transection and repair and randomization to injection of either phosphate buffered solution (PBS) or myogenic stem cells (SC) at the transection site. Sphincter complexes, previously evaluated for neurophysiological function, were processed for histology and analyzed for possible disruption, amount of inflammation, and volume of striated muscle. The relationship between the muscular disruption and contractile force of sphincters was evaluated.

RESULTS

Disruption was seen in 100 % of sphincters 7 days after repair for both SC and control animals. Eighty-nine percent of controls and 78% of SC-administered animals had intact sphincters at 90 days. Significant inflammatory infiltrate was seen in repaired anal sphincters for both the PBS and the SC groups at 7 days, and persisted at 90 days, with no difference between treatment groups. Striated muscle volume increased from 7 to 90 days for both control and SC-administered animals. Although there was no difference in volume between treatments, there was substantial temporal improvement in contractile force generation of the sphincters receiving SC compared with those receiving PBS.

CONCLUSION

In this animal model, administration of myogenic stem cells to transected/repaired anal sphincters did not alter the amount of inflammation nor the volume of striated muscle, suggesting that stem cells might improve contractile function through other cellular processes.

Voiding dysfunction due to detrusor underactivity: an overview

Detrusor underactivity (DUA) is defined as a voiding contraction of reduced strength and/or duration, which prolongs urination and/or prevents complete emptying of the bladder within a 'normal' period of time. This issue is associated with voiding and postmicturition urinary symptoms, and can predispose to urinary infections and acute urinary retention. The aetiology of DUA is influenced by multiple factors, including ageing, bladder outlet obstruction, neurological disease, and autonomic denervation. The true prevalence of this condition remains unknown, as most data come from referral populations. Urodynamic testing is used to diagnose the condition, either by assessing the relationship between bladder pressures and urinary flow, or by interrupting voiding to measure detrusor pressure change under isovolumetric conditions. Current treatments for DUA have poor efficacy and tolerability, and often fail to improve quality of life; muscarinic receptor agonists, in particular, have limited efficacy and frequent adverse effects. Bladder emptying might be achieved through Valsalva straining, and intermittent or indwelling catheterization, although sacral nerve stimulation can reduce dependency on catheterization. Novel stem-cell-based therapies have been attempted; however, new drugs that increase contractility are currently largely conceptual, and the complex pathophysiology of DUA, difficulty achieving organ specificity of treatment, the limited availability of animal models, and the subjective nature of current outcome measures must be addressed to facilitate the development of such agents.

Muscular tubes of urethra engineered from adipose-derived stem cells and polyglycolic acid mesh in a bioreactor

We have explored the feasibility of using adipose-derived stem cells (ADSCs) and polyglycolic acid (PGA) for constructing muscular tubes of urethra in a bioreactor. With the induction of by 5-azacytidine, ADSCs were found to acquire a myoblast phenotype. Here we seeded ADSCs in a PGA mesh to construct the cell-PGA complex that was cultured statically for 1 week. Afterwards, the cell-PGA complex was subjected to extension stimulation in a bioreactor for 5 weeks. A muscular tube of urethra was formed after 6 weeks. Histological examination showed differentiated ADSCs and collagenous fibers had orientated well. This study demonstrates that tissue engineering of urethra tissues in vitro by using a bioreactor leads to tissue maturation and the differentiation of ADSCs. This novel technique could provide an effective approach for urethra tissue engineering.

Towards a Treatment of Stress Urinary Incontinence: Application of Mesenchymal Stromal Cells for Regeneration of the Sphincter Muscle

Stress urinary incontinence is a significant social, medical, and economic problem. It is caused, at least in part, by degeneration of the sphincter muscle controlling the tightness of the urinary bladder. This muscular degeneration is characterized by a loss of muscle cells and a surplus of a fibrous connective tissue. In Western countries approximately 15% of all females and 10% of males are affected. The incidence is significantly higher among senior citizens, and more than 25% of the elderly suffer from incontinence. When other therapies, such as physical exercise, pharmacological intervention, or electrophysiological stimulation of the sphincter fail to improve the patient’s conditions, a cell-based therapy may improve the function of the sphincter muscle. Here, we briefly summarize current knowledge on stem cells suitable for therapy of urinary incontinence: mesenchymal stromal cells, urine-derived stem cells, and muscle-derived satellite cells. In addition, we report on ways to improve techniques for surgical navigation, injection of cells in the sphincter muscle, sensors for evaluation of post-treatment therapeutic outcome, and perspectives derived from recent pre-clinical studies.

Applications of tissue engineering in the genitourinary tract

Congenital abnormalities and acquired disorders can lead to organ damage or loss of tissue within the genitourinary tract. For reconstructive purposes, tissue-engineering efforts are currently underway for virtually every type of tissue and organ within the urinary tract. Tissue engineering incorporates the fields of cell transplantation, materials science and engineering for the purpose of creating functional replacement tissue. This article reviews some of the principles of tissue engineering and some of the applications of these principles to the genitourinary tract.

Restoration of anal sphincter function after myoblast cell therapy in incontinent rats

Fecal incontinence (FI) remains a socially isolating condition with profound impact on quality of life for which autologous myoblast cell therapy represents an attractive treatment option. We developed an animal model of FI and investigated the possibility of improving sphincter function by intrasphincteric injection of syngeneic myoblasts. Several types of anal cryoinjuries were evaluated on anesthetized Fischer rats receiving analgesics. The minimal lesion yielding sustainable anal sphincter deficiency was a 90° cryoinjury of the sphincter, repeated after a 24-h interval. Anal sphincter pressure was evaluated longitudinally by anorectal manometry under local electrostimulation. Myoblasts were prepared using a protocol mimicking a clinical-grade process and further transduced with a GFP-encoding lentiviral vector before intrasphincteric injection. Experimental groups were uninjured controls, cryoinjured + PBS, and cryoinjured + myoblasts (different doses or injection site). Myoblast injection was well tolerated. Transferred myoblasts expressing GFP integrated into the sphincter and differentiated in situ into dystrophin-positive mature myofibers. Posttreatment sphincter pressures increased over time. At day 60, pressures in the treated group were significantly higher than those of PBS-injected controls and not significantly different from those of normal rats. Longitudinal follow-up showed stability of the therapeutic effect on sphincter function over a period of 6 months. Intrasphincteric myoblast injections at the lesion borders were equally as effective as intralesion administration, but an injection opposite to the lesion was not. These results provide proof of principle for myoblast cell therapy to treat FI in a rat model. This strategy is currently being evaluated in humans in a randomized double-blind placebo-controlled clinical trial.

Regenerative medicine as a new therapeutic strategy for lower urinary tract dysfunction

The use of regenerative medicine for the treatment of organic and functional disorders intractable to conventional treatment has increased worldwide. This innovative medical field might particularly hold promise for the treatment of life-threatening diseases or healing of irreplaceable organs, such as the heart, liver and brain. Dysfunction of the urogenital tract and associated organs other than the kidney might not have immediate life-threatening implications; furthermore, the effectiveness of alternative therapy, such as enterocystoplasty for bladder cancer, has been shown. Therefore, most physicians or scientists do not give much importance to these disorders. However, urological disease has increased in developed societies in recent years. Furthermore, medical costs have also escalated. Disorders of the lower urinary tract, such as urinary disturbance or incontinence, can lead to other complications, impairing quality of life and ultimately increasing short- and long-term medical expenses. Regenerative medicine might hold potential solutions to these problems. Recent advances in urogenital regenerative medicine are reviewed in the present article, with particular reference to lower urinary tract reconstruction. The potential of regenerative medicine for the treatment of intractable lower urinary tract dysfunction compared with conventional treatment is also discussed.

Effect of human muscle-derived stem cells on cryoinjured mouse bladder contractility

OBJECTIVE

To investigate the effect of human muscle-derived stem cells (hMDSCs) on ameliorating impaired detrusor contractility in a cryoinjured bladder murine model.

METHODS

The hMDSCs were isolated and cultured by modified preplate technique, and only CD34-positive hMDSCs were extracted by Mini-MACS kits. Isolated hMDSCs were prelabeled with PKH26 and injected into the cryoinjured bladder to observe the pattern and characteristics. The nude mice were subdivided into three groups: normal group (N), cryoinjury bladder group with saline injection (C), and hMDSCs injection group after cryoinjury (M). At 2 weeks after injecting hMDSCs, we compared the contractility of bladder muscle strip stimulated by electrical field stimulation (EFS), acetylcholine (Ach.), and adenosine triphosphate (ATP), and the bladder smooth muscle tissue was examined by immunohistochemistry.

RESULTS

The contractile powers of bladder muscle strip in the C group were more decreased than the N group after EFS, Ach, and ATP treatment (P < .05). The bladder contractility of the M group was more increased than in the C group (P < .05), but was lower than the N group after EFS and Ach treatment. However, there was no significant difference of contractile power between the C and M groups after ATP stimulation. In immunohistochemical staining, the thickness of the bladder smooth muscle layer in the M group was significantly increased compared with the C group, and PKH26-labeled implanted cells were positive for smooth muscle cell differentiation marker (α-SMA) in the injected region.

CONCLUSION

hMDSCs injection increased cholinergic bladder contractile power but not the purinergic component of bladder contraction after cryoinjury.

Muscle Precursor Cells for the Restoration of Irreversibly Damaged Sphincter Function

Multiple modalities, including injectable bulking agents and surgery, have been used to treat stress urinary incontinence. However, none of these methods is able to fully restore normal striated sphincter muscle function. In this study, we explored the possibility of achieving functional recovery of the urinary sphincter muscle using autologous muscle precursor cells (MPCs) as an injectable, cell-based therapy. A canine model of striated urinary sphincter insufficiency was created by microsurgically removing part of the sphincter muscle in 24 dogs. Autologous MPCs were obtained, expanded in culture, and injected into the damaged sphincter muscles of 12 animals. The animals were followed for up to 6 months after injection, and urodynamic studies, functional organ bath studies, ultrastructural and histological examinations were performed. Animals receiving MPC injections demonstrated sphincter pressures of approximately 80% of normal values, while the pressures in the control animals without cells dropped and remained at 20% of normal values. Histological analysis indicated that the implanted cells survived and formed tissue, including new innervated muscle fibers, within the injected region of the sphincter. These results indicate that autologous muscle precursor cells may be able to restore otherwise irreversibly damaged urinary sphincter function clinically.

Stem cells in gynecology

Stem cell based therapies hold promise for the obstetrician and gynecologist. This article reviews the history of stem cells and some of their current applications in gynecology. Currently, mesenchymal and muscle-derived stem cells are being explored for the treatment of urinary and anal incontinence. Potential stem cell treatments include fistula repair, vaginal tissue engineering, and graft material enhancement. Published animal and human pilot studies demonstrate improved histologic and functional outcomes in those receiving stem cells. Transplanted cells may improve function by local engraftment, trophic factors, or modulation of inflammation. Further clinical and safety studies are needed before clinical application.

Allogenic myoblast transplantation in the rat anal sphincter

OBJECTIVES

: To determine the feasibility of injecting rat myoblasts into the intact anal sphincter as a potential treatment for anal incontinence, and to detect transferred myoblast survival and integration.

STUDY DESIGN

: A pilot study using nonpregnant female Sprague Dawley rodents of 8 to 10 weeks of age. A biopsy of skeletal muscle was harvested from a study animal and recovered myoblasts were expanded in vitro over 10 days. Myoblasts were then tagged with a cytomegalovirus promoter to transduce green fluorescent protein (GFP) into the myoblasts. The cell aspirate was injected directly into the intact external anal sphincter using an electromyographic guidance. The animals received 1.5 or 4.5 × 10 cells of GFP-labeled myoblasts, dividing the dose between three injection sites. The remaining in vitro myoblasts were still viable 28 days post-harvest. Ten days after transplantation the anal sphincter complex was surgically extracted.

RESULTS

: The presence of GFP-labeled myoblasts was confirmed within the external anal sphincter.

CONCLUSIONS

: This demonstrates that myoblasts can be successfully extracted, cultivated in vitro, transplanted and will integrate into the host tissue.

An orthotopic bladder tumor model and the evaluation of intravesical saRNA treatment

We present a novel method for treating bladder cancer with intravesically delivered small activating RNA (saRNA) in an orthotopic xenograft mouse bladder tumor model. The mouse model is established by urethral catheterization under inhaled general anesthetic. Chemical burn is then introduced to the bladder mucosa using intravesical silver nitrate solution to disrupt the bladder glycosaminoglycan layer and allows cells to attach. Following several washes with sterile water, human bladder cancer KU-7-luc2-GFP cells are instilled through the catheter into the bladder to dwell for 2 hours. Subsequent growth of bladder tumors is confirmed and monitored by in vivo bladder ultrasound and bioluminescent imaging. The tumors are then treated intravesically with saRNA formulated in lipid nanoparticles (LNPs). Tumor growth is monitored with ultrasound and bioluminescence. All steps of this procedure are demonstrated in the accompanying video.