Extracorporeal shock wave stimulates expression of the angiogenic genes via mechanosensory complex in endothelial cells: mimetic effect of fluid shear stress in endothelial cells

Radial Type Low-Intensity Extracorporeal Shockwave Therapy Enhances Penile Microvascular Perfusion in an Aging Rat Model: A Novel Interventional Strategy to Treat Erectile Dysfunction

PURPOSE

Physiological aging is associated with microvascular dysfunction, including in the penis, and this may contribute to age-related erectile dysfunction (ED). Low-intensity extracorporeal shockwave therapy (Li-ESWT) is a non-invasive intervention for ED, but its effect on penile microvascular function, remains unclear. Our objectives are to (i) evaluate the effect of Li-ESWT (specifically radial type ESWT [rESWT]) on penile microvascular perfusion (PMP) in aging rats, (ii) elucidate a possible mechanism, and (iii) evaluate its impact on angiogenic and smooth muscle biomarkers in cavernosal tissue.

MATERIALS AND METHODS

Male rats (n=9; 15-18 months) were anesthetized and subjected to rESWT while monitoring PMP. The nitric oxide (NO) pathway involvement was assessed by measuring the effect of rESWT on PMP following an intracavernosal injection of N(G)-nitroarginine methyl ester (L-NAME) (NO synthase inhibitor). To elucidate the cellular mechanism, another group of rats received repeated rESWT (n=4) or no treatment (n=4) three times/week for two weeks. Rats were euthanized at the end of the study and penile tissues were analyzed for angiogenic markers (vascular endothelial growth factor-A [VEGF-A], endothelial nitric oxide synthase [eNOS]) and smooth muscle content (α-actin) using immunostaining, Western blot, and quantitative polymerase chain reaction (qPCR).

RESULTS

rESWT resulted in more than a 2-fold increase in PMP (from 68.5 arbitrary units; 163.7 AU). L-NAME injection produced a <40%-50% decrease (185.3 to 101.0 AU) in rESWT-induced PMP response. Immunostaining revealed increased α-actin, eNOS, and VEGF-A in the cavernosum and these findings were confirmed by qPCR and Western blot results.

CONCLUSIONS

rESWT improved PMP, which may be mediated via increased VEGF expression, which stimulates the NO/cyclic guanosine monophosphate pathway, resulting in sustained PMP. rESWT devices could offer a safe, non-invasive treatment for age-related ED.

Platelet Releasate and Extracorporeal Shock Wave Therapy (ESWT) for Treatment of a Partial Supraspinatus Tear in an Adolescent Baseball Player

Supraspinatus tears are a common injury, particularly among athletes who engage in sports that include repetitive overhead motions, such as baseball players. Standard conservative therapies include rest and activity modification, physical therapy, non-steroidal anti-inflammatory drugs (NSAIDs), cold/heat therapy, and corticosteroid injections. Ongoing research and anecdotal evidence support using platelet-rich plasma (PRP) for supraspinatus/rotator cuff tears. Platelet releasate is obtained from PRP via the activation of platelets, subsequently releasing bioactive substances. Activation can be achieved through various methods, some of which include the addition of calcium chloride, thrombin, or exposure to low-level lasers. Platelet releasate has the potential to assist in the healing of tears by releasing growth factors that facilitate muscle and tendon repair. This case presentation discusses the outcomes of platelet releasate paired with extracorporeal shock wave therapy (ESWT) for the treatment of a partial-thickness supraspinatus tear in an 18-year-old male baseball athlete. After exploring conservative treatment options, the patient opted for a single platelet releasate injection along with a four-part series with ESWT. Four weeks post-procedure, the patient reported a 25% improvement. He was able to fully return to play for the entire baseball season. Although the effectiveness of platelet releasate is still a topic of debate and further investigation, this case demonstrates how platelet releasate shows promising results in accelerating the treatment recovery for a partial supraspinatus tear. Further investigation and research could support the benefit of this procedure for accelerated recovery of injuries compared to PRP.

A prospective randomized controlled trial to determine the safety and efficacy of extracorporeal shock waves therapy for primary prevention of subclinical cardiotoxicity in breast cancer patients without a cardiovascular risk treated with doxorubicin

Background

Doxorubicin is a highly effective anti-cancer drug that causes left ventricular (LV) dysfunction and induces late-onset cardiomyopathy. However, an effective and clinically applicable preventive treatment is yet to be discovered.

Objective

Cardiac-Extracorporeal shockwave therapy (C-ESWT) has been suggested to treat inflammatory and ischemic diseases and protect cardiomyocytes from doxorubicin-induced cardiomyopathy. This study aims to assess the safety and efficacy of C-ESWT in the prevention of subclinical cardiotoxicity.

Methods

We enrolled 64 breast cancer patients. C-ESWT group 33 patients were treated with our C-ESWT (200 shots/spot at 0.09 mJ/mm2 for 20 spots, 3 times every six weeks). The efficacy endpoints were the difference in left ventricular global longitudinal strain (LVGLS) change by 2D speckle tracking echocardiography and chemotherapy-related cardiac dysfunction (CTRCD). Echocardiography was performed on the baseline line and every 4 cycles of chemotherapy, followed by a follow-up 3,6 months after chemotherapy to compare the incidence of cardiomyopathy of subclinical LV dysfunction due to chemotherapy between the two groups.

Results

Participants averaged 50 ± 9 years in age, 100% female. In the results of follow-up 6 months after the end of chemotherapy, there was a significant difference in delta LVGLS between the C-ESWT group and the control group (LVGLS; -1.1 ± 10.9% vs. -11.5 ± 11.6% p-value; <0.001). A total of 23% (15 patients) of patients developed CTRCD (Control group; 13 vs. C-ESWT group; (2). C-ESWT was performed safely without any serious adverse events.

Conclusion

In this prospective study, C-ESWT established efficacy in preventing subclinical cardiotoxicity, especially in breast cancer patients using doxorubicin chemotherapy, and the safety of C-ESWT.

Clinical Trial Registration

ClinicalTrials.gov, identifier (NCT05584163).

The effects and underlying mechanism of extracorporeal shockwave therapy on fracture healing

The clinical efficacy of ESWT in treating bone non union has been widely recognized, but the biological mechanism of ESWT promoting bone non union healing is still unclear. ESWT can make old callus micro fracture through mechanical conduction, form subperiosteal hematoma, promote the release of bioactive factors, reactivate the fracture healing mechanism, rebalance the activities of osteoblasts and osteoclast, promote the angiogenesis of fracture site, and accelerate the healing of bone nonunion.Over recent years, great efforts have been made by both scientists and clinicians to explore the underlying mechanism behind the healing effect of ESWT on bone fractures. In this review, we introduced the growth factors during osteogenesis induced by ESWT hoping to provide new insights in the clinical use of ESWT.

Low-Intensity Extracorporeal Shockwave Therapy (LI-ESWT) in Renal Diseases: A Review of Animal and Human Studies

Background

Low-intensity extracorporeal shockwave therapy (LI-ESWT) has been suggested as a treatment for vascular diseases such as ischemic heart disease, diabetic foot ulcers, and erectile dysfunction. Primarily, LI-ESWT is known for its ability to stimulate angiogenesis and activation of stem cells in target tissues. Application of LI-ESWT in chronic progressive renal diseases is a novel area. The aim of the present review was to summarize available data on the effects of LI-ESWT used in the setting of renal diseases.

Methods

We systematically searched PubMed, Medline, and Embase databases for relevant studies. Our review included the results from preclinical animal experiments and clinical research.

Results

Eleven animal studies and one clinical study were included in the review. In the animal studies, LI-ESWT was used for the treatment of hypertensive nephropathy (n=1), diabetic nephropathy (n=1), or various types of ischemic renal injury (ie, artery occlusion, reperfusion injury) (n=9). The clinical study was conducted in a single-arm cohort as a Phase 1 study with patients having diabetic nephropathy. In animal studies, the application of LI-ESWT was associated with several effects: LI-ESWT led to increased VEGF and endothelial cell proliferation and improved vascularity and perfusion of the kidney tissue. LI-ESWT reduced renal inflammation and fibrosis. LI-ESWT caused only mild side effects in the clinical study, and, similarly, there were no signs of kidney injury after LI-ESWT in the animal studies.

Conclusion

LI-ESWT, as a non-invasive treatment, reduces the pathological manifestations (inflammation, capillary rarefaction, fibrosis, decreased perfusion) associated with certain types of renal disease. The efficacy of renal LI-ESWT needs to be confirmed in randomized clinical trials.

Biomechanics and mechanobiology of the bone matrix

The bone matrix plays an indispensable role in the human body, and its unique biomechanical and mechanobiological properties have received much attention. The bone matrix has unique mechanical anisotropy and exhibits both strong toughness and high strength. These mechanical properties are closely associated with human life activities and correspond to the function of bone in the human body. None of the mechanical properties exhibited by the bone matrix is independent of its composition and structure. Studies on the biomechanics of the bone matrix can provide a reference for the preparation of more applicable bone substitute implants, bone biomimetic materials and scaffolds for bone tissue repair in humans, as well as for biomimetic applications in other fields. In providing mechanical support to the human body, bone is constantly exposed to mechanical stimuli. Through the study of the mechanobiology of the bone matrix, the response mechanism of the bone matrix to its surrounding mechanical environment can be elucidated and used for the health maintenance of bone tissue and defect regeneration. This paper summarizes the biomechanical properties of the bone matrix and their biological significance, discusses the compositional and structural basis by which the bone matrix is capable of exhibiting these mechanical properties, and studies the effects of mechanical stimuli, especially fluid shear stress, on the components of the bone matrix, cells and their interactions. The problems that occur with regard to the biomechanics and mechanobiology of the bone matrix and the corresponding challenges that may need to be faced in the future are also described.

Application of extracorporeal shock wave therapy in nervous system diseases: A review

Neurological disorders are one of the leading causes of morbidity and mortality worldwide, and their therapeutic options remain limited. Recent animal and clinical studies have shown the potential of extracorporeal shock wave therapy (ESWT) as an innovative, safe, and cost-effective option to treat neurological disorders. Moreover, the cellular and molecular mechanism of ESWT has been proposed to better understand the regeneration and repairment of neurological disorders by ESWT. In this review, we discuss the principles of ESWT, the animal and clinical studies involving the use of ESWT to treat central and peripheral nervous system diseases, and the proposed cellular and molecular mechanism of ESWT. We also discuss the challenges encountered when applying ESWT to the human brain and spinal cord and the new potential applications of ESWT in treating neurological disorders.

Biological response of extracorporeal shock wave therapy to tendinopathy in vivo (review)

Tendinopathy is a degenerative disease of the tendons caused by prolonged overstretching or overuse of the tendons. It accounts for a large proportion of musculoskeletal disorders which can occur in all age groups. The management of tendinopathy is typically conservative. In clinical practice, when other conservative treatments fail, extracorporeal shock wave therapy (ESWT) is normally used as an efficient alternative to surgical management. Several basic studies have shown that ESWT with lower energy flux densities can produce some biological responses in vivo to tendinopathy and may accelerate the initiation of the healing process in injured tendons. ESWT has a positive impact on the interactive chain of biological response, enhancing the signaling pathways of angiogenesis through mechanical conduction, and promoting cell proliferation and collagen formation. Finally, it helps tissue regeneration by controlling inflammation. The purpose of this review is to summarize the biological responses generated by ESWT in tendinopathy through a comprehensive review of the published literature. Although ESWT has been used clinically for the treatment of tendinopathies for nearly decades, less is known about the experimental studies of its biological effects on tendon tissue. Further studies on the biological response of ESWT for tendon injuries in vivo are needed in the future in order to provide better management to patients.

Piezo1 Channels as Force Sensors in Mechanical Force-Related Chronic Inflammation

Mechanical damage is one of the predisposing factors of inflammation, and it runs through the entire inflammatory pathological process. Repeated or persistent damaging mechanical irritation leads to chronic inflammatory diseases. The mechanism of how mechanical forces induce inflammation is not fully understood. Piezo1 is a newly discovered mechanically sensitive ion channel. The Piezo1 channel opens in response to mechanical stimuli, transducing mechanical signals into an inflammatory cascade in the cell leading to tissue inflammation. A large amount of evidence shows that Piezo1 plays a vital role in the occurrence and progression of chronic inflammatory diseases. This mini-review briefly presents new evidence that Piezo1 responds to different mechanical stresses to trigger inflammation in various tissues. The discovery of Piezo1 provides new insights for the treatment of chronic inflammatory diseases related to mechanical stress. Inhibiting the transduction of damaging mechanical signals into inflammatory signals can inhibit inflammation and improve the outcome of inflammation at an early stage. The pharmacology of Piezo1 has shown bright prospects. The development of tissue-specific Piezo1 drugs for clinical use may be a new target for treating chronic inflammation.

Extracorporeal Cardiac Shock Waves Therapy Improves the Function of Endothelial Progenitor Cells After Hypoxia Injury via Activating PI3K/Akt/eNOS Signal Pathway

Background: Extracorporeal cardiac shock waves (ECSW) have great potential in the treatment of coronary heart disease. Endothelial progenitor cells (EPCs) are a class of pluripotent progenitor cells derived from bone marrow or peripheral blood, which have the capacity to migrate to ischemic myocardium and differentiate into mature endothelial cells and play an important role in neovascularization and endothelial repair. In this study, we investigated whether ECSW therapy can improve EPCs dysfunction and apoptosis induced by hypoxia and explored the underlying mechanisms.

Methods: EPCs were separated from ApoE gene knockout rat bone marrow and identified using flow cytometry and fluorescence staining. EPCs were used to produce in vitro hypoxia-injury models which were then divided into six groups: Control, Hypoxia, Hypoxia + ECSW, Hypoxia + LY294002 + ECSW, Hypoxia + MK-2206 + ECSW, and Hypoxia + L-NAME + ECSW. EPCs from the Control, Hypoxia, and Hypoxia + ECSW groups were used in mRNA sequencing reactions. mRNA and protein expression levels were analyzed using qRT-PCR and western blot analysis, respectively. Proliferation, apoptosis, adhesion, migration, and angiogenesis were measured using CCK-8, flow cytometry, gelatin, transwell, and tube formation, respectively. Nitric oxide (NO) levels were measured using an NO assay kit.

Results: Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that differentially expressed genes were enriched in cancer signaling, PI3K-Akt signaling, and Rap1 signaling pathways. We selected differentially expressed genes in the PI3K-Akt signaling pathway and verified them using a series of experiments. The results showed that ECSW therapy (500 shots at 0.09 mJ/mm²) significantly improved proliferation, adhesion, migration, and tube formation abilities of EPCs following hypoxic injury, accompanied by upregulation of p-PI3K, p-Akt, p-eNOS, Bcl-2 protein and NO, PI3K, and Akt mRNA expression, and downregulation of Bax and Caspase3 protein expression. All these effects of ECSW were eliminated using inhibitors specific to PI3K (LY294002), Akt (MK-2206), and eNOS (L-NAME).

Conclusion: ECSW exerted a strong repaired effect on EPCs suffering inhibited hypoxia injury by inhibiting cell apoptosis and promoting angiogenesis, mainly through activating the PI3K/Akt/eNOS signaling pathway, which provide new evidence for ECSW therapy in CHD.

Effects of Extracorporeal Shock Waves on Microcirculation and Angiogenesis in the in vivo Wound Model of the Diver Box

INTRODUCTION

Extracorporeal shock waves (ESWs) have been shown to have a positive effect on skin wound healing; however, little is known on the regeneration of the microcirculation and angiogenesis as well as the different application modes.

METHODS

A total of 40 BALB/c mice were provided with dorsal skin fold chambers and were divided into 3 therapy groups (n = 30) and one control group (n = 10). The 3 therapy groups were treated with shock waves at different pulse rates (500-1,000 pulses/min) and application frequencies (day 0 and day 6 or day 0 only). Photographic documentation and intravital microscopy were carried out on day 1, 2, 4, and 6 after wounding.

RESULTS

Using the newly developed Diver Box, shock waves could be applied in vivo without mechanical tissue damage. Shock wave therapy to skin wounds demonstrated to induce faster wound closure rates in the beginning than controls in groups with higher pulse rates and frequencies of the shock waves. Furthermore, the regeneration of microcirculation and perfusion in the healing skin was significantly improved after the application of, in particular, higher pulse rates as given by increased numbers of perfused capillaries and functional vessel density. The study of inflammation showed, especially in high-pulse ESW groups, higher leukocyte counts, and rolling leukocytes over time until day 6 as a response to the induction of inflammatory reaction after ESW application. Angiogenesis showed a marked increase in positive areas as given by sprouts, coils, and recruitments in all ESW groups, especially between days 4 and 6.

CONCLUSION

The major findings of this trial demonstrate that ESW therapy to skin wounds is effective and safe. This is demonstrated by the initially faster wound closure rate, but later the same wound closure rate in the treatment groups than in controls. Furthermore, during the regeneration of microcirculation and perfusion in the healing skin, a significant improvement was observed after the application of, in particular, higher ESW pulse rates, suggesting an ESW-related increase in nutrient and oxygen supply in the wound tissue.

Low-Intensity Shockwave Therapy (LI-ESWT) in Diabetic Kidney Disease: Results from an Open-Label Interventional Clinical Trial

Purpose

Treatment with low-intensity shockwave therapy (LI-ESWT) is associated with angiogenesis and is suggested as a treatment for different types of vascular diseases. It was hypothesized that LI-ESWT improves the renal filtration barrier and halts the progression of GFR decline in diabetic kidney disease (DKD) potentially through VEGF and NO formation. We present the first data on LI-ESWT in human DKD.

Methods

The study was designed as an interventional, prospective, one-arm, Phase 1 study. We investigated change in GFR and albuminuria in 28 patients with DKD treated with six sessions of LI-ESWT over three weeks. The patients were followed for six months. Urine excretion of kidney injury markers, vascular endothelial growth factor (VEGF) and nitric oxide metabolites (NOx) was studied after LI-ESWT.

Results

There were no significant changes in GFR and albuminuria up to six months after LI-ESWT compared to baseline. Urine VEGF was transiently reduced one month after LI-ESWT, but there were no other significant changes in urine VEGF or NOx after LI-ESWT. Secondary analysis showed that NOx increased after LI-ESWT in patients who had low levels of NOx at baseline. Kidney injury marker trefoil factor 3 (TFF3) increased acutely after the first session of LI-ESWT indicating transient endothelial repair. Other markers of kidney injury were stable in relation to LI-ESWT.

Conclusion

LI-ESWT treatment did not significantly improve kidney function and albumin excretion. It is concluded that LI-ESWT is not harmful. A randomized blinded study should be performed to clarify whether adjunctive treatment with LI-ESWT is superior to standard treatment of DKD.

Mesenchymal Stem Cell-Derived Small Extracellular Vesicles Protect Cardiomyocytes from Doxorubicin-Induced Cardiomyopathy by Upregulating Survivin Expression via the miR-199a-3p-Akt-Sp1/p53 Signaling Pathway

Cardiotoxicity is associated with the long-term clinical application of doxorubicin (DOX) in cancer patients. Mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs) including exosomes have been suggested for the treatment of various diseases, including ischemic diseases. However, the effects and functional mechanism of MSC-sEVs in DOX-induced cardiomyopathy have not been clarified. Here, MSC-sEVs were isolated from murine embryonic mesenchymal progenitor cell (C3H/10T1/2) culture media, using ultrafiltration. H9c2 cardiac myoblast cells were pretreated with MSC-sEVs and then exposed to DOX. For in vivo studies, male C57BL/6 mice were administered MSC-sEVs intravenously, prior to a single dose of DOX (15 mg/kg, intraperitoneal). The mice were sacrificed 14 days after DOX treatment. The results showed that MSC-sEVs protected cardiomyocytes from DOX-induced cell death. H9c2 cells treated with DOX showed downregulation of both phosphorylated Akt and survivin, whereas the treatment of MSC-sEVs recovered expression, indicating their anti-apoptotic effects. Three microRNAs (miRNAs) (miR 199a-3p, miR 424-5p, and miR 21-5p) in MSC-sEVs regulated the Akt-Sp1/p53 signaling pathway in cardiomyocytes. Among them, miR 199a-3p was involved in regulating survivin expression, which correlated with the anti-apoptotic effects of MSC-sEVs. In in vivo studies, the echocardiographic results showed that the group treated with MSC-sEVs recovered from DOX-induced cardiomyopathy, showing improvement of both the left ventricle fraction and ejection fraction. MSC-sEVs treatment also increased both survivin and B-cell lymphoma 2 expression in heart tissue compared to the DOX group. Our results demonstrate that MSC-sEVs have protective effects against DOX-induced cardiomyopathy by upregulating survivin expression, which is mediated by the regulation of Akt activation by miRNAs in MSC-sEVs. Thus, MSC-sEVs may be a novel therapy for the prevention of DOX-induced cardiomyopathy.

Low-intensity shock wave therapy for the treatment of vasculogenic erectile dysfunction: a narrative review of technical considerations and treatment outcomes

Erectile dysfunction (ED) impacts a significant portion of the aging male population. Standard treatments such as oral medications, intracavernosal injections, intraurethral suppositories, vacuum erection aids, and penile prosthesis placement have stood the test of time. Recently, there has been a growing interest in the concept of regenerative medicine with the goal of restoring or renewing functional tissue. Low intensity shock wave therapy (LiSWT) is one example of a regenerative therapy. A strong body of basic science data suggests that shockwaves, when applied to local tissue, will encourage blood vessel and nerve regeneration. Clinical evidence supports the use of LiSWT to treat conditions ranging from ischemic heart disease, musculoskeletal injuries, and even chronic non-healing wounds. LiSWT is also being used to treat male sexual dysfunction conditions such as Peyronie's Disease and ED. The first studied application of LiSWT for ED was published in 2010. Since then multiple randomized, sham-controlled trials have sought to evaluate outcomes for this novel therapy in men with vasculogenic ED. Additionally, several meta-analyses are available with pooled data suggesting that LiSWT results in a significantly greater improvement in erectile function relative to sham-control. Despite these promising findings, the current body of literature is marred by significant heterogeneity relating to treatment protocols, patient populations, and follow-up duration. Further work is necessary to determine optimal device technologies, patient characteristics, and treatment duration prior to considering LiSWT as standard of care for men with ED.

The role of shockwaves in the enhancement of bone repair - from basic principles to clinical application

Extracorporeal shockwave therapy is a treatment modality, originally introduced into the clinic as lithotripsie, which has also been successfully used in the last two decades in the non-invasive treatment of delayed or non-healing fractures. Initially, the mechanism of action was attributed to microfracture-induced repair, but intensive basic research has now shown that the shockwave generates its effect in tissue via mechanotransduction. Numerous signal transduction pathways have already been demonstrated, which in their entirety trigger an endogenous regeneration process via cell proliferation, migration and differentiation. Clinically, these shockwave-conveyed biological signals support healing of acute, delayed and non-union fractures. The attainable outcome is comparable to surgery but avoiding an open approach with associated potential complications. These advantageous properties with a clearly positive cost-benefit ratio make shockwave therapy a first line treatment in delayed and non-union fractures.

The waves that make the pattern: a review on acoustic manipulation in biomedical research

Novel approaches, combining technology, biomaterial design, and cutting-edge cell culture, have been increasingly considered to advance the field of tissue engineering and regenerative medicine. Within this context, acoustic manipulation to remotely control spatial cellular organization within a carrier matrix has arisen as a particularly promising method during the last decade. Acoustic or sound-induced manipulation takes advantage of hydrodynamic forces exerted on systems of particles within a liquid medium by standing waves. Inorganic or organic particles, cells, or organoids assemble within the nodes of the standing wave, creating distinct patterns in response to the applied frequency and amplitude. Acoustic manipulation has advanced from micro- or nanoparticle arrangement in 2D to the assembly of multiple cell types or organoids into highly complex in vitro tissues. In this review, we discuss the past research achievements in the field of acoustic manipulation with particular emphasis on biomedical application. We survey microfluidic, open chamber, and high throughput devices for their applicability to arrange non-living and living units in buffer or hydrogels. We also investigate the challenges arising from different methods, and their prospects to gain a deeper understanding of in vitro tissue formation and application in the field of biomedical engineering.

•

Work on sound waves to spatially control particulate systems is reviewed.

•

Classification of surface acoustic waves, bulk acoustic waves, and Faraday waves.

•

Sound can be used to arrange, separate, or filter polymer particles.

•

Sound can pattern cells in 3D to induce morphogenesis.

•

Long-term applied sound induces differentiation and tissue formation.

Low-intensity shockwave therapy in the treatment of diabetic nephropathy: a prospective Phase 1 study

BACKGROUND

Low-intensity shockwave therapy (LI-SWT) is suggested as a therapy for promoting tissue regeneration. In pigs, it was recently found that LI-SWT improved renal function after ischaemic injury. Our objectives were to study glomerular filtration rate (GFR) and albuminuria in diabetic nephropathy (DN) after treatment with LI-SWT. The present pilot study reports on the clinical safety of LI-SWT in DN.

METHODS

A total of 14 patients with diabetes mellitus and Stage 3 chronic kidney disease were recruited for this prospective, one-arm Phase 1 study. The patients were treated with six sessions of LI-SWT during a 3-week period. At each session, 3000 shockwaves were applied to each kidney with 0.265 mJ/mm2, extended focal size and 4 Hz. Follow-up visits were performed at 1, 3 and 6 months.

RESULTS

In general, the treatment was well tolerated. Transient macroscopic haematuria was observed in three patients immediately after LI-SWT. The majority of patients experienced lower back tenderness lasting up to 2 days after treatment. There was no need for analgesic treatment. LI-SWT showed no negative effect on GFR and albuminuria. At baseline, median (interquartile range) GFR was 33.5 mL/min/1.73 m2 (27.8-43.8) compared with 36.0 mL/min/1.73 m2 (27.5-52.0) at 6 months follow-up. In parallel, median albuminuria was 256 mg/24 h (79-619) at baseline and tended to decrease to 137 mg/24 h (41-404) 6 months after LI-SWT. There was no statistical difference between baseline and follow-up results.

CONCLUSIONS

LI-SWT is a safe treatment for DN. Inclusion of more patients is needed to determine whether LI-SWT can improve renal functional outcomes.

Activation of Piezo1 by ultrasonic stimulation and its effect on the permeability of human umbilical vein endothelial cells

The acoustic radiation forces produced by ultrasonic stimulation induce shear stress on objects in the acoustic field. Piezo1, a mechanosensitive ion channel protein that is expressed on the plasma membranes of vertebrate cells, can sense shear stress and transduce it into downstream signaling. In this study, we examined the sensitivity of Piezo1 to ultrasonic stimulation and assessed its downstream biological functions in human umbilical vein endothelial cells (HUVECs). Ultrasonic stimulation using a stimulation power of 0.2 W and a frequency of 1 MHz for 10 s did not induce cell damage. However, ultrasonic stimulation induced an influx of calcium ions, which increased with an increase in the stimulation duration. Knockdown of Piezo1 protein decreased the influx of calcium ions during ultrasonic stimulation, which demonstrated that Piezo1 may be activated by the shear stress produced by ultrasonic stimulation. The influx of calcium ions in response to ultrasonic stimulation could be modulated by the Piezo1 protein level. Additionally, ultrasonic stimulation reduced the levels of downstream factors such as MLCK and ATP, which are involved in the Ca²⁺/CaM/MLCK pathway, by suppressing Piezo1. As the Ca²⁺/CaM/MLCK pathway influences the permeability of the cell membrane, the internalization of FITC-Dextran into cells under ultrasonic stimulation was validated. Ultrasonic stimulation was demonstrated to promote the increase in cell permeability, and the suppression of Piezo1 was shown to induce the decrease in cell permeability. Therefore, this study shows that ultrasonic stimulation may modulate the permeability of the membrane of HUVECs by modulating the expression of Piezo1 protein.

The Basic Science Behind Low-Intensity Extracorporeal Shockwave Therapy for Erectile Dysfunction: A Systematic Scoping Review of Pre-Clinical Studies

INTRODUCTION

Despite recent promising clinical results, the underlying mechanism of action of low-intensity extracorporeal shockwave therapy (Li-ESWT) for erectile dysfunction (ED) is mostly unclear and currently under investigation.

AIM

To systematically identify and evaluate evidence regarding the basic science behind Li-ESWT for ED, discuss and propose a putative mechanism of action, address the limitations, and imply insights for further investigation in the field.

METHODS

Using Cochrane's methodologic recommendations on scoping studies and systematic reviews, we conducted a systematic scoping review of the literature on experimental research regarding Li-ESWT for ED and other pathologic conditions. The initial systematic search was carried between January and November 2017, with 2 additional searches in April and August 2018. All studies that applied shockwave treatment at an energy flux density >0.25 mJ/mm² were excluded from the final analysis.

MAIN OUTCOME MEASURE

We primarily aimed to clarify the biological responses in erectile tissue after Li-ESWT that could lead to improvement in erectile function.

RESULTS

59 publications were selected for inclusion in this study. 15 experimental research articles were identified on Li-ESWT for ED and 44 on Li-ESWT for other pathologic conditions. Li-ESWT for ED seems to improve erectile function possibly through stimulation of mechanosensors, inducing the activation of neoangiogenesis processes, recruitment and activation of progenitor cells, improving microcirculation, nerve regeneration, remodeling of erectile tissue, and reducing inflammatory and cellular stress responses.

CLINICAL IMPLICATIONS

Improving our understanding of the mechanism of action of Li-ESWT for ED can help us improve our study designs, as well as suggest new avenues of investigation.

STRENGTHS & LIMITATIONS

A common limitation in all these studies is the heterogeneity of the shockwave treatment application and protocol.

CONCLUSION

Li-ESWT for ED, based on current experimental studies, seems to improve erectile function by inducing angiogenesis and reversing pathologic processes in erectile tissue. These studies provide preliminary insights, but no definitive answers, and many questions remain unanswered regarding the mechanism of action, as well as the ideal treatment protocol. Sokolakis I, Dimitriadis F, Teo P, et al. The Basic Science Behind Low-Intensity Extracorporeal Shockwave Therapy for Erectile Dysfunction: A Systematic Scoping Review of Pre-Clinical Studies. J Sex Med 2019;16:168-194.

Blood Flow in the Scaphoid Is Improved by Focused Extracorporeal Shock Wave Therapy

BACKGROUND

Extracorporeal shock wave therapy (ESWT) has shown benefits in patients with nonunion or delayed bone healing, pseudarthrosis, and avascular necrosis of bone. Until now, these effects were explained by the release of growth factors, activation of cells, and microfractures occurring after ESWT. Microcirculation is an important factor in bone healing and may be compromised in fractured scaphoids because its blood supply comes from the distal end. Due to this perfusion pattern, the scaphoid bone is prone to nonunion after fracture. The ability of ESWT to enhance microcirculation parameters in soft tissue was of interest to determine if it improves microcirculation in the scaphoid.

QUESTIONS/PURPOSES

(1) Does capillary blood flow increase after a single session of ESWT in the scaphoid? (2) Do oxygen saturation in the bone and postcapillary venous filling pressure increase after a single session of ESWT in the scaphoid?

METHODS

ESWT (0.3 mJ/mm, 8Hz, 1000 impulses) was applied to the intact scaphoid of 20 volunteers who were without wrist pain and without any important metabolic disorders. Mean age was 43 ± 14 years, 12 men and eight women (40% of total). Volunteers were recruited from January 2017 to May 2017. No anesthetic was given before application of ESWT. An innovative probe designed for measurements in bone by compressing soft tissue and combining laser-Doppler flowmetry and spectrophotometry was used to noninvasively measure parameters of microcirculation in the scaphoid. Blood flow, oxygenation, and venous filling pressure were assessed before and at 1, 2, 3, 5, 10, 15, 20, 25, and 30 minutes after ESWT application. Room temperature, humidity, ambient light and measuring sequences were kept consistent. A paired t-test was performed to compare experimental data with baseline (p < 0.05 taken as significant).

RESULTS

At baseline, capillary blood flow of the bone was 108 ± 46 arbitrary units (AUs) (86 to 130). After treatment with ESWT, it was 129 ± 44 AUs (106 to 150; p = 0.011, percentage change of 19 %) at 1 minute, 138 ± 46 AUs (116 to 160; p = 0.002, percentage change of 28%) at 2 minutes, 146 ± 54 AUs (121 to 171; p = 0.002, percentage change of 35%) at 3 minutes and 150 ± 52 AUs (126 to 174; p < 0.001, percentage change of 39%) at 5 minutes. It remained elevated until the end of the measuring period at 30 minutes after treatment at 141 ± 42 AUs (121 to 161; p = 0.002) versus baseline). Oxygen saturation and postcapillary venous filling pressure in bone showed no change, with the numbers available.

CONCLUSIONS

A single session of ESWT increased capillary blood flow in the scaphoid during measuring time of 30 minutes. Bone oxygenation and postcapillary venous filling pressure, however, did not change. Because increased oxygenation is needed for improved bone healing, it remains unclear if a sole increase in capillary blood flow can have clinical benefits. As the measuring period was limited to only 30 minutes, bone oxygenation and postcapillary filling pressure may subsequently show change only after the measuring-period ended.

CLINICAL RELEVANCE

Further studies need to evaluate if increased capillary blood flow can be sustained for longer periods and if bone oxygenation and postcapillary venous filling pressure remain unchanged even after prolonged or repetitive ESWT applications. Moreover, clinical studies must validate if increased microcirculation has a positive impact on bone healing and to determine if ESWT can be therapeutically useful on scaphoid fractures and nonunions.

Extracorporeal shock waves protect cardiomyocytes from doxorubicin-induced cardiomyopathy by upregulating survivin via the integrin-ILK-Akt-Sp1/p53 axis

Doxorubicin (DOX) is a widely used anti-cancer drug; however, it has limited application due to cardiotoxicity. Extracorporeal shock waves (ESW) have been suggested to treat inflammatory and ischemic diseases, but the concrete effect of ESW in DOX-induced cardiomyopathy remain obscure. After H9c2 cells were subjected to ESW (0.04 mJ/cm²), they were treated with 1 μM DOX. As a result, ESW protected cardiomyocytes from DOX-induced cell death. H9c2 cells treated with DOX downregulated p-Akt and survivin expression, whereas the ESW treatment recovered both, suggesting its anti-apoptotic effect. ESW activated integrin α_vβ₃ and α_vβ₅, cardiomyocyte mechanosensors, followed by upregulation of ILK, p-Akt and survivin levels. Further, Sp1 and p53 were determined as key transcriptional factors mediating survivin expression via Akt phosphorylation by ESW. In in vivo acute DOX-induced cardiomyopathy model, the echocardiographic results showed that group subjected to ESW recovered from acute DOX-induced cardiomyopathy; left ventricular function was improved. The immunohistochemical staining results showed increased survivin and Bcl2 expression in ESW + DOX group compared to those in the DOX-injected group. In conclusion, non-invasive shockwaves protect cardiomyocytes from DOX-induced cardiomyopathy by upregulating survivin via integrin-ILK-Akt-Sp1/p53 pathway. In vivo study proposed ESW as a new kind of specific and safe therapy against acute DOX-induced cardiomyopathy.

Shock-Wave Therapy Improves Myocardial Blood Flow Reserve in Patients with Refractory Angina: Evaluation by Real-Time Myocardial Perfusion Echocardiography

BACKGROUND

Cardiac shock-wave therapy (CSWT) has been demonstrated as an option for the treatment of patients with refractory angina (RA), promoting immediate vasodilatory effects and, in the long-term, neoangiogenic effects that would be responsible for reducing the myocardial ischemic load. The aim of this study was to determine the effects of CSWT on myocardial blood flow reserve (MBFR) assessed by quantitative real-time myocardial perfusion echocardiography in patients with RA.

METHODS

Fifteen patients (mean age 61.5 ± 12.8 years) with RA who underwent CSWT during nine sessions, over 3 months of treatment, were prospectively studied. A total of 32 myocardial segments with ischemia were treated, while another 31 did not receive therapy because of technical limitations. Myocardial perfusion was evaluated at rest and after dipyridamole stress (0.84 mg/kg) before and 6 months after CSWT, using quantitative real-time myocardial perfusion echocardiography. Clinical effects were evaluated using Canadian Cardiovascular Society grading of angina and the Seattle Angina Questionnaire.

RESULTS

The ischemic segments treated with CSWT had increased MBFR (from 1.33 ± 0.22 to 1.74 ± 0.29, P < .001), a benefit that was not observed in untreated ischemic segments (1.51 ± 0.29 vs 1.54 ± 0.28, P = .47). Patients demonstrated increased global MBFR (from 1.78 ± 0.54 to 1.89 ± 0.49, P = .017). Semiquantitative single-photon emission computed tomographic analysis of the treated ischemic segments revealed a score reduction from 2.10 ± 0.87 to 1.68 ± 1.19 (P = .024). There was improvement in Canadian Cardiovascular Society score (from 3.20 ± 0.56 to 1.93 ± 0.70, P < .05) and in Seattle Angina Questionnaire score (from 42.3 ± 12.99 to 71.2 ± 14.29, P < .05). No major cardiovascular events were recorded during follow-up.

CONCLUSIONS

CSWT improved MBFR in ischemic segments, as demonstrated by quantitative real-time myocardial perfusion echocardiography. These results suggest that CSWT has the potential to increase myocardial blood flow, with an impact on symptoms and quality of life in patients with RA.

Low-energy shock waves evoke intracellular Ca2+ increases independently of sonoporation

Low-energy shock waves (LESWs) accelerate the healing of a broad range of tissue injuries, including angiogenesis and bone fractures. In cells, LESW irradiations enhance gene expression and protein synthesis. One probable mechanism underlying the enhancements is mechanosensing. Shock waves also can induce sonoporation. Thus, sonoporation is another probable mechanism underlying the enhancements. It remains elusive whether LESWs require sonoporation to evoke cellular responses. An intracellular Ca²⁺ increase was evoked with LESW irradiations in endothelial cells. The minimum acoustic energy required for sufficient evocation was 1.7 μJ/mm². With the same acoustic energy, sonoporation, by which calcein and propidium iodide would become permeated, was not observed. It was found that intracellular Ca²⁺ increases evoked by LESW irradiations do not require sonoporation. In the intracellular Ca²⁺ increase, actin cytoskeletons and stretch-activated Ca²⁺ channels were involved; however, microtubules were not. In addition, with Ca²⁺ influx through the Ca²⁺ channels, the Ca²⁺ release through the PLC-IP₃-IP₃R cascade contributed to the intracellular Ca²⁺ increase. These results demonstrate that LESW irradiations can evoke cellular responses independently of sonoporation. Rather, LESW irradiations evoke cellular responses through mechanosensing.

A Novel Pulse Damper for Endothelial Cell Flow Bioreactors

PURPOSE

Peristaltic pumps (PP) are favored in flow bioreactors for their non-contact sterile design. But they produce pulsatile flow, which is consequential for the cultured cells. A novel pulse damper (PD) is reported for pulsatility elimination.

METHODS

The PD design was implemented to target static pressure pulsatility and flow rate (velocity) pulsatility from a PP. Damping effectiveness was tested in a macro-scale, closed-loop recirculating bioreactor mimicking the aortic arch at flow rates up to (4 L/min). Time-resolved particle image velocimetry was used to characterize the velocity field. Endothelial cells (EC) were grown in the bioreactor, and subjected to continuous flow for 15 min with or without PD.

RESULTS

The PD was found to be nearly 90% effective at reducing pulsatility. The EC exposed to low PP flow without PD exhibited distress signaling in the form of increased ERK1/2 phosphorylation (2.5 folds) when compared to those exposed to the same flow with PD. At high pump flow without PD, the cells detached and did not survive, while they were perfectly healthy with PD.

CONCLUSIONS

Flow pulsatility from PP causes EC distress at low flow and cell detachment at high flow. Elevated temporal shear stress gradient combined with elevated shear stress magnitude at high flow are believed to be the cause of cell detachment and death. The proposed PD design was effective at minimizing the hemodynamic stressors in the pump's output, demonstrably reducing cell distress. Adoption of the proposed PD design in flow bioreactors should improve experimental protocols.

The protective effect of low-energy shock wave on testicular ischemia-reperfusion injury is mediated by the PI3K/AKT/NRF2 pathway

AIMS

Testicular ischemia-reperfusion (IR) injury is the primary pathophysiological consequence of testicular torsion. Low-energy shock wave (LESW) is an effective treatment for certain diseases. The present study investigated whether LESW could improve on testicular IR injury in rats and examined the involved mechanism.

MAIN METHODS

Testicular reperfusion was induced in rats after 1-h ischemia. The first LESW treatment was performed 30 min prior to testicular reperfusion, and then every other day for another 3 applications. LY294002 was applied to investigate the involved mechanism. Testicular morphological changes and malonaldehyde (MDA) level were respectively assessed by hematoxylin-eosin staining. Western blot and thiobarbituric acid method. Western blot, real-time quantitative PCR and immunohistochemistry were performed to assess the apoptosis, the activation of phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B (PI3K/AKT) pathway the nuclear factor erythroid 2-related factor 2 (NRF2) and vascular endothelial growth factor A (VEGF-A) level in the testis of rats.

KEY FINDINGS

LESW improved testicular IR injury in rats. Moreover, LESW upregulated the phosphorylation levels of AKT and glycogen synthase kinase 3β (GSK-3β). Also, it upregulated the levels of nuclear NRF2, heme oxygenase 1 (HO-1) and NAD(P)H quinone dehydrogenase 1 (NQO-1) in these rats. Nevertheless, LY294002 blocked these protective effects. LESW also upregulated VEGF-A level in rats with testicular IR injury.

SIGNIFICANCE

This study demonstrated that LESW could ameliorate testicular IR injury in rats, which might be attributed to the activation of PI3K/AKT/NRF2 pathway. These findings suggested the potential of LESW in the treatment of testicular torsion.

A multicenter trial of extracorporeal cardiac shock wave therapy for refractory angina pectoris: report of the highly advanced medical treatment in Japan

We have previously demonstrated that cardiac shock wave therapy (CSWT) effectively improves myocardial ischemia through coronary neovascularization both in a porcine model of chronic myocardial ischemia and in patients with refractory angina pectoris (AP). In this study, we further addressed the efficacy and safety of CSWT in a single-arm multicenter study approved as a highly advanced medical treatment by the Japanese Ministry of Health, Labour and Welfare. Fifty patients with refractory AP [mean age 70.9 ± 12.6 (SD) years, M/F 38/12] without the indications of percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) were enrolled in 4 institutes in Japan. Ischemic myocardial regions in the left ventricle (LV) were identified by drug-induced stress myocardial perfusion imaging (MPI). Shock waves (200 shots/spot at 0.09 mJ/mm²) were applied to 40-60 spots in the ischemic myocardium 3 times in the first week. The patients were followed up for 3 months thereafter. Forty-one patients underwent CSWT and completed the follow-up at 3 months. CSWT markedly improved weekly nitroglycerin use [from 3.5 (IQR 2 to 6) to 0 (IQR 0 to 1)] and the symptoms [Canadian Cardiovascular Society functional class score, from 2 (IQR 2 to 3) to 1 (IQR 1 to 2)] (both P < 0.001). CSWT also significantly improved 6-min walking distance (from 384 ± 91 to 435 ± 122 m, P < 0.05). There were no significant changes in LV ejection fraction evaluated by echocardiography and LV stroke volume evaluated by cardiac magnetic resonance imaging (from 56.3 ± 14.7 to 58.8 ± 12.8%, P = 0.10, and from 52.3 ± 17.4 to 55.6 ± 15.7 mL, P = 0.15, respectively). Percent myocardium ischemia assessed by drug-induced stress MPI tended to be improved only in the treated segments (from 16.0 ± 11.1 to 12.1 ± 16.2%, P = 0.06), although no change was noted in the whole LV. No procedural complications or adverse effects related to the CSWT were noted. These results of the multicenter trial further indicate that CSWT is a useful and safe non-invasive strategy for patients with refractory AP with no options of PCI or CABG.

Fluid shear stress regulates the expression of Lectin-like oxidized low density lipoprotein receptor-1 via KLF2-AP-1 pathway depending on its intensity and pattern in endothelial cells

BACKGROUND AND AIMS

Vascular endothelial cells (ECs) are exposed to fluid shear stress (FSS), which modulates vascular pathophysiology. Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is crucial in endothelial dysfunction and atherosclerosis. We elucidated the mechanism regulating LOX-1 expression in ECs by FSS.

METHODS

Human umbilical vein endothelial cells were exposed to laminar shear stress (LSS) of indicated intensities using a unidirectional steady flow, or to oscillatory shear stress (OSS) using a bidirectional disturbed flow. In vivo studies were performed in a mouse model of partial carotid ligation and human pulmonary artery sections.

RESULTS

Within ECs, OSS upregulated LOX-1 expression, while LSS (20 dyne/cm²) downregulated it. We confirmed that OSS-induced LOX-1 expression was suppressed when the mechanotransduction was inhibited by knockdown of the mechanosensory complex. In addition, we demonstrated that Kruppel-like factor 2 (KLF2) has an inhibitory role on OSS-induced LOX-1 expression. Next, we determined that activator protein-1 (AP-1) was the key transcription factor inducing LOX-1 expression by OSS, which was inhibited by KLF2 overexpression. To explore whether the intensity of LSS affects LOX-1 expression, we tested three different intensities (20, 60, and 120 dyne/cm²) of LSS. We observed higher LOX-1 expression with high shear stresses of 120 dyne/cm² compared to 20 and 60 dyne/cm², with OSS-like KLF2-AP-1 signaling patterns. Furthermore, ECs within disturbed flow regions showed upregulated LOX-1 expression in vivo.

CONCLUSIONS

We concluded that LOX-1 expression on ECs is regulated via FSS depending on its intensity as well as pattern. Furthermore, this is mediated through the KLF2-AP1 pathway of mechanotransduction.

Low-energy extracorporeal shockwave therapy (ESWT) improves metaphyseal fracture healing in an osteoporotic rat model

Purpose

As result of the current demographic changes, osteoporosis and osteoporotic fractures are becoming an increasing social and economic burden. In this experimental study, extracorporeal shock wave therapy (ESWT), was evaluated as a treatment option for the improvement of osteoporotic fracture healing.

Methods

A well-established fracture model in the metaphyseal tibia in the osteoporotic rat was used. 132 animals were divided into 11 groups, with 12 animals each, consisting of one sham-operated group and 10 ovariectomized (osteoporotic) groups, of which 9 received ESWT treatment. Different energy flux intensities (0.15 mJ/mm², 0.35 mJ/mm², or 0.55 mJ/mm²) as well as different numbers of ESWT applications (once, three times, or five times throughout the 35-day healing period) were applied to the osteoporotic fractures. Fracture healing was investigated quantitatively and qualitatively using micro-CT imaging, quantitative real-time polymerase chain reaction (qRT-PCR) analysis, histomorphometric analysis and biomechanical analysis.

Results

The results of this study show a qualitative and quantitative improvement in the osteoporotic fracture healing under low-energy (energy flux intensity: 0,15 mJ/mm²) ESWT and with fewer treatment applications per healing period.

Conclusion

In conclusion, low-energy ESWT seems to exhibit a beneficial effect on the healing of osteoporotic fractures, leading to improved biomechanical properties, enhanced callus-quantity and -quality, and an increase in the expression of bone specific transcription factors. The results suggest that low-energy ESWT, as main treatment or as adjunctive treatment in addition to a surgical intervention, may prove to be an effective, simple to use, and cost-efficient option for the qualitative and quantitative improvement of osteoporotic fracture healing.

Potential applications of low-energy shock waves in functional urology

A shock wave, which carries energy and can propagate through a medium, is a type of continuous transmitted sonic wave with a frequency of 16 Hz-20 MHz. It is accompanied by processes involving rapid energy transformations. The energy associated with shock waves has been harnessed and used for various applications in medical science. High-energy extracorporeal shock wave therapy is the most successful application of shock waves, and has been used to disintegrate urolithiasis for 30 years. At lower energy levels, however, shock waves have enhanced expression of vascular endothelial growth factor, endothelial nitric oxide synthase, proliferating cell nuclear antigen, chemoattractant factors and recruitment of progenitor cells; shock waves have also improved tissue regeneration. Low-energy shock wave therapy has been used clinically with musculoskeletal disorders, ischemic cardiovascular disorders and erectile dysfunction, through the mechanisms of neovascularization, anti-inflammation and tissue regeneration. Furthermore, low-energy shock waves have been proposed to temporarily increase tissue permeability and facilitate intravesical drug delivery. The present review article provides information on the basics of shock wave physics, mechanisms of action on the biological system and potential applications in functional urology.

Radial Extracorporeal Shock Wave Therapy for Relief of Arthralgia in Rheumatoid Arthritis

More than one-third of the population with rheumatoid arthritis requires adjuvant analgesic treatment after antirheumatic therapy. In addition to analgesics, another option is radial extracorporeal shock wave therapy (rESWT), a novel physical therapy that has been successfully used in the treatment of many types of chronic soft tissue pain. We report a series of 15 patients who suffered from arthralgia after being on disease-modifying antirheumatic drugs for more than 3 months. Participants received rESWT for 3 months as an adjuvant therapy. Compared to the pretherapy baseline, follow-up at 3 months post-therapy revealed a significant reduction in resting state visual analog scale scores from 2.90 ± 0.74 to 0.80 ± 0.79 (P = 0.004), active state visual analog scale scores from 5.70 ± 1.33 to 2.20 ± 0.63 (P < 0.001), morning stiffness duration from 2.25 ± 0.79 to 1.05 ± 0.69 hours (P = 0.004), disease activity score with 28-joint counts based on erythrocyte sedimentation rate from 6.34 ± 0.72 to 4.19 ± 0.59 (P = 0.001), and Health Assessment Questionnaire scores from 10.20 ± 2.35 to 5.00 ± 2.62 (P = 0.005). The pre-post changes in erythrocyte sedimentation rate and C-reactive protein were not statistically significant. By the end of treatment, 11 participants stopped analgesics completely; the other 4 participants were on a smaller dosage. No severe adverse effects related to rESWT were observed. To our knowledge, this is the first report using this therapy to treat arthralgia in rheumatoid arthritis.

Extracorporeal shockwave therapy in the treatment of chronic diabetic foot ulcers: a prospective randomised trial

OBJECTIVE

To investigate the efficacy of extracorporeal shockwave therapy (ESWT) on healing chronic diabetic foot ulcers (DFU).

METHOD

Patients with chronic DFUs were randomised (1:1) to receive a series of six ESWT treatments over 3 weeks in combination with standard care or standard care alone. ESWT was performed on DFUs using 250 shocks/cm² and 500 shocks on arterial beds supplying the ulcer location.

RESULTS

We recruited 23 patients, 11 in the intervention group and 12 in the control. Transcutaneous oxygen tension was significantly increased in patients treated with ESWT compared with those receiving standard care alone at 3 weeks (p=0.044). Ulcer area reduction was 34.5% in the intervention group versus 5.6% in the control group at 7 weeks (p=0.387). Within-group analysis revealed a significant reduction of ulcer area in the intervention group (p<0.01), while healing was not demonstrated in the control group (p>0.05) (data tested for trend).

CONCLUSION

This randomised study indicates a potential beneficial effect of ESWT on ulcer healing as well as tissue oxygenation. Owing to weaknesses of the study and the fact that ulcer healing was not significantly improved in the intervention group compared with the control group, a larger randomised trial with blinded design is suggested.

Shock Wave Enhances Angiogenesis through VEGFR2 Activation and Recycling

Although low-energy shock wave (SW) is adopted to treat ischemic diseases because of its pro-angiogenic properties, the underlying mechanism remains unclear. This study aimed at testing whether SW-induced angiogenesis may be through endothelial vascular endothelial growth factor receptor 2 (VEGFR2) signaling and trafficking. Phosphorylation of VEGFR2-Akt-eNOS axis and production of nitric oxide (NO) were determined in human umbilical vein endothelial cells (HUVECs) treated with SW. Carotid artery in ob/ob mice was treated with SW before evaluation with sprouting assay. Critical limb ischemia was induced in ob/ob mice to evaluate blood flow recovery after SW treatment. Tube formation and migration assays were also performed with/without SW treatment in the presence/absence of SU5416 (VEGFR2 kinase inhibitor) and siRNA-driven silencing of VEGFR2. Chloroquine was used for disrupting endosome, and Rab11a controlling slow endocytic recycling was silenced with siRNA in vitro. Following SW treatment, augmented ligand-independent phosphorylation in VEGFR2-Akt-eNOS axis and endogenous NO production, increased cellular migration and tube formation, elevated sprouting of carotid artery and blood flow in ischemic limb in ob/ob mice were noted. Moreover, SU5416 and VEGFR2 silencing both inhibited SW-induced angiogenesis. SW-induced angiogenesis, which was accompanied by increased VEGFR2 protein expression without transcriptional change, was suppressed by chloroquine and Rab11a silencing. We concluded that SW enhanced angiogenesis via ligand-independent activation of VEGFR2 and further prolonged through endosome-to-plasma membrane recycling in endothelial cells.

Immediate Dose-Response Effect of High-Energy Versus Low-Energy Extracorporeal Shock Wave Therapy on Cutaneous Microcirculation

Elucidation of the precise mechanisms and therapeutic options of extracorporeal shock wave therapy (ESWT) is only at the beginning. Although immediate real-time effects of ESWT on cutaneous hemodynamics have recently been described, the dose response to different ESWT energies in cutaneous microcirculation has never been examined. Thirty-nine Sprague-Dawley rats were randomly assigned to three groups that received either focused high-energy shock waves (group A: total of 1000 impulses, 10 J) to the lower leg of the hind limb, focused low-energy shock waves (group B: total of 300 impulses, 1 J) or placebo shock wave treatment (group C: 0 impulses, 0 J) using a multimodality shock wave delivery system (Duolith SD-1 T-Top, Storz Medical, Tägerwilen, Switzerland). Immediate microcirculatory effects were assessed with the O2C (oxygen to see) system (LEA Medizintechnik, Giessen, Germany) before and for 20 min after application of ESWT. Cutaneous tissue oxygen saturation increased significantly higher after high-energy ESWT than after low-energy and placebo ESWT (A: 29.4% vs. B: 17.3% vs. C: 3.3%; p = 0.003). Capillary blood velocity was significantly higher after high-energy ESWT and lower after low-energy ESWT versus placebo ESWT (group A: 17.8% vs. group B: -22.1% vs. group C: -5.0%, p = 0.045). Post-capillary venous filling pressure was significantly enhanced in the high-energy ESWT group in contrast to the low-energy ESWT and placebo groups (group A: 25% vs. group B: 2% vs. group C: -4%, p = 0.001). Both high-energy and low-energy ESWT affect cutaneous hemodynamics in a standard rat model. High-energy ESWT significantly increases parameters of cutaneous microcirculation immediately after application, resulting in higher tissue oxygen saturation, venous filling pressure and blood velocity, which suggests higher tissue perfusion with enhanced oxygen saturation, in contrast to low-energy as well as placebo ESWT. Low-energy ESWT also increased tissue oxygen saturation, albeit to a lower extent, and decreases both blood velocity and venous filling pressure. Low-energy ESWT reduced tissue perfusion, but improved oxygen saturation immediately after the application.

Dose-dependent and cell type-specific cell death and proliferation following in vitro exposure to radial extracorporeal shock waves

Radial extracorporeal shock wave (rESW) therapy is widely used in musculoskeletal disorders and wound repair. However, the mechanisms of action are still largely unknown. The current study compared the effects of rESWs on two cell types. Human fetal foreskin fibroblasts (HFFF2) and human placental choriocarcinoma cell line JEG-3 were exposed to 0, 100, 200, 500 or 5000 rESWs generated with a Swiss DolorClast device (2.5 bar, 1 Hz). FACS analysis immediately after rESW exposure showed that initially, rESWs rather induced mechanical cell destruction than regulated or programmed cell death. Cell damage was nearly negated by reducing cavitation. Furthermore, cell viability decreased progressively with higher numbers of rESWs. Exposure to rESWs had no impact on growth potential of JEG-3 cells, but dose-dependently increased growth potential of HFFF2 cells. Cultivation of cells that were initially exposed to sham-rESWs in conditioned media increased the growth potential of HFFF2 cells, nevertheless, an even stronger effect was achieved by direct exposure to rESWs. Additionally, cell cycle distribution analysis demonstrated a shift in proportion from G0/G1 to G2/M phase in HFFF2 cells, but not in JEG-3 cells. These data demonstrate that rESWs leads to initial and subsequent dose-dependent and cell type-specific effects in vitro.

Molecular mechanisms of the angiogenic effects of low-energy shock wave therapy: roles of mechanotransduction

We have previously demonstrated that low-energy extracorporeal cardiac shock wave (SW) therapy improves myocardial ischemia through enhanced myocardial angiogenesis in a porcine model of chronic myocardial ischemia and in patients with refractory angina pectoris. However, the detailed molecular mechanisms for the SW-induced angiogenesis remain unclear. In this study, we thus examined the effects of SW irradiation on intracellular signaling pathways in vitro. Cultured human umbilical vein endothelial cells (HUVECs) were treated with 800 shots of low-energy SW (1 Hz at an energy level of 0.03 mJ/mm(2)). The SW therapy significantly upregulated mRNA expression and protein levels of vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS). The SW therapy also enhanced phosphorylation of extracellular signal-regulated kinase 1/2 (Erk1/2) and Akt. Furthermore, the SW therapy enhanced phosphorylation of caveolin-1 and the expression of HUTS-4 that represents β1-integrin activity. These results suggest that caveolin-1 and β1-integrin are involved in the SW-induced activation of angiogenic signaling pathways. To further examine the signaling pathways involved in the SW-induced angiogenesis, HUVECs were transfected with siRNA of either β1-integrin or caveolin-1. Knockdown of either caveolin-1 or β1-integrin suppressed the SW-induced phosphorylation of Erk1/2 and Akt and upregulation of VEGF and eNOS. Knockdown of either caveolin-1 or β1-integrin also suppressed SW-induced enhancement of HUVEC migration in scratch assay. These results suggest that activation of mechanosensors on cell membranes, such as caveolin-1 and β1-integrin, and subsequent phosphorylation of Erk and Akt may play pivotal roles in the SW-induced angiogenesis.

Extracorporeal shockwave therapy (ESWT) ameliorates healing of tibial fracture non-union unresponsive to conventional therapy

Tibial non-unions are common cause of demanding revision surgeries and are associated with a significant impact on patients' quality of life and health care costs. Extracorporeal shockwave therapy (ESWT) has been shown to improve osseous healing in vitro and in vivo. The main objective of present study was to evaluate the efficacy of ESWT in healing of tibial non-unions unresponsive to previous surgical and non-surgical measures. A retrospective multivariant analysis of a prospective open, single-centre, clinical trial of tibia non-union was conducted. 56 patients with 58 eligible fractures who met the FDA criteria were included. All patients received 3000-4000 impulses of electrohydraulic shockwaves at an energy flux density of 0.4mJ/mm(2) (-6dB). On average patients underwent 1.9 times (±1.3SD) surgical interventions prior to ESWT displaying the rather negatively selected cohort and its limited therapy responsiveness. In 88.5% of patients receiving ESWT complete bone healing was observed after six months irrespective of underlying pathology. The multivariant analysis showed that time of application is important for therapy success. Patients achieving healing received ESWT earlier: mean number of days between last surgical intervention and ESWT (healed - 355.1 days±167.4SD vs. not healed - 836.7 days±383.0SD; p<0.0001). ESWT proved to be a safe, effective and non-invasive treatment modality in tibial non-unions recalcitrant to standard therapies. The procedure is well tolerated, time-saving, lacking side effects, with potential to significantly decrease health care costs. Thus, in our view, ESWT should be considered the treatment of first choice in established tibial non-unions.

Discovery of novel peptides targeting pro-atherogenic endothelium in disturbed flow regions -Targeted siRNA delivery to pro-atherogenic endothelium in vivo

Atherosclerosis occurs preferentially in arterial regions exposed to disturbed blood flow. Targeting these pro-atherogenic regions is a potential anti-atherogenic therapeutic approach, but it has been extremely challenging. Here, using in vivo phage display approach and the partial carotid ligation model of flow-induced atherosclerosis in mouse, we identified novel peptides that specifically bind to endothelial cells (ECs) exposed to disturbed flow condition in pro-atherogenic regions. Two peptides, CLIRRTSIC and CPRRSHPIC, selectively bound to arterial ECs exposed to disturbed flow not only in the partially ligated carotids but also in the lesser curvature and branching point of the aortic arch in mice as well as human pulmonary artery branches. Peptides were conjugated to branched polyethylenimine-polyethylene glycol polymer to generate polyplexes carrying siRNA targeting intercellular adhesion molecule-1 (siICAM-1). In mouse model, CLIRRTSIC polyplexes carrying si-ICAM-1 specifically bound to endothelium in disturbed flow regions, reducing endothelial ICAM-1 expression. Mass spectrometry analysis revealed that non-muscle myosin heavy chain II A (NMHC IIA) is a protein targeted by CLIRRTSIC peptide. Further studies showed that shear stress regulates NMHC IIA expression and localization in ECs. The CLIRRTSIC is a novel peptide that could be used for targeted delivery of therapeutics such as siRNAs to pro-atherogenic endothelium.

Fluid Flow Regulation of Revascularization and Cellular Organization in a Bioengineered Liver Platform

OBJECTIVE

Modeling of human liver development, especially cellular organization and the mechanisms underlying it, is fundamental for studying liver organogenesis and congenital diseases, yet there are no reliable models that mimic these processes ex vivo.

DESIGN

Using an organ engineering approach and relevant cell lines, we designed a perfusion system that delivers discrete mechanical forces inside an acellular liver extracellular matrix scaffold to study the effects of mechanical stimulation in hepatic tissue organization.

RESULTS

We observed a fluid flow rate-dependent response in cell distribution within the liver scaffold. Next, we determined the role of nitric oxide (NO) as a mediator of fluid flow effects on endothelial cells. We observed impairment of both neovascularization and liver tissue organization in the presence of selective inhibition of endothelial NO synthase. Similar results were observed in bioengineered livers grown under static conditions.

CONCLUSION

Overall, we were able to unveil the potential central role of discrete mechanical stimulation through the NO pathway in the revascularization and cellular organization of a bioengineered liver. Last, we propose that this organ bioengineering platform can contribute significantly to the identification of physiological mechanisms of liver organogenesis and regeneration and improve our ability to bioengineer livers for transplantation.

Ursodeoxycholic Acid (UDCA) Exerts Anti-Atherogenic Effects by Inhibiting RAGE Signaling in Diabetic Atherosclerosis

A naturally occurring bile acid, ursodeoxycholic acid (UDCA), is known to alleviate endoplasmic reticulum (ER) stress at the cellular level. However, the detailed action mechanisms of UDCA in atherosclerosis are not fully understood. In this study, we demonstrated whether UDCA exerts anti-atherogenic activity in diabetic atherosclerosis by targeting ER stress and “receptor for advanced glycation endproduct” (RAGE) signaling. UDCA markedly reduced ER stress, RAGE expression, and pro-inflammatory responses [including NF-κB activation and reactive oxygen species (ROS) production] induced in endothelial cells (ECs) by high glucose (HG). In particular, UDCA inhibited HG-induced ROS production by increasing the Nrf2 level. In macrophages, UDCA also blocked HG-induced RAGE and pro-inflammatory cytokine expression and inhibited foam cell formation via upregulation of the ATP-binding cassette (ABC) transporters, ABCA1 and ABCG1. In the diabetic mouse model, UDCA inhibited atheromatous plaque formation by decreasing ER stress, and the levels of RAGE and adhesion molecules. In conclusion, UDCA exerts an anti-atherogenic activity in diabetic atherosclerosis by targeting both ER stress and RAGE signaling. Our work implicates UDCA as a potential therapeutic agent for prevention or treatment of diabetic atherosclerosis.

Shock wave as biological therapeutic tool: From mechanical stimulation to recovery and healing, through mechanotransduction

Extracorporeal Shock Wave Therapy (ESWT) is a form of "mechanotherapy", that, from its original applications as urological lithotripsy, gained the field of musculo-skeletal diseases as Orthotripsy (mainly tendinopaties and bone regenerative disorders) and Regenerative Medicine as well. The mechanisms of action of Shock Waves (SW), when applied in non-urological indications, are not related to the direct mechanical effect, but to the different pathways of biological reactions, that derive from that acoustic stimulations, through "mechano-transduction". So, the "mechanical model" of urological lithotripsy has been substituted by a "biological model", also supported by current knowledge in "mechanobiology", the emerging multidisciplinary field of science that investigates how physical forces and changes in cell/tissue mechanics can influence the tissue development, physiology and diseases. Although some details are still under study, it is known that SW are able to relief pain, as well to positively regulate inflammation (probably as immunomodulator), to induce neoangiogenesis and stem cells activities, thus improving tissue regeneration and healing. ESWT can be nowadays considered an effective, safe, versatile, repeatable, noninvasive therapy for the treatment of many musculo-skeletal diseases, and for some pathological conditions where regenerative effects are desirable, especially when some other noninvasive/conservative therapies have failed. Moreover, based on the current knowledge in SW mechanobiology, it seems possible to foresee new interesting and promising applications in the fields of Regenerative Medicine, tissue engineering and cell therapies.

Extracorporeal shockwave therapy (ESWT)--First choice treatment of fracture non-unions?

Fracture non-unions are still a challenging problem in orthopedics. The treatment of non-unions remains highly individualized, complex, and demanding. In most countries the surgical approach with debridement of the non-union gap, anatomical reduction and appropriate osteosynthesis along with autologous bone grafting is considered as the standard of care. One of the very first non-urologic applications of extracorporeal shockwave treatment (ESWT) concerned non-healing fractures. Since the early 1990ties the knowledge of the working mechanism has increased enormously. The purpose of this review article is to demonstrate by peer-reviewed literature in conjunction with our own experiences that ESWT can be an efficient, non-invasive, almost complication-free and cost effective alternative to surgical treatment of non-healing fractures.

Ursodeoxycholic Acid (UDCA) Exerts Anti-Atherogenic Effects by Inhibiting Endoplasmic Reticulum (ER) Stress Induced by Disturbed Flow

Disturbed blood flow with low-oscillatory shear stress (OSS) is a predominant atherogenic factor leading to dysfunctional endothelial cells (ECs). Recently, it was found that disturbed flow can directly induce endoplasmic reticulum (ER) stress in ECs, thereby playing a critical role in the development and progression of atherosclerosis. Ursodeoxycholic acid (UDCA), a naturally occurring bile acid, has long been used to treat chronic cholestatic liver disease and is known to alleviate endoplasmic reticulum (ER) stress at the cellular level. However, its role in atherosclerosis remains unexplored. In this study, we demonstrated the anti-atherogenic activity of UDCA via inhibition of disturbed flow-induced ER stress in atherosclerosis. UDCA effectively reduced ER stress, resulting in a reduction in expression of X-box binding protein-1 (XBP-1) and CEBP-homologous protein (CHOP) in ECs. UDCA also inhibits the disturbed flow-induced inflammatory responses such as increases in adhesion molecules, monocyte adhesion to ECs, and apoptosis of ECs. In a mouse model of disturbed flow-induced atherosclerosis, UDCA inhibits atheromatous plaque formation through the alleviation of ER stress and a decrease in adhesion molecules. Taken together, our results revealed that UDCA exerts anti-atherogenic activity in disturbed flow-induced atherosclerosis by inhibiting ER stress and the inflammatory response. This study suggests that UDCA may be a therapeutic agent for prevention or treatment of atherosclerosis.

Novel mechanism of gene transfection by low-energy shock wave

Extracorporeal shock wave (SW) therapy has been studied in the transfection of naked nucleic acids into various cell lines through the process of sonoporation, a process that affects the permeation of cell membranes, which can be an effect of cavitation. In this study, siRNAs were efficiently transfected into primary cultured cells and mouse tumor tissue via SW treatment. Furthermore SW-induced siRNA transfection was not mediated by SW-induced sonoporation, but by microparticles (MPs) secreted from the cells. Interestingly, the transfection effect of the siRNAs was transferable through the secreted MPs from human umbilical vein endothelial cell (HUVEC) culture medium after treatment with SW, into HUVECs in another culture plate without SW treatment. In this study, we suggest for the first time a mechanism of gene transfection induced by low-energy SW through secreted MPs, and show that it is an efficient physical gene transfection method in vitro and represents a safe therapeutic strategy for site-specific gene delivery in vivo.

Fractionated Repetitive Extracorporeal Shock Wave Therapy: A New Standard in Shock Wave Therapy?

Background. ESWT has proven clinical benefit in dermatology and plastic surgery. It promotes wound healing and improves tissue regeneration, connective tissue disorders, and inflammatory skin diseases. However, a single treatment session or long intervals between sessions may reduce the therapeutic effect. The present study investigated the effects of fractionated repetitive treatment in skin microcirculation. Methods. 32 rats were randomly assigned to two groups and received either fractionated repetitive high-energy ESWT every ten minutes or placebo shock wave treatment, applied to the dorsal lower leg. Microcirculatory effects were continuously assessed by combined laser Doppler imaging and photospectrometry. Results. In experimental group, cutaneous tissue oxygen saturation was increased 1 minute after the first application and until the end of the measuring period at 80 minutes after the second treatment (P < 0.05). The third ESWT application boosted the effect to its highest extent. Cutaneous capillary blood flow showed a significant increase after the second application which was sustained for 20 minutes after the third application (P < 0.05). Placebo group showed no statistically significant differences. Conclusions. Fractionated repetitive extracorporeal shock wave therapy (frESWT) boosts and prolongs the effects on cutaneous hemodynamics. The results indicate that frESWT may provide greater benefits in the treatment of distinct soft tissue disorders compared with single-session ESWT.

Remotely triggered micro-shock wave responsive drug delivery system for resolving diabetic wound infection and controlling blood sugar levels

A novel, micro-shock wave responsive spermidine and dextran sulfate microparticle was developed.