Safety of Intracavernous Bone Marrow-Mononuclear Cells for Postradical Prostatectomy Erectile Dysfunction: An Open Dose-Escalation Pilot Study

Research Advances in Stem Cell Therapy for Erectile Dysfunction

Erectile dysfunction (ED) is a common clinical condition that mainly affects men aged over 40 years. Various causes contribute to the progression of ED, including pelvic nerve injury, diabetes, metabolic syndrome, age, Peyronie's disease, smoking, and psychological disorders. Current treatments for ED are limited to symptom relief and do not address the root cause. Stem cells, with their powerful ability to proliferate and differentiate, are a promising approach for the treatment of male ED and are gradually gaining widespread attention. Current uses for treating ED have been studied primarily in experimental animals, with most studies observing improvements in erectile quality as well as improvements in erectile tissue. However, research on stem cell therapy for human ED is still limited. This article summarizes the recent literature on basic stem cell research on ED, including cavernous nerve injury, aging, diabetes, and sclerosing penile disease, and describes mechanisms of action and therapeutic effects of various stem cell therapies in experimental animals. Stem cells are also believed to interact with host tissue in a paracrine manner, and improved function can be supported through both implantation and paracrine factors. To date, stem cells have shown some preliminary promising results in animal and human models of ED.

The pathogenic role of the immune system in erectile dysfunction and Peyronie's disease: focusing on immunopathophysiology and potential therapeutic strategies

INTRODUCTION

Erectile dysfunction (ED) represents the major cause of male sexual dysfunction, which is often associated with obesity, diabetes mellitus, atherosclerotic cardiovascular disease, and cigarette smoking. Peyronie's disease is a chronic disorder associated with irreversible fibrotic damage of the tunica albuginea leading to ED, painful erection, coital disturbance, and physical and social complaints. Both conditions are characterized by chronic inflammation, oxidative stress, and significant changes in intracavernous hydrodynamics. In this scenario, oxidized lipoproteins, M1-polarized macrophages, proinflammatory cytokines (such as the tumor necrosis factor α), endothelial nitric oxide synthase, penile smooth muscle cells, and toll-like receptors represent the main triggers of the inflammatory process in ED. Phosphodiesterase-5 inhibitors are the most common treatment for ED. This treatment is used intermittently, as it is conceived as a symptomatic and not curative therapy. Moreover, not all patients respond to phosphodiesterase-5 inhibitors (35%-85%), particularly those with dysmetabolic phenotypes. Additional or alternative treatments are therefore desirable, mostly in refractory cases.

OBJECTIVES

In this review, we describe the immune-mediated pathogenesis of ED and Peyronie's disease (PD). In our literature search we placed particular emphasis on potentially practical therapeutic approaches, including natural products (such as polyphenols), due to their anti-inflammatory and antioxidant activities, stem cell therapy, and platelet-derived preparations.

METHODS

We searched PubMed/MEDLINE, Web of Science, Scopus, Cochrane Library, Google Scholar, and institutional websites. Original studies, narrative reviews, systematic reviews, and meta-analyses written in English were searched, screened, and selected.

RESULTS

In animal models of ED and PD, therapeutic approaches, including anti-inflammatory and antioxidant agents, stem cell therapy, and platelet-derived preparations, have provided positive results, including improved penile function, reduced inflammation and oxidative stress, and promotion of tissue repair. However, clinical evidence of improvement in human patients is still insufficient.

CONCLUSION

Promising results for treating ED and PD have been shown in preclinical and pilot clinical studies, but specific clinical trials are needed to validate the efficacy of these therapeutic approaches in men with ED.

Bibliometric and Visualization Analysis of Stem Cell Therapy for Erectile Dysfunction

Purpose

As a common male disease, erectile dysfunction (ED) seriously affects the physical and mental health of patients. In recent years, studies have continued to point out the great potential of stem cell therapy (SCT) in the treatment of ED. The purpose of this study is to comprehensively analyze the research of SCT for ED and understand the development trends and research frontiers in this field.

Methods

Publications regarding SCT and ED were retrieved and collected from the Web of Science Core Collection. CiteSpace and VOSviewer software were then utilized for bibliometric and visualization analysis.

Results

A total of 524 publications were eventually included in this study. The annual number of publications in this field was increasing year by year. China and the USA were the two most productive countries. Lin GT, Lue TF and Lin CS, and the University of California San Francisco where they worked were the most productive research group and institution, respectively. The journal with the largest number of publications was The Journal of Sexual Medicine, and the following were mostly professional journals of urology and andrology. Diabetes mellitus-induced ED and cavernous nerve injury-related ED were the two most commonly constructed models of ED in studies. Concerning the types of stem cells, mesenchymal stem cells derived from adipose and bone marrow were most frequently used. Moreover, future research would mainly focus on exosomes, tissue engineering technology, extracorporeal shockwave therapy, and clinical translation.

Conclusion

The research of SCT for ED will receive increasing global attention in the future. Our study provided bibliometric and visualization analysis of published literature, helping researchers understand the global landscape and frontiers in this field. More preclinical and clinical studies should be conducted to more deeply explore the underlying mechanisms of treatment and promote clinical translation.

Stem cell therapy for erectile dysfunction: a systematic review

INTRODUCTION

Erectile dysfunction (ED) is a common condition that negatively affects men's quality of life. It can have various causes, including psychological, vascular, and neurologic factors. Existing treatments for ED mainly focus on symptom relief rather than addressing the underlying cause. Stem cells (SCs) have shown potential as a therapeutic approach for ED due to their anti-inflammatory properties.

OBJECTIVES

This systematic review aims to assess the current status of trials and determine the potential impact of SCs on male sexual health.

METHODS

A comprehensive search strategy was employed to gather relevant articles from 6 electronic databases. The search included articles published until March 2023. The reference lists of articles were manually reviewed to identify additional studies of relevance. The eligibility criteria for inclusion in the analysis focused on clinical trials involving humans that evaluated the safety and efficacy of SC therapy for ED. Exclusion criteria encompassed case reports, case series, abstracts, reviews, and editorials, as well as studies involving animals or SC derivatives. Data extraction was performed via a standardized form with a focus on erectile outcomes.

RESULTS

A total of 2847 articles were initially identified; 18 were included in the final analysis. These studies involved 373 patients with ED and various underlying medical conditions. Multiple types of SC were utilized in the treatment of ED: mesenchymal SCs, placental matrix-derived mesenchymal SCs, mesenchymal SC-derived exosomes, adipose-derived SCs, bone marrow-derived mononuclear SCs, and umbilical cord blood SCs.

CONCLUSION

SC therapy shows promise as an innovative and safe treatment for organic ED. However, the lack of standardized techniques and controlled groups in many studies hampers the ability to evaluate and compare trials.

Reviving intimacy: Penile rehabilitation strategies for men after prostate cancer treatment

There have been considerable advances in the field of penile rehabilitation for upwards of 90% of men adversely affected by either short-term or long-term erectile dysfunction after definitive prostate cancer treatment. Despite the evolving landscape of treatment modalities for penile rehabilitation, there is a lack of consensus in the urologic community on the best therapies due to the level of evidence and efficacies of the current and emerging offerings. This review of current and next-generation interventions provides a practical approach to the myriad of data to make a better-informed decision based on the pathophysiology and highest-quality evidence available.

Autologous mesenchymal stem cell therapy for diabetic men with erectile dysfunction. Is it promising? A pilot study

PURPOSE

to assess safety and efficacy of autologous mesenchymal bone marrow stem cell injection in penile cavernosal tissue for erectile dysfunction therapy in diabetic men.

METHODS

The subjects of this study were diabetic men suffering erectile dysfunction, non-responding to maximum dose of oral PDE5I. Mesenchymal bone marrow stem cells were aspirated and injected after preparation in both corpora cavernosa at 3, 9 o'clock position. Erectile function was assessed by the International Index of Erectile Function and penile Doppler study, before and after 6 months after injection.

RESULTS

4 patients out of 10 achieve hard erection adequate for satisfactory coitus, and 2 patients achieved penile hardness with addition of pharmacological therapy with sildenafil 100mg. Peak systolic velocity increased significantly in 4 patients (2 arteriogenic and 2 mixed erectile dysfunction), from 12∼22 cm/s to 32∼69 cm/s. Variations in end-diastolic velocity increased substantially in 2 patients with venogenic insufficiency alone at follow-up from 4∼5 cm /s to -4∼-3 cm/s.

CONCLUSIONS

Despite promising stem cell treatment efficacy for patients with erectile dysfunction, more clinical studies and researches are still warranted.

CD31 defines a subpopulation of human adipose-derived regenerative cells with potent angiogenic effects

Cellular heterogeneity represents a major challenge for regenerative treatment using freshly isolated Adipose Derived Regenerative Cells (ADRCs). Emerging data suggest superior efficacy of ADRCs as compared to the ex vivo expanded and more homogeneous ADRCs (= ASCs) for indications involving (micro)vascular deficiency, however, it remains unknown which ADRC cell subtypes account for the improvement. Surprisingly, we found regarding erectile dysfunction (ED) that the number of injected CD31+  ADRCs correlated positively with erectile function 12 months after one bolus of autologous ADRCs. Comprehensive in vitro and ex vivo analyses confirmed superior pro-angiogenic and paracrine effects of human CD31+ enriched ADRCs compared to the corresponding CD31- and parent ADRCs. When CD31+, CD31- and ADRCs were co-cultured in aortic ring- and corpus cavernous tube formation assays, the CD31+  ADRCs induced significantly higher tube development. This effect was corroborated using conditioned medium (CM), while quantitative mass spectrometric analysis suggested that this is likely explained by secretory pro-angiogenic proteins including DKK3, ANGPT2, ANAX2 and VIM, all enriched in CD31+  ADRC CM. Single-cell RNA sequencing showed that transcripts of the upregulated and secreted proteins were present in 9 endothelial ADRC subsets including endothelial progenitor cells in the heterogenous non-cultured ADRCs. Our data suggest that the vascular benefit of using ADRCs in regenerative medicine is dictated by CD31+  ADRCs.

Erectile Dysfunction Treatment Using Stem Cell Delivery Patch in a Cavernous Nerve Injury Rat Model

Erectile dysfunction (ED) is a common and feared complication of radical prostatectomy (RP) for prostate cancer. Recently, tissue engineering for post-prostatectomy ED has been attempted in which controlled interactions between cells, growth factors, and the extracellular matrix (ECM) are important for the structural integrity if nerve regeneration. In this study, we evaluated the effects of a biomechanical ECM patch on the morphology and behavior of human bone marrow-derived mesenchymal stem cells (hBMSCs) in a bilateral cavernous nerve injury (BCNI) rat model. The ECM patch, made of decellularized human fibroblast-derived ECM (hFDM) and a biocompatible polyvinyl alcohol (PVA) hydrogel, was tested with human bone marrow-derived mesenchymal stem cells (hBMSCs) on a bilateral cavernous nerve injury (BCNI) rat model. In vitro analysis showed that the hFDM/PVA + hBMSCs patches significantly increased neural development markers. In vivo experiments demonstrated that the rats treated with the hFDM/PVA patch had higher ICP/MAP ratios, higher ratios of smooth muscle to collagen, increased nNOS content, higher levels of eNOS protein expression, and higher cGMP levels compared to the BCNI group. These results indicate that the hFDM/PVA patch is effective in promoting angiogenesis, smooth muscle regeneration, and nitrergic nerve regeneration, which could contribute to improved erectile function in post-prostatectomy ED.

Vascular endothelium is the basic way for stem cells to treat erectile dysfunction: a bibliometric study

Vascular endothelial is considered to be a key factor in the pathogenesis of erectile dysfunction (ED). The purpose is to reveal the research trend of the field of ED and vascular endothelium. In addition, the goal is to discover the role and mechanism of vascular endothelium in ED. Bibliometrics and visualization methods based on CiteSpace were selected. We conducted the co-authorship analysis of countries, institutions and authors, co-occurrence analysis of keywords, and co-citation analysis of literature and authors through CiteSpace 6.1.R3. 1431 articles from Web of Science Core Collection (WOSCC) were included in the analysis from 1991 to 2022. We found some influential and cutting-edge nodes in each map, including countries, institutions, authors, articles, etc. Stem cell, therapy, oxidative stress, cavernous nerve injury, radical prostatectomy, fibrosis, erectile function, mesenchymal stem cell, and apoptosis may be hot keywords. In conclusion, the efficacy and mechanisms of stem cells and their derivatives in the treatment of diabetes (DM) ED and cavernous nerve injury (CNI) ED are the future research trends. Stem cells therapy for ED is a hot spot in this field, which side notes that stem cells may work mainly through improving endothelial function. Vascular endothelial cells and VEGF may repair nerve and cavernous smooth muscle directly or indirectly, and finally polish up erectile function.

Penile Rehabilitation after Prostate Cancer Treatment: Which Is the Right Program?

The management of sexual complications after treatment of localized prostate cancer, such as erectile dysfunction, changes in the length of the penis, pain during sexual intercourse, and lack of orgasm, is still an unsolved problem with an important impact on patients’ quality of life. In this review, we summarize the current scientific literature about the rehabilitation of erectile dysfunction after prostate cancer treatment. The therapy for penile rehabilitation includes different types of treatments: the combination of phosphodiesterase type 5 inhibitors (PDE5-I) and the vacuum erectile device (VED) are considered first-line treatment options. When therapy begins, the duration of treatment, the dosage and the drug used all play very important roles in the treatment outcome. Intracavernous injection (ICI) therapy represents the second-line option for patients ineligible for PDE5-I therapy. Technological development has led to the emergence of devices for the stimulation of the penis without the use of drugs, such as penile vibratory stimulation (PVS) for stimulation of ejaculation in spinal cord injury and low-intensity extracorporeal shockwave therapy (LIESWT). The rapid diffusion of the latter, thanks to its easy use, attains good results without side effects. The panorama of penile rehabilitation after PC treatments is vast and many studies are needed, especially on new technologies, to find the best therapeutic regimen possible, personalized to the patient’s characteristics and the type of treatment for PC.

Stem Cell Therapy for Erectile Dysfunction: A Step towards a Future Treatment

Background: The improvement of absent or partial response in the medical treatment of erectile dysfunction (ED) has led to the development of minimally invasive new treatment modalities in the field of regenerative medicine. Methods: A literature review on stem cell therapy for the treatment of ED was performed. We searched for the terms "erectile dysfunction" and "stem cell therapy" in PubMed and Clinicaltrials.gov. Literature searching was conducted in English and included articles from 2010 to 2022. Results: New treatment modalities for ED involving stem cell therapy are not only conceived with a curative intent but also aim to avoid unnecessary adverse effects. Several sources of stem cells have been described, each with unique characteristics and potential applications, and different delivery methods have been explored. A limited number of interventional studies over the past recent years have provided evidence of a safety profile in their use and promising results for the treatment of ED, although there are not enough studies to generate an appropriate protocol, dose or cell lineage, or to determine a mechanism of action. Conclusions: Stem cell therapy is a novel treatment for ED with potential future applications. However, most urological societies agree that further research is required to conclusively prove its potential benefit.

Feasibility of minimally invasive, same-day injection of autologous adipose-derived stem cells in the treatment of erectile dysfunction

OBJECTIVE

To investigate feasibility and safety of a new minimally invasive same-day method of autologous adipose derived stem cell (ADSC) transplantation in men suffering from ED.

MATERIALS AND METHODS

Prospective case series of 10 men with an IIEF-EF domain score <17. The IIEF questionnaire was filled out at baseline and 1, 2 and 3 months after treatment. Side effects were assessed by investigations and interviews until 6 months after treatment. The myStem® X2 kit was used for preparation of ADSC: Adipose tissue was harvested from the patient himself under local anesthesia and immediately prepared and injected into the penis. Primary endpoints were feasibility and safety. Secondary outcomes included effects on ED and changes in the remaining IIEF domains.

RESULTS

Ten men were included. Only one adverse event in the form of minor blue discoloration at the fat harvest site was registered. There were statistically significant improvements in IIEF-EF at one, two and three months after treatment compared to baseline with the median score increasing from 5.5 to 10.5, 10.5 and 10, respectively. Considering the individual patients, 3/10 men achieved an improvement equal to or greater than the minimal clinically important difference according to their baseline IIEF-EF score.

CONCLUSIONS

Our study confirms the feasibility and safety of this minimally invasive, same-day delivery of ADSC. Due to the design and size on the study, conclusions should not be drawn regarding efficacy, but the method seems worthy of further study.

Recent advances in stem cell therapy for erectile dysfunction: a narrative review

INTRODUCTION

While phosphodiesterase type 5 inhibitors (PDE5is) and others are used to treat Erectile dysfunction (ED), many patients are either unresponsive or resistant to it. Stem cell therapy (SCT) is a promising alternative approach. Numerous preclinical trials have demonstrated improved erectile function in animal models using SCT, although the number of clinical trials investigating SCT for men with ED is limited. Nonetheless, findings from human clinical trials suggest that SCT may be a useful treatment option.

AREAS COVERED

Biomedical literature, including PubMed, ClinicalTrials.gov, and European Union Clinical Trials Registry, were analyzed to summarize and synthesize information on stem cell therapy for ED in this narrative review. The achievements in preclinical and clinical evaluations are presented and critically analyzed.

EXPERT OPINION

SCT has demonstrated some benefits in improving erectile function, while further studies are urgently needed. Such studies would provide valuable insights into the optimal use of stem cell therapy and its potential as a therapeutic option for ED. Taking advantage of different mechanisms of action involved in various regenerative therapies, combination therapies such as SCT and low-energy shock waves or platelet-rich plasma may provide a more effective therapy and warrant further research.

The Current Role and Implications of Stem Cell Therapy in Erectile Dysfunction: A Transformation from Caterpillar to Butterfly Is Required

Current noninvasive treatments for erectile dysfunction (ED) include oral medications, intracavernosal injections, and vacuum-assisted devices. Although these therapies work well for many, some patients experience side effects or are unsatisfied with these therapeutic modalities. Restorative therapies are the newest frontier for ED treatments and are focused on regenerating injured tissue and delivering a possible "cure". Stem cell therapy is a regenerative treatment aimed at restoring normal erectile physiology and curing ED. It is promising in cell-based and animal studies and has now been studied in humans. Although the clinical results are not robust, future research may shed more light on the efficacy of this treatment for ED. PATIENT SUMMARY: Stem cell therapy is a promising regenerative treatment for erectile dysfunction, but the clinical results are not robust. It is currently considered an experimental treatment and should not be used outside a clinical trial setting.

Human umbilical cord mesenchymal stem cells ameliorate erectile dysfunction in rats with diabetes mellitus through the attenuation of ferroptosis

Background

Erectile dysfunction (ED), as one of the most prevalent consequences in male diabetic patients, has a serious impact on men's physical and mental health, and the treatment effect of diabetic mellitus erectile dysfunction (DMED) is often worse. Therefore, the development of a novel therapeutic approach is urgent. As stem cells with high differentiation potential, human umbilical cord mesenchymal stem cells (HUCMSCs) have been widely used in the treatment of diseases in other systems, and are expected to be a promising strategy for the treatment of DMED. In this study, we investigated the role of HUCMSCs in managing erectile function in rat models of type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) and compared the effects of two different injection methods.

Methods

T1DM and T2DM ED rats were given labelled HUCMSCs by corpus cavernosum injection and tail vein injection, respectively. ICP and MAP were monitored simultaneously by electrical stimulation four weeks after injection to indicate the erectile function of rats. To track the development and colonisation capabilities of stem cells, we performed EdU assay with penile tissue. The histological changes of the penis were observed by hematoxylin–eosin staining, and Masson’s trichrome staining was conducted to evaluate the smooth muscle content and the degree of fibrosis in the rat penis. Then, we employed specific kits to measure the level of NO, cGMP, MDA, SOD and Fe in penis. Electron transmission microscopy was implemented to observe morphology of mitochondria. Besides, western blot and immunofluorescence staining were performed to demonstrate the expression of ferroptosis-related genes.

Results

We found that HUCMSCs improved erectile function in T1DM and T2DM ED rats, with no difference in efficacy between corpus cavernosum injection and tail vein injection. The EdU assay revealed that only a tiny percentage of HUCMSCs colonised the corpus cavernosum, while smooth muscle in the penis expanded and collagen decreased following HUCMSC injection. Moreover, the levels of oxidative stress in the penis of the rats given HUCMSCs were dramatically reduced, as was the tissue iron content. HUCMSCs normalised mitochondrial morphology within corpus cavernosum smooth muscle cells (CCSMCs), which were characteristically altered by high glucose. Furthermore, the expression of ferroptosis inhibitory genes SLC7A11 and GPX4 was obviously elevated in CCSMCs after stem cell management, but the abundances of ACSL4, LPCAT3 and ALOX15 showed the polar opposite tendency.

Conclusions

HUCMSCs can effectively and safely alleviate erectile dysfunction in T1DM and T2DM ED rats, while restoring erectile function by attenuating diabetes-induced ferroptosis in CCSMCs. Additionally, this study provides significant evidence for the development of HUCMSCs as a viable therapeutic strategy for DMED.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03147-w.

An update on the current status and future prospects of erectile dysfunction following radical prostatectomy

BACKGROUND

Radical prostatectomy (RP) and radiation treatment are standard options for localized prostate cancer. Even though nerve-sparing techniques have been increasingly utilized in RP, erectile dysfunction (ED) due to neuropraxia remains a frequent complication. Erectile function recovery rates after RP remain unsatisfactory, and many men still suffer despite the availability of various therapies.

OBJECTIVE

This systematic review aims to summarize the current treatments for post-RP-ED, assess the underlying pathological mechanisms, and emphasize promising therapeutic strategies based on the evidence from basic research.

METHOD

Evaluation and review of articles on the relevant topic published between 2010 and 2021, which are indexed and listed in the PubMed database.

RESULTS

Phosphodiesterase type 5 inhibitors, intracavernosal and intraurethral injections, vacuum erection devices, pelvic muscle training, and surgical procedures are utilized for penile rehabilitation. Clinical trials evaluating the efficacy of erectogenic drugs in this setting are conflicting and far from being conclusive. The use of androgen deprivation therapy in certain scenarios after RP further exacerbates the already problematic situation and emphasizes the need for effective treatment strategies.

CONCLUSION

This article is a detailed overview focusing on the pathophysiology and mechanism of the nerve injury developed during RP and a compilation of various strategies to induce cavernous nerve regeneration to improve erectile function (EF). These strategies include stem cell therapy, gene therapy, growth factors, low-intensity extracorporeal shockwave therapy, immunophilins, and various pharmacological approaches that have induced improvements in EF in experimental models of cavernous nerve injury. Many of the mentioned strategies can improve EF following RP if transformed into clinically applicable safe, and effective techniques with reproducible outcomes.

Pilot study of intra-cavernous injections of platelet-rich plasma (P-shot®) in the treatment of vascular erectile dysfunction

INTRODUCTION

Intracavernosal injections of platelet-rich plasma (PRP) or P-shot® are increasingly proposed as a curative treatment for organic sexual dysfunction despite the lack of evidence of effectiveness.

OBJECTIVES

We conducted a pilot study to evaluate the safety and efficacy of intracavernous PRP injections in patients with vascular erectile dysfunction (ED).

METHODS

Three intracavernosal injections of PRP were performed 15days apart in 15 patients with vascular ED unresponsive to medical treatment with 5-phosphodiesterase inhibitors and/or prostaglandin E instillations or injections. Questionnaires assessing erectile function (IIEF-EF, EHS, SEP, Sexual discomfort score) were completed prior to treatment and 1, 3 and 6 months after the last injection.

RESULTS

No side effects were noted during the study period. The IIEF-EF score was significantly improved after treatment (P<0.001) with a gain of 5 points at 1month, 4 points at 3months and 3 points at 6months (respectively P=0.001, P=0.003 and P=0.022). The other questionnaires did not change significantly. In total, 20% of patients considered that the erection lasted long enough to have a sexual intercourse (SEP score) before P-shot® versus 26.7% after the treatment (P=1).

CONCLUSION

This study suggests that the effect of P-Shot® remains moderate in cases of ED with vascular origin. Larger clinical studies are needed to determine the real effectiveness of this therapeutic strategy.

LEVEL OF PROOF

2.

Autologous Immune Cell-Based Regenerative Therapies to Treat Vasculogenic Erectile Dysfunction: Is the Immuno-Centric Revolution Ready for the Prime Time?

About 35% of patients affected by erectile dysfunction (ED) do not respond to oral phosphodiesterase-5 inhibitors (PDE5i) and more severe vasculogenic refractory ED affects diabetic patients. Innovative approaches, such as regenerative therapies, including stem cell therapy (SCT) and platelet-rich plasma (PRP), are currently under investigation. Recent data point out that the regenerative capacity of stem cells is strongly influenced by local immune responses, with macrophages playing a pivotal role in the injury response and as a coordinator of tissue regeneration, suggesting that control of the immune response could be an appealing approach in regenerative medicine. A new generation of autologous cell therapy based on immune cells instead of stem cells, which could change regenerative medicine for good, is discussed. Increasing safety and efficacy data are coming from clinical trials using peripheral blood mononuclear cells to treat no-option critical limb ischemia and diabetic foot. In this review, ongoing phase 1/phase 2 stem cell clinical trials are discussed. In addition, we examine the mechanism of action and rationale, as well as propose a new generation of regenerative therapies, evolving from typical stem cell or growth factor to immune cell-based medicine, based on autologous peripheral blood mononuclear cells (PBMNC) concentrates for the treatment of ED.

Is there a role for stem cell therapy in erectile dysfunction secondary to cavernous nerve injury? Network meta-analysis from animal studies and human trials

Introduction:

We carried out systematic review and network meta-analysis to investigate the role of stem cell therapy (SCT) in the management of erectile dysfunction (ED) secondary to cavernous nerve injury in rats and post-radical prostatectomy (RP) in humans.

Patients and Methods:

The protocol was registered with PROSPERO database. We searched studies analyzing the efficacy of SCT for ED due to bilateral cavernous nerve injury (BCNI) in rats using Healthcare Databases Advanced Search (HDAS) Export software (MEDLINE, EMBASE, Scopus) from inception to September 2020. The outcome measurements, for 29 animal studies, were intracavernosal pressure (ICP), ICP/MAP (mean arterial pressure) ratio, and histological/molecular changes. All three available human trials evaluating SCT in post-RP ED were assessed for International Index for Erectile Function (IIEF) Score and Erection Hardness Score (EHS).

Results:

For ICP measurement, animal studies were divided into adipose-derived stem cells (ADSCs) subgroup and bone marrow–derived stem cells (BMSCs) subgroup. Pooled analysis of these studies showed a beneficial effect of SCT in improving erectile function in rats with BCNI using network meta-analysis (95% confidence interval, CI; p < 0.001). There was an increase in ICP/MAP ratio in stem cell groups (including co-intervention) compared with control BCNI group. Histological and molecular evaluation of penile tissue revealed an increase in neuronal nitric oxide synthase (nNOS), smooth muscle content, and anti-apoptotic activity. Human trials revealed improved IIEF (70–150% from baseline at 6 months) and EHS (80–200% from baseline).

Conclusion:

Our results confirm that SCT does improve the erectile function in rats having cavernous nerve injury. Similarly, early human results have shown promising results.

PROSPERO registration ID:

CRD42020201343.

Cavernous Nerve Injury Resulted Erectile Dysfunction and Regeneration

Erectile dysfunction (ED) is an important cause of reduced quality of life for men and their partners. Recent studies have found that cavernous nerve injury (CNI) during prostate cancer surgery and other pelvic surgery results in medically induced CNIED in more than 80% of patients. The efficacy of first- and second-line treatment options for ED is poor. A great deal of research has been devoted to exploring new methods of neuroprotection and nerve regeneration to save erectile function in patients with CNIED, especially in patients with cavernous nerve injury after prostate cancer surgery. In addition, such as neuromodulatory proteins, proimmune ligands, gene therapy, stem cell therapy, and the current cutting-edge low-energy shock wave therapy have shown advantages in basic research and limited clinical studies. In the context of today's modern medicine, these new therapeutic techniques are expected to be new tools in the treatment of cavernous nerve injury erectile dysfunction. This article presents the main causes, mechanisms, and treatment of cavernous nerve injury erectile dysfunction and combines them with new treatment strategies.

Effects of Stem Cell Therapy on Diabetic Mellitus Erectile Dysfunction: A Systematic Review and Meta-analysis

BACKGROUND

Stem cell is considered a potential therapy for treating erectile dysfunction (ED), including diabetic mellitus erectile dysfunction (DMED), which was investigated in some preclinical studies. Several trials introduced stem cell into clinical practice, but divergences emerged.

AIM

To further investigate the therapeutic effects of stem cell on DMED in preclinical studies and investigate some possible factors that influence curative effects.

METHODS

The literature research was conducted in Web of Science and PubMed to retrieve studies utilizing stem cell to treat DMED. Revman 5.3 was used to perform subgroup analysis of intracavernosal pressure/mean artery pressure (ICP/MAP) and structural changes. Publication bias was assessed with Egger's test, funnel plot, and sensitivity analysis by Stata 15.0.

OUTCOMES

The ICP/MAP and structural changes before and after stem cell treatment.

RESULTS

Of 2,115 studies retrieved, 23 studies are eligible. Plus 10 studies from a meta-analysis published in 2016, 33 studies were enrolled. Pooled analysis showed that stem cell ameliorates damaged ICP/MAP (WMD 0.26; 95% CI 0.23-0.29; P < .001) and structural changes induced by diabetes. Subgroup analysis indicated that adipose-derived mesenchymal stem cell (ADSC) may have better efficacy than bone marrow-derived mesenchymal stem cell (BMSC) (χ2= 4.21, P = .04; ADSC WMD 0.28, 95% CI [0.24-0.32] vs BMSC WMD 0.22 95% CI [0.17-0.26]). Transplantation type, diabetes type, and cell number make no difference to curative effects. Gene modification and therapy combination proved promising in improving the therapeutic effects of stem cell.

CLINICAL TRANSLATION

The evidence reminded that ADSC may be prior to BMSC in clinical trials and autotransplantation is probably not compulsory in the clinical practice of stem cell.

STRENGTHS AND LIMITATIONS

The study number and sample size are large enough. However, high degree of heterogeneity remains after subgroup analysis.

CONCLUSION

This meta-analysis suggests the efficacy of stem cell therapy for DMED and the possible superiority of ADSC over BMSC in erection restoration and structure renovation.

Phytochemical Screening by LC-ESI-MS/MS and Effect of the Ethyl Acetate Fraction from Leaves and Stems of Jatropha macrantha Müll Arg. on Ketamine-Induced Erectile Dysfunction in Rats

Jatropha macrantha Müll Arg. L is also known as “huanarpo macho” and used in the Peruvian traditional medicine as an aphrodisiac and erectile dysfunction (ED). The aim of this study was to determine the phytochemical constituents in leaves and stems ethyl acetate fraction (LEAF and SEAF) of J. macrantha and to compare the antioxidant activity and the ameliorative effect on ketamine-induced erectile dysfunction in rats. The phytochemical constituents were determined by LC-ESI-MS/MS, the total phenolic compounds and total flavonoids (TPC and TF) by Folin-Ciocalteu and aluminum chloride, respectively. The antioxidant activity was determined by DPPH, ABTS, and FRAP assays. Experimental groups were divided as follows: I: negative control; II: positive control (ketamine at 50 mg/ kg/d); III: sildenafil 5 mg/kg; IV, V, VI: LEAF at 25, 50 and 100 mg/kg, respectively, and VII, VIII, IX: SEAF at 25, 50, and 100 mg/kg, respectively. The phytochemical analysis revealed the presence mainly of coumarins, flavonoids, phenolic acids, and terpenes. TPC of LEAF and SEAF were 359 ± 5.21 mg GAE/g and 306 ± 1.93 mg GAE/g, respectively; TF in LEAF and SEAF were 23.7 ± 0.80 mg EQ/g, and 101 ± 1.42 mg EQ/g, respectively. The DPPH, ABTS, FRAP in SEAF were 647 ± 3.27; 668 ± 2.30; and 575 ± 2.86 μmol TE/g, respectively, whilst LEAF showed 796 ± 3.15; 679 ± 0.85; and 806 ± 3.42 μmol TE/g, respectively. Regarding sexual behavior, LEAF showed a better effect in mount frequency, intromission frequency, ejaculation frequency, mount latency, intromission latency, ejaculatory latency, and post ejaculatory latency than SEAF. As conclusion, LEAF of J. macrantha at 50 mg/kg showed a better effect on sexual behavior in male rats with erectile dysfunction than SEAF but not higher than sildenafil.

Progress and prospect of stem cell therapy for diabetic erectile dysfunction

Diabetic erectile dysfunction (DED) is a common complication of diabetes mellitus, significantly impairing the quality of life of patients. The conventional clinical treatment still has limitations. Stem cells (SCs), as a type of cells with multidirectional or directional differentiation capability and sustainable self-renewal potential, are widely used in regenerative medicine and tissue engineering. With the continuous update of regenerative medicine theory and the success of animal experiments, SCs as a treatment for male erectile dysfunction, especially DED, have attracted widespread attention because of curable possibility. This review focus on the current progress in the clinical application of SC treatment for DED. Moreover, we summarize the development prospects of SCs in the field of DMED therapy.

The potential of platelet-rich plasma injections and stem cell therapy for penile rejuvenation

Penile concerns include erectile dysfunction (ED) and Peyronie disease (PD). Restorative therapies including Stem Cell Therapy (SCT) and Platelet Rich Plasma (PRP) injections are proposed to treat these concerns. SCT encompasses the harvesting and injection of mesenchymal stem cells or stromal vascular fractions from various tissue sources. PRP is derived autologously from a patient's plasma and is then injected into the penile tissue. These therapies repair damaged penile tissue and promote both new cellular and vascular growth, as demonstrated in basic science studies. Human trials on SCT and PRP for both ED and PD and have yielded promising results with few side effects. While encouraging, small cohort size and lack of blinding or placebo control limit these studies' external validity. Recently, the first double-blinded randomized controlled trial on PRP for ED was published, providing significant evidence of efficacy. With the rapid commercial availability of SCT and PRP for ED and PD, it is imperative to perform more randomized and placebo-controlled trials with standardized procedures and preparations to evaluate efficacy and safety. This narrative review will summarize the available literature on these penile restorative therapies to date.

Tissue Engineering and Its Potential to Reduce Prostate Cancer Treatment Sequelae-Narrative Review

Tissue engineering offers the possibility to overcome limitations of current management for postprostatectomy incontinence and ED. Developed in recent years biotechnological feasibility of mesenchymal stem cell isolation, in vitro cultivation and implantation became the basis for new cell-based therapies oriented to induce regeneration of adult tissue. The perspective to offer patients suffering from post-prostatectomy incontinence or erectile dysfunction minimal invasive one-time procedure utilizing autologous stem cell transplantation is desired management.

A review of regenerative therapies as penile rehabilitation in men following primary prostate cancer treatment: Evidence for erectile restoration and cavernous nerve regeneration

Objective

Methods

Results

Conclusion

Stem Cell and Gene-Based Therapy for Erectile Dysfunction: Current Status and Future Needs

Erectile dysfunction affects an increasing number of men. The mainstays of management include oral medications, local erectogenic agents, and surgical placement of prosthetic devices. Newer technologies such as stem cell and gene therapy have been investigated as a means to restore spontaneous erectile capacity. Mesenchymal stem cells are thought to produce a local immunomodulatory and pro-repair milieu at the area of injury or needed repair. Gene therapy involves targeting the erectogenic pathway to augment factors involved in producing a natural erection. Such therapies are considered experimental and should be used in the setting of a clinical trial with appropriate oversight.

Regenerative technology to restore and preserve erectile function in men following prostate cancer treatment: evidence for penile rehabilitation in the context of prostate cancer survivorship

Introduction

Erectile dysfunction (ED) following prostate cancer treatment is not uncommon and penile rehabilitation is considered the standard of care in prostate cancer survivorship (PCS), where both patient and his partner desire to maintain and/or recover pre-treatment erectile function (EF). There is a clinical interest in the role of regenerative therapy to restore EF, since existing ED treatments do not always achieve adequate results.

Aim

To review regenerative therapies for the treatment of ED in the context of PCS.

Materials and Methods

A review of the existing PubMed literature on low-intensity extracorporeal shockwave therapy (LIESWT), stem cell therapy (SCT), platelet-rich plasma (PRP), gene therapy, and nerve graft/neurorrhaphy in the treatment of ED and penile rehabilitation, was undertaken.

Results

IESWT promotes neovascularization and neuroprotection in men with ED. While several systematic reviews and meta-analyses showed positive benefits, there is limited published clinical data in men following radical prostatectomy. Cellular-based technology such as SCT and PRP promotes cellular proliferation and the secretion of various growth factors to repair damaged tissues, especially in preclinical studies. However, longer-term clinical outcomes and concerns regarding bioethical and regulatory frameworks need to be addressed. Data on gene therapy in post-prostatectomy ED men are lacking; further clinical studies are required to investigate the optimal use of growth factors and the safest vector delivery system. Conceptually interpositional cavernous nerve grafting and penile re-innervation technique using a somatic-to-autonomic neurorrhaphy are attractive, but issues relating to surgical technique and potential for neural 'regeneration' are questionable.

Conclusion

In contrast to the existing treatment regime, regenerative ED technology aspires to promote endothelial revascularization and neuro-regeneration. Nevertheless, there remain considerable issues related to these regenerative technologies and techniques, with limited data on longer-term efficacy and safety records. Further research is necessary to define the role of these alternative therapies in the treatment of ED in the context of penile rehabilitation and PCS.

Safety of autologous bone marrow-derived mesenchymal stem cells in erectile dysfunction: an open-label phase 1 clinical trial

BACKGROUND AIMS

The efficacy of phosphodiesterase type 5 inhibitors (PDE5Is), which are commonly used to treat erectile dysfunction (ED), is not satisfactory in patients with denervation of the cavernous nerve due to pelvic surgeries and diabetes mellitus (DM). Pre-clinical studies using bone marrow-derived mesenchymal stem cells (BMSCs) to treat ED have shown promising results. The authors conducted a phase 1 clinical trial with autologous BMSCs in patients with ED due to radical prostatectomy or DM.

METHODS

Ten patients (five with post-prostatectomy ED and five with DM-associated ED) who could not perform sexual activity despite taking the maximum dose of a PDE5I were enrolled. The brief clinical trial protocol was registered with the US National Institutes of Health on ClinicalTrials.gov (NCT02344849). The primary outcome was the safety of stem cell therapy, and the secondary outcome was the improvement of erectile function.

RESULTS

Of the 13 patients screened, 10 were registered in the clinical trial and received autologous BMSCs and nine completed the clinical trial. One patient with post-prostatectomy ED experienced two treatment-emergent adverse events (TEAEs) (pyrexia and back pain), and two patients with DM-associated ED experienced a total of five TEAEs (one case each of viral upper respiratory tract infection, prostatitis and pruritus and two cases of hyperglycemia). Of these patients, one with DM-associated ED experienced two serious TEAEs (two instances of hyperglycemia). All TEAEs were considered not to be related to autologous BMSC therapy. In addition, no clinical significance was identified related to other safety measures, such as laboratory tests and vital signs. The mean International Index of Erectile Function score increased significantly at 1 month versus baseline (24.9 versus 18.1, P = 0.0222).

CONCLUSIONS

This phase 1 clinical trial confirmed the safety and potential efficacy of autologous BMSC therapy in patients with ED. The authors' results need to be confirmed by a phase 2 clinical trial.

Restorative Therapies for Erectile Dysfunction: Position Statement From the Sexual Medicine Society of North America (SMSNA)

INTRODUCTION

Current non-invasive treatments for erectile dysfunction (ED) include oral medications, intracavernosal injections, and vacuum-assisted devices. Though these therapies work well for many, a subset of patients have contraindications or are unsatisfied with these options. Restorative therapies for ED are a new frontier of treatments focused on regenerating diseased tissue and providing a potential "cure" for ED.

AIM

The aim of this position statement is to examine existing clinical trial data for restorative therapies and identify elements that require further research before widespread adoption.

METHODS

A literature review was performed to identify all clinical trials performed with regenerative therapy for ED. This includes treatments such as stem cell therapy (SCT), platelet rich plasma (PRP), and restorative related technologies like low-intensity shockwave therapy (LiSWT).

MAIN OUTCOME MEASURES

Most clinical trials in restorative therapies were assessed for safety, feasibility, or efficacy. This included recording adverse events, changes in sexual function and erectile function questionnaires, and diagnostics measures.

RESULTS

To date there is an absence of robust clinical data supporting the efficacy of restorative therapies regarding ED, though technologies such as LiSWT have established relative safety.

CONCLUSIONS

Restorative therapies are a promising technology that represents a new frontier of treatment geared towards reversing disease pathology rather than just treating symptoms. However, current published clinical studies are limited. Future work needs to be adequately powered, multi-center, randomized, sham/placebo-controlled trials in well-characterized patient populations to ensure safety and demonstrate efficacy. Until these studies are done, restorative therapies should be reserved for clinical trials and not offered in routine clinical practice. Liu JL, Chu KY, Gabrielson AT, et al. Restorative Therapies for Erectile Dysfunction: Position Statement From the Sexual Medicine Society of North America (SMSNA). J Sex Med 2021;9:100343.

Role of regenerative therapies on erectile dysfunction after radical prostatectomy

The present study provides a review of stem cell therapy as a treatment of erectile dysfunction from peer-reviewed human and animal trials. A literature search was conducted in PubMed-Medline, Scopus, Embase, and Cochrane databases. Tweenty-three animal studies and seven human studies in the period from 1st of January 2000 to 1st of Mai 2020 were included. The seven included human studies are primary phase one trials, and most of them treat erectile dysfunction following radical prostatectomy by injection of stem cells into the corpus cavernosum. The primary outcome measure in all human trials is safety and secondary can stem cells play a role in the recovery of erectile function. All studies conclude that it is safe to use stem cells and the majority of the studies demonstrate an improvement in erectile function. The results from both animal and human trials are promising for stem cells as a restorative treatment, but data from large randomized human phase two trials is missing before it can be concluded, that stem cells is an effective treatment for erectile dysfunction in humans.

Anatomy, Pathophysiology, Molecular Mechanisms, and Clinical Management of Erectile Dysfunction in Patients Affected by Coronary Artery Disease: A Review

Erectile dysfunction (ED) has been defined as the inability to attain or maintain penile erection sufficient for successful sexual intercourse. ED carries a notable influence on life quality, with significant implications for family and social relationships. Because atherosclerosis of penile arteries represents one of the most frequent ED causes, patients presenting with it should always be investigated for potential coexistent coronary or peripheral disease. Up to 75% of ED patients have a stenosis of the iliac-pudendal-penile arteries, supplying the male genital organ’s perfusion. Recently, pathophysiology and molecular basis of male erection have been elucidated, giving the ground to pharmacological and mechanical revascularization treatment of this condition. This review will focus on the normal anatomy and physiology of erection, the pathophysiology of ED, the relation between ED and cardiovascular diseases, and, lastly, on the molecular basis of erectile dysfunction.

Engineered Stem Cells Improve Neurogenic Bladder by Overexpressing SDF-1 in a Pelvic Nerve Injury Rat Model

There is still a lack of sufficient research on the mechanism behind neurogenic bladder (NB) treatment. The aim of this study was to explore the effect of overexpressed stromal cell-derived factor-1 (SDF-1) secreted by engineered immortalized mesenchymal stem cells (imMSCs) on the NB. In this study, primary bone marrow mesenchymal stem cells (BM-MSCs) were transfected into immortalized upregulated SDF-1-engineered BM-MSCs (imMSCs/eSDF-1⁺) or immortalized normal SDF-1-engineered BM-MSCs (imMSCs/eSDF-1⁻). NB rats induced by bilateral pelvic nerve (PN) transection were treated with imMSCs/eSDF-1⁺, imMSCs/eSDF-1⁻, or sham. After a 4-week treatment, the bladder function was assessed by cystometry and voiding pattern analysis. The PN and bladder tissues were evaluated via immunostaining and western blotting analysis. We found that imMSCs/eSDF-1⁺ expressed higher levels of SDF-1 in vitro and in vivo. The treatment of imMSCs/eSDF-1⁺ improved NB and evidently stimulated the recovery of bladder wall in NB rats. The recovery of injured nerve was more effective in the NB+imMSCs/eSDF-1⁺ group than in other groups. High SDF-1 expression improved the levels of vascular endothelial growth factor and basic fibroblast growth factor. Apoptosis was decreased after imMSCs injection, and was detected rarely in the NB+imMSCs/eSDF-1⁺ group. Injection of imMSCs boosted the expression of neuronal nitric oxide synthase, p-AKT, and p-ERK in the NB+imMSCs/eSDF-1⁺ group than in other groups. Our findings demonstrated that overexpression of SDF-1 induced additional MSC homing to the injured tissue, which improved the NB by accelerating the restoration of injured nerve in a rat model.

Alternative Treatment for Erectile Dysfunction: a Growing Arsenal in Men's Health

PURPOSE OF REVIEW

To highlight and review encouraging preliminary studies behind several alternative products and interventions for erectile dysfunction (ED).

RECENT FINDINGS

Alternative treatments for ED are becoming more prevalent with increased consumer interest. "Natural" products are sold online, and numerous clinics offer various off-label and investigational interventions. These alternative treatments have demonstrated varying degrees of efficacy in randomized trials and meta-analyses, but none of these interventions has robust enough evidence to be considered first-line therapy. These treatments may find a role in combination with guideline treatments or may be used in novel penile rehabilitation research protocols. With growing interest in alternative treatment for men's health, an awareness of the literature is imperative for patient counsel. Alternative treatments, like L-arginine, have a growing body of evidence for efficacy in combination with PDE5i, and low-intensity shock wave therapy and stem cell therapy continue to demonstrate encouraging outcomes in ED trials.

Erectile Dysfunction Treatment Using Stem Cells: A Review

Erectile dysfunction (ED) is a disorder that affects the quality of life and the sexual relations of more than half of the male population aged over 40 years. The prediction regarding the incidence of ED is devastating as it is expected that this disorder will affect more than 300 million men in the next five years. Several studies have suggested the use of stem cells for the treatment of ED and showed that this type of treatment is promising in terms of damaged tissue repair as well as of clinical efficacy; however, there are several gaps in the knowledge and evidence is lacking. In order to highlight a few of them in this review, we performed a research of the literature focusing on currently available clinical studies regarding the clinical efficacy of stem cell administration for the treatment of ED. We reviewed the methods of administration, the cell types used in the performed clinical trials and the safety and efficiency of such procedures. We conclude that there are rapidly expanding and promising results from the reported clinical studies indicating that stem cells could indeed be a potential treatment for patients with ED although more studies are necessary.

Reviewing the evidence for shockwave- and cell-based regenerative therapies in the treatment of erectile dysfunction

Erectile dysfunction (ED) is both a common and complex disease process. Existing ED treatments do not always achieve adequate results. There is clinical interest in employing regenerative therapies, including low-intensity extracorporeal shockwave therapy (Li-ESWT), platelet rich plasma (PRP), and stem cell therapy (SCT), in the treatment of ED as adjunct or alternative treatments. Here, we present evidence for emerging shockwave- and cell-based regenerative therapies for the treatment of ED following a thorough review of the existing PubMed literature pertaining to Li-ESWT, PRP, and SCT in relation to the treatment of ED. Li-ESWT causes microtrauma in tissue that hypothetically upregulates angiogenesis and recruits stem cells. Several large-scale systematic reviews and meta-analyses have reported that Li-ESWT improved ED in humans. Additionally, evidence has commenced to show that Li-ESWT may be effective against two recognized and complex etiologies of ED: diabetic and neurogenic. PRP delivers an autologous sample rich in growth factors to damaged tissue. Animal model studies have demonstrated improved erectile function recovery as well as preservation of cavernous nerve axons. Studies with PRP in humans are limited. SCT utilizes the regenerative potential of stem cells for healing of damaged tissue. In the treatment of ED, SCT has been used in the setting of diabetic and post-prostatectomy ED. Results of human studies are varied, although SCT treatments did result in increased erectile rigidity with some patients recovering the ability to achieve penetration. While these regenerative therapies show potential to augment the current treatment regimen for ED, there is a paucity of evidence to support the safety and efficacy of these treatments. Further research is necessary to define the role of these alternative therapies in the treatment of ED.

N-acetylcysteine maintains penile length and erectile function in bilateral cavernous nerve crush rat model by reducing penile fibrosis

Penile length shortening and erectile dysfunction are common complications after radical prostatectomy. Various methods have been used to maintain erectile function, but less attention has been paid to preserving penis length. N-acetylcysteine (NAC) has the effect of antioxidation and antifibrotic, which may be beneficial to improve those postoperative complications. This study investigated the effect of NAC on maintaining the penile length and the erectile function after bilateral cavernous nerve crush (BCNC) and its underlying mechanism. Twenty-four male rats were randomly divided into three groups: control group, BCNC group, and BCNC + NAC group. NAC or equal volume of saline was daily administrated by intragastric gavage for 4 weeks. The initial and end penile lengths were measured. Intracavernosal pressure/mean arterial pressure (ICP/MAP) ratio was calculated to assess erectile function. Hematoxylin–eosin staining, Masson's trichrome staining, immunohistochemistry, and Western blot were performed to explore cellular and molecular changes of the penis. Compared to the BCNC group, the penile length, ICP/MAP ratio and smooth muscle/collagen ratio in the BCNC + NAC group were improved significantly (all P < 0.05), and the expressions of endothelial nitric oxide synthase, α-smooth muscle actin, glutathione, and glutathione peroxidase 1 were significantly increased after NAC treated (all P < 0.05), along with the decreased expressions of hypoxia-inducible factor-1α, transforming growth factor-β1, collagen I, collagen III, collagen IV, malonaldehyde, and lysine oxidase (all P < 0.05). This study demonstrated that NAC could maintain penile length and partly improve erectile function. Possible mechanism is directly and/or indirectly related to antihypoxic and antifibrosis.

Generating comprehensive comparative evidence on various interventions for penile rehabilitation in patients with erectile dysfunction after radical prostatectomy: a systematic review and network meta-analysis

Background

We aim to present a comprehensive comparison of various treatments in the management of penile recovery after radical prostatectomy (RP) and provide recommendations for future research.

Methods

Literature search of electronic databases including PubMed, the Cochrane Library, Embase, PsycInfo, and Web of Science, and manual retrieval were conducted from inception through March 2020. “Erectile dysfunction” and “prostatectomy” were used as the Mesh terms. The patients, intervention, comparison, outcome, and study design (PICOS) approach were used to define study eligibility. Two authors independently selected studies, evaluated the methodological quality, and extracted data using Cochrane Collaboration’s tools. The data analysis was completed by STATA version 14.2.

Results

A total of 24 studies with 3,500 patients were incorporated in the final analysis after screening 6,131 records. Our findings indicated that vacuum constriction devices (VCD) ranked 1st which meant that patients in VCD group had the best effect regarding mean IIEF scores within 3 months after RP, and no significant difference was observed between VCD and VCD with 20 mg/day tadalafil (V20DT) (MD: 5.44; 95% CI: −0.81 to 11.69). VCD and 50 mg/day sildenafil (VC50DS) showed superiority over 50 mg/day sildenafil (50DS) (MD: 3.75; 95% CI: 2.74–4.76) and intraurethral alprostadil 125–250 µg (MD: 3.05; 95% CI: 0.38 to 5.72), respectively. Moreover, V20DT showed significant superiority over the other interventions for ≥6 months mean International Index Erectile of Function (IIEF) scores after RP. Monotherapy appeared to have similar efficacy in terms of mean IIEF scores and proportion of patients return to baseline, and the effect of phosphodiesterase type 5 inhibitors (PDE5is) did not seem to be affected by the patterns of administration (regular or on demand).

Conclusions

The combination therapy showed certain advantages over monotherapy, and we recommended the combination of VCD and PDE5is to be considered in the clinical management of penile rehabilitation after RP.

Current management strategy of treating patients with erectile dysfunction after radical prostatectomy: a systematic review and meta-analysis

The aim of this study is to present a summary of current evidence concerning the various treatments in the management of penile rehabilitation after radical prostatectomy (RP) and provide recommendations for future research. Randomized controlled trials (RCTs) were identified from electronic databases including PubMed, the Cochrane Library, Embase, and Web of Science from inception through March 2020 with no limitation to language. Comparable data from each study were combined in a meta-analysis where possible, otherwise data were synthesized narratively. The data analysis was completed by Review Manager version 5.3. A total of 39 RCTs were included in this study. At present, phosphodiesterase type 5 inhibitors (PDE5is) remain the first-line treatment for patients with erectile dysfunction (ED) after RP. Compared with the placebo group, patients in regular PDE5is group (mean difference (MD): 0.76; 95% confidence interval (CI): 1.69-4.44; p < 0.0001) and on demand group (MD: 3.92; 95% CI: 2.95-4.88; p < 0.00001) had a significantly higher mean Erectile Function domain of the International Index of Erectile Function (IIEF-EF) scores within 3 months after RP. As for the proportion of IIEF-EF ≥ 22, patients in regular PDE5is group and on demand PDE5is group had significantly higher proportion than those in placebo group 6 months after RP, and the odds ratios were 1.87 (95% CI: 1.32-2.66; p = 0.0005) and 2.17 (95% CI: 1.20-3.93; p = 0.01), respectively. No significant difference was observed between regular PDE5is group and on demand group regardless of mean IIEF-EF score or the proportion of IIEF-EF ≥ 22. Intracorporeal injection therapy seemed to have similar efficacy to PDE5is. The International Index of Erectile Function-5 items (IIEF-5) scores were significantly higher in vacuum constriction devices group than control group at 6-9 months after RP (MD: 6.70, 95% CI: 2.30-11.10, p = 0.003) with great between-study heterogeneity (p = 0.06, I² = 72%). The other therapeutics including low-intensity extracorporeal shockwave therapy, statin therapy, psychotherapy interventions, and pelvic floor muscle training plus electrical stimulation showed certain improvement on erectile function. We found that the combination therapy showed certain advantages over monotherapy. Currently, PDE5is-based combination therapy remains the mainstream treatment for ED after RP. Intracorporeal injection therapy and vacuum therapy could be served as alternative treatments if PDE5is are ineffective and contraindicated.

[Biotherapies for erectile dysfunction and Peyronie's disease: Where are we now?]

INTRODUCTION

Clinical trials of cell therapy for erectile dysfunction (ED) and Peyronie's disease (PD) were recently conducted after preclinical studies.

AIMS

The aims of this study are to give an update on biotherapy for ED and PD and to describe the regulatory framework for these therapies.

MATERIALS AND METHODS

A literature review was performed through PubMed and Clinical.trials.gov addressing cell therapy for ED and PD and using following keywords "erectile dysfunction", "Peyronie's disease", "stem cell", and "platelet-rich plasma".

RESULTS

Preclinical studies in rodent models have shown the potential benefit of cell therapy for ED after radical prostatectomy or caused by metabolic diseases, and PD. The tissues used to obtain the therapeutic product were bone marrow, adipose tissue and blood (PRP, platelet-rich plasma). Mechanism of action was shown to be temporary and mainly paracrine. Four clinical trials were published concerning ED after radical prostatectomy and in diabetic patients and one for PD. Eleven clinical trials including three randomized trials are currently going on. Preclinical and preliminary clinical results suggested the possibility to improve spontaneous erectile function and response to pharmaceutical treatment in initially non-responder patients. This effect is mediated by an improvement of penile vascularization. A reduction of penile curvature without side effect was noted after injections into the plaque of PD patients. Most of these therapeutic strategies using autologous cells were considered as "Advanced Therapy Medicinal Products" with strict regulatory frameworks imposing heavy constraints, in particular in case of "substantial" modification of the cells. The regulatory framework remains unclear and more permissive for PRP and cell therapy processes with extemporaneous preparation/injection and no "substantial" modifications.

CONCLUSIONS

First results on cell therapy for ED and PD are promising. The regulatory framework can significantly change according to cell preparations and origins leading to various constraints. This regulatory framework is crucial to consider for the choice of the procedure.

Platelet-Rich Plasma and Cellular Therapies for Sexual Medicine and Beyond

INTRODUCTION

Efforts to understand and unlock the body's potential for regeneration have increased dramatically in recent years. So-called "biohacking" hopes to improve functionality and reverse disease processes.

OBJECTIVES

This review will seek to summarize the available data for the use of platelet-rich plasma, cellular therapies, and other novel therapeutics within sexual medicine.

METHODS

The PubMed database search was performed using the keywords "Stem cell therapy in Erectile dysfunction (ED)", "Gene therapy in ED", "Novel therapeutics for ED", and "Biohacking". Popular news articles for regulation of stem cell therapy were reviewed.

RESULTS

Research efforts have managed to produce an array of novel therapeutics, including stem cell therapy and platelet-rich plasma. Although the use of these items has been largely focused within specialties other than urology, applications involving sexual medicine have been documented and appear to be increasing.

CONCLUSION

Despite evidence of these technologies being adopted within clinical practices as revenue-generators, quality data to support efficacy are quite limited. Matz EL, Scarberry K, Terlecki R, Platelet-Rich Plasma and Cellular Therapies for Sexual Medicine and Beyond. Sex Med Rev 2020;XX:XXX-XXX.

Probucol enhances the therapeutic efficiency of mesenchymal stem cells in the treatment of erectile dysfunction in diabetic rats by prolonging their survival time via Nrf2 pathway

BACKGROUND

Intracavernous injection of mesenchymal stem cells (MSCs) is a promising method for diabetic mellitus-induced erectile dysfunction (DMED), but short survival time of MSCs in cavernous is a fatal defect for therapy. This study investigated therapeutic efficiency and potential mechanism of probucol combined with MSCs.

METHODS

In vivo study, a total of forty-eight 10-week-old male Sprague-Dawley (SD) rats were used. Twelve rats received intraperitoneal injection of PBS as the sham group; the rest received intraperitoneal injection of 60 mg/kg streptozotocin to establish DM models. DM rats were randomly divided into three groups: received intracavernosal (IC) injection of either PBS (DM group), MSCs (M group), or administrated probucol after intracavernosal injection of MSCs (P + M group). Erectile function was assessed by electrical stimulation of the cavernous nerves with real-time intracavernous pressure measurement. After euthanasia, penile tissue was investigated for histologic examination and Western blotting. In in vitro experiment, H2O2 was used to create oxidative stress environment to detect changes in cell viability. CCK8 was used to measure cell viability of MSCs treated with or without probucol. Intracellular ROS changes were detected by flow cytometry. Autophagy and apoptosis were detected by Western blotting and confocal microscopy.

RESULTS

Recovery of erectile function was observed in the P + M group. The combination therapy decreased fibrosis and increased endothelial function compared with MSC therapy alone. Western blotting results confirmed the increased expression of Nrf2 and HO-1 in cavernous body. H2O2 induced high oxidative stress and reduced cell viability in vitro, which was gradually reversed with increased concentration of probucol. H2O2 reduced Nrf2 expression, which was reversed by probucol's intervention. Furthermore, the expression of Bax, Caspase3, and Cleaved-Caspase3 decreased, and the expression of Bcl-2 increased in a dose-dependent manner because of probucol's intervention. In addition, Beclin1 and LC3II both increased in a dose-dependent manner. Meanwhile, the expression of P62 decreased. In the study of autophagy flux, we found probucol did not block it.

CONCLUSION

Probucol enhanced therapeutic efficiency of MSCs in DMED by prolonging their survival time, which mediated through improving the transplanted microenvironment of MSCs, increasing self-antioxidant ability of MSCs, strengthening protective autophagy, and inhibiting apoptosis of MSCs via Nrf2 pathway. Schematic model showing combined probucol and MSCs to improve DMED. Probucol increases self-antioxidant ability of MSCs, strengthening protective autophagy and inhibiting apoptosis via Nrf2/HO-1 and Nrf2/autophagy pathways.

Stem-cell therapy for erectile dysfunction: a review of clinical outcomes

The prevalence of erectile dysfunction (ED) has increased in recent decades. Although many treatments offer some benefits for patients with ED, unmet therapeutic needs remain, and promising new approaches are under investigation. One of these approaches is the use of stem-cell (SC) therapy for ED. We comprehensively reviewed the published literature and ongoing phase 1 and phase 2 trials and identified 27 trials by using SC therapy to treat ED. Of the 27 trials, three have been withdrawn, nine have published results, six are complete but without published results, and nine trials are ongoing or have an "unknown" status. Our analysis revealed that SC therapy represents a promising option to treat ED, although published data exist for less than 100 patients. Large placebo-controlled trials with longer follow-up are needed to confirm the long-term safety and efficacy of SC therapy for ED.

The Combined Use of Stem Cells and Platelet Lysate Plasma for the Treatment of Erectile Dysfunction: A Pilot Study-6 Months Results

Background: The current treatment of Erectile Dysfunction (ED) is mainly based on the use of drugs that provide erections shortly after use but they do not really treat the problem. Stem cell therapy is a novel treatment with regenerative properties that can possibly treat erectile dysfunction. Methods: Five patients with erectile disease were treated with Adipose-Derived Stem Cells (ADSCs) and Platelet Lysate Plasma (PLP). ADSCs were obtained through abdominal liposuction and PLP was prepared after obtaining blood samples from peripheral veins. Erectile function was evaluated with the International Index of Erectile Function questionnaire (IIEF-5) questionnaire, penile triplex at the 1st, 3rd, 6th and 12th month post-treatment. A CT scan of the head, thorax and abdomen was done before treatment and at the 12th month. Results: IIEF-5 scores were improved in all patients at the 6th month although not in the same pattern in all patients. Peak Systolic Velocity (PSV) also improved at the 6th month in all patients but also with different patterns in each patient, while End Diastolic Velocity (EDV) was more variable. Two patients decreased the treatment they used in order to obtain erection (from Intracavernosal injections (ICI) they used PDE-5Is), two had unassisted erections and one had an initial improvement which decreased at the 6th month. There were no side effects noted. Conclusions: Stem cell therapy in combination with PLP appears to show some improvement in erectile function and has minimal side effects in the short term.

Novel Emerging Therapies for Erectile Dysfunction

Currently, several treatments exist for the improvement of erectile dysfunction (ED). These include medical therapies such as phosphodiesterase type 5 inhibitors (PDE5-Is), invasive methods such as intracavernosal injection therapy of vaso-active substances, vacuum erection devices, and penile prosthesis implants. However, the percentage of patients that are unresponsive to available treatments and who drop out from treatments remains high. Current evidence reveals that the pathogenesis of ED is related to multiple factors including underlying comorbidities, previous surgery, and psychological factors. Diverse approaches using novel molecular pathways or new technologies have been tested as potential therapeutic options for difficultto-treat ED populations. Melanocortin receptor agonist, a centrally acting agent, showed promising results by initiating erection without sexual stimulation in non-responders to PDE5-Is. Recent clinical and pre-clinical studies using human tissues suggested that new peripherally acting agents including the Max-K channel activator, guanylate cyclase activator, and nitric oxide donor could be potential therapies either as a monotherapy or in combination with PDE5-Is in ED patients. According to several clinical trials, regeneration therapy using stem cells showed favorable data in men with diabetic or post-prostatectomy ED. Low-intensity shock wave therapy also demonstrated promising results in patients with vasculogenic ED. There are growing evidences which suggest the efficacy of these emerging therapies, though most of the therapies still need to be validated by well-designed clinical trials. It is expected that, should their long-term safety and efficacy be proven, the emerging treatments can meet the needs of patients hitherto unresponsive to or unsatisfied by current therapies for ED.

The good, bad, and the ugly of regenerative therapies for erectile dysfunction

Erectile dysfunction (ED) is a common condition which reduces quality of life of both patients and their partners, and is a significant health care expense every year. Although phosphodiesterase type-5 inhibitors are the current first-line treatment for men with ED, they are limited by their on-demand dosing, intolerance, and variable efficacy in complex patient populations such as men with multiple medical comorbidities or ED after pelvic surgery. Regenerative medicine has been introduced and investigated in andrology as an encouraging strategy to restore diseased erectile tissue structure and function. Novel regenerative therapies for ED are controversial but are perceived to offer a durable and safe tissue restorative approach to act as a long-term solution to this cumbersome disease process. Here, we review platelet-rich plasma, amniotic fluid membranes, low-intensity extracorporeal shockwave therapy, and stem cell therapy as regenerative strategies to treat ED. Most of these approaches have preclinical and occasionally clinical data to support their ongoing investigation; however, none of these treatments are currently supported for use in ED patients outside of clinical trials.

Harnessing the mesenchymal stem cell secretome for regenerative urology

The extensive arsenal of bioactive molecules secreted by mesenchymal stem cells (MSCs), known as the secretome, has demonstrated considerable therapeutic benefit in regenerative medicine. Investigation into the therapeutic potential of the secretome has enabled researchers to replicate the anti-inflammatory, pro-angiogenic and trophic effects of stem cells without the need for the cells themselves. Furthermore, treatment with the MSC secretome could circumvent hurdles associated with cellular therapy, including oncogenic transformation, immunoreactivity and cost. Thus, a clear rationale exists for investigating the therapeutic potential of the MSC secretome in regenerative urology. Indeed, preclinical studies have demonstrated the therapeutic benefits of the MSC secretome in models of stress urinary incontinence, renal disease, bladder dysfunction and erectile dysfunction. However, the specific mechanisms underpinning therapeutic activity are unclear and require further research before clinical translation. Improvements in current proteomic methods used to characterize the secretome will be necessary to provide further insight into stem cells and their secretome in regenerative urology.

Dynamic Changes in Erectile Function and Histological Architecture After Intracorporal Injection of Human Placental Stem Cells in a Pelvic Neurovascular Injury Rat Model

INTRODUCTION

The human placenta provides a bountiful and noncontroversial source of stem cells which have the potential for regeneration of injured tissue. These cells may restore erectile function after neurovascular tissue injury such as that seen in radical pelvic surgeries and pelvic trauma.

AIM

To determine the effect of human placenta-derived stem cells on erectile function recovery and histological changes at various time points in a cavernous nerve injury rat model and to study the fate of injected stem cells throughout the regenerative process.

METHODS

Human placental stem cells (PSCs) were dual labeled with monomeric Katushka far red fluorescent protein (mKATE)-renLUC using a lentivirus vector. A pelvic neurovascular injury-induced erectile dysfunction model was established in male, athymic rats by crushing the cavernous nerves and ligating the internal pudendal neurovascular bundles, bilaterally. At the time of defect creation, nonlabeled PSCs were injected into the corpus cavernosum at a concentration of 2.5 × 10⁶ cells/0.2 mL. The phosphate-buffered saline-treated group served as the negative control group, and age-matched rats (age-matched controls) were used as the control group. Erectile function, histomorphological analyses, and Western blot were assessed at 1, 6, and 12 weeks after model creation. The distribution of implanted, dual-labeled PSCs was monitored using an in vivo imaging system (IVIS). Implanted cells were further tracked by detection of mKATE fluorescence in histological sections.

MAIN OUTCOME MEASURE

The main outcome measure includes intracavernous pressure/mean arterial pressure ratio, neural, endothelial, smooth muscle cell regeneration, mKATE fluorescence, and IVIS imaging.

RESULTS

The ratio of intracavernous pressure to mean arterial pressure significantly increased in PSC-injected rats compared with phosphate-buffered saline controls (P < 0.05) at the 6- and 12-week time points, reaching 72% and 68% of the age-matched control group, respectively. Immunofluorescence staining and Western blot analysis showed significant increases in markers of neurons (84.3%), endothelial cells (70.2%), and smooth muscle cells (70.3%) by 6 weeks in treatment groups compared with negative controls. These results were maintained through 12 weeks. IVIS analysis showed luminescence of implanted PSCs in the injected corpora immediately after injection and migration of cells to the sites of injury, including the incision site and periprostatic vasculature by day 1. mKATE fluorescence data revealed the presence of PSCs in the penile corpora and major pelvic ganglion at 1 and 3 days postoperatively. At 7 days, immunofluorescence of penile PSCs had disappeared and was diminished in the major pelvic ganglion.

CLINICAL IMPLICATIONS

Placenta-derived stem cells may represent a future "off-the-shelf" treatment to mitigate against development of erectile dysfunction after radical prostatectomy or other forms of pelvic injury.

STRENGTH & LIMITATIONS

Single dose injection of PSCs after injury resulted in maximal functional recovery and tissue regeneration at 6 weeks, and the results were maintained through 12 weeks. Strategies to optimize adult stem cell therapy might achieve more effective outcomes for human clinical trials.

CONCLUSION

Human PSC therapy effectively restores the erectile tissue and function in this animal model. Thus, PSC therapy may provide an attractive modality to lessen the incidence of erectile dysfunction after pelvic neurovascular injury. Further improvement in tissue regeneration and functional recovery may be possible using multiple injections or systemic introduction of stem cells. Gu X, Thakker PU, Matz EL, et al. Dynamic Changes in Erectile Function and Histological Architecture After Intracorporal Injection of Human Placental Stem Cells in a Pelvic Neurovascular Injury Rat Model. J Sex Med 2020;17:400-411.