Application Of Low-intensity Pulsed Ultrasound Research Articles

Clinical efficacy of low-intensity pulsed ultrasound in Parkinson's disease with cognitive impairment.

Low-intensity pulsed ultrasound (LIPUS), is a new technique for invasive brain stimulation and modulation that has emerged recently, but the effects in Parkinson's disease with cognitive impairment (PD-CI) have been less observed. In this study, we collected 56 patients with PD-CI who were continuously treated with LIPUS for 8 weeks, and observed the clinical efficacy of LIPUS on PD-CI patients by comparing with the Sham stimulation continuous treatment. Fifty-six PD-CI patients were divided into the Sham group (given Sham stimulation on top of conventional medication, n = 28) and the LIPUS group (given LIPUS stimulation on top of conventional medication, n = 28), and both groups continued treatment for 8 weeks. Post-treatment efficacy and pre- and post-treatment cognitive function [Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA)], emotional state [Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI)], quality of life [Unified Parkinson's Disease Rating Scale (UPDRS), 39-item Parkinson's Disease Questionnaire (PDQ-39)], and serologic indices [5-hydroxytryptamine (5-HT), norepinephrine (NE), and dopamine (DA)] were compared. The total effective rate of the LIPUS group was higher versus that of the Sham group. In both groups, MMSE and MoCA scores increased; BDI and BAI scores decreased; UPDRS and PDQ-39 scores were reduced; the levels of 5-HT, NE, and DA were elevated. The above changes were more pronounced in the LIPUS group (all P < 0.05). The application of LIPUS on PD-CI could ameliorate patients' cognitive function, emotional state and quality of life, and regulate and optimize neurotransmitter expression levels.

Research trends and perspective of low-intensity pulsed ultrasound in orthopedic rehabilitation treatment based on Web of Science: A bibliometric analysis.

Ultrasound has a long history as a diagnostic and therapeutic tool. Low-intensity pulsed ultrasound (LIPUS), whose intensity is below 300 mW/cm2, has been widely used in orthopedic rehabilitation treatment. However, the detailed bioeffects and underlying mechanisms of LIPUS treatment need to be explored. To make a comprehensive view of the field, bibliometric and visualization analysis was used to reveal the global research trends of LIPUS in orthopedics and rehabilitation treatment between 1994 and 2023. All literature data on LIPUS were retrieved from the Web of Science Core Collection database. VOSviewer and CiteSpace were applied for the bibliometric and visualization analysis. A total of 760 publications were included. The distribution of publications generally showed an unstable rising trend. China had the highest number of publications (28.0%), and Chong Qing Medical University was the organization with the highest number of publications (5.8%). Ultrasound in Medicine and Biology had the highest number of publications (8.8%), while BMJ-British Medical Journal had the highest impact factor among the retrieved journals. Ling Qin from the Chinese University of Hong Kong was the most active researcher. Our overlay visualization map showed that the keywords such as pain, knee osteoarthritis, apoptosis, chondrocytes, cartilage, and autophagy, which link to osteoarthritis, have becoming the new research trends and hotspots. LIPUS is a popular and increasingly important area of orthopedic rehabilitation, and collaboration of authors from different countries should be further strengthened. Predictably, clinical application of LIPUS on chronic inflammation-related diseases and regenerative medicine, and in-depth biological mechanisms are the orientations of LIPUS in orthopedic rehabilitation treatment.

Low-intensity pulsed ultrasound phonophoresis with diclofenac alleviated inflammation and pain via downregulation of M1 macrophages in rats with carrageenan-induced knee joint arthritis

ObjectiveThis study aimed to investigate the effects of low-intensity pulsed ultrasound (LIPUS) phonophoresis with diclofenac on inflammation and pain in the acute phase of carrageenan-induced arthritis in rats. Design60 male Wistar rats were randomly divided into the arthritis, diclofenac, LIPUS, phonophoresis, and sham-arthritis control groups. LIPUS and transdermal diclofenac gel were applied to the lateral side of the inflamed knee for 7 days, initiated postinjection day 1. In the phonophoresis group, diclofenac gel was rubbed onto the skin, followed by LIPUS application over the medication. Knee joint transverse diameters, pressure pain thresholds (PPTs), and paw withdrawal thresholds (PWT) were evaluated. The number of CD68-, CD11c-, and CD206-positive cells, and IL-1β and COX-2 mRNA expression were analyzed 8 days after injection. ResultsIn the phonophoresis group, the transverse diameter, PPT, PWT significantly recovered at the day 8 compared to those in the LIPUS and diclofenac groups. The number of CD68- and CD11c-positive cells in the phonophoresis group was significantly lower than that in the LIPUS and diclofenac groups, but no significant differences were observed among three groups in CD206-positive cells. IL-1β and COX-2 mRNA levels were lower in the phonophoresis group than in the arthritis group, although there were no differences among the LIPUS, diclofenac, and phonophoresis groups. ConclusionLIPUS phonophoresis with diclofenac is more effective to ameliorate inflammation and pain compared to diclofenac or LIPUS alone, and the mechanism involves the decrease of M1 macrophages.

Evaluation of Low-Intensity Pulsed Ultrasound on Stress Fractures to Reduce the Time to Return to Sport or Activity in the Physically Active Population: A Systematic Review.

Stress fractures are a common and significant source of pain and burden that can require long periods of rest from physical activity to allow adequate healing. Specifically in athletes or those with physically demanding occupations, the prolonged period of rest and the potential for requiring surgical intervention in the case of poor or delayed healing can have devastating impacts on these individuals' careers and socioeconomic well-being. In this population, successful healing, in addition to a quicker healing time and a sooner return to activity, are important outcomes when faced with treating stress fractures. The use of low-intensity pulsed ultrasound (LIPUS) to accelerate bone healing has been a topic of investigation, though little research has explored the use of LIPUS specifically in the physically active population. The purpose of this study was to review the existing literature on the use of LIPUS for stress fracture healing in the physically active population with the outcome of a quicker return to sport or physical duties. The PubMed and Embase databases were screened for relevant articles using defined Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Two independent researchers screened articles using PICOS criteria for inclusion in the review. Data were independently extracted regarding study and population characteristics as well as outcome measures, including time to healing of fractures and time to return to sport or physical activity. Five studies were ultimately included in the systematic review. One study investigated the use of LIPUS in pediatric athletes with spondylolysis, while four studies investigated lower extremity stress fractures in adult populations. All reported the outcomes of either rate or time to healing and ability to return to sport or activity. One study found a statistically significant improvement in the rate of bone union in the intervention group undergoing LIPUS compared to the control. Two studies found a statistically significant decrease in the time to resolution of symptoms, allowing an earlier return to sport or physical duties. Two studies found no difference in the time to healing or success rate of healing between the LIPUS group and the control group. This review of the literature suggests that the use of LIPUS for the treatment of stress fractures in the athletic or physically active population has the potential to expedite the resolution of symptoms and return to activity. Due to the heterogeneity of the existing studies, more research is needed to definitively determine the most appropriate clinical application of LIPUS and its most effective ultrasound settings. Further research should be directed toward more controlled studies specifically investigating the athletic and physically active population.

Protective effects of low-intensity pulsed ultrasound (LIPUS) against cerebral ischemic stroke in mice by promoting brain vascular remodeling via the inhibition of ROCK1/p-MLC2 signaling pathway.

Vascular remodeling is essential for patients with cerebral ischemic stroke (CIS). Our previous study proved that low-intensity pulsed ultrasound (LIPUS) could increase cortical hemodynamics. However, the effects and mechanisms of LIPUS on cerebral vascular remodeling after CIS are still unknown. In this study, we applied LIPUS to the mouse brain at 0.5h after distal middle cerebral artery occlusion (dMCAO) and subsequently daily for a stimulation time of 30min. Results showed that compared with the dMCAO group, LIPUS markedly increased cerebral blood flow (CBF), reduced brain swelling, and improved functional recovery at day 3 after CIS. LIPUS promoted leptomeningeal vasculature remodeling, enlarged vascular diameter, and increased the average vessel length and density at day 3 after CIS. Proteomic analysis highlighted that LIPUS mainly participated in the regulation of actin cytoskeleton pathway. Rho kinase 1 (ROCK1) was downregulated by LIPUS and participated in regulation of actin cytoskeleton. Subsequently, we verified that ROCK1 was mainly expressed in pericytes. Furthermore, we demonstrated that LIPUS inhibited ROCK1/p-MLC2 signaling pathway after CIS, which had positive effects on vascular remodeling and cerebral blood circulation. In conclusion, our preliminary study revealed the vascular remodeling effects and mechanism of LIPUS in CIS, provided evidence for potential clinical application of LIPUS.

Therapeutic Myogenesis Induced by Ultrasound Exposure in a Volumetric Skeletal Muscle Loss Injury Model

Background: Low-intensity pulsed ultrasound (LIPUS) irradiation has been shown to induce various responses in different cells. It has been shown that LIPUS activates extracellular signal–regulated kinase 1/2 (ERK1/2) through integrin. Purpose: To study the effects of LIPUS on myogenic regulatory factors and other related myogenesis elements in a volumetric skeletal muscle loss injury model. Study Design: Controlled laboratory study. Methods: C57BL/6J mice were subjected to full-thickness muscle defect injury of the quadriceps and treated with direct application of LIPUS 20 min/d or non-LIPUS treatment (control) for 3, 7, and 14 days. LIPUS was also applied to C2C12 cells in culture in the presence of low and high doses of lipopolysaccharides. The expression levels of myogenic regulatory factors and the expression levels of myokine-related and angiogenic-related proteins of the control and LIPUS groups were analyzed. Results: Muscle volume in the injury site was restored at day 14 with LIPUS treatment. Paired-box protein 7, myogenic factor 5, myogenin, and desmin expressions were significantly different between control and LIPUS groups at days 7 and 14. Myokine and angiogenic cytokine-related factors were significantly increased in the LIPUS group at day 3 and decreased with no significant difference between the groups by day 14. LIPUS induced different responses of myogenic regulatory factors in C2C12 cells with low and high doses of lipopolysaccharides. LIPUS promoted myogenesis through short-lived increase in interleukin-6 and heme oxygenase 1, together with activation of ERK1/2. Conclusion: LIPUS had a constant effect on the variables of tissue damage, from macrotrauma to microtrauma, leading to efficient muscle regeneration. Clinical Relevance: The focus of therapeutic strategies with LIPUS has been not only for microvascular regeneration but also for skeletal muscle and related local tissue recovery from acute or chronic damage.

Knowledge mapping and global trends in the field of low-intensity pulsed ultrasound and endocrine and metabolic diseases: a bibliometric and visual analysis from 2012 to 2022.

Low-intensity pulsed ultrasound (LIPUS) is a highly promising therapeutic method that has been widely used in rehabilitation, orthopedics, dentistry, urology, gynecology, and other multidisciplinary disease diagnoses and treatments. It has attracted extensive attention worldwide. However, there is currently a lack of comprehensive and systematic research on the current status and future development direction of the LIPUS field. Therefore, this study comprehensively analyzed LIPUS-related reports from the past decade using bibliometrics methods, and further conducted research specifically focusing on its application in endocrine and metabolic diseases. We downloaded LIPUS literature from 2012 to 2022 reported in the Web of Science Core Collection Science Citation Index-Expanded and Social Sciences Citation Index, and used bibliometric analysis software such as VOSviewer and CiteSpace to execute the analysis and visualize the results. We searched for 655 English articles published on LIPUS from 2012 to 2022. China had the highest number of published articles and collaborations between China and the United States were the closest in this field. Chongqing Medical University was the institution with the highest output, and ULTRASOUND IN MEDICINE AND BIOLOGY was the journal with the most related publications. In recent years, research on the molecular mechanisms of LIPUS has continued to deepen, and its clinical applications have also continued to expand. The application of LIPUS in major diseases such as oxidative stress, regeneration mechanism, and cancer is considered to be a future research direction, especially in the field of endocrinology and metabolism, where it has broad application value. Global research on LIPUS is expected to continue to increase, and future research will focus on its mechanisms of action and clinical applications. This study comprehensively summarizes the current development status and global trends in the field of LIPUS, and its research progress in the field of endocrine and metabolic diseases, providing valuable reference for future research in this field.

Low-intensity pulsed ultrasound in obstetrics and gynecology: advances in clinical application and research progress.

In the past decade, research on ultrasound therapy in obstetrics and gynecology has rapidly developed. Currently, high-intensity ultrasound has been widely used in clinical practice, while low-intensity ultrasound has gradually emerged as a new trend of transitioning from pre-clinical research to clinical applications. Low-intensity pulsed ultrasound (LIPUS), characterized by a non-invasive low-intensity pulse wave stimulation method, employs its non-thermal effects to achieve safe, economical, and convenient therapeutic outcomes. LIPUS converts into biochemical signals within cells through pathways such as cavitation, acoustic flow, and mechanical stimulation, regulating molecular biological mechanisms and exerting various biological effects. The molecular biology mechanisms underlying the application of LIPUS in obstetrics and gynecology mainly include signaling pathways, key gene expression, angiogenesis, inflammation inhibition, and stem cell differentiation. LIPUS plays a positive role in promoting soft tissue regeneration, bone regeneration, nerve regulation, and changes in cell membrane permeability. LIPUS can improve the treatment benefit of premature ovarian failure, pelvic floor dysfunction, nerve damage caused by intrauterine growth restriction, ovariectomized osteoporosis, and incomplete uterine involution through the above biological effects, and it also has application value in the adjuvant treatment of malignant tumors such as ovarian cancer and cervical cancer. This study outlines the biological mechanisms and applications of LIPUS in treating various obstetric and gynecologic diseases, aiming to promote its precise application and provide a theoretical basis for its use in the field.

Therapeutic ultrasound treatment for the prevention of chronic kidney disease-associated muscle wasting in mice

Low-intensity pulsed ultrasound (LIPUS) is a kind of therapeutic ultrasound. It can help improve bone fracture repair and soft tissue healing. Our previous study found that LIPUS treatment could halt the chronic kidney disease (CKD) progression in mice; unexpectedly, we observed the improvement of CKD-reduced muscle weights by LIPUS treatment. Here, we further tested the protective potential of LIPUS on CKD-associated muscle wasting/sarcopenia using the CKD mouse models. Mouse models of both unilateral renal ischemia/reperfusion injury (IRI) with nephrectomy and adenine administration were used to induce CKD. LIPUS with condition of 3 MHz, 100 mW/cm2, 20 min/day was applied to the kidney of CKD mice. LIPUS treatment significantly reversed the increased serum BUN/creatinine levels in CKD mice. LIPUS effectively prevented the decrease in grip strength, muscle weight (soleus, tibialis anterior, and gastrocnemius muscles), cross-section areas of muscle fibres, and muscular phosphorylated Akt protein expression by immunohistochemistry, and the increase in muscular atrogenes Atrogin1 and MuRF1 protein expression by immunohistochemistry in CKD mice. These results indicated that LIPUS could help improve weak muscle strength, muscle mass loss, muscle atrophy-related protein expression, and Akt inactivation. LIPUS application may be an alternative non-invasive therapeutic intervention on the management of CKD-associated muscle wasting.

Transabdominal ultrasound alleviates LPS-induced neuroinflammation by modulation of TLR4/NF-κB signaling and tight junction protein expression

AimInflammatory bowel disease (IBD) may be a risk factor in the development of brain inflammation. It has been demonstrated noninvasive neuromodulation through sub-organ ultrasound stimulation. The purpose of this study was to investigate whether abdominal low-intensity pulsed ultrasound (LIPUS) alleviates lipopolysaccharide (LPS)-induced cortical inflammation via inhibition of colonic inflammation. Materials and methodsColonic and cortical inflammation was induced in mice by LPS (0.75 mg/kg, i.p. injection) for 7 days, followed by application of LIPUS (0.5 and 1.0 W/cm2) to the abdominal area for 6 days. Biological samples were collected for Western blot analysis, gelatin zymography, colon length measurement, and histological evaluation. Key findingsLIPUS treatment significantly attenuated LPS-induced increases in IL-6, IL-1β, COX-2, and cleaved caspase-3 expression in the colon and cortex of mice. Moreover, LIPUS significantly increased the levels of tight junction proteins in the epithelial barrier in the mouse colon and cortex with LPS-induced inflammation. Compared to the group treated only with LPS, the LIPUS-treated groups showed decreased muscle thickness and increased crypt length and colon length. Furthermore, LIPUS treatment reduced inflammation by inhibiting the LPS-induced activation of TLR4/NF-κB inflammatory signaling in the brain. SignificanceWe found that LIPUS alleviated LPS-induced colonic and cortical inflammation through abdominal stimulation of mice. These results suggest that abdominal LIPUS stimulation may be a novel therapeutic strategy against neuroinflammation via enhancement of tight junction protein levels and inhibition of inflammatory responses in the colon.

Low-Intensity Pulsed Ultrasound Attenuates Periodontal Ligament Cells Apoptosis by Activating Yes-Associated Protein-Regulated Autophagy

The goal of the work described here was to determine if low-intensity pulsed ultrasound (LIPUS) has an anti-inflammatory effect on lipopolysaccharide (LPS)-induced inflammation in periodontal ligament cells (PDLCs). The mechanism underlying this effect remains to be explored and is likely related to PDLC apoptosis regulated by Yes-associated protein (YAP) and autophagy. To verify this hypothesis, we used a rat model of periodontitis and primary human PDLCs. We examined alveolar bone resorption in rats and apoptosis, autophagy and YAP activity in LPS-treated PDLCs with and without application of LIPUS by cellular immunofluorescence, transmission electron microscopy and Western blotting. Then, siRNA transfection was used to decrease YAP expression to confirm the regulatory role of YAP in the anti-apoptotic effect of LIPUS on PDLCs. We found that LIPUS attenuated alveolar bone resorption in rats and this was accompanied by YAP activation. LIPUS inhibited hPDLC apoptosis by YAP activation, and promoted autophagic degradation to help autophagy completion. These effects were reversed after YAP expression was blocked. LIPUS attenuates PDLC apoptosis by activating Yes-associated protein-regulated autophagy.

Effects of Low-Intensity Pulsed Ultrasound in Tendon Injuries.

Tendon injuries are the most common soft tissue injuries, caused by tissue overuse and age-related degeneration. However, the tendon repair process is slow and inefficient due to the lack of cellular structure and blood vessels in the tendon. Low-intensity pulsed ultrasound (LIPUS) has received increasing attention as a non-invasive, simple, and safe way to promote tendon healing. This review summarizes the effects and underlying mechanisms of LIPUS on tendon injury by comprehensively examining the published literature, including in vitro, in vivo, and clinical studies. This review reviewed 24 studies, with 87.5% showing improvement. The application of LIPUS in tendon diseases is a promising field worthy of further study.

Application of low-intensity pulsed ultrasound on tissue resident stem cells: Potential for ophthalmic diseases.

Tissue-resident stem cells (TRSCs) have the ability to self-renew and differentiate throughout an individual's lifespan, and they utilize both mechanisms to maintain homeostasis and regenerate damaged tissues. Several studies suggest that these stem cells can serve as a potential source for cell-replacement-based therapy by promoting differentiation or expansion. In recent years, low-intensity pulsed ultrasound (LIPUS) has been demonstrated to effectively stimulate stem cell proliferation and differentiation, promote tissue regeneration, and inhibit inflammatory responses. To present a comprehensive overview of current application and mechanism of LIPUS on tissue resident stem cells. We searched PubMed, Web of Science for articles on the effects of LIPUS on tissue resident stem cells and its application. The LIPUS could modulate cellular activities such as cell viability, proliferation and differentiation of tissue resident stem cells and related cells through various cellular signaling pathways. Currently, LIPUS, as the main therapeutic ultrasound, is being widely used in the treatment of preclinical and clinical diseases. The stem cell research is the hot topic in the biological science, while in recent years, increasing evidence has shown that TRSCs are good targets for LIPUS-regulated regenerative medicine. LIPUS may be a novel and valuable therapeutic approach for the treatment of ophthalmic diseases. How to further improve its efficiency and accuracy, as well as the biological mechanism therein, will be the focus of future research.

Therapeutic Ultrasound Halts Progression of Chronic Kidney Disease In Vivo via the Regulation of Markers Associated with Renal Epithelial-Mesenchymal Transition and Senescence.

Low-intensity pulsed ultrasound (LIPUS), a therapeutic type of ultrasound, is known to enhance bone fracture repair processes and help some tissues to heal. Here, we investigated the therapeutic potential of LIPUS for the treatment of chronic kidney disease (CKD) in two CKD mouse models. CKD mice were induced using both unilateral renal ischemia/reperfusion injury (IRI) with nephrectomy and adenine administration. The left kidneys of the CKD mice were treated using LIPUS with the parameters of 3 MHz, 100 mW/cm2, and 20 min/day, based on the preliminary experiments. The mice were euthanized 14 days after IRI or 28 days after the end of adenine administration. LIPUS treatment effectively alleviated the decreases in the body weight and albumin/globulin ratio and the increases in the serum renal functional markers, fibroblast growth factor-23, renal pathological changes, and renal fibrosis in the CKD mice. The parameters for epithelial-mesenchymal transition (EMT), senescence-related signal induction, and the inhibition of α-Klotho and endogenous antioxidant enzyme protein expression in the kidneys of the CKD mice were also significantly alleviated by LIPUS. These results suggest that LIPUS treatment reduces CKD progression through the inhibition of EMT and senescence-related signals. The application of LIPUS may be an alternative non-invasive therapeutic intervention for CKD therapy.

Low-intensity pulsed ultrasound partially reversed the deleterious effects of a severe spinal cord injury-induced bone loss and osteoporotic fracture healing in paraplegic rats.

To evaluate the effects of low-intensity pulsed ultrasound (LIPUS) on the quality of femoral fracture callus formation in rats with severe osteoporosis secondary to spinal cord injury (SCI). Forty-five male rats were equally divided into three groups: the Sham group underwent sham surgery for SCI followed by surgery for femoral fracture on day ten post-spine surgery; the SCI group sustained a complete transection of the spinal cord and a femoral fracture ten days post-SCI; and the SCI group treated with ultrasound (SCI + US), which also sustained a femoral fracture on day ten post-SCI, concomitant with daily application of LIPUS at the fracture site. At the non-fractured tibias, LIPUS counteracted the SCI-induced bone loss by normalizing the osteoblastic-related gene expression, decreasing resorptive area, increasing trabecular area, and decreasing RANK and RANK-L-positive areas, which resulted in higher cortical volume and stronger tibias. Likewise, LIPUS was effective at restoring bone fracture healing in SCI rats; by promoting endochondral ossification, increasing collagen deposition and OPG-positive-area, decreasing resorptive area, which led to higher density and improved microarchitecture, ultimately resulting in stronger fracture callus. At the tibias, LIPUS counteracted the SCI-induced bone loss effects by simultaneously increasing bone formation and decreasing bone resorption. We also evidenced the osteogenic effects of LIPUS at partially restoring the endochondral ossification during callus formation, leading to a newly formed tissue with improved microarchitecture and mechanical integrity. Therefore, LIPUS may be an efficient and non-invasive approach to prevent bone loss and osteoporotic fracture in SCI individuals.

Effectiveness and Mechanisms of Low-Intensity Pulsed Ultrasound on Osseointegration of Dental Implants and Biological Functions of Bone Marrow Mesenchymal Stem Cells.

Dental implant restoration is the preferred choice for patients with dentition defects or edentulous patients, and obtaining stable osseointegration is the determining factor for successful implant healing. The risk of implant failure during the healing stage is still an urgent problem in clinical practice due to differences in bone quality at different implant sites and the impact of some systemic diseases on bone tissue metabolism. Low-intensity pulsed ultrasound (LIPUS) is a noninvasive physical intervention method widely recognized in the treatment of bone fracture and joint damage repair. Moreover, many studies indicated that LIPUS could effectively promote the osseointegration of dental implants and improve the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). This review is aimed at investigating the research progress on the use of LIPUS in dental implant medicine from three aspects: (1) discuss the promoting effects of LIPUS on osseointegration and peri-implant bone regeneration, (2) summarize the effects and associated mechanisms of LIPUS on the biological functions of BMSCs, and (3) introduce the application and prospects of LIPUS in the clinical work of dental implantation. Although many challenges need to be overcome in the future, LIPUS is bound to be an efficient and convenient therapeutic method to improve the dental implantation success rate and expand clinical implant indications.

Low-intensity pulsed ultrasound promotes periodontal regeneration in a beagle model of furcation involvement.

Objective: To evaluate the regeneration potential of periodontitis tissue treated by low-intensity pulsed ultrasound (LIPUS) combined with the guided tissue regeneration (GTR) technique in a beagle model of furcation involvement (FI). Background: Achieving predictable regeneration remains a clinical challenge for periodontitis tissue due to the compromised regenerative potential caused by chronic inflammation stimulation. LIPUS, an FDA-approved therapy for long bone fracture and non-unions, has been demonstrated effective in the in vitro attenuation of inflammation-induced dysfunction of periodontal ligament stem cells (PDLSCs), the key cells contributing to periodontal regeneration. However, the in vivo effect of LIPUS on periodontitis tissue is rarely reported. Methods: A beagle model of FI was established, and the experimental teeth were randomly assigned into three groups: control group, GTR group, and GTR+LIPUS group. Radiographic examinations were performed, and clinical periodontal parameters were recorded to reflect the periodontal condition of different groups. Histological analyses using H&E and Masson’s staining were conducted to evaluate the periodontal tissue regeneration. Results: LIPUS could enhance new periodontal bone formation and bone matrix maturity in FI after GTR treatment. Moreover, clinical assessment and histomorphometric analyses revealed less inflammatory infiltration and superior vascularization within bone grafts in the LIPUS treatment group, indicating the anti-inflammatory and pro-angiogenic effects of LIPUS in FI. Conclusion: Our investigation on a large animal model demonstrated that LIPUS is a promising adjunctive approach for the regeneration of periodontitis tissue, paving a new avenue for LIPUS application in the field of periodontal regenerative medicine.

Enhanced Bone Regeneration by Bone Morphogenetic Protein-2 after Pretreatment with Low-Intensity Pulsed Ultrasound in Distraction Osteogenesis.

Bone morphogenetic protein 2 (BMP-2) and low-intensity pulsed ultrasound (LIPUS) have been used to enhance bone healing in distraction osteogenesis (DO). The aim of this study was to assess the synergistic effect of BMP-2 and LIPUS on bone regeneration in DO and to determine the optimal treatment strategy for enhanced bone regeneration. Rat mesenchymal stromal cells were treated with various application protocols of BMP-2 and LIPUS, and cell proliferation, alkaline phosphatase activity, and osteogenesis-related marker expression were evaluated. In vivo experiments were performed in a rabbit DO model according to the application protocols with different timings of BMP-2 and LIPUS application. Application of BMP-2 after LIPUS pretreatment (BMP-2 after LIPUS) showed greater cell proliferation than LIPUS treatment alone, and higher ALP activity than all other treatment protocols. BMP-2 after LIPUS also exhibited increased gene expression levels of ALP, Cbfa1, and Osterix compared with LIPUS treatment alone. In vivo experiments revealed no significant differences in bone healing based on the timing of LIPUS treatment in DO. The combination of BMP-2 and LIPUS resulted in increased bone volume and bone mineral density compared with BMP-2 or LIPUS. Regarding the timing of BMP-2 application, the application of BMP-2 after LIPUS pretreatment led to greater bone volume than the application of BMP-2 before LIPUS. The results of this study suggest that the combined treatment of BMP-2 and LIPUS can lead to enhanced bone healing in DO and that effective bone healing can be achieved through the application of LIPUS before BMP-2.

Pulsed ultrasound for bone regeneration - outcomes and hurdles in the clinical application: a systematic review.

Impaired bone-fracture healing is associated with long-term musculoskeletal disability, pain and psychological distress. Low-intensity pulsed ultrasound (LIPUS) is a non-invasive and side-effect-free treatment option for fresh, delayed- and non-union bone fractures, which has been used in patients since the early 1990s. Several clinical studies, however, have questioned the usefulness of the LIPUS treatment for the regeneration of long bones, including those with a compromised healing. This systematic review addresses the hurdles that the clinical application of LIPUS encounters. Low patient compliance might disguise the effects of the LIPUS therapy, as observed in several studies. Furthermore, large discrepancies in results, showing profound LIPUS effects in regeneration of small-animal bones in comparison to the clinical studies, could be caused by the suboptimal parameters of the clinical set-up. This raises the question of whether the so-called "acoustic dose" requires a thorough characterisation to reveal the mechanisms of the therapy. The adequate definition of the acoustic dose is especially important in the elderly population and patients with underlying medical conditions, where distinct biological signatures lead to a delayed regeneration. Non-industry-funded, randomised, double-blind, placebo-controlled clinical trials of the LIPUS application alone and as an adjuvant treatment for bones with complicated healing, where consistent control of patient compliance is ensured, are required.

Low-intensity pulsed ultrasound induces metabolic lipolysis of adipocytes

We used low-intensity pulsed ultrasound (LIPUS) to uncover underlying lipolysis mechanism of 3T3-L1 adipocyte. Ultrasound pulses with the center frequency of 2 MHz were applied for 10 min/day to promote the lipolysis of white adipocyte. Lipolysis is the process of breaking down lipids and the metabolic pathway through which lipid triglycerides are hydrolyzed into a glycerol and three fatty acids. The proliferation of 3T3-L1 adipocytes was detected by cell viability XXT assay, RT-PCR and Western blot. The Triglyceride Assay quantitatively measures triglycerides levels in differentiated adipocytes. LIPUS reduced the triglycerol content significantly in adipocytes. The differences between transcriptional genes and metabolites were analyzed by transcript analysis and metabolomic profiling experiments. The results of RT-PCR, and Western blot after LIPUS showed the increased lipolysis. The expression of genes related to lipolysis-related factors, ATGLand HSL, was up-regulated. In addition, cellular RNA-sequencing (RNA-Seq) showed an increase in lipolysis and adaptive immune cells under ultrasound stimulation. The algorithm and additional analysis reveals a gene network that is predicted to be associated and potentially drive adipocyte lipolysis and heterogeneity. LIPUS can promote the lipolytic capacity of 3T3-L1 cells in the differentiated state. This study provides an important experimental and theoretical basis for the clinical application of LIPUS in promoting the lipolysis of 3T3-L1 adipocytes.