Therapeutic opportunities in biological responses of ultrasound

Research status of biomaterials based on physical signals for bone injury repair

Bone defects repair continues to be a significant challenge facing the world. Biological scaffolds, bioactive molecules, and cells are the three major elements of bone tissue engineering, which have been widely used in bone regeneration therapy, especially with the rise of bioactive molecules in recent years. According to their physical properties, they can be divided into force, magnetic field (MF), electric field (EF), ultrasonic wave, light, heat, etc. However, the transmission of bioactive molecules has obvious shortcomings that hinder the development of the tissue-rearing process. This paper reviews the mechanism of physical signal induction in bone tissue engineering in recent years. It summarizes the application strategies of physical signal in bone tissue engineering, including biomaterial designs, physical signal loading strategies and related pathways. Finally, the ongoing challenges and prospects for the future are discussed.

Efficacy and safety of low-intensity ultrasound therapy for myofascial pain syndrome: a systematic review and meta-analysis

BACKGROUND

Myofascial Pain Syndrome (MPS) is a common pain disorder characterized by the presence of trigger points within the muscles or fascia. Low-intensity ultrasound therapy, as a noninvasive modality, has indeed found application in the management of MPS, but its efficacy for myofascial pain syndrome has still been controversial. The objective of this systematic review was to assess the safety and efficacy of low-intensity ultrasound therapy for MPS.

METHODS

We searched PubMed, Embase, PEDro, Web of Science, and CENTRAL for RCTs on ultrasound therapy in MPS patients. We included RCTs comparing ultrasound with other therapies or placebo-sham ultrasound. Clinical outcomes included pain scores and physical functional performance. Risk of bias and heterogeneity were assessed. Two authors of the review independently evaluated the risk of bias of each trial and extracted the data.

RESULTS

This systematic review included sixteen RCTs involving a total of 1063 participants with MPS. None of the included studies reported adverse events. Comparing with sham or no treatment, the application of low-intensity ultrasound yielded additional benefits for pain (SMD [CI] = - 1.04 [- 1.72, - 0.36], P < 0.0003), with high heterogeneity (χ2 = 116.63, P < 0.00001, I2 = 91%). Patients receiving low-intensity ultrasound had improved on pressure pain threshold. Compared with other treatments, there were no differences in outcomes functional scores.

CONCLUSIONS

The current study indicates that low-intensity ultrasound effectively reduces pain intensity in MPS patients. The heterogeneity regarding the parameters of ultrasound, including frequency, intensity, time was found to be high among the included studies. Each therapeutic modality works differently in various situations and may lead to multitudinous effects. The positive impact of low-intensity ultrasound on functional improvement needs to be further analyzed through more high-quality clinical trials with large sample sizes in the future.

TRIAL REGISTRATION

This study was registered on the following website: https://www.crd.york.ac.uk/PROSPERO/ . The PROSPERO registered ID is CRD42023472032.

Ultrasound Therapy With High-Pressure Pulses Is Effective to Reduce the Effects of Collagenase-Induced Tendinopathy in Rat's Achilles Tendon

OBJECTIVE

We propose an ultrasonic treatment for collagenase-induced tendinopathy in rat's Achilles tendon using pulses with a low number of cycles, high acoustic pressure and very low duty cycle.

METHODS

Twenty rats were used to perform the experiment. Four experimental groups of calcaneal tendons were studied: control (n = 6), sham (n = 4), collagenase-induced tendinopathy (n = 8) and ultrasound-treated collagenase-induced tendinopathy (n = 8). Surgical intervention was performed to expose the tendons prior to collagenase injection. A 1 MHz ultrasonic tansducer with a focusing lens was used. Ultrasonic treatments were used with an average total treatment time of 2.5 min, 20-cycle pulses, pressure amplitude p = 7 MPa, and 0.02% duty cycle. Histopathology of the samples was performed to evaluate nuclear density, acute inflammation, and signs of neovascularization. Collagen (types I and III), elastic fibers, and glycosaminoglycans were also analyzed.

RESULTS

No tendon involvement was found by the surgical process. Ultrasonic treatment is safe, as it does not affect healthy tendons. When collagenase infiltrated animals were treated with US, a clear predominance of type I collagen fibers and a similar collagen ratio profile to that observed in the control and sham groups was observed, with a higher density of elastic fibers compared to the control and sham groups and a significant increase in the density of glycosaminoglycans.

CONCLUSION

The ultrasound treatment proposed reduces the effects of the artificial collagenase lesion to reach the basal level after 45 d.

Ultrasound Imaging in Knee Osteoarthritis: Current Role, Recent Advancements, and Future Perspectives

While conventional radiography and MRI have a well-established role in the assessment of patients with knee osteoarthritis, ultrasound is considered a complementary and additional tool. Moreover, the actual usefulness of ultrasound is still a matter of debate in knee osteoarthritis assessment. Despite that, ultrasound offers several advantages and interesting aspects for both current clinical practice and future perspectives. Ultrasound is potentially a helpful tool in the detection of anomalies such as cartilage degradation, osteophytes, and synovitis in cases of knee osteoarthritis. Furthermore, local diagnostic and minimally invasive therapeutic operations pertaining to knee osteoarthritis can be safely guided by real-time ultrasound imaging. We are constantly observing a growing knowledge and awareness among radiologists and other physicians, concerning ultrasound imaging. Ultrasound studies can be extremely useful to track the response to various therapies. For this specific aim, tele-ultrasonography may constitute an easy tool aiding precise and repeated follow-up controls. Moreover, raw radio-frequency data from US backscattering signals contain more information than B-mode imaging. This paves the way for quantitative in-depth analyses of cartilage, bone, and other articular structures. Overall, ultrasound technologies and their rapid evolution have the potential to make a difference at both the research and clinical levels. This narrative review article describes the potential of such technologies and their possible future implications.

Can Combining Hyaluronic Acid and Physiotherapy in Knee Osteoarthritis Improve the Physicochemical Properties of Synovial Fluid?

Known as the degenerative disease of the knee with the highest prevalence, knee osteoarthritis (KOA) is characterized by a gradual destructive mechanism that, in severe cases, can provoke the need for total knee substitution. As the disease progresses, various enzymatic, immunological, and inflammatory processes abnormally degrade hyaluronic acid (HA), SF's main component, and affect the concentrations of specific proteins, with the final results seriously endangering synovial fluid (SF)'s rheological and tribological features and characteristics. No effective treatments have been found to stop the progression of KOA, but the injection of HA-based viscoelastic gels has been considered (alone or combined with physiotherapy (PT)) as an alternative to symptomatic therapies. In order to evaluate the effect of viscosupplementation and PT on the characteristics of SF, SF aspirated from groups treated for KOA (HA Kombihylan® and groups that received Kombihylan® and complex PT) was analyzed and compared from analytical, spectrophotometrical, and rheological perspectives. In the patients treated with PT, the SF extracted 6 weeks after viscosupplementation had a superior elastic modulus (G') and viscous moduli (G″), as well as a homogeneous distribution of proteins and polysaccharides. The viscosupplementation fluid improved the bioadhesive properties of the SF, and the use of the viscosupplementation fluid in conjunction with PT was found to be favorable for the distribution of macromolecules and phospholipids, contributing to the lubrication process and the treatment of OA-affected joints.

Phase aberration correction for ultrasound imaging guided extracorporeal shock wave therapy (ESWT): Feasibility study

Image guidance of extracorporeal shock wave therapy (ESWT) is important to enhance its efficacy while lowering pain in patients. Real-time ultrasound imaging is an appropriate modality for image guidance, but its image quality substantially reduces due to severe phase aberration from the different speed of sound between soft tissues and a gel pad, which is utilized to control a therapeutic focal point in ESWT. This paper presents a phase aberration correction method for improving image quality in the ultrasound imaging guided ESWT. To correct an error from phase aberration, a time delay based on a two-layer model with different speeds of sound is calculated for dynamic receive beamforming. For the phantom and in vivo studies, a rubber type gel pad (i.e., 1400 m/s) with a specific thickness (3 or 5-cm) was placed on the top of soft tissue and full scanline RF data were acquired. In the phantom study, with phase aberration correction, image quality was highly increased compared to image reconstructions with a fixed speed of sound (i.e., 1540 or 1400 m/s), i.e., 1.1 vs. 2.2 and 1.3 mm in -6dB lateral resolution and 0.64 vs. 0.61 and 0.56 in contrast-to-noise ratio (CNR), respectively. From an in vivo musculoskeletal (MSK) imaging, the phase aberration correction method provided a clearly improved depiction of muscle fibers in a rectus femoris region. These results indicate that the proposed method enables effective imaging guidance of ESWT by improving image quality of ultrasound imaging in real-time.

Device for Dual Ultrasound and Dry Needling Trigger Points Treatment

Ultrasound is a well-known tool to produce thermal and non-thermal effects on cells and tissues. These effects require an appropriate application of ultrasound in terms of localization and acoustic energy delivered. This article describes a new device that combines ultrasound and dry needling treatments. The non-thermal effects of ultrasound should locally amplify the needle's effects. The ultrasound transducer can mechanically rotate in 3D space to align itself in the direction of the needle. The transducer electronically focuses the acoustic pressure automatically on the needle tip and its surroundings. A computer, using graphical interface software, controls the angulation of the array and the focus position.

System and method for applying physiotherapeutic focused ultrasound

Despite many years of clinical use of ultrasound, the results of different reviews of controlled trials on the efficacy of ultrasound physical therapy for different musculoskeletal injuries continue to question its efficacy. However, "in vitro" experiments with well-controlled cell cultures and experiments with animal models show positive results. The question is whether the commercial systems used by physiotherapists can deliver the required ultrasonic dose to the exact location on the body. The object of this work is the design, realization and testing of a new concept of ultrasound system for Physiotherapy capable of focusing the ultrasound beam to apply the required ultrasonic energy dose at the point targeted by the physiotherapist. The system is designed for non-thermal effects Physiotherapy. The system consists of conceptually new piezocomposite arrays with a metallic delay line, multi-pulser electronics for emission focusing, parallel robots for mechanical steering and positioning of the array transducers, and linear and angular encoders to allow the physiotherapist to direct the focus to the target. The multi-pulser and parallel robot angulation are controlled by the computer, using a graphical interface software.

Rehabilitation of Patients with Moderate Knee Osteoarthritis Using Hyaluronic Acid Viscosupplementation and Physiotherapy

Knee osteoarthritis (KOA) is one of the most common public health problems which cannot be cured and ultimately leads to disability. Current management is largely limited to the treatment of the symptoms. To avoid the late stages of KOA that lead to knee replacement, the key point is to control and reduce destructive processes using efficient pharmacological products combined with physiotherapy (PT). Herein, we perform a monocentric observational study to compare the effect of combining a multi-modal physiotherapy regime and intra-articular (IA) injection with hyaluronic acid (HA) on the non-surgical treatment of KOA. Patients with mild KOA were randomly assigned to two groups to receive an HA injection with PT or an HA injection only. The assessment tools for pain, clinical disease severity, and disability were the total score on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) (scores range from 0 to 96, with higher scores indicating worse pain, function, and stiffness), knee range of motion (ROM), pain on the visual analog scale (VAS), and muscle strength testing (MST). All tests were evaluated every 3 months up to 1 year from the baseline. The study enrolled 52 patients with ages between 47 and 61 years who were divided into two groups. Thirty-seven (n = 37) patients were randomized in the pilot group (PG) and received IA injections with the viscoelastic hyaluronic acid product (HA) combined with a multi-modal PT regime. The PT program included 10 sessions of transcutaneous electrical nerve stimulation, low-level laser therapy, ultrasound, physical exercise, and cryotherapy. Fifteen patients (n = 15) from the control group (CG) received the IA HA injections only. All patients were confirmed with mild KOA of Kellgren–Lawrence grade 2 on radiographs at the beginning of the treatment. The baseline characteristics, including the severity of pain and level of disability, were similar in the two groups. At baseline, the mean (±SD) WOMAC scores reported were 64.6 ± 4.08 in the CG and 64.5 ± 2.99 in the PG. Notably, at only 3 months into the study, the mean scores were significantly improved to 56.7 ± 5 in the CG and 48.27 ± 2.13 in the PG (mean between-group difference = 16.19 points; 95% confidence interval), finding favor for the combination of HA injections and physiotherapy. At the study’s endpoint (12 months), the scores were improved in both groups, with the mean between-group difference remaining significant (7.08 points, 95% confidence interval). A decrease in pain, as evaluated by the VAS scale, was reported for both groups, with the PG reporting a better VAS score that decreased from 5.7 to 2 when compared to the CG, which decreased from 5.7 to 3. The physical assessment parameters (ROM and MST) followed the same trend, with a rapid improvement in the ROM in the PG, changing from 98° to 115° in the first 3 months, and a slower and more steady evolution in the CG group, changing from 100° to 112° in 9 months. Herein, we report on the combination therapy of an intra-articularly administered HA viscoelastic product and a multi-modal physiotherapy regime, which can play a key role in the non-surgical treatment of KOA, effectively controlling pain, stiffness, and the ROM value and improving patients’ quality of life.

Therapeutic ultrasound for knee osteoarthritis: A systematic review and meta-analysis with grade quality assessment

BACKGROUND

Therapeutic ultrasound (US) is a widely used intervention in physical therapy to manage pain and to aid in the healing of soft tissue.

OBJECTIVE

This systematic review aimed to determine the effects of therapeutic US on knee osteoarthritis (KOA) symptoms.

METHODS

PubMed, MEDLINE, EMBASE, Google Scholar, and the Cochrane databases were searched from inception to April 2019. Randomized controlled trials (RCTs) involving adults with symptomatic KOA that compared therapeutic US with a sham or other control were included. The methodological quality of the trials was assessed at the study level using the Cochrane Risk of Bias tool. The quality of evidence at the outcome level- and overall- was assessed using GRADE methodology. Meta-analyses were conducted using random effects models, and heterogeneity was assessed using the I2 statistic.

RESULTS

Four studies (N = 234 participants) were eligible for inclusion in our primary analyses assessing therapeutic US versus sham. The methodological quality of the included RCTs ranged from moderate to very low. Treatment with therapeutic US resulted in small, statistically significant benefits for pain (approximate 9.6% improvement on a 0-100 visual analog scale [95% confidence interval: 2, 17.4%]) and self-reported measures of function (approximate 12.8% improvement on a 0-100 visual analog scale [0.4, 25.2%]). The overall quality of the evidence was very low. No adverse events were reported in any of the included studies.

CONCLUSIONS

The use of therapeutic US may provide additional benefits to physical therapy regimens in terms of symptom relief in individuals with KOA. However, it is not possible to make any meaningful recommendations for clinical practice due to the small number of applicable RCTs and the low methodological quality of the RCTs deemed eligible for this study.

Biofilm Management in Wound Care

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the basics of biofilm infection and be able to distinguish between planktonic and biofilm modes of growth. 2. Have a working knowledge of conventional and emerging antibiofilm therapies and their modes of action as they pertain to wound care. 3. Understand the challenges associated with testing and marketing antibiofilm strategies and the context within which these strategies may have effective value.

SUMMARY

The Centers for Disease Control and Prevention estimate for human infectious diseases caused by bacteria with a biofilm phenotype is 65 percent and the National Institutes of Health estimate is closer to 80 percent. Biofilms are hostile microbial aggregates because, within their polymeric matrix cocoons, they are protected from antimicrobial therapy and attack from host defenses. Biofilm-infected wounds, even when closed, show functional deficits such as deficient extracellular matrix and impaired barrier function, which are likely to cause wound recidivism. The management of invasive wound infection often includes systemic antimicrobial therapy in combination with débridement of wounds to a healthy tissue bed as determined by the surgeon who has no way of visualizing the biofilm. The exceedingly high incidence of false-negative cultures for bacteria in a biofilm state leads to missed diagnoses of wound infection. The use of topical and parenteral antimicrobial therapy without wound débridement have had limited impact on decreasing biofilm infection, which remains a major problem in wound care. Current claims to manage wound biofilm infection rest on limited early-stage data. In most cases, such data originate from limited experimental systems that lack host immune defense. In making decisions on the choice of commercial products to manage wound biofilm infection, it is important to critically appreciate the mechanism of action and significance of the relevant experimental system. In this work, the authors critically review different categories of antibiofilm products, with emphasis on their strengths and limitations as evident from the published literature.

Time- and Dose-Dependent Effects of Pulsed Ultrasound on Dermal Repair in Diabetic Mice

Chronic wounds, including diabetic, leg and pressure ulcers, impose a significant health care burden worldwide. Some evidence indicates that ultrasound can enhance soft tissue repair. However, therapeutic responses vary among individuals, thereby limiting clinical translation. Here, effects of pulsed ultrasound on dermal wound healing were assessed using a murine model of chronic, diabetic wounds. An ultrasound exposure system was developed to provide daily ultrasound exposures to full-thickness, excisional wounds in genetically diabetic mice. Wounds were exposed to 1 MHz ultrasound (2 ms pulse, 100 Hz pulse repetition frequency, 0-0.4 MPa) for 2 or 3 wk. Granulation tissue thickness and wound re-epithelialization increased as a function of increasing ultrasound pressure amplitude. At 2 wk after injury, significant increases in granulation tissue thickness and epithelial ingrowth were observed in response to 1 MHz pulsed ultrasound at 0.4 MPa. Wounds exposed to 0.4 MPa ultrasound for 3 wk were characterized by collagen-dense, revascularized granulation tissue with a fully restored, mature epithelium. Of note, only half of wounds exposed to 0.4 MPa ultrasound showed significant granulation tissue deposition after 2 wk of treatment. Thus, the db+/db+ mouse model may help to identify biological variables that influence individual responses to pulsed ultrasound and accelerate clinical translation.

Effect of Therapeutic Ultrasound for Neck Pain: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the effects and safety of therapeutic ultrasound in patients with neck pain.

DATA SOURCES

The PubMed, EMBASE, CENTRAL, and Physiotherapy Evidence databases were searched for articles published before December 1, 2020.

STUDY SELECTION

Randomized controlled trials that compared the effects of therapeutic ultrasound on neck pain were included in this review. The included studies compared therapeutic ultrasound plus other treatments with the other treatments alone or compared therapeutic ultrasound with sham or no treatment. Outcome measures involved the effects on pain, disability, and quality of life. Other treatments included all nonultrasonic therapies (eg, various exercises, massage, electrotherapy).

DATA EXTRACTION

Data on the study population, therapeutic ultrasound intervention, combined intervention, outcome measures, and follow-up were extracted.

DATA SYNTHESIS

Twelve randomized controlled trials (705 patients) fulfilled the inclusion criteria. Seven studies compared therapeutic ultrasound plus other treatments vs the other treatments alone (449 patients). Therapeutic ultrasound yielded additional benefits for pain, but there was high heterogeneity and we could not draw a clear conclusion. Ultrasound did not have a better effect on disability or quality of life when it was combined with other treatments. Five studies compared therapeutic ultrasound with sham or no treatment (256 patients), and the pooled data showed that therapeutic ultrasound significantly reduced pain intensity. No adverse events of therapeutic ultrasound were reported in the included studies.

CONCLUSIONS

Therapeutic ultrasound may reduce the intensity of pain more than sham or no treatment, and it is a safe treatment. Whether therapeutic ultrasound in combination with other conventional treatments produced additional benefits on pain intensity, disability, or quality of life is not clear. The randomized trials included in this review had different levels of quality and high heterogeneity. A large trial using a valid methodology is warranted.

Janus 3D printed dynamic scaffolds for nanovibration-driven bone regeneration

The application of physical stimuli to cell cultures has shown potential to modulate multiple cellular functions including migration, differentiation and survival. However, the relevance of these in vitro models to future potential extrapolation in vivo depends on whether stimuli can be applied “externally”, without invasive procedures. Here, we report on the fabrication and exploitation of dynamic additive-manufactured Janus scaffolds that are activated on-command via external application of ultrasounds, resulting in a mechanical nanovibration that is transmitted to the surrounding cells. Janus scaffolds were spontaneously formed via phase-segregation of biodegradable polycaprolactone (PCL) and polylactide (PLA) blends during the manufacturing process and behave as ultrasound transducers (acoustic to mechanical) where the PLA and PCL phases represent the active and backing materials, respectively. Remote stimulation of Janus scaffolds led to enhanced cell proliferation, matrix deposition and osteogenic differentiation of seeded human bone marrow derived stromal cells (hBMSCs) via formation and activation of voltage-gated calcium ion channels.

Fabrication of dynamic, reversible and biocompatible scaffolds with non-invasive external triggers has so far been limited. Here, the authors report on the creation of 3D printed scaffolds with Janus structure that produce nanovibrations when exposed to ultrasound, promoting bone regeneration.

Ultrasonic therapy modulates the expression of genes related to neovascularization and inflammation in fibroblasts

Abstract Introduction: In the rehabilitation of musculoskeletal injuries, ultrasound is widely used in clinical practice. Objective: To evaluate the effects of pulsed ultrasonic therapy on the viability and modulation of genes involved in inflammation (IL-6) and neovascularization (VEGF) processes of L929 fibroblast cells. Methods: For irradiation with ultrasound the cells were subdivided into groups: G1 (without irradiation), G2 (0.3 W/cm2-20%) and G3 (0.6 W/cm2-20%), with periods of treatment at 24, 48 and 72 hours. The cell viability assay was analyzed by the MTT method and gene modulation was analyzed by RT-qPCR method. Results: After the comparative analysis between groups, only G2 and G3 (48-hour) presented statistically significant differences in relation to the control. In relation to the gene expression, the selection of the groups analyzed was delimited according to the comparative analysis of the values obtained by the MTT test. After the achievement of RT-qPCR, it could be observed that in G2 the amount of VEGF gene transcripts increased by 1.125-fold compared to endogenous controls, and increased 1.388-fold in G3. The IL-6 gene, on the other hand, had its transcripts reduced in both G2 (5.64x10-9) and G3 (1.91x10-6). Conclusion: Pulsed ultrasound in L929 fibroblasts showed a significant biostimulatory effect in the 48-hour period, with increased cell viability, and the same effect in the modulation of gene expression related the neovascularization and inflammation, mediating the acceleration of the tissue repair cascade.

Low-intensity ultrasound attenuates paw edema formation and decreases vascular permeability induced by carrageenan injection in rats

Background

Therapeutic potential of low-intensity ultrasound (LIUS) has become evident in various musculoskeletal diseases. We have previously shown that LIUS has an inhibitory effect on local edema in various diseases including the arthritis and brain injury. In this study, we examined whether LIUS can attenuate paw edema formation vis-à-vis vascular permeability and inflammation in rats induced by carrageenan. LIUS with a frequency of 1 MHz and the intensities of 50, 100, or 200 mW/cm² were exposed on rat paws for 10 min immediately after carrageenan injection.

Results

Carrageenan injection induced paw edema which was peaked at 6 h and gradually decreased nearly to the initial baseline value after 72 h. LIUS showed a significant reduction of paw edema formation at 2 and 6 h at all intensities tested. The highest reduction was observed at the intensity of 50 mW/cm². Histological analyses confirmed that LIUS clearly decreased the carrageenan-induced swelling of interstitial space under the paw skin and infiltration of polymorphonuclear leukocytes. Moreover, Evans Blue extravasation analyses exhibited a significant decreases of vascular permeability by LIUS. Finally, immunohistochemical staining showed that expression of pro-inflammatory proteins, namely, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) induced by carrageenan injection was reduced back to the normal level after LIUS stimulation.

Conclusions

These results provide a new supporting evidence for LIUS as a therapeutic alternative for the treatment of edema in inflammatory diseases such as cellulitis.

In vitro Ultrasonic Potentiation of 2-Phenylethynesulfonamide/Magnetic Fluid Hyperthermia Combination Treatments for Ovarian Cancer

Background

Magnetic Fluid Hyperthermia (MFH) is a promising adjuvant for chemotherapy, potentiating the action of anticancer agents. However, drug delivery to cancer cells must be optimized to improve the overall therapeutic effect of drug/MFH combination treatments.

Purpose

The aim of this work was to demonstrate the potentiation of 2-phenylethynesulfonamide (PES) at various combination treatments with MFH, using low-intensity ultrasound as an intracellular delivery enhancer.

Methods

The effect of ultrasound (US), MFH, and PES was first evaluated individually and then as combination treatments. Definity^® microbubbles and polyethylene glycol (PEG)-coated iron oxide nanoparticles were used to induce cell sonoporation and MFH, respectively. Assessment of cell membrane permeabilization was evaluated via fluorescence microscopy, iron uptake by cells was quantified by UV-Vis spectroscopy, and cell viability was determined using automatic cell counting.

Results

Notable reductions in cancer cell viability were observed when ultrasound was incorporated. For example, the treatment US+PES reduced cell viability by 37% compared to the non-toxic effect of the drug. Similarly, the treatment US+MFH using mild hyperthermia (41°C), reduced cell viability by an additional 18% when compared to the effect of MH alone. Significant improvements were observed for the combination of US+PES+MFH with cell viability reduced by an additional 26% compared to the PES+MFH group. The improved cytotoxicity was attributed to enhanced drug/nanoparticle intracellular delivery, with iron uptake values nearly twice those achieved without ultrasound. Various treatment schedules were examined, and all of them showed substantial cell death, indicating that the time elapsed between sonoporation and magnetic field exposure was not significant.

Conclusion

Superior cancer cell-killing patterns took place when ultrasound was incorporated thus demonstrating the in vitro ultrasonic potentiation of PES and mild MFH. This work demonstrated that ultrasound is a promising non-invasive enhancer of PES/MFH combination treatments, aiming to establish a sono-thermo-chemotherapy in the treatment of ovarian cancer.

Intensity-dependent effect of pulsed and continuous therapeutic ultrasound on endothelial function: a randomised crossover clinical trial

Background/Aims

The aim of this study was to evaluate the effects of different intensities and waveforms of therapeutic ultrasound on endothelial function in typically healthy participants.

Methods

A total of 15 participants were evaluated over 2 consecutive days. Different intensities of continuous and pulsed (20% duty cycle) 1-MHz ultrasound were applied to the brachial artery for 5 minutes each. Endothelial function was measured using flow-mediated dilation technique before and immediately after ultrasound was applied.

Results

Compared to baseline values, endothelium-dependent vasodilation increased with both continuous (2.8%) and pulsed (1.6%) ultrasound at an intensity of 0.4 W/cm2SPTA. At 1.2 W/cm2SPTA, endothelium-dependent vasodilation was 4.1% above baseline for pulsed and 5.3% above baseline for continuous waveforms. There was no additional increase in vasodilation at intensities above 1.2 W/cm2SPTA. The percentage of endothelium-dependent vasodilation was similar for the all of the different waveforms studied.

Conclusions

Both continuous and pulsed ultrasound waveforms promote endothelium-dependent vasodilation. There was a dose-dependent increase in vasodilation at intensities from 0.4 W/cm2SPTA to 1.2 W/cm2SPTA. Pulsed is more efficient than continuous ultrasound because it produces the same effect on endothelium-dependent vasodilation while employing 20% of the energy applied with continuous ultrasound.

Technological Advances in Wound Treatment of Exotic Pets

Although most research about the use of technological advances for wound healing was performed in laboratory animals but oriented to human medicine, recent technological advances allowed its application not only to small animals but also to exotic pets. This article reviews the literature available about some of these techniques (negative wound pressure therapy, photobiomodulation [laser therapy], electrical stimulation therapy, therapeutic ultrasonography, hyperbaric oxygen therapy), and other advances in wound management (skin expanders, xenografts, and bioengineered autologous skin substitutes) in exotic pet species.

Role of Acid Sphingomyelinase and Ceramide in Mechano-Acoustic Enhancement of Tumor Radiation Responses

Background

High-dose radiotherapy (>8-10 Gy) causes rapid endothelial cell death via acid sphingomyelinase (ASMase)-induced ceramide production, resulting in biologically significant enhancement of tumor responses. To further augment or solicit similar effects at low radiation doses, we used genetic and chemical approaches to evaluate mechano-acoustic activation of the ASMase-ceramide pathway by ultrasound-stimulated microbubbles (USMB).

Methods

Experiments were carried out in wild-type and acid sphingomyelinase (asmase) knockout mice implanted with fibrosarcoma xenografts. A cohort of wild-type mice received the ASMase-ceramide pathway inhibitor sphingosine-1-phosphate (S1P). Mice were treated with varying radiation doses, with or without a priori USMB exposure at different microbubble concentrations. Treatment response was assessed with quantitative 3D Doppler ultrasound and immunohistochemistry at baseline, and at three, 24, and 72 hours after treatment, with three to five mice per treatment group at each time point. All statistical tests were two-sided.

Results

Results confirmed an interaction between USMB and ionizing radiation at 24 hours (P < .001), with a decrease in tumor perfusion of up to 46.5% by three hours following radiation and USMB. This peaked at 24 hours, persisting for up to 72 hours, and was accompanied by extensive tumor cell death. In contrast, statistically nonsignificant and minimal tumor responses were noted in S1P-treated and asmase knockout mice for all treatments.

Conclusions

This work is the first to confirm the involvement of the ASMase-ceramide pathway in mechanotransductive vascular targeting using USMB. Results also confirm that an acute vascular effect is driving this form of enhanced radiation response, and that it can be elicited at low radiation doses (<8-10 Gy) by a priori USMB exposure.

Effects of therapeutic ultrasound for knee osteoarthritis: a systematic review and meta-analysis

Objective:

To assess the effectiveness and safety of therapeutic ultrasound with sham ultrasound on pain relief and functional improvement in knee osteoarthritis patients. As phonophoresis is a unique therapeutic ultrasound, we also compared the effects of phonophoresis with conventional non-drug ultrasound.

Data sources:

PubMed, EMBASE, and the Cochrane Library were systematically searched for randomized controlled trials from inception up to June 2019.

Review methods:

Randomized controlled trials comparing therapeutic ultrasound with sham ultrasound in knee osteoarthritis patients were included. Phonophoresis in the experimental and control groups were compared through conventional ultrasound, and corresponding trials were also included. Two reviewers independently identified eligible studies and extracted data. Risk of bias assessments and therapeutic ultrasound safety assessments were also performed.

Results:

Fifteen studies including three phonophoresis-related studies with 1074 patients were included. Meta-analyses demonstrated that therapeutic ultrasound significantly relieved pain ( P < 0.00001) and reduced the Western Ontario and McMaster Universities (WOMAC) physical function score ( P = 0.03). In addition, therapeutic ultrasound increased the active range of motion ( P < 0.00001) and reduced the Lequesne index ( P < 0.00001). Subgroup analysis of phonophoresis ultrasound illustrated significant differences on the visual analogue scale ( P = 0.009), but no significant differences on WOMAC pain subscales ( P = 0.10), and total WOMAC scores were observed ( P = 0.30). There was no evidence to suggest that ultrasound was unsafe treatment.

Conclusions:

Therapeutic ultrasound is a safe treatment to relieve pain and improve physical function in patients with knee osteoarthritis. However, phonophoresis does not produce additional benefits to functional improvement, but may relieve pain compared to conventional non-drug ultrasound.

Effectiveness of Ultrasound Therapy on Myofascial Pain Syndrome of the Upper Trapezius: Randomized, Single-Blind, Placebo-Controlled Study

Objectives

This study aims to evaluate the effectiveness of conventional ultrasound (US) therapy in the treatment of myofascial pain syndrome.

Patients and methods

Fifty-four patients (23 males, 31 females; mean age 29.8±5.2 years; range, 22 to 46 years) with myofascial pain syndrome were included in this prospective, randomized, single-blind, placebo-controlled study. Patients were randomized into two groups by computerized method as US group (n=27) and placebo group (n=27). Ten sessions of US were applied to the US group and 10 sessions of placebo US were applied to the placebo group. Treatment effectiveness was evaluated with Visual Analog Scale (VAS), algometer, palpable muscle spasm degree (PMSD), and Beck Depression Inventory (BDI) before and after treatment.

Results

Pain values after treatment in both groups decreased significantly (p<0.05) compared to before treatment. In the US group, the decrease in VAS and palpable muscle degree before and after treatment was significantly higher (p<0.05) than in the placebo group. In the US group, the decrease in PMSD after treatment was significantly higher than the placebo group (p<0.05). The amount of decrease in BDI score before and after treatment in the US group did not differ significantly from the placebo group (p>0.05).

Conclusion

Our findings show that conventional US therapy is effective in the treatment of myofascial pain syndrome.

Novel Cranial Implants of Yttria-Stabilized Zirconia as Acoustic Windows for Ultrasonic Brain Therapy

Therapeutic ultrasound can induce changes in tissues by means of thermal and nonthermal effects. It is proposed for treatment of some brain pathologies such as Alzheimer's, Parkinson's, Huntington's diseases, and cancer. However, cranium highly absorbs ultrasound reducing transmission efficiency. There are clinical applications of transcranial focused ultrasound and implantable ultrasound transducers proposed to address this problem. In this paper, biocompatible materials are proposed for replacing part of the cranium (cranial implants) based on low porosity polycrystalline 8 mol% yttria-stabilized-zirconia (8YSZ) ceramics as acoustic windows for brain therapy. In order to assess the viability of 8YSZ implants to effectively transmit ultrasound, various 8YSZ ceramics with different porosity are tested; their acoustic properties are measured; and the results are validated using finite element models simulating wave propagation to brain tissue through 8YSZ windows. The ultrasound attenuation is found to be linearly dependent on ceramics' porosity. Results for the nearly pore-free case indicate that 8YSZ is highly effective in transmitting ultrasound, with overall maximum transmission efficiency of ≈81%, compared to near total absorption of cranial bone. These results suggest that 8YSZ polycrystals could be suitable acoustic windows for ultrasound brain therapy at 1 MHz.

Implementation of Nanoparticles in Cancer Therapy

Cancer is a wide group of diseases and generally characterized by uncontrolled proliferation of cells whose metabolic activities are disrupted. Conventionally, chemotherapy, radiotherapy, and surgery are used in the treatment of cancer. However, in theory, even a single cancer cell may trigger recurrence. Therefore, these treatments cannot provide high survival rate for deadly types. Identification of alternative methods in treatment of cancers is inevitable because of adverse effects of conventional methods. In the last few decades, nanotechnology developed by scientists working in different disciplines—physics, chemistry, and biology—offers great opportunities. It is providing elimination of both circulating tumor cells and solid cancer cells by targeting cancer cells. In this chapter, inadequate parts of conventional treatment methods, nanoparticle types used in new treatment methods of cancer, and targeting methods of nanoparticles are summarized; furthermore, recommendations of future are provided.

Experimental Verification of Modeled Thermal Distribution Produced by a Piston Source in Physiotherapy Ultrasound

Objectives. To present a quantitative comparison of thermal patterns produced by the piston-in-a-baffle approach with those generated by a physiotherapy ultrasonic device and to show the dependency among thermal patterns and acoustic intensity distributions. Methods. The finite element (FE) method was used to model an ideal acoustic field and the produced thermal pattern to be compared with the experimental acoustic and temperature distributions produced by a real ultrasonic applicator. A thermal model using the measured acoustic profile as input is also presented for comparison. Temperature measurements were carried out with thermocouples inserted in muscle phantom. The insertion place of thermocouples was monitored with ultrasound imaging. Results. Modeled and measured thermal profiles were compared within the first 10 cm of depth. The ideal acoustic field did not adequately represent the measured field having different temperature profiles (errors 10% to 20%). Experimental field was concentrated near the transducer producing a region with higher temperatures, while the modeled ideal temperature was linearly distributed along the depth. The error was reduced to 7% when introducing the measured acoustic field as the input variable in the FE temperature modeling. Conclusions. Temperature distributions are strongly related to the acoustic field distributions.

Uncertainty estimation for temperature measurement with diagnostic ultrasound

Background

Ultrasound therapies are promising, non-invasive applications with potential to significantly improve, e.g. cancer therapies like viro- or immunotherapy or surgical applications. However, a crucial step towards their breakthrough is still missing: affordable and easy-to-handle quality assurance tools for therapy devices and ways to verify treatment planning algorithms. This deficiency limits the safety and comparability of treatments.

Methods

To overcome this deficiency accurate spatial and temporal temperature maps could be used. In this paper, the suitability of temperature calculation based on time-shifts of diagnostic ultrasound backscattered signals (echo-time-shift) is investigated and associated uncertainties are estimated. Different analysis variations were used to calculate the time-shifts: discrete and continuous methods as well as different frames as a reference for temperature calculation (4 s before, 16 s before the frame of interest, base frame). A sigmoid function was fitted and used to calculate temperatures. Two-dimensional temperature maps recorded during and after therapeutic ultrasound sonication were examined. All experiments were performed in agar-graphite phantoms mimicking non-fatty tissue, with high-intensity focused ultrasound being the source of heating.

Results

Continuous methods are more accurate than discrete ones, and uncertainties of calculated temperatures are in general lower, the earlier the reference frame was recorded. Depending on the purpose of the measurement, a compromise has to be made between the following: calculation accuracy (early reference frame), tolerance towards small movements (late reference frame), reproducing large temperature changes or cooling processes (reference frame at a certain point in time), speed of the algorithm (discrete (fast) vs. continuous (slower) shift calculation), and spatial accuracy (interval size for index-shift calculation). Within the range from 20 °C to 44 °C, uncertainties as low as 12.4 % are possible, being mainly due to medium properties.

Conclusions

Temperature measurements using the echo-time-shift method might be useful for validation of treatment plan algorithms. This might also be a comparatively accurate, fast, and affordable method for laboratory and clinical quality assessment. Further research is necessary to improve filter algorithms and to extend this method to multiple foci and the usage of temperature-dependent tissue quantities. We used an analytical approach to investigate the uncertainties of temperature measurement. Different analysis variations are compared to determine temperature distribution and development over time.

Assessing heating distribution by therapeutic ultrasound on bone phantoms and in vitro human samples using infrared thermography

Background

Bioheat models have been proposed to predict heat distribution in multilayered biological tissues after therapeutic ultrasound (TUS) stimulation. However, evidence on its therapeutic benefit is still controversial for many clinical conditions. The aim of this study was to evaluate and to compare the TUS heating distribution on commercially available bone phantoms and in vitro femur and tibia human samples, at 1 MHz and several ultrasonic pulse regimens, by means of a thermographic image processing technique.

Methods

An infrared camera was used to capture an image after each 5-min 1-MHz TUS stimulation on bone phantoms, as well as in vitro femur and tibia samples (N = 10). An intensity-based processing algorithm was applied to estimate temperature distribution. Sections of five femurs in the coronal plane were also used for the evaluation of heat distribution inside the medullar canal.

Results

Temperature increased up to 8.2 and 9.8 °C for the femur and tibia, respectively. Moreover, the temperature increased up to 10.8 °C inside the medullar canal. Although temperature distributions inside the region of interest (ROI) were significantly different (p < 0.001), the average and standard deviation values for bone phantoms were more similar to the femur than to the tibia samples. Pulsed regimens caused lower increments in temperature than continuous sonication, as expected.

Conclusions

Commercially available bone phantoms could be used in research focusing on thermal effects of ultrasound. Small differences in mean and standard deviation temperatures were observed between bone samples and phantoms. Temperature can reach more than 10 °C inside the medullar canal on a fixed probe position which may lead to severe cellular damage.

Effects of therapeutic ultrasound on pain, physical functions and safety outcomes in patients with knee osteoarthritis: a systematic review and meta-analysis

OBJECTIVE

To explore the effects of therapeutic ultrasound with sham or no intervention on pain, physical function and safety outcomes in patients with knee osteoarthritis.

DATA SOURCES

This systematic review was searched on CENTRAL, EMBASE, MEDLINE, CINAHL, Physiotherapy Evidence Database, Open Gray on 4 September 2015. Trials included randomized controlled trials that compared therapeutic ultrasound with a sham or no intervention in patients with osteoarthritis of the knee.

REVIEW METHODS

Eligible trials and extracted data were identified by two independent investigators. Standardized mean differences (SMDs) and 95% confidence interval (CI) were calculated for pain and physical function outcomes. Heterogeneity was assessed by the I² test and inverse-variance random-effects analysis was applied to all trials.

RESULTS

Ten randomized controlled trials (645 patients) met the inclusion criteria. Therapeutic ultrasound showed a positive effect on pain (SMD = -0.93, 95%, CI = -1.22 to -0.64, p < 0.01, p for heterogeneity = 0.12, I² = 42%). For physical function, therapeutic ultrasound was advantageous for reducingWestern Ontario and McMaster Universities physical function score (SMD = -0.37, 95% CI = -0.73 to -0.01, p = 0.04, p for heterogeneity = 0.94, I² = 0%). In terms of safety, no occurrence of adverse events caused by therapeutic ultrasound was reported in any trial.

CONCLUSION

The authors suggested that therapeutic ultrasound is beneficial for reducing knee pain and improving physical functions in patients with knee osteoarthritis and could be a safe treatment.

Mechanical high-intensity focused ultrasound destruction of soft tissue: working mechanisms and physiologic effects

The best known method of high-intensity focused ultrasound is thermal ablation, but interest in non-thermal, mechanical destruction is increasing. The advantages of mechanical ablation are that thermal protein denaturation remains limited and less damage is created to the surrounding tissue by thermal diffusion. The two main techniques for mechanical fragmentation of tissue are histotripsy and boiling histotripsy. These techniques can be used for complete liquefaction of tumor tissue into submicron fragments, after which the fragmented tissue can be easily removed by natural (immunologic) responses. Interestingly it seems that there is a correlation between the degree of destruction and tissue specific characteristics based on the treatment settings used. In this review article, the technical aspects of these two techniques are described, and an overview of the in vivo pathologic and immunologic responses is provided.

Ultrasound induced cancer immunotherapy

Recently, the use of ultrasound (US) has been shown to have potential in cancer immunotherapy. High intensity focused US destruction of tumors may lead to immunity forming in situ in the body by immune cells being exposed to the tumor debris and immune stimulatory substances that are present in the tumor remains. Another way of achieving anti-cancer immune responses is by using US in combination with microbubbles and nanobubbles to deliver genes and antigens into cells. US leads to bubble destruction and the forces released to direct delivery of the substances into the cytoplasm of the cells thus circumventing the natural barriers. In this way tumor antigens and antigen-encoding genes can be delivered to immune cells and immune response stimulating genes can be delivered to cancer cells thus enhancing immune responses. Combination of bubbles with cell-targeting ligands and US provides an even more sophisticated delivery system whereby the therapy is not only site specific but also cell specific. In this review we describe how US has been used to achieve immunity and discuss the potential and possible obstacles in future development.

Enhanced homing permeability and retention of bone marrow stromal cells by noninvasive pulsed focused ultrasound

Bone marrow stromal cells (BMSCs) have shown significant promise in the treatment of disease, but their therapeutic efficacy is often limited by inefficient homing of systemically administered cells, which results in low number of cells accumulating at sites of pathology. BMSC home to areas of inflammation where local expression of integrins and chemokine gradients is present. We demonstrated that nondestructive pulsed focused ultrasound (pFUS) exposures that emphasize the mechanical effects of ultrasound-tissue interactions induced local and transient elevations of chemoattractants (i.e., cytokines, integrins, and growth factors) in the murine kidney. pFUS-induced upregulation of cytokines occurred through approximately 1 day post-treatment and returned to contralateral kidney levels by day 3. This window of significant increases in cytokine expression was accompanied by local increases of other trophic factors and integrins that have been shown to promote BMSC homing. When BMSCs were intravenously administered following pFUS treatment to a single kidney, enhanced homing, permeability, and retention of BMSC was observed in the treated kidney versus the contralateral kidney. Histological analysis revealed up to eight times more BMSC in the peritubular regions of the treated kidneys on days 1 and 3 post-treatment. Furthermore, cytokine levels in pFUS-treated kidneys following BMSC administration were found to be similar to controls, suggesting modulation of cytokine levels by BMSC. pFUS could potentially improve cell-based therapies as a noninvasive modality to target homing by establishing local chemoattractant gradients and increasing expression of integrins to enhance tropism of cells toward treated tissues.

Effects of phonophoresis of piroxicam and ultrasound on symptomatic knee osteoarthritis

OBJECTIVE

To compare the effects of phonophoresis of piroxicam (PhP) and ultrasound therapy (UT) in patients with mild to moderate, symptomatic knee osteoarthritis (OA).

DESIGN

A randomized, double-blind, controlled trial.

SETTING

Department of rehabilitation medicine, university hospital.

PARTICIPANTS

Patients with knee OA (N=46; mean age ± SD, 58.91±10.50y) who had visual analog scale (VAS) scores of 50 to 92mm (mean, 71.5mm) for knee pain intensity and Kellgren-Lawrence grades of I to III were randomly allocated into 2 groups: PhP and UT (23 in each group).

INTERVENTIONS

Both the PhP and UT groups were treated with an ultrasound program using the stroking technique, continuous mode, 1.0W/cm(2), 10 minutes per session, and 5 times per week for 2 weeks. Four grams of 0.5% piroxicam gel (20mg of piroxicam drug) was used in the PhP group, while the nondrug coupling gel was used in the UT group.

MAIN OUTCOME MEASURES

A 100-mm VAS for usual pain and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were evaluated before and after treatment in both groups using a double-blinded procedure.

RESULTS

The VAS and total WOMAC scores were significantly improved after treatment in both groups (P<.001). The PhP group showed more significant effects than the UT group, both in reducing the VAS pain score (P=.009) and in improving the WOMAC score, although it did not reach the level of significance (P=.143).

CONCLUSIONS

Our results indicated that PhP was significantly more effective than UT in reducing pain and tended to improve knee functioning in Kellgren-Lawrence grades I to III knee OA. PhP is suggested as a new, effective method for treatment of symptomatic knee OA.

Effects of therapeutic pulsed ultrasound and dimethylsulfoxide phonophoresis on oxidative stress parameters after injury induced by eccentric exercise

INTRODUCTION

The aim of the study was to evaluate the effects of TPU together with DMSO on oxidative stress parameters after eccentric exercise.

METHODS

Thirty and six animals were divided in control; eccentric exercise (EE); EE+saline gel 0.9%; EE+TPU 0.8 W/cm(2); EE+DMSO gel; EE+TPU+DMSO gel and submitted to one 90-min downhill run (1.0 km h(-1)). TPU was used 2, 12, 24, 46 h after exercise session and 48 h after the animals were killed and the gastrocnemius muscles were surgically removed. Production of superoxide anion, creatine kinase (CK) levels, lipoperoxidation, carbonylation, and antioxidants enzymes were analyzed.

RESULTS

Showed that TPU and gel-DMSO improved muscle healing. Moreover, superoxide anion production, TBARS level and protein carbonyls levels, superoxide dismutase and catalase activity were all decreased in the group TPU plus gel-DMSO.

DISCUSSION

Our results show that DMSO is effective in the reduction of the muscular lesion and in the oxidative stress after eccentric exercise only when used with TPU.

Anti-inflammatory effect of low intensity ultrasound (LIUS) on complete Freund's adjuvant-induced arthritis synovium

OBJECTIVES

Arthritis with intra-articular inflammation was accompanied by joint pain, swelling, and stiffness leading to significant functional impairment. Thus, regulation of joint inflammation is a good therapeutic approach for patients with arthritis. In this study, the effect of low intensity ultrasound (LIUS) applied to an adjuvant-induced arthritic rat model on the synovium was investigated.

DESIGN

Synovial inflammation was induced by complete Freund's adjuvant (CFA)-injection into the rat knee joint. LIUS (200 mW/cm(2)) was applied on the ipsilateral knee everyday for 10 min beginning 1 day after inflammation induction. The expression of proinflammatory factors and immunohistochemical staining pattern of the synovium were assessed.

RESULTS

CFA induced an increase of the knee circumference that was significantly diminished by LIUS. Synovial membrane hyperplasia in the ipsilateral joint was also affected by LIUS. The inflammatory mediators, COX-1/2, IL-1β, and iNOS, but not TNF-α, in the synovial membrane were induced after 3 days, and they closely correlated with the degree of edema. In the synovial membrane, the expression of inflammatory mediators was reduced by LIUS. The chemoattractant chemokine receptor CCR5 also was involved. On immunohistochemical analysis, CFA caused increased infiltration of CD11b-positive cells in the synovium. After 3 days, neutrophils, myeloperoxidase (MPO)-positive cells filled the inflammatory core; later, monocytes and macrophages, ionized calcium binding adaptor molecule 1 (Iba1)-positive cells in the periphery infiltrated the core by day 5. LIUS markedly reduced CFA-induced inflammatory cells infiltration.

CONCLUSION

LIUS showed a potent anti-inflammatory effect in this animal arthritis model with reduced infiltration of inflammatory cells into the synovium.

Pulsed ultrasound associated with gold nanoparticle gel reduces oxidative stress parameters and expression of pro-inflammatory molecules in an animal model of muscle injury

Background

Nanogold has been investigated in a wide variety of biomedical applications because of the anti-inflammatory properties. The purpose of this study was to evaluate the effects of TPU (Therapeutic Pulsed Ultrasound) with gold nanoparticles (GNP) on oxidative stress parameters and the expression of pro-inflammatory molecules after traumatic muscle injury.

Materials and methods

Animals were divided in nine groups: sham (uninjured muscle); muscle injury without treatment; muscle injury + DMSO; muscle injury + GNP; muscle injury + DMSO + GNP; muscle injury + TPU; muscle injury + TPU + DMSO; muscle injury + TPU + GNP; muscle injury + TPU + DMSO + GNP. The ROS production was determined by concentration of superoxide anion, modulation of antioxidant defenses was determined by the activity of superoxide dismutase, catalase and glutathione peroxidase enzymes, oxidative damage determined by formation of thiobarbituric acid-reactive substance and protein carbonyls. The levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were measured as inflammatory parameters.

Results

Compared to muscle injury without treatment group, the muscle injury + TPU + DMSO + GNP gel group promoted a significant decrease in superoxide anion production and lipid peroxidation levels (p < 0.050). It also showed a significant decrease in TNF-α and IL-1β levels (p < 0.050) when compared to muscle injury without treatment group.

Conclusions

Our results suggest that TPU + DMSO + GNP gel presents beneficial effects on the muscular healing process, inducing a reduction in the production of ROS and also the expression of pro-inflammatory molecules.

Recent advances in stealth coating of nanoparticle drug delivery systems

Modifying surfaces of nanoparticles (NPs) with polyethylene glycol (PEG), the so-called PEGylation, is the most commonly used method for reducing premature clearance of NPs from the circulation. However, several reports point out that PEGylation may negatively influence the performance of NPs as a drug carrier. Alternative surface modification strategies, including substitute polymers, conditional removal of PEG, and biomimetic surface modification, may provide solutions for the limitations of PEG.

Osteogenic effect of low intensity pulsed ultrasound on rat adipose-derived stem cells in vitro

The osteogenic in vitro effect of low intensity pulsed ultrasound (LIPUS) on SD rat adipose-derived stem cells (ADSCs) was investigated. Rat ADSCs underwent LIPUS (intensity=100 mW/cm(2)) or sham exposure for 8 min per treatment once everyday in vitro, and then the alkaline phosphatase (ALP) activity and mineralized nodule formation were assessed to evaluate the osteogenic effect of LIPUS on ADSCs. To further explore the underlying mechanism, the osteogenic-related gene mRNA expression was determined by using reverse transcriptase-polymerase chain reaction (RT-PCR) at 1st, 3rd, 5th, 7th day after exposure repectively. Westen blot was used to evaluate the protein expression levels of two osteogenic differentiation associated genes at 7th and 14th day repectively. It was found that ALP activity was increased after LIPUS exposure and LIPUS resulted in mineralized nodule formation of ADSCs in vitro. LIPUS-treated ADSCs displayed higher mRNA expression levels of runt-related transcription factor 2 (Runx2), osteocalcin (OCN), ALP and bone sialoprotein (BSP) genes than controls, and the protein levels of Runx2 and BSP were also increased. The results suggested that LIPUS may induce the osteogenic differentiation of ADSCs in vitro.

Intervenção fisioterapêutica nas sequelas de drenagem linfática manual iatrogênica: relato de caso

Atualmente, a drenagem linfática manual (DLM) é um dos recursos de grande destaque no tratamento de edemas, linfedemas e condições inestéticas, porém, na prática clínica têm-se observado sua aplicação de forma iatrogênica. Os objetivos deste relato de caso foram apontar as sequelas da aplicação iatrogênica da DLM, em uma jovem caucasiana, e verificar os efeitos da intervenção fisioterapêutica no tratamento dessas. Voluntária de 27 anos, apresentava-se com uma equimose importante na região lateral da coxa esquerda (28 x 9,5 cm), telangiectasias, microvaricosidades e petéquias em ambas as coxas e pernas, dor de forte intensidade e edema, após ter se submetido a um procedimento manual iatrogênico com finalidade estética há dois dias. As condutas fisioterapêuticas adotadas foram: Ultrassom 3 MHz, pulsado (2 ms on, 8 ms off), 0,4 W/cm² SATP na região da equimose e DLM (Método Leduc) durante 20 minutos, na coxa esquerda. Foram realizadas nove sessões até a alta no 16º dia pós-lesão, observando-se apenas a redução gradativa da dor e da equimose. Verificou-se a efetividade da intervenção fisioterapêutica em apenas algumas das sequelas provocadas pela iatrogenia, sem desconsiderar que a remissão espontânea dos sinais e sintomas também pode ter contribuído para tal. Destaca-se a importância de conscientizar os fisioterapeutas que atuam com este procedimento para que o aplique de forma adequada, evitando tais iatrogenias.

Enhancement and control of acoustic cavitation yield by low-level dual frequency sonication: a subharmonic analysis

Evaluation of inertial cavitation is a significant problem where this mechanism of action is responsible for therapeutic applications such as drug delivery. It has shown that using multiple frequencies one is able to enhance and control induced cavitation. In this study, we used different sonication frequencies as 28 kHz, 130 kHz, 1 MHz, 3 MHz and their dual combinations to enhance acoustic cavitation. At each frequency, two different intensities were used and the subharmonic amplitude of each frequency in combinations was measured. It was observed that in combinations which include 28 kHz, the cavitation activity is enhanced. The 28 kHz subharmonic amplitude was used to compare these protocols in their ability to enhance cavitation. Besides, the area of cavitation damage was determined using an aluminum foil. Our results showed that the inertial cavitation activity increased at higher intensities and there is a significant correlation between the subharmonic amplitude and sonication intensity at each frequency (R>0.90). In addition, simultaneous combined dual-frequency orthogonal sonication at 28 kHz with other frequencies used can significantly increase the inertial cavitation activity as compared to the algebraic sum of the individual ultrasound irradiations in 28 kHz subharmonic frequency. The 28 kHz subharmonic amplitude for 28 kHz (0.04 W/cm(2)) and 3 MHz (2 and 1 W/cm(2)) combined dual frequency were about 4.6 and 1.5 times higher than that obtained from the algebraic sum of 28 kHz and 3 MHz irradiation, respectively. Also the 28 kHz subharmonic amplitude for combination of 28 kHz (0.04 W/cm(2)) and 1 MHz (2 and 1 W/cm(2)) were about 2.4 and 1.6 times higher than that obtained with their algebraic sum. Among different combinations, the continuous mode for two ultrasound sources of 28 kHz (0.04 W/cm(2)) and 3 MHz (2 W/cm(2)) is more effective than other combinations (p-value<0.05). The results of effective irradiation area showed no damaged aluminum foil in MHz sonication alone. However, there is significant difference between the effective irradiation area of combined dual frequency 28 kHz and 3 MHz with other irradiation modes (p-value<0.05) and it is limited locally.

Enhancing the transdermal delivery of rigid nanoparticles using the simultaneous application of ultrasound and sodium lauryl sulfate

The potential of rigid nanoparticles to serve as transdermal drug carriers can be greatly enhanced by improving their skin penetration. Therefore, the simultaneous application of ultrasound and sodium lauryl sulfate (referred to as US/SLS) was evaluated as a skin pre-treatment method for enhancing the passive transdermal delivery of nanoparticles. We utilized inductively coupled plasma mass spectrometry and an improved application of confocal microscopy to compare the delivery of 10- and 20-nm cationic, neutral, and anionic quantum dots (QDs) into US/SLS-treated and untreated pig split-thickness skin. Our findings include: (a) ∼0.01% of the QDs penetrate the dermis of untreated skin (which we quantify for the first time), (b) the QDs fully permeate US/SLS-treated skin, (c) the two cationic QDs studied exhibit different extents of skin penetration and dermal clearance, and (d) the QD skin penetration is heterogeneous. We discuss routes of nanoparticle skin penetration and the application of the methods described herein to address conflicting literature reports on nanoparticle skin penetration. We conclude that US/SLS treatment significantly enhances QD transdermal penetration by 500-1300%. Our findings suggest that an optimum surface charge exists for nanoparticle skin penetration, and motivate the application of nanoparticle carriers to US/SLS-treated skin for enhanced transdermal drug delivery.

Ultrasound-stimulated peripheral nerve regeneration within asymmetrically porous PLGA/Pluronic F127 nerve guide conduit

Recently, we developed a novel method to fabricate a nerve guide conduit (NGC) with asymmetrical pore structure and hydrophilicity using poly(lactic-co-glycolic acid) (PLGA) and Pluronic F127 by a modified immersion precipitation method. From the animal study using a rat model (sciatic nerve defect of rat), we recognized that the unique PLGA/Pluronic F127 tube provided good environments for nerve regeneration. In this study, we applied low-intensity pulsed ultrasound as a simple and noninvasive stimulus at the PLGA/F127 NGC-implanted site transcutaneously in rats to investigate the feasibility of ultrasound for the enhanced nerve regeneration through the tube. The nerve regeneration behaviors within the ultrasound-stimulated PLGA/Pluronic F127 NGCs were compared with the NGCs without the ultrasound treatment as well as normal nerve by histological and immunohistochemical observations. It was observed that the PLGA/Pluronic F127 tube-implanted group applied with the ultrasound had more rapid nerve regeneration behavior (approximately 0.71 mm/day) than the tube-implanted group without the ultrasound treatment (approximately 0.48 mm/day). The ultrasound-treated tube group also showed greater neural tissue area as well as larger axon diameter and thicker myelin sheath than the tube group without the ultrasound treatment, indicating better nerve regeneration. The better nerve regeneration behavior in the our NGC/ultrasound system may be caused by the synergistic effect of the asymmetrically porous PLGA/Pluronic F127 tube with unique properties (selective permeability, hydrophilicity, and structural stability, which can provide good environment for nerve regeneration) and physical stimulus (stimulation of the Schwann cells and activation of the neurotrophic factors).

Evaluation of correlation between chemical dosimetry and subharmonic spectrum analysis to examine the acoustic cavitation

Currently several therapeutic applications of ultrasound in cancer treatment are under progress which uses cavitation phenomena to deliver their effects. There are several methods to evaluate cavitation activity such as chemical dosimetry and measurement of subharmonic signals. In this study, the cavitation activity induced by the ultrasound irradiation on exposure parameters has been measured by terephthalic acid chemical dosimetry and subharmonic analysis. Experiments were performed in the near 1 MHz fields in the progressive wave mode and effect of duty cycles changes with 2 W/cm(2) intensity (I(SATA)) and acoustic intensity changes in continuous mode on both fluorescence intensity and subharmonic intensity were measured. The dependence between fluorescence intensity of terephthalic acid chemical dosimetry and subharmonic intensity analysis were analyzed by Pearson correlation (p-value <0.05). It has been shown that the subharmonic intensity and the fluorescence intensity for continuous mode is higher than for pulsing mode (p-value <0.05). Also results show that there is a significant difference between the subharmonic intensity and the fluorescence intensity with sonication intensity (p-value <0.05). A significant correlation between the fluorescence intensity and subharmonic intensity at different duty cycles (R=0.997, p-value <0.05) and different intensities (R=0.985, p-value <0.05) were shown. The subharmonic intensity (microW/cm(2)) significantly correlated with the fluorescence intensity (count) (R=0.901; p<0.05) and the fluorescence intensity due to chemical dosimetry could be estimated with subharmonic intensity due to subharmonic spectrum analysis. It is concluded that there is dependence between terephthalic acid chemical dosimetry and subharmonic spectrum analysis to examine the acoustic cavitation activity.

Low-intensity pulsed ultrasound-dependent osteoblast proliferation occurs by via activation of the P2Y receptor: role of the P2Y1 receptor

Low-intensity pulsed ultrasound (LIPUS) is commonly used in the treatment of fractures and nonunion-promoting acceleration of healing fractures. In this report, we investigated the implication of the P2 receptors in osteoblast proliferation induced with LIPUS treatment. We observed that ADP, ATP, UTP, and UDP promote osteoblast increase and an increase of intracellular Ca(2+), through activation of P2Y receptors. Osteoblasts' expression of the P2Y(1), P2Y(2), P2Y(4), P2Y(6), P2Y(11), P2Y(12), and P2Y(13) receptors was confirmed. In addition, the participation of the P2Y(1) receptor in osteoblast increase and the ADP-dependent increase of Ca(2+) concentration were shown. Furthermore, release of ATP/purines was induced by LIPUS treatment. Finally, LIPUS-dependent osteoblast increase was abolished in the presence of the Ca(2+) chelator (BAPTA), the inositol 1,4,5-trisphosphate receptor antagonist (2-APB), and the selective P2Y(1) receptor antagonist (MRS2179). In conclusion, LIPUS treatment induces osteoblastogenesis via the release of purines, such as ATP, activating P2Y receptors, mainly the P2Y(1) receptor.

Effects of therapeutic pulsed ultrasound and dimethylsulfoxide (DMSO) phonophoresis on parameters of oxidative stress in traumatized muscle

Many studies have demonstrated an increase in reactive oxygen species (ROS) and oxidative damage markers after muscle damage. Phonophoresis aims to achieve therapeutically relevant concentrations of the transdermally introduced drug in the tissues subjected to the procedure by the use ultrasound waves. The aim of the study was to evaluate the effects on the therapeutic pulsed ultrasound (TPU) together with gel-dimethylsulfoxide (DMSO) in the parameters of muscular damage and oxidative stress. Male Wistar rats were divided randomly into six groups (n=6): sham (uninjured muscle); muscle injury without treatment; muscle injury and treatment with gel-saline (0.9%); muscle injury and treatment with gel-DMSO (15mg/kg); muscle injury and TPU plus gel-saline; and muscle injury and TPU plus gel-DMSO. Gastrocnemius injury was induced by a single impact blunt trauma. TPU (6min duration, frequency of 1.0MHz, intensity of 0.8W/cm(2)) was used 2, 12, 24, 48, 72, 96 and 120h after muscle trauma. The CK and acid phosphatase activity in serum was used as an indicator of skeletal muscle injury. Superoxide anion, TBARS, protein carbonyls, superoxide dismutase (SOD) and catalase (CAT) activity was used as indicators of stress oxidative. Results showed that TPU and gel-DMSO improved muscle healing. Moreover, superoxide anion production, TBARS level and protein carbonyls levels, superoxide dismutase (SOD) and catalase (CAT) activity were all decreased in the group TPU plus gel-DMSO. Our results show that DMSO is effective in the reduction of the muscular lesion and in the oxidative stress after mechanical trauma only when used with TPU. (E-mail: silveira_paulo2004@yahoo.com.br).