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

Exploring the role of laser therapy for stress urinary incontinence: a literature review

Stress urinary incontinence (SUI) significantly impacts the quality of life, necessitating innovative treatment options beyond conventional approaches. This comprehensive review aimed to evaluate laser therapy as a promising intervention for SUI management. A systematic search was conducted using the keywords "laser" and "stress urinary incontinence" in the PubMed, Scopus, Web of Science, and Embase databases. The search covers studies from January 1, 2014, to November 30, 2024. A comparative analysis with traditional treatments, such as pelvic floor exercises and medications, underscores the potential advantages and limitations of laser therapy. Clinical studies and research findings are examined to evaluate the efficacy and safety profile of laser therapy, including its short-term success rates and potential complications. Patient experiences and perspectives provide a qualitative dimension, offering insights into the real-world impact and challenges associated with laser therapy for SUI. This review also explores the cost-effectiveness of laser therapy and compares its long-term and short-term effects, positioning it within the broader landscape of SUI management. Future trends and ongoing research are outlined, highlighting the potential integration of laser therapy with multimodal approaches. Recommendations for clinical practice emphasize patient selection criteria and address concerns and expectations, ensuring laser therapy is adopted as a valuable and evidence-based addition to SUI management.

Implantation of Autologous Skeletal Muscle-Derived Cells Combined with Electrical Stimulation in Patients with Stress Urinary Incontinence

INTRODUCTION AND HYPOTHESIS

Intrasphincteric injection of autologous skeletal muscle-derived cells (aSMDCs) is a minimally invasive treatment for stress urinary incontinence (SUI). This study investigated two cell counts (high/low dose) for functional urethral sphincter regeneration in combination with electrical stimulation, treatment safety and efficacy, and its potential superiority to duloxetine-placebo or duloxetine.

METHODS

This phase II, placebo-controlled trial randomised women with SUI to cell implantation (low or high cell number) and to control groups (duloxetine-placebo or duloxetine), each treatment combined with electrical stimulation. The primary efficacy endpoint was the mean reduction of incontinence episode frequency (IEF) at 12 weeks post-treatment compared with baseline. Secondary efficacy parameters included 1-h pad test, visual analogue scale (VAS), Incontinence Quality of Life questionnaire, clinical global impression score and frequency of responders based on IEF. Adverse events were analysed for safety evaluation. Additional follow-up data on IEF and selected secondary efficacy variables were obtained in a sub-population of patients after 12 and 48 months.

RESULTS

The mean reduction ± SD in IEF after 12 weeks was: low cells: -16.4 ± 13.3 (61 patients), high cells: -18.5 ± 18.7 (56), placebo: -9.7 ± 13.7 (68), duloxetine -11.2 ± 19.6 (32). Cell treatments were significantly superior over placebo regarding IEF reduction and all secondary endpoints except for VAS. No safety issues were observed following cell implantation. Improvements were sustained over 12 and 48 months, with no difference between low and high cell implantation groups.

CONCLUSIONS

Therapy for SUI with aSMDCs in combination with electrical stimulation is safe, effective and sustained over at least 48 months.

Development of a natural rubber latex-based biodevice with mesenchymal stem cells as a potential treatment for skeletal muscle regeneration in gestational diabetes-induced myopathy

Women with gestational diabetes mellitus show a high risk of developing Gestational Diabetes Induced Myopathy (GDiM). GDiM is characterized by significant pelvic floor skeletal muscle atrophy and urinary incontinence. This study aimed to develop a natural rubber latex (NRL) based biodevice with mesenchymal/stromal stem cells (MSCs) for skeletal muscle regeneration for women with GDiM. NRL showed porosity, roughness, biocompatibility, and bioactivity. MSCs adhesion on the NRL scaffold surface was assessed by scanning electron microscopy (SEM), confocal microscopy, and zymography. The scaffold's physicochemical and biological properties were carried out by Fourier transform infrared spectroscopy (FTIR), swelling and degradation studies, hemolytic activity, and antioxidant activity (AA), using Electronic Paramagnetic Resonance (EPR). MSCs in culture expressed CD90, adhered to plastic, differentiated, and produced fibroblast colonies. A high rate of cell proliferation was seen in MSCs on the NRL scaffold. FTIR analysis confirmed protein structures and polyisoprene in the scaffold. Swelling and degradation showed low water uptake and weight loss. Furthermore, NRL presented a hemolytic rate of 2.90 ± 0.26 % for 24 h, and EPR revealed the scaffold's strong AA. The generated biodevice has potential for muscle regeneration and may be useful as a therapeutic option for skeletal muscle disorders in GDiM or urinary incontinence.

Relationship Between the PERFECT Scheme, Vaginal Manometry, and Transperineal Ultrasound in Women With and Without Stress Urinary Incontinence: A Cross-Sectional Study

INTRODUCTION AND HYPOTHESIS

The objective was to compare the functional assessment of the pelvic floor (PERFECT [P = power; E = endurance; R = repetitions; F = fast contractions; ECT = every contraction timed] scheme), vaginal manometry and transperineal ultrasound in women with and in those without stress urinary incontinence (SUI) and to evaluate the correlation among the variables of the three modalities of assessment in both groups.

METHODS

This was a cross-sectional study involving nonpregnant women with and those without SUI aged between 18 and 60 years. Women with sphincter deficiency, Oxford scale = 0, and prolapse grade ≥ 2 were excluded. Women were evaluated using the PERFECT scheme, vaginal manometry, and transperineal ultrasound. Groups were compared using the Student's t test, the chi-square test and general linear models. The Spearman correlation test was also performed.

RESULTS

Fifty-one women with SUI (aged 48.5 ± 9.5 years) and 47 women without SUI (aged 47.2 ± 9.2 years) were evaluated. In women with SUI, there was a correlation between vaginal manometry and power (r = 0.87), endurance (r = 0.47) and fast (r = 0.69); between power and endurance (r = 0.53) and fast (r = 0.67); and between endurance and fast (r = 0.61). For the ultrasound variables, there was correlation between the bladder neck and H height, both at rest (r = 0.44) and under stress (r = -0.62); between the ureteric angle at stress and H height at rest (r = 0.49); the ureteric angle at rest (r = 0.74); and the levator anterior area (r = 0.40; p = 0.05 for all measures). None of the ultrasound variables correlated with the PERFECT scheme or the vaginal manometry.

CONCLUSION

There was no correlation between the ultrasound variables and vaginal manometry or the PERFECT scheme. There was correlation between specific measurements of the PERFECT scheme and vaginal manometry and among some of the ultrasound variables.

Cytokine modulation in pelvic organ prolapse and urinary incontinence: from molecular insights to therapeutic targets

Pelvic organ prolapse (POP) and urinary incontinence (UI) are common disorders that significantly impact women's quality of life. Studies have demonstrated that cytokines, including pro- and anti-inflammatory immune mediators, play a role in illness genesis and progression. Research on the inflammatory milieu of the pelvic floor has shown that POP patients have increased inflammation in vaginal tissues. This evidence revealed that significant changes in the inflammatory milieu of the pelvic floor are an aspect of the pathogenesis of POP. POP patients exhibit increased levels of inflammatory cytokines (IL-1, TNF, IFN, and others) in the front vaginal wall, which may alter collagen metabolism and contribute to POP. Studies indicate that cytokines such as IL-6, IL-10, and TGF, which are involved in inflammation, remodelling, and repair, have dual effects on POP and UI. They can promote tissue healing and regeneration but also exacerbate inflammation and fibrosis, contributing to the progression of these conditions. Understanding the dual roles of these cytokines could help us improve the vaginal microenvironment of women and treat POP and UI. Given the considerable changes in these cytokines, this review addresses studies published between 2000 and 2024 on the molecular mechanisms by which pro- and anti-inflammatory cytokines affect women with POP and UI. Furthermore, we explain novel therapeutic strategies for cytokine regulation, emphasizing the possibility of personalized treatments that address the underlying inflammatory milieu of the vagina in POP and UI patients. This thorough analysis aims to establish a foundation for future research and clinical applications, ultimately improving patient outcomes via designed cytokine-based therapies.

Postoperative PFME versus PFME alone for moderate SUI in pre-menopause women and influencing factors: a comparative effectiveness study

PURPOSE

To explore the effectiveness of sling surgery followed by pelvic floor muscle exercises (PFME) or PFME alone for moderate stress urinary incontinence (SUI) in women and its influencing factors.

METHODS

This is a prospective observational cohort study investigating whether sling surgery or PFME is preferred for pre-menopause women with moderate uncomplicated SUI. Those who received PFME alone or sling surgery were divided to PT or TVT group, respectively. The primary outcome was objective cure at 12 months. The secondary outcomes included Incontinence Impact Questionnaire-Short Form (IIQ-7) scores and PFME adherence.

RESULTS

The study sample comprised 130 and 74 patients in the PT and TVT groups, respectively. There was 38.2% of patients adhered to PFME twice weekly or more often, and the compliance varied by education level. At 12 months, the objective cure rate was significantly higher in the TVT versus PT group (75.7% vs 47.7%; adjusted OR = 4.27; 95% CI, 2.05-8.87; P < 0.001). In addition, the mean reduction in IIQ-7 scores was greater in the TVT group (16.2 vs 10.0; adjusted OR = 3.38; 95% CI, 1.93-4.82; P < 0.001). However, among patients with lower education or those without adherence to PFME at 12 months, the TVT was also favorized, and the discrepancy in cure rates was greater between the two groups.

CONCLUSION

Sling procedures followed by PFME demonstrate greater efficacy versus physiotherapy alone for moderate female SUI management. Continued adherence to PFME was important, even for patients undergoing sling procedures. Educational factors influenced patient PFME adherence and the advantage conferred by sling procedures.

Cellular regenerative therapy in stress urinary incontinence: new frontiers?-a narrative review

Background and Objective

Even if treatment with stem cells has been shown to be safe and effective in many patients with stress urinary incontinence (SUI), there is still room for improvement using other regenerative medicine alternatives. Since the beneficial effects of stem cells are probably mediated by secretion of factors rather than by the cells themselves there is a good rationale for further exploring the therapeutic effects of the secretome and/or its components. However, homing factors such as stromal derived growth factor 1 (SDF-1; CXCL12), stimulation of stem cell growth and stem cell mobilization in vivo using low intensity shock wave therapy (Li-ESWT) or regenerative electrical stimulation (RES), are also promising approaches.

Methods

A literature search was performed based on PubMed, Scopus and Google Scholar. The search criteria included original basic science articles, systematic reviews and randomized control trials. All studies were published between 2000 and 2023. Selected, peer-reviewed studies were further analyzed to identify those of relevance. Keywords searched included: "female stress incontinence", "homing factors", "CXCL12", "secretome", "low intensity shockwave therapy" and "regenerative electrical stimulation". The peer-reviewed publications on the key word subjects that contained a novel addition to the existing body of literature were included.

Key Content and Findings

There is evidence from studies on non-human primates (NHPs) with experimental urinary sphincter injury that CXCL12 can restore sphincter structure and function. Studies with homing factors in human patients with SUI are still to be performed. A large number of clinical studies on the use of secretome or secretome products from mesenchymal stem cells (MSCs) on indications other than human SUI are already available. However, controlled clinical trials on patients with SUI, have to the best of our knowledge, not yet been performed. Also, RES has not been studied in patients with SUI. In contrast, there is clinical evidence that Li-ESWT may improve female SUI.

Conclusions

Treatment with homing factors, MSC secretome/secretome components, Li-ESWT and RES are promising frontiers in the treatment of human SUI caused by sphincter damage.

Urethral Bulking

OBJECTIVE

This Clinical Practice Statement aims to provide clinicians with evidence-based guidance for the use of urethral bulking agents (UBAs) in the treatment of stress urinary incontinence (SUI).

METHODS

We conducted a structured search of the English literature published from January 1960 to November 2022. Search terms identified studies of both current and historic UBAs. Data extracted at the time of full-text review included type of study, research setting, number of participants, age group, bulking agent, primary outcome, secondary outcome, efficacy, and complications.

RESULTS

One thousand five hundred ninety-four nonduplicate articles were identified using the search criteria. After limiting the article types to randomized control led trials, prospective studies, guideline documents, reviews, meta-analyses, and case reports of complications, 395 studies were screened.

CONCLUSIONS

Based on our findings, we propose the following recommendations for clinicians when considering UBA: First, UBA is indicated in cases of demonstrable SUI. Intrinsic sphincter deficiency is not predictive of patient outcomes. Second, patients should be counseled on the risks, lack of long-term efficacy data, potential need for repeat injections, possible need for surgery for recurrent SUI, implications for future procedures, and pelvic imaging findings that may be observed after UBA. Third, UBA may be considered for initial management of SUI. Fourth, UBA is an option for patients with persistent or recurrent SUI after a sling procedure. Fifth, clinicians may prioritize UBA over surgery in specific patient populations. Sixth, polyacrylamide hydrogel demonstrates marginally improved safety and durability data over other available agents.

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.

Association of plasma high-density lipoprotein cholesterol level with risk of stress urinary incontinence in women: a retrospective study

BACKGROUND

Studies have found that high density lipoprotein cholesterol (HDL-C) levels are linked to a variety of diseases. However, evidence for the relationship between stress urinary incontinence (SUI) and HDL-C remain limited.

METHODS

590 eligible women were enrolled. Basic characteristic, gynecological examinations and blood sampling were collected. The examination of the possible link between HDL-C and SUI was done using univariate and multivariate logistic regression. Feature importance ranking and Receiver operating characteristic (ROC) curves were performed to further evaluate the association between HDL-C and SUI in women.

RESULTS

A significant association was found between HDL-C and SUI in women, revealing higher HDL-C levels were related to a lower risk of SUI (OR 0.238; 95%CI: 0.091-0.623; P < 0.01) after adjustment for potential key confounders. The AUC for the SUI predicted by the combined HDL-C was 0.845 (95%CI: 0.798-0.891, P < 0.001). The feature importance ranking revealed that vaginal delivery, HDL-C were the top two important factors.

CONCLUSIONS

HDL-C levels were correlated with the development of SUI. In addition to physical and surgical treatments, HDL-C may offer the possibility of potential targeted treatment and prevention of SUI afterwards.

Production of Proliferation- and Differentiation-Competent Porcine Myoblasts for Preclinical Studies in a Porcine Large Animal Model of Muscular Insufficiency

Muscular insufficiency is observed in many conditions after injury, chronic inflammation, and especially in elderly populations. Causative cell therapies for muscle deficiencies are not state of the art. Animal models to study the therapy efficacy are, therefore, needed. We developed an improved protocol to produce myoblasts suitable for pre-clinical muscle therapy studies in a large animal model. Myoblasts were isolated from the striated muscle, expanded by employing five different protocols, and characterized on transcript and protein expression levels to determine procedures that yielded optimized regeneration-competent myoblasts and multi-nucleated myotubes. We report that swine skeletal myoblasts proliferated well under improved conditions without signs of cellular senescence, and expressed significant levels of myogenic markers including Pax7, MyoD1, Myf5, MyoG, Des, Myf6, CD56 (p ≤ 0.05 each). Upon terminal differentiation, myoblasts ceased proliferation and generated multi-nucleated myotubes. Injection of such myoblasts into the urethral sphincter complex of pigs with sphincter muscle insufficiency yielded an enhanced functional regeneration of this muscle (81.54% of initial level) when compared to the spontaneous regeneration in the sham controls without myoblast injection (67.03% of initial level). We conclude that the optimized production of porcine myoblasts yields cells that seem suitable for preclinical studies of cell therapy in a porcine large animal model of muscle insufficiency.

Cell Therapy by Mesenchymal Stromal Cells Versus Myoblasts in a Pig Model of Urinary Incontinence

The leading cause of stress urinary incontinence (SUI) in women is the urethral sphincter muscle deficiency caused by mechanical stress during pregnancy and vaginal delivery. In men, prostate cancer surgery and injury of local nerves and muscles are associated with incontinence. Current treatment often fails to satisfy the patient's needs. Cell therapy may improve the situation. We therefore investigated the regeneration potential of cells in ameliorating sphincter muscle deficiency and UI in a large animal model. Urethral sphincter deficiency was induced surgically in gilts by electrocautery and balloon dilatation. Adipose tissue-derived stromal cells (ADSCs) and myoblasts from Musculus semitendinosus were isolated from male littermates, expanded, characterized in depth for expression of marker genes and in vitro differentiation, and labeled. The cells were injected into the deficient sphincter complex of the incontinent female littermates. Incontinent gilts receiving no cell therapy served as controls. Sphincter deficiency and functional regeneration were recorded by monitoring the urethral wall pressure during follow-up by two independent methods. Cells injected were detected in vivo during follow-up by transurethral fluorimetry, ex vivo by fluorescence imaging, and in cryosections of tissues targeted by immunofluorescence and by polymerase chain reaction of the sex-determining region Y (SRY) gene. Partial spontaneous regeneration of sphincter muscle function was recorded in control gilts, but the sphincter function remained significantly below levels measured before induction of incontinence (67.03% ± 14.00%, n = 6, p < 0.05). Injection of myoblasts yielded an improved sphincter regeneration within 5 weeks of follow-up but did not reach significance compared to control gilts (81.54% ± 25.40%, n = 5). A significant and full recovery of the urethral sphincter function was observed upon injection of ADSCs within 5 weeks of follow-up (100.4% ± 23.13%, n = 6, p < 0.05). Injection of stromal cells provoked slightly stronger infiltration of CD45pos leukocytes compared to myoblasts injections and controls. The data of this exploratory study indicate that ADSCs inherit a significant potential to regenerate the function of the urethral sphincter muscle.

Serum albumin levels and stress urinary incontinence in females: A retrospective study based on NHANES 2007-2016

Background

Serum albumin (sAlb) is an essential indicator of human physiological function. However, the correlation between the concentration of sAlb and stress urinary incontinence (SUI) remains poorly understood.

Methods

The sAlb was measured using the bichromatic digital endpoint method. The SUI was assessed according to information from the National Health and Nutrition Examination Survey (NHANES) questionnaire. Univariate and multivariate logistic regression analyses of the potential correlation between sAlb and stress incontinence were performed. Subgroup analysis was also conducted according to body mass index (BMI).

Results

After adjusting for potential key confounders, sAlb was found to have a significant association with SUI in adult females, and higher sAlb levels were associated with a lower risk of SUI (OR = 0.849; 95 % CI: 0.724-0.994; P = 0.042). Furthermore, subgroup analysis indicated that sAlb was associated with reduced SUI risk only in the subgroup with a body mass index (BMI) ≥ 30 (OR = 0.762; 95 % CI: 0.595-0.975; P = 0.030).

Conclusion

Female SUI was correlated with sAlb concentration, and a lower risk of SUI was seen in those with greater sAlb levels. These findings provide new insights into SUI prevention.

Stress Urinary Incontinence: An Unsolved Clinical Challenge

Stress urinary incontinence is still a frequent problem for women and men, which leads to pronounced impairment of the quality of life and withdrawal from the social environment. Modern diagnostics and therapy improved the situation for individuals affected. But there are still limits, including the correct diagnosis of incontinence and its pathophysiology, as well as the therapeutic algorithms. In most cases, patients are treated with a first-line regimen of drugs, possibly in combination with specific exercises and electrophysiological stimulation. When conservative options are exhausted, minimally invasive surgical therapies are indicated. However, standard surgeries, especially the application of implants, do not pursue any causal therapy. Non-absorbable meshes and ligaments have fallen into disrepute due to complications. In numerous countries, classic techniques such as colposuspension have been revived to avoid implants. Except for tapes in the treatment of stress urinary incontinence in women, the literature on randomized controlled studies is insufficient. This review provides an update on pharmacological and surgical treatment options for stress urinary incontinence; it highlights limitations and formulates wishes for the future from a clinical perspective.

Research trends of acupuncture therapy on stress urinary incontinence from 1992 to 2022: A bibliometric analysis

Background

Stress urinary incontinence (SUI), the most prevalent type of urinary incontinence disorder, has aroused increasing attention among societies since it has caused much inconvenience in daily life. In addition to conventional conservative treatments like medication and pelvic floor muscle training, acupuncture is now frequently advised. However, a bibliometric analysis of the trend of SUI therapies is still lacking.

Objectives

This article was carried out using CiteSpace (6.3.1) software to research the use of acupuncture therapy on SUI worldwide over the past 30 years (since the database's inception).

Methods

All related articles included were retrieved from the Web of Science Core Collection. CiteSpace (6.3.1) software was used to analyze the number of publications, countries and institutions, authors and cited authors, and burst keywords to assess the hotspots and trends over the previous three decades. And Microsoft Office Excel 2019 was also used for sorting data and generating tables.

Results

The articles were retrieved on August 31, 2022. A total of 108 records with publication dates ranging from 1992 to 2022 were discovered. The annual number of publications generally increased. In the aspect of publication regions, the USA ranked first in centrality, but China had the largest number of publications. The China Academic of Chinese Medical Sciences, Beijing University of Chinese Medicine, and Shanghai University of Traditional Chinese Medicine were the top 3 institutions, according to the institution map. Liu Z (Liu ZS) was the most productive author, and Chen Y ranked first in the centrality. The article published by Liu Z (Liu ZS) in 2017 was the most cited reference. "Bladder neck suspension", "electrical stimulation" and "acupuncture" were popular therapies mentioned among the top ten hot topics. The keywords "therapy", "postprostatectomy incontinence", "muscle", "cell therapy", and "symptom" ranked in the top five on citation burst. The four frontier topics were "efficacy", "symptom", "cell therapy", and "medical technology".

Conclusion

This study illustrated that the application of acupuncture on SUI had an increasing acceptance worldwide. Recent research has concentrated mainly on acupuncture and electroacupuncture, however, there is still not enough literature on these topics. The valuable information was provided for acupuncture researchers to identify prospects including potential collaborators, cooperation institutions, hot themes, and research frontiers.

Effects of Age and Multiple Vaginal Births on Lower Urinary Tract Structure and Function in Nonhuman Primates

Purpose: The relative roles of urinary sphincter damage, aging, and childbirth in stress urinary incontinence (SUI), have not been established. This study was performed to elucidate the roles of these factors.Methods: The study included: (1) 8 female cynomolgus monkeys (17–19 years of age and 7–8 vaginal births each); (2) six 5-yearold nulliparous monkeys with surgically created chronic urinary sphincter dysfunction; and (3) six 5-year-old, nulliparous, nosurgery controls. Sedated abdominal leak point pressure (ALPP) and maximum urethral sphincter pressures (MUP) were measured. Sphincters, bladders, and pelvic support muscles were quantified for collagen content. Additionally, bladders were analyzed for collagen fiber thickness, length, and angle using CT-FIRE analysis of Picrosirius red-stained tissues.Results: Resting MUP values were similar in the controls and older multiparous monkeys (P>0.05). However, aging and multiple births reduced pudendal nerve-stimulated increases in MUP (P<0.05 vs. controls). ALPP values were lower in the older multiparous versus younger groups of monkeys (P<0.05). Sphincter collagen content was greater, and muscle content less, in the injury model (P<0.05 vs. controls). However, these measures were not affected by age and childbirth (P>0.05 vs. young groups). Bladder collagen content was greater, and muscle content less, in the old multiparous monkeys (P<0.05 vs. younger groups). Additionally, collagen fibers were thicker and more angular in the bladders of the older multiparous monkeys than in the other nonhuman primate groups (P<0.05). Pelvic support muscles had higher collagen and lower muscle content in the older multiparous monkeys than in the younger groups of monkeys (P<0.05).Conclusions: SUI, associated with aging and multiple childbirths, appeared to be more strongly associated with bladder dysfunction, reduced pelvic muscle support, and the compensatory response to neural stimulation than with selective urinary sphincter dysfunction.

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.

Stem cell therapy combined with controlled release of growth factors for the treatment of sphincter dysfunction

Sphincter dysfunction often occurs at the end of tubule organs such as the urethra, anus, or gastroesophageal sphincters. It is the primary consequence of neuromuscular impairment caused by trauma, inflammation, and aging. Despite intensive efforts to recover sphincter function, pharmacological treatments have not achieved significant improvement. Cell- or growth factor-based therapy is a promising approach for neuromuscular regeneration and the recovery of sphincter function. However, a decrease in cell retention and viability, or the short half-life and rapid degradation of growth factors after implantation, remain obstacles to the translation of these therapies to the clinic. Natural biomaterials provide unique tools for controlled growth factor delivery, which leads to better outcomes for sphincter function recovery in vivo when stem cells and growth factors are co-administrated, in comparison to the delivery of single therapies. In this review, we discuss the role of stem cells combined with the controlled release of growth factors, the methods used for delivery, their potential therapeutic role in neuromuscular repair, and the outcomes of preclinical studies using combination therapy, with the hope of providing new therapeutic strategies to treat incontinence or sphincter dysfunction of the urethra, anus, or gastroesophageal tissues, respectively.

Human primary muscle stem cells regenerate injured urethral sphincter in athymic rats

Background

The aim of the study was to demonstrate the efficacy of human muscle stem cells (MuSCs) isolated using innovative technology in restoring internal urinary sphincter function in a preclinical animal model.

Methods

Colonies of pure human MuSCs were obtained from muscle biopsy specimens. Athymic rats were subjected to internal urethral sphincter damage by electrocauterization. Five days after injury, 2 × 10⁵ muscle stem cells or medium as control were injected into the area of sphincter damage (n = 5 in each group). Peak bladder pressure and rise in pressure were chosen as outcome measures. To repeatedly obtain the necessary pressure values, telemetry sensors had been implanted into the rat bladders 10 days prior to injury.

Results

There was a highly significant improvement in the ability to build up peak pressure as well as a pressure rise in animals that had received muscle stem cells as compared to control (p = 0.007) 3 weeks after the cells had been injected. Only minimal histologic evidence of scarring was observed in treated rats.

Conclusion

Primary human muscle stem cells obtained using innovative technology functionally restore internal urethral sphincter function after injury. Translation into use in clinical settings is foreseeable.

Replacing Needle Injection by a Novel Waterjet Technology Grants Improved Muscle Cell Delivery in Target Tissues

Current regimen to treat patients suffering from stress urinary incontinence often seems not to yield satisfactory improvement or may come with severe side effects. To overcome these hurdles, preclinical studies and clinical feasibility studies explored the potential of cell therapies successfully and raised high hopes for better outcome. However, other studies were rather disappointing. We therefore developed a novel cell injection technology to deliver viable cells in the urethral sphincter complex by waterjet instead of using injection needles. We hypothesized that the risk of tissue injury and loss of cells could be reduced by a needle-free injection technology. Muscle-derived cells were obtained from young male piglets and characterized. Upon expansion and fluorescent labeling, cells were injected into cadaveric tissue samples by either waterjet or injection needle. In other experiments, labeled cells were injected by waterjet in the urethra of living pigs and incubated for up to 7 days of follow-up. The analyses documented that the cells injected by waterjet in vitro were viable and proliferated well. Upon injection in live animals, cells appeared undamaged, showed defined cellular somata with distinct nuclei, and contained intact chromosomal DNA. Most importantly, by in vivo waterjet injections, a significantly wider cell distribution was observed when compared with needle injections (P < .05, n ≥ 12 samples). The success rates of waterjet cell application in living animals were significantly higher (≥95%, n = 24) when compared with needle injections, and the injection depth of cells in the urethra could be adapted to the need by adjusting waterjet pressures. We conclude that the novel waterjet technology injects viable muscle cells in tissues at distinct and predetermined depth depending on the injection pressure employed. After waterjet injection, loss of cells by full penetration or injury of the tissue targeted was reduced significantly in comparison with our previous studies employing needle injections.

Stem Cells in Clinical Trials for Pelvic Floor Disorders: a Systematic Literature Review

Pelvic floor disorders (PFDs) include a series of conditions that can be poorly tolerated, negatively affecting the quality of life. Current treatment options show unsatisfactory results and new ones are therefore needed. Stem cell (SC) therapy might be an alternative treatment strategy. This systematic review aims to define the state of art of SC therapy for PFDs in clinical trials, by systematically reviewing the available evidence. A systematic search strategy was conducted up to November 7, 2020, in PubMed, Scopus, Cochrane Library, and ISI Web of Science. Preclinical studies on animal models were not considered. Studies were included when the patients were affected by any PFDs and cells were isolated, cultured, and characterized as SC. The study protocol was registered in PROSPERO (CRD42020216551). A total of 11 prospective clinical studies were included in the final assessment, specifically 7 single-arm studies dealing with SC therapy for stress urinary incontinence and 4 with anal incontinence. Among the latter, there were two prospective, single-arm studies and two randomized controlled trials. No papers concerning the use of SC for prolapse repair were retrieved. Due to the great heterogeneity, data pooling was not possible. Stem cell injection resulted in a safe procedure, with few mild adverse side effects, mostly related to harvesting sites. However, a clear beneficial impact of SC treatment for the treatment of pelvic floor disorders could not be demonstrated. Further larger targeted studies with control arms are needed before any conclusions can be made.