In vivo effect of platelet gel on human tendon and ligament healing: A narrative review

Tendon and ligament injuries remain a significant challenge for clinicians, despite considerable efforts to develop effective treatment methods. This study reviewed in vivo human studies investigating the use of platelet gel, a blood-derived biomaterial that enhances tissue healing, for treating tendon and ligament injuries. Only eight relevant articles were identified, highlighting the limited number of available studies on this topic. Of these eight articles, three reported significant positive treatment effects, two found no significant benefit, and three observed varying degrees of improvement, although not always statistically significant. Overall, six of the eight studies indicated positive effects of platelet gel based on clinical and radiographic outcomes, suggesting its potential as a promising treatment. Further clinical studies are required to confirm its efficacy and establish its role in tendon and ligament healing.

Low-frequency ultrasound alleviates pulmonary inflammation induced by Klebsiella pneumoniae in mice by inhibiting the TNFR1/NF-κB pathway

BACKGROUND

Therapeutic ultrasound has been found to promote tissue healing and reduce inflammation in non-infectious diseases, but its efficacy in infectious inflammation remains unclear. Here, we employ the mice pneumonia model to explore the anti-inflammatory effects of low-frequency ultrasound (LFU) and elucidate its potential molecular mechanisms.

METHODS

Pneumonia in mice was induced by intratracheal instillation of 100 μL of a 4.5 × 108 CFU/mL Klebsiella pneumoniae (Kp) bacterial suspension. A single LFU treatment (29.36 kHz, 270 mW/cm2, 10 min) was applied to the chest of mice at 6 or 48 h after infection. Biological samples were collected for gene, protein, and cellular experiments.

RESULTS

LFU demonstrated good anti-inflammatory effects in mice during the recovery phase of Kp infection (48 h after infection). Although LFU alone had no bactericidal effects, it slightly reduced the pathological score of lung injury and significantly decreased the infiltration of CD45+ leukocytes. Additionally, the protein levels of TNF-α, GM-CSF and COX-2 in the bronchoalveolar lavage fluid were significantly reduced. Bulk RNA-sequencing results showed that the TNF receptor (TNFR)/NF-κB pathway was up-regulated after Kp infection, which was suppressed after LFU treatment. Western blot and immunofluorescence revealed LFU significantly reduced the protein levels of TNFR1, p-p65, and nuclear p65. The anti-inflammatory effect of LFU was comparable to a 20 mg/kg NF-κB inhibitor and superior to a 15 mg/kg TNFR antagonist.

CONCLUSION

LFU exerts anti-inflammatory effects by inhibiting the TNFR1/NF-κB pathway during the recovery period of Kp infection, reducing inflammatory transcription and thereby decreasing the release of inflammatory factors.

Therapeutic Effects of Different Ultrasound Intensity Stimulation on Brown Adipose Tissue for the Treatment of Type 2 Diabetes

Type 2 diabetes (T2D) is a persistent illness that has a high incidence rate. Still, there is no conclusive evidence on effectively improving blood sugar levels in patients through physical therapy. This study examined the regulatory effects of different intensities of low-intensity pulsed ultrasound (LIPUS) on T2D by stimulating brown adipose tissue (BAT). Eight-week-old C57BL/6J mice were divided into six groups (n = 10 per group): Control sham (C-Sham), Control-LIPUS (C-LIPUS), T2D-sham (T2D-Sham), T2D groups treated with LIPUS at spatial average-temporal-average intensity (Isata) of 60mW/cm² (T2D-L-60), 80mW/cm² (T2D-L-80), and 100mW/cm² (T2D-L-100). T2D models were induced by intraperitoneal injection of 40 mg/kg streptozotocin (STZ) three times after 12 wks of high-fat diet (HFD). The T2D-LIPUS group received LIPUS stimulation for 20 minutes per day for 6 weeks. The LIPUS stimulation had a duty cycle of 20%, a frequency of 1 MHz, and Isata of 60mW/cm², 80mW/cm², 100mW/cm². Subsequently, glucose tolerance tests (GTT) and insulin tolerance tests (ITT) were performed, and body fat content in mice was analyzed using nuclear magnetic resonance (NMR). Metabolic changes were monitored using metabolic cages. The results indicated that 80mW/cm² intensity level significantly improved glucose tolerance, insulin sensitivity, and metabolic function after LIPUS exposure. Significant reductions in body fat content and enhanced thermogenesis were observed, highlighting the potential of LIPUS in T2D management. This provides the basis for the dose study of LIPUS in the treatment of T2D.

Low-intensity pulsed ultrasound affects proliferation and migration of human hepatocellular carcinoma cells

PURPOSE

Low-intensity pulsed ultrasound (LIPUS) is an effective ancillary treatment modality for various malignancies. However, the mechanisms underlying the role of LIPUS in cancer treatment have not been fully elucidated. We investigated the effects and underlying mechanism of LIPUS on the proliferation, apoptosis, migration, and invasion of hepatocellular carcinoma (HCC) cells.

METHODS

The HCC cell lines SMMC7721 and HCCLM3 were exposed to 1 MHz LIPUS at intensities of 0.5, 1.0, 1.5 W/cm2 for 60 s. Cell morphology, viability, apoptosis, colony formation, migration, and invasion were assessed. Intracellular reactive oxygen species (ROS) levels and mitochondrial membrane potential were evaluated using a ROS assay kit and a JC-1 staining kit. Western blotting was performed to quantify changes in matrix metallopeptidases and epithelial-mesenchymal transition-related proteins. Orthotopic Hep3B-Luc tumor-bearing mice were treated with LIPUS at 1.5 W/cm2 or 0 W/cm2 and growth trend was measured.

RESULTS

The results showed that different intensities of ultrasound affected cellular activity, inhibited cell proliferation and cloning, facilitated intracellular cytoskeletal protein reorganization, and induced cell apoptosis, particularly at the intensity of 1.5 W/cm2, through the ROS/mitochondria pathway. LIPUS enhanced SMCC7721 and HCCLM3 cell migration and invasion in a dose-dependent manner by regulating matrix metallopeptidases and epithelial-mesenchymal transition-related proteins. In vivo experiments confirmed the inhibitory effect of LIPUS at 1.5 W/cm2 on tumor growth.

CONCLUSIONS

Although LIPUS induced cell apoptosis and inhibited cell proliferation, it also promoted the invasion and metastasis of HCC cells under certain conditions, which was related to the regulation of matrix metallopeptidases and epithelial-mesenchymal transition-related proteins.

Mechanism and Treatment of Right Ventricular Failure Due to Pulmonary Hypertension in Children

Pulmonary hypertension (PH) is a progressive disorder characterized by obstructive changes in the pulmonary vasculature, leading to increased pulmonary vascular resistance (PVR), right ventricular (RV) strain, and eventual RV failure (RVF). Despite advancements in medical therapy, PH remains associated with significant morbidity and mortality, particularly in children. RVF is a clinical syndrome resulting from complex structural and functional remodeling of the right heart, leading to inadequate pulmonary circulation, reduced cardiac output, and elevated venous pressure. Management paradigms for pediatric PH diverge significantly from those in adults, particularly due to the predominance of congenital heart disease (CHD) and the dynamic nature of pediatric cardiovascular and pulmonary development. CHD remains a principal driver of PH in children, and its associated pathophysiology demands a nuanced approach. In patients with unrepaired left-to-right shunts, elevated pulmonary blood flow can lead to progressive pulmonary vascular remodeling and increased PVR. The postoperative persistence or progression of PH may occur if irreversible vascular changes have already developed. Current PH treatments primarily focus on reducing PVR, yet distinguishing between therapeutic approaches that target the pulmonary vasculature and those aimed at improving RV function remain challenging. In pediatric patients with progressive PH despite optimal therapy, additional targeted interventions may be necessary to mitigate RV dysfunction and disease progression. This review provides a comprehensive analysis of the mechanisms underlying RVF in PH, incorporating insights from clinical studies in adults and experimental models, while highlighting the unique considerations in children. Furthermore, it explores current pharmacological and interventional treatment strategies, emphasizing the need for novel therapeutic approaches aimed at directly reversing RV remodeling. Given the complexities of RV adaptation in pediatric PH, further research into disease-modifying treatments and innovative interventions is crucial to improving long-term outcomes in affected children.

Frequency-Regulated Repeated Micro-Vibration Promotes Osteoblast Differentiation Through BMP Signaling in MC3T3-E1 Cells

Physical stimulation, which is a key factor affecting the metabolism of osteoblasts and their precursor cells, plays an important role in bone remodeling; however, the role of micro-vibrations in osteoblast differentiation is unclear. In the present study, we determined the effects of frequency-regulated repeated micro-vibration (FRMV) on cell proliferation and established a method to induce osteoblast differentiation through FRMV using the mouse pre-osteoblast-like cell line MC3T3-E1, which is widely used in bone metabolism research. The results indicated that FRMV significantly influenced the proliferation of MC3T3-E1 cells in a normal growth medium. FRMV at 42.2 Hz significantly promoted proliferation, whereas FRMV at 92.1 Hz showed no effect on the proliferation rate. Moreover, FRMV at 42.2 Hz significantly increased alkaline phosphatase (ALP) enzyme activity and ALP gene expression in MC3T3-E1 cells. Treatment with LDN193189, a bone morphogenetic protein (BMP) signaling inhibitor, revealed that the FRMV-induced upregulation in ALP enzyme activity and ALP gene expression were significantly suppressed in MC3T3-E1 cells. The results suggest that the FRMV protocol developed in the present study induces osteoblast differentiation through the BMP signaling pathway. Thus, FRMV may contribute to the development of effective bone regeneration technologies.

LIPUS Promotes Calcium Oscillation and Enhances Calcium Dependent Autophagy of Chondrocytes to Alleviate Osteoarthritis

Osteoarthritis (OA) is a degenerative disease which places an enormous burden on society, effective treatments are still limited. As a non-invasive and safe physical therapy, low-intensity pulsed ultrasound (LIPUS) can alleviate OA progression, but the underlying mechanism is not fully understood, especially the mechanical transduction between LIPUS and the organism. In this pioneering study, the biomechanical effects of LIPUS on living mice chondrocytes and living body zebrafish are investigate by using fluorescence imaging technology, to dynamically "visualize" its invisible mechanical stimuli in the form of calcium oscillations. It is also confirmed that LIPUS maintains cartilage homeostasis by promoting chondrocyte autophagy in a calcium-dependent manner. In addition, chondrocyte ion channels are screened by scRNA-seq and confirm that the mechanosensitive ion channel transient receptor potential vanilloid 4 (TRPV4) mediated the biological effects of LIPUS on chondrocytes. Finally, it is found that a combination of pharmacologically induced and LIPUS-induced Ca2+ influx in chondrocytes enhances the cartilage-protective effect of LIPUS, which may provide new insights for optimizing LIPUS in the treatment of OA.

Low-intensity pulsed ultrasound elevates blood pressure for shock

Fluid replacement is the primary treatment for life-threatening shock but is challenging in harsh environments. This study explores low-intensity pulsed ultrasound (LIPUS) as a resuscitation strategy. Cervical LIPUS stimulation effectively elevated blood pressure in shocked rats. It also improved cerebral and multiorgan perfusion. Mechanistically, LIPUS activated pathways related to sympathetic nerve excitation and vascular smooth muscle contraction, increasing plasma catecholamines and stimulating blood pressure-regulating neural nuclei. Partial sympathetic nerve transection reduced LIPUS efficacy, while complete inhibition of these nuclei abolished the response. Preliminary clinical trials demonstrated LIPUS's ability to raise blood pressure in shock patients. The findings suggest that LIPUS enhances sympathetic nerve activity and activates blood pressure-regulating nuclei, offering a noninvasive, neuromodulation-based approach to shock treatment. This method holds potential for improving blood pressure and organ perfusion in shock patients, especially in resource-limited environments.

Synergistic Effects of Low-Frequency Ultrasound and Therapeutic Agents on Endothelial and Renal Cells: Emphasis on Cell Functionality, Oxidative Stress, and Inflammatory Markers

Background: Ischemic heart disease remains the leading cause of death worldwide, with coronary microvascular dysfunction (CMD) as a key complication after ST-elevation myocardial infarction (STEMI). Endothelial dysfunction contributes to CMD, impairing vascular tone and increasing inflammation. While angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) aid vascular health, their efficacy may improve with therapeutic ultrasound, which enhances drug delivery and endothelial response. This study explores the combined effects of ultrasound and pharmacological treatment on the ACE axis and inflammation in endothelial and renal cells. Methods: Human umbilical vein endothelial cells (HUVECs) and human renal proximal tubular epithelial cell line RPTEC/TERT1 were treated with captopril, losartan, and dexamethasone, alone or combined with low-frequency ultrasound (LFU). Cell viability and wound-healing assays assessed cellular function, while nitric oxide (NO) and reactive oxygen species (ROS) assays were used to evaluate redox signaling. Gene expression related to the ACE axis, inflammation, and vascular and renal cell function was analyzed via qPCR. Results: Captopril and losartan combined with LFU improved endothelial cell viability, wound healing, and NO production at various concentrations, whereas only losartan with LFU enhanced cell viability and wound healing in renal cells. Dexamethasone with LFU increased ROS levels and had variable effects on RPTEC/TERT1 cell survival. Gene expression analysis showed that LFU alone reduced pro-inflammatory markers VCAM-1, ICAM-1, and PTGS2 in captopril-treated HUVECs and similarly affected CYP4F2 in losartan-treated HUVECs. LFU also decreased PTGS2 expression at higher dexamethasone concentrations. In RPTEC/TERT1 cells, LFU alone did not impact SGLT2 or GGT1 expression, but captopril with LFU downregulated GGT1, and dexamethasone with LFU upregulated SGLT2 at higher concentrations. Conclusions: This study demonstrates that LFU enhances the effects of RAS inhibitors by promoting NO synthesis and reducing oxidative stress, while its combination with dexamethasone may have variable, potentially cytotoxic effects on renal cells. Gene expression patterns suggest LFU's anti-inflammatory potential and its role in modulating drug efficacy.

Overview of Therapeutic Ultrasound Applications and Safety Considerations: 2024 Update

A 2012 review of therapeutic ultrasound was published to educate researchers and physicians on potential applications and concerns for unintended bioeffects (doi: 10.7863/jum.2012.31.4.623). This review serves as an update to the parent article, highlighting advances in therapeutic ultrasound over the past 12 years. In addition to general mechanisms for bioeffects produced by therapeutic ultrasound, current applications, and the pre-clinical and clinical stages are outlined. An overview is provided for image guidance methods to monitor and assess treatment progress. Finally, other topics relevant for the translation of therapeutic ultrasound are discussed, including computational modeling, tissue-mimicking phantoms, and quality assurance protocols.

Low-intensity pulsed ultrasound enhances delivery of 30 nm Q10 for improving mental and memory disorder in APP/PS1 mice

Patients with Alzheimer's disease (AD) often experience mental and memory disorders with poor outcomes. Coenzyme Q10 can degrade formaldehyde (FA) and improve Alzheimer-related symptoms, but its ability to cross the blood-brain barrier (BBB) is limited. This study investigated whether low-intensity pulsed ultrasound (LIPUS) enhances 30 nm Q10 delivery and improve symptoms in AD model mice. Here, 30 nm Q10 was prepared by encapsulating Q10 in liposomes coupled with PEG, creating PEG-Q10@NPs under 30 nm in diameter. Wild-type mice and APPswe/PS1dE9 mice (a familial AD model) received 30 nm Q10 via intraperitoneal injection, or a combination of 30 nm Q10 and LIPUS (50 or 100 100 mW/cm2). Then the mice's anxiety-like and depression-like behaviors and biochemical index were evaluated. We found that the combination therapy of LIPUS at 100 mW/cm2 and 30 nm Q10 was more effective in ameliorating psychosis in AD mice than individual treatments with 30 nm Q10. This effectiveness was linked to higher levels of brain Q10, serotonin (5-HT), and dopamine (DA), along with lower levels of FA and plaques. Especially, excessive FA directly inactivated 5-HT and DA in vitro. The enhanced cellular uptake of Q10 and improved BBB permeability facilitated by LIPUS were confirmed in both cultured cells and wild-type mice. Unexpectedly, LIPUS at the different intensity only partially alleviated anxiety and depression symptoms and memory deficits in AD mice. Hence, this combination therapy of LIPUS and 30 nm Q10 is an innovative strategy for ameliorating mental and cognitive disorders in AD.

Low-intensity pulsed ultrasound promotes proliferation and differentiation of neural stem cells to enhance spinal cord injury recovery

BACKGROUND

Neural stem cells (NSCs) are known for their high capacity for proliferation, self-renewal, and multidirectional differentiation. However, they often fail to survive or differentiate into mature neurons capable of replacing lost neurons. This study evaluated the potential role of low-intensity pulsed ultrasound (LIPUS) in promoting NSC proliferation and differentiation both in vitro and in vivo, as well as its role in enhancing spinal cord injury (SCI) recovery.

METHODS

NSCs were isolated, stimulated with LIPUS, and characterized through identification and detection assays. The safety and efficacy of LIPUS in promoting NSC proliferation and differentiation were assessed through cell viability and apoptosis assays, and neuronal marker expression analysis. In vivo, NSCs encoding fluorescent proteins were transplanted into a rat model of SCI. The SCI rats received LIPUS for 4 weeks. Later, functional recovery, morphological changes and neuronal structures were evaluated.

RESULT

The isolated NSCs were successfully identified. LIPUS significantly enhanced NSC proliferation and increased the expression of key neurogenic markers and neurotrophic factors, while reducing GFAP expression and avoiding apoptosis. In vivo, the NSCs/LIPUS + group demonstrated higher survival and differentiation of transplanted NSCs, along with improved BBB scores and enhanced neural marker expression compared with the NSCs/LIPUS - group.

CONCLUSION

LIPUS stimulation effectively promoted NSC proliferation and differentiation and enhanced the survival and function of transplanted NSCs at the SCI site, leading to improved SCI recovery.

Low-intensity pulsed ultrasound induces multifaced alterations in chromosome segregation, cytoskeletal filaments and cell junctions

Low-intensity pulsed ultrasound (LIPUS) is a widely used non-invasive approach with therapeutic purposes since it provides physical stimulation with minimal thermal effects. The skin epithelium is the first barrier of the human body that interfaces with LIPUS and is subjected to the highest intensity. Little is known about the impact of LIPUS on the skin surface. This work investigates the biological effects of one-hour exposure to 1 MHz LIPUS on human keratinocytes HaCaT and tumoral SK-MEL-28 skin cells. Specifically, we evaluated the cellular state immediately after LIPUS treatment by analyzing cytogenetic endpoints and the response of cytoskeleton and cell junction proteins. Herein we demonstrate that LIPUS induces genomic damage as shown by an increase of chromosome malsegregation and a consequent decrease of cellular proliferation. The mechanical stimulus produced by LIPUS is also transmitted to the cytoskeletal compartment, inducing the expression and re-organization of junction proteins (i.e., E-cadherin and Desmosomes) and intermediate filaments (i.e., F-actin and Cytokeratins) with impact on cell morphology and cell adhesion. These in vitro results highlight the different outcomes following the cytogenetic damage and the resilience response exerted by the cytoskeleton upon mechanical stress, laying the foundation for future in vivo investigations.

Effect of low-intensity pulsed ultrasound on the mineralization of force-treated cementoblasts and orthodontically induced inflammatory root resorption via the Lamin A/C-Yes associated protein axis

AIMS

Orthodontic treatment commonly results in orthodontically induced inflammatory root resorption (OIIRR). This condition arises from excessive orthodontic force, which triggerslocal inflammatory responses and impedes cementoblasts' mineralization capacity. Low-intensity pulsed ultrasound (LIPUS) shows potential in reducing OIIRR. However, the precise mechanisms through which LIPUS reduces OIIRR remain unclear. This study aimed to explore the effects and mechanisms of LIPUS on the mineralization of force-treated cementoblasts and its impact on OIIRR.

METHODS

We established a rat OIIRR model and locally administered LIPUS stimulation for 7 and 14 days. We analyzed root resorption volume, osteoclast differentiation, and the expression of osteocalcin and yes-associated protein 1 (YAP1) using micro-computed tomography (micro-CT), hematoxylin and eosin, tartrate-resistant acid phosphatase, immunofluorescence and immunohistochemistry staining. In vitro, we applied compressive force and LIPUS to the immortalized mouse cementoblasts (OCCM30). We assessed mineralization using alkaline phosphatase (ALP) staining, alizarin red staining, real-time quantitative polymerase chain reaction, Western blotting and immunofluorescence staining.

RESULTS

In rats, LIPUS reduced OIIRR, as evidenced by micro-CT analysis and histological staining. In vitro, LIPUS enhanced mineralization of force-treated OCCM30 cells, as indicated by ALP and alizarin red staining, upregulated mRNA expression of mineralization-related genes, and increased protein expression of mineralization markers. Mechanistically, LIPUS activated YAP1 signaling via the cytoskeleton-Lamin A/C pathway, supported by immunofluorescence and Western blot analysis.

CONCLUSION

This study demonstrates that LIPUS promotes mineralization in force-treated cementoblasts and reduces OIIRR by activating YAP1 through the cytoskeletal-Lamin A/C signaling pathway. These findings provide fresh insights into how LIPUS benefits orthodontic treatment and suggest potential strategies for preventing and treating OIIRR.

Abdominal LIPUS Stimulation Prevents Cognitive Decline in Hind Limb Unloaded Mice by Regulating Gut Microbiota

Weightlessness usually causes disruption of the gut microbiota and impairs cognitive function. There is a close connection between gut microbiota and neurological diseases. Low-intensity pulsed ultrasound (LIPUS) has a beneficial effect on reducing intestinal inflammation. So we wondered if abdominal LIPUS stimulation can have a positive impact on weightlessness induced cognitive decline by reducing intestinal dysfunction. The findings revealed that the hind limb unloaded mice exhibited evident disruption in intestinal structure and gut microbial homeostasis, along with impairment in their learning and memory capabilities. However, 4-week abdominal LIPUS treatment improved intestinal function in hind limb unloaded mice, characterized by upregulation of tight junction proteins ZO-1 and Occludin expression in the colon, increased diversity and abundance of intestinal microbiota, decreased serum lipopolysaccharide (LPS), and increased short chain fatty acids in colon contents. The hind limb unloaded mice treated with LIPUS exhibited heightened activity levels, improved exploratory tendencies, and significantly enhanced learning and memory faculties, and elevated expression of neuroadaptation-related proteins such as PSD95, GAP43, P-CREB, BDNF, and its receptor TRKB in the hippocampus. Furthermore, the hind limb unloaded mice receiving fecal transplants from the mice whose abdomens were irradiated with LIPUS displayed enhanced cognitive abilities and improved intestinal structure, akin to the outcomes observed in hind limb unloaded mice who received LIPUS abdominal treatment directly. The above results indicate that LIPUS enhances intestinal structure and microbiota, which helps alleviate cognitive impairment caused by weightlessness. LIPUS could be a potential strategy to simultaneously improve gut dysfunction and cognitive decline in astronauts or bedridden patients.

Biophysical aspects of mechanotransduction in cells and their physiological/biological implications in vocal fold vibration: a narrative review

Mechanotransduction is a crucial property in all organisms, modulating cellular behaviors in response to external mechanical stimuli. Given the high mobility of vocal folds, it is hypothesized that mechanotransduction significantly contributes to their tissue homeostasis. Recent studies have identified mechanosensitive proteins in vocal fold epithelia, supporting this hypothesis. Voice therapy, which, involves the mobilization of vocal folds, aims to rehabilitate vocal function and restore homeostasis. However, establishing a direct causal link between specific mechanical stimuli and therapeutic benefits is challenging due to the variability in voice therapy techniques. This challenge is further compounded when investigating biological benefits in humans. Vocal fold tissue cannot be biopsied without significant impairment of the vibratory characteristics of the vocal folds. Conversely, studies using vocal fold mimetic bioreactors have demonstrated that mechanical stimulation of vocal fold fibroblasts can lead to highly heterogeneous responses, depending on the nature and parameters of the induced vibration. These responses can either aid or impede vocal fold vibration at the physiological level. Future research is needed to determine the specific mechanical parameters that are biologically beneficial for vocal fold function.

Efficacy and safety of non-focused low-intensity ultrasound technology for subcutaneous lipolysis in the lower abdomen: a clinical study

BACKGROUND

With rising demand for non-invasive body contouring, this study aimed to evaluate the efficacy and safety of non-focused, low-intensity ultrasound for lower abdominal lipolysis.

METHODS

The enrolled subjects prospectively received 6 weekly sessions of well-setting ultrasound treatment with frequency of 1 MHz and an intensity of 2.2 W/cm2, to target the subcutaneous fat of lower abdomen with three regions (left, middle, and right). Evaluations included ultrasound measurements and blood biochemical analyses at the baseline, pre-4th session, and at 1 and 2-month post-treatment points to confirm the efficacy and safety.

RESULTS

A total of 17 subjects completed the whole treatment. Significant reductions in superficial abdominal fat layer thickness of all three regions were observed (all P-values of ANOVA <0.001), without severe adverse events reported. Post-hoc analysis showed the superficial fat layers of all the three regions at 1-month post-treatment significant reductions comparing the baseline (all adjusted P < 0.05). The reduction effects for superficial fat layers were still available at the 2-month post-treatment follow-up at the left and middle regions. Conversely, there was no significant improvements among the deep fat layers at the three regions.

CONCLUSION

Non-focused, low-intensity ultrasound demonstrate its potential of efficacy and safety for reducing superficial abdominal fat, and may maintain the capability for at least two months. Further studies are needed to confirm long-term efficacy and optimize treatment parameters.   What is already known on this topic? Non-focused ultrasound with low-intensity is recognized for its potential in non-invasive body contouring, but detailed efficacy and safety data were limited, especially for lower abdominal lipolysis. What this study adds? Our research demonstrated the efficacy and safety of non-focused ultrasound with low-intensity in reducing superficial abdominal fat, with sustained effects for at least two months. How this study might affect research, practice, or policy? This study could guide future researches toward long-term effects and optimization of ultrasound treatments, and influence clinical practice by providing a validated method for non-invasive fat reduction.

Low-Intensity Pulsed Ultrasound Treatment Selectively Stimulates Senescent Cells to Promote SASP Factors for Immune Cell Recruitment

As emerging therapeutic strategies for aging and age-associated diseases, various biochemical approaches have been developed to selectively remove senescent cells, but how physical stimulus influences senescent cells and its possible application in senolytic therapy has not been reported yet. Here we developed a physical method to selectively stimulate senescent cells via low-intensity pulsed ultrasound (LIPUS) treatment. LIPUS stimulation did not affect the cell cycle, but selectively enhanced secretion of specific cytokines in senescent cells, known as the senescence-associated secretory phenotype (SASP), resulting in enhanced migration of monocytes/macrophages and upregulation of phagocytosis of senescent cells by M1 macrophage. We found that LIPUS stimulation selectively perturbed the cellular membrane structure in senescent cells, which led to activation of the intracellular reactive oxygen species-dependent p38-NF-κB signaling pathway. Using a UV-induced skin aging mouse model, we confirmed enhanced macrophage infiltration followed by reduced senescent cells after LIPUS treatment. Due to the advantages of ultrasound treatment, such as non-invasiveness, deep penetration capability, and easy application in clinical settings, we expect that our method can be applied to treat various senescence-associated diseases or combined with other established biochemical therapies to enhance efficacy.

Low-intensity pulsed ultrasound enhances the osteogenic potential of PDLSCs-derived extracellular vesicles through COMP/PI3K/AKT

The therapeutic potential of extracellular vesicles (EVs) in bone regeneration is noteworthy; however, their clinical application is impeded by low yield and limited efficacy. This study investigated the effect of low-intensity pulsed ultrasound (LIPUS) on the therapeutic efficacy of EVs derived from periodontal ligament stem cells (PDLSCs) and preliminarily explored its mechanism. PDLSCs were cultured with osteogenic media and stimulated with or without LIPUS, and then EVs and LIPUS-stimulated EVs (L-EVs) were isolated separately. We investigated the biological characteristics and effects of these two EVs on cell proliferation, migration, osteogenic differentiation, and bone regeneration in vivo and in vitro, and explored the potential mechanism by analyzing protein profiles. LIPUS significantly stimulated the secretion of PDLSCs-EVs, and L-EVs exhibited stronger efficacy in promoting cell proliferation, migration, and osteogenic differentiation, thereby enhancing new bone formation. LIPUS stimulation affected the protein profile of PDLSCs-EVs, and 42 proteins were upregulated and 4 proteins downregulated in L-EVs when compared with EVs. LIPUS significantly upregulated the level of cartilage oligomeric matrix protein (COMP) in EVs, which enhanced EVs' osteogenic ability via the PI3K/AKT pathway. This study proposes that LIPUS has potential as an optimization method for enhancing the therapeutic effects of EVs in tissue regeneration.

Mechanosensitive Ca2+ channel TRPV1 activated by low-intensity pulsed ultrasound ameliorates acute kidney injury through Notch1-Akt-eNOS signaling

Acute Kidney Injury (AKI) is a significant medical condition characterized by the abrupt decline in kidney function.Low-intensity pulsed ultrasound (LIPUS), a non-invasive therapeutic technique employing low-intensity acoustic wave pulses, has shown promise in promoting tissue repair and regeneration. A novel LIPUS system was developed and evaluated in rat AKI models, focusing on its effects on glomerular filtration rate (GFR), blood urea nitrogen (BUN), serum creatinine (SCr), and the Notch1-Akt-eNOS signaling pathway. The results demonstrated that LIPUS treatment improved GFR, BUN, SCr levels, and renal pathology in AKI rats. In vitro experiments using HUVEC cells revealed that LIPUS stimulation promoted angiogenesis, cell migration mechanically-dependent calcium ion influx, which was partially attenuated by TRPV1 knockdown. RNA sequencing analysis indicated LIPUS-induced activation of the Notch pathway, phosphorylation of Akt and eNOS. Furthermore, inhibition or genetic silencing of Notch1 abolished the beneficial effects of LIPUS on angiogenesis, renal function, and Akt-eNOS phosphorylation in both cells and AKI rats. These findings suggest that LIPUS-induced calcium influx promotes Akt-eNOS phosphorylation, nitric oxide (NO) production, angiogenesis, and improved renal function in AKI via Notch1-Akt-eNOS signaling, positioning LIPUS as a promising therapeutic strategy for AKI by targeting vascular regeneration.

Modulation of GABAergic neurons in acute epilepsy using sonogenetics

Epilepsy, a neurological disorder caused by hypersynchronous neural disturbances, has traditionally been treated with surgery, pharmacotherapy, and neuromodulation techniques such as deep brain stimulation and vagus nerve stimulation. However, these methods are often limited by invasiveness, off-target effects, and poor resolution. We present a noninvasive alternative utilizing sonogenetics to selectively stimulate γ-aminobutyric acid (GABA)ergic neurons in the amygdala through engineered auditory-sensing protein, mPrestin (N7T, N308S), in a pentylenetetrazole-induced rat model. Activation of GABAergic neurons induced by the sonication with 0.5-MHz transcranial ultrasound can modulate epileptiform activity by 50 %. Electrophysiological recordings confirmed effective neuromodulation and persistent seizure suppression up to 60 min post-treatment without tissue damage, inflammation, or apoptosis. This sonogenetic approach offers a promising, safe method for epilepsy management by targeting GABAergic neurons.

The Therapeutic Potential of Low-Intensity Pulsed Ultrasound in Enhancing Gallbladder Function and Reducing Inflammation in Cholesterol Gallstone Disease

BACKGROUND

Cholesterol gallstone disease (CGS) is often accompanied by gallbladder contraction dysfunction and chronic inflammation, but effective therapeutic options remain limited. This study investigates whether a low-intensity pulsed ultrasound (LIPUS) treatment can improve gallbladder motility and alleviate chronic inflammation while exploring the underlying mechanisms.

METHODS

Gallbladder motility was assessed through in vitro and in vivo contraction tests, while bile condition was evaluated by observing bile crystal clearance. Tissue analysis and Western blotting were performed to examine the expression of the cholecystokinin A receptor (CCKAR) and α-smooth muscle actin (α-SMA) as markers of gallbladder smooth muscle health and the inflammatory microenvironment. Blood cholesterol levels were measured via biochemical assays.

RESULTS

LIPUS treatment obviously enhanced gallbladder contractility in response to CCK-8 stimulation and accelerated bile crystal clearance. It also reduced inflammatory cell infiltration and tissue edema, and promoted new capillary formation in the gallbladder, mitigating the progression of CGS. Furthermore, LIPUS restored CCKAR expression and improved the thickness of the gallbladder smooth muscle layer, providing a structural basis for increased smooth muscle contractility.

CONCLUSION

LIPUS improves gallbladder motility and reduces chronic inflammation in CGS by enhancing CCKAR expression and smooth muscle integrity. These findings highlight the potential of LIPUS as a non-invasive therapeutic approach for managing CGS.

LIPUS promotes osteogenic differentiation of rat BMSCs and osseointegration of dental implants by regulating ITGA11 and focal adhesion pathway

BACKGROUND

Low-intensity pulsed ultrasound (LIPUS) has been used as an effective noninvasive method for treating fractures and osteoarthrosis, but the application in the field of oral implantation is in its infancy. This study aimed to clarify the effect and mechanism of LIPUS on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and implant osseointegration, and to provide an experimental basis for future clinical applications.

METHODS

Dental implants were inserted into Wistar rat femurs, and LIPUS was performed for 4 weeks. Micro-CT and toluidine blue staining were used to assess implant osseointegration. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used to identify enriched functional terms and signalling pathways for differentially expressed genes from LIPUS-treated rat BMSC RNAseq data obtained from the GEO database. The random forest method was used to identify key risk genes according to the mean decrease Gini (MDG) coefficient. Then, LIPUS was applied to treat rat BMSCs, and alkaline phosphatase (ALP) staining, alizarin red staining, RT-PCR and western blotting were used to determine whether LIPUS could promote BMSC osteogenic differentiation via integrin α11 (ITGA11) and the focal adhesion pathway.

RESULTS

Our in vivo experimentations verified that LIPUS significantly increased new bone formation and osseointegration around the implant in rats. Bioinformatics analysis of RNA-seq data revealed that the upregulated genes in BMSCs after LIPUS treatment were significantly enriched in osteoblast differentiation-related functions and focal adhesion-related pathways. Random forest analysis revealed that ITGA11 was the most significant factor affecting BMSC osteogenic differentiation among the differentially expressed genes. In addition, LIPUS significantly increased ALP expression and mineralized nodule formation in rat BMSCs by upregulating ITGA11 and increasing the activity of FAK/PI3K/AKT/GSK3β/β-catenin pathway.

CONCLUSIONS

LIPUS can effectively promote implant osseointegration in rats and improve rat BMSC osteogenic differentiation by upregulating ITGA11 and increasing the activity of the downstream focal adhesion pathway.

Low-intensity pulsed ultrasound improves metabolic dysregulation in obese mice by suppressing inflammation and extracellular matrix remodeling

Chronic inflammation in white adipose tissue is crucial in obesity and related metabolic disorders. Low-intensity pulsed ultrasound (LIPUS) is renowned for its anti-inflammatory effects as a non-invasive treatment, yet its precise role in obesity has been uncertain. Our study investigates the therapeutic effect of LIPUS and its underlying mechanism on obesity in mice, thereby offering a novel approach for non-invasive treatment of obesity and associated metabolic disorders for human. Male C57BL/6J mice aged 10 weeks were fed a high-fat diet (HFD) for 8 weeks to establish obesity model, then underwent 8 weeks of LIPUS (frequency: 1.0 MHz, duty cycle: 20 %, Isata: 58-61 mW/cm2, 20 min per day) stimulation of the epididymal white adipose tissue. Fat and lean mass were measured using nuclear magnetic resonance (NMR), while energy homeostasis was evaluated using metabolic cages. Insulin resistance was assessed using glucose tolerance tests (GTT) and insulin tolerance tests (ITT). Regulatory mechanisms were explored using RNA sequencing. Results showed that LIPUS significantly reduced obesity markers in obese mice, including body and adipose tissue weight, and improved insulin resistance, without affecting food intake. RNA sequencing showed 250 up-regulated and 351 down-regulated genes between HFD-LIPUS group and HFD-Sham group, suggesting anti-inflammatory action. Quantitative PCR confirmed reduced pro-inflammatory gene expression and macrophage infiltration in eWAT. Gene set enrichment analysis showed decreased NF-κB signaling and extracellular matrix-receptor interactions in LIPUS-treated mice. Thus, LIPUS effectively mitigates metabolic dysregulation in HFD-induced obesity through inflammation suppression and extracellular matrix remodeling, which provides a potential physical therapy for metabolic syndrome in clinic.

Low-intensity pulsed ultrasound regulates bone marrow mesenchymal stromal cells differentiation and inhibits bone loss by activating the IL-11-Wnt/β-catenin signaling pathway

BACKGROUND

Osteoporosis (OP) is a common metabolic bone disease. Low-intensity pulsed ultrasound (LIPUS) can effectively promote bone formation and fracture healing. The Wnt/β-catenin signaling pathway is crucial for regulating bone homeostasis and bone diseases, and its downregulation is one of the main mechanisms of osteoporosis pathogenesis. Interleukin-11 (IL-11), which is regulated by mechanical stress, is a key factor in bone remodeling. Here, we investigated the optimal intervention parameters for LIPUS, the relationships among LIPUS, IL-11, and the Wnt/β-catenin signaling pathway, and the effects of LIPUS on bone loss and potential molecular mechanisms in ovariectomized (OVX) mice.

METHODS

Bone marrow mesenchymal stromal cells (BMSCs) were subjected to LIPUS intervention for 0, 10, or 20 min to determine the optimal intervention time. The mediating role of IL-11 in LIPUS intervention was explored through IL-11 knockdown and overexpression. Finally, animal experiments were conducted to investigate the in vivo therapeutic effects of LIPUS.

RESULTS

The optimal intervention time for LIPUS was 20 min. LIPUS promoted IL-11 expression and upregulated the Wnt/β-catenin signaling pathway, thereby promoting osteogenic differentiation and inhibiting adipogenic differentiation of BMSCs. IL-11 mediates the regulation of the Wnt/β-catenin signaling pathway by LIPUS. Additionally, LIPUS effectively improved the bone microstructure in ovariectomized mice, inhibited bone loss, promoted IL-11 expression in bone tissue, and activated the Wnt/β-catenin signaling pathway in the femur.

CONCLUSION

Low-intensity pulsed ultrasound can regulate BMSCs differentiation and inhibit bone loss by promoting IL-11 expression and activating the Wnt/β-catenin signaling pathway.

The potential of low‐intensity pulsed ultrasound to apply the long‐term ovary protection from injury induced by 4‐vinylcyclohexene diepoxide through inhibiting granulosa cell apoptosis

The potential of low‐intensity pulsed ultrasound (LIPUS) in regulating ovarian function has been demonstrated; however, there is a lack of scientific evidence regarding the long‐term efficacy of LIPUS in treating ovarian injury and understanding its regulatory mechanisms. In this study, 4‐vinylcyclohexene diepoxide (VCD) was used to induce ovarian injury in rats, and LIPUS was applied to target the damaged ovarian tissues. The research aimed to investigate the long‐term protective effect of LIPUS against ovum toxicity induced by VCD and elucidate the associated molecular mechanisms. During the experiment, HE staining was employed for observing the morphology and structure of the ovary, while protein sequencing was utilized for identifying and confirming the molecular mechanism through which LIPUS restores the damaged ovarian structure. The long‐term effectiveness of LIPUS in protecting against ovarian injury was evaluated through ELISA, estrous cycle monitoring, fertility testing, and behavioral analysis. The results indicated that LIPUS effectively restored the structure of damaged ovaries. Both in vivo and in vitro studies revealed that this protective effect may be attributed to LIPUS inhibiting apoptosis of ovarian granulosa cells (GCs) by regulating Daxx‐mediated ASK1/JNK signaling pathway. Subsequent functional tests demonstrated significant improvements in sex hormone secretion and regulation of estrous cycle within 6 cycles following LIPUS treatment. Additionally, there was a notable increase in offspring numbers after mating. Behavioral analysis revealed that LIPUS effectively alleviated menopausal symptoms resulting from ovarian injury including mood fluctuations, cognitive behavior changes, and reduced muscle excitability levels. These findings suggest that beneficial effects of LIPUS may help reduce VCD‐induced ovarian damage with long‐term efficacy.

Repeated pulses of ultrasound maintain sperm motility

Sperm motility is a primary criterion for selecting viable and functional sperm in assisted reproduction, where the most motile sperm are used to increase the likelihood of successful conception. Traditional chemical agents to enhance motility pose embryo-toxicity risks, necessitating safer alternatives. This study investigates the use of low-intensity pulsed ultrasound exposure as a non-invasive treatment within an acoustofluidic device to maintain sperm motility. We utilized a droplet-based platform to examine the effects of repeated ultrasound pulses on single human sperm cells. Our findings demonstrate that repeated pulsed ultrasound maintains sperm motility over an hour, with significant improvements in motility parameters by at least 25% as compared to non-exposed sperm. Moreover, we show that the motility enhancements by repeated pulsed ultrasound are more significant in initially non-progressive sperm. Importantly, this method did not compromise sperm viability or DNA integrity. These results suggest a viable, sperm safe approach to enhance and maintain sperm motility, potentially improving assisted reproduction outcomes.

Metal-Dependent Cell Death in Renal Fibrosis: Now and in the Future

Renal fibrosis is a common final pathway underlying nearly almost all progressive kidney diseases. Metal ions are essential trace elements in organisms and are involved in important physiological activities. However, aberrations in intracellular metal ion metabolism may disrupt homeostasis, causing cell death and increasing susceptibility to various diseases. Accumulating evidence suggests a complex association between metal-dependent cell death and renal fibrosis. In this article, we provide a comprehensive overview of the specific molecular mechanisms of metal-dependent cell death and their crosstalk, up-to-date evidence supporting their role in renal fibrosis, therapeutic targeting strategies, and research needs, aiming to offer a rationale for future clinical treatment of renal fibrosis.

Jingle Cell Rock: Steering Cellular Activity With Low-Intensity Pulsed Ultrasound (LIPUS) to Engineer Functional Tissues in Regenerative Medicine

Acoustic manipulation or perturbation of biological soft matter has emerged as a promising clinical treatment for a number of applications within regenerative medicine, ranging from bone fracture repair to neuromodulation. The potential of ultrasound (US) endures in imparting mechanical stimuli that are able to trigger a cascade of molecular signals within unscathed cells. Particularly, low-intensity pulsed ultrasound (LIPUS) has been associated with bio-effects such as activation of specific cellular pathways and alteration of cell morphology and gene expression, the extent of which can be modulated by fine tuning of LIPUS parameters including intensity, frequency and exposure time. Although the molecular mechanisms underlying LIPUS are not yet fully elucidated, a number of studies clearly define the modulation of specific ultrasonic parameters as a means to guide the differentiation of a specific set of stem cells towards adult and fully differentiated cell types. Herein, we outline the applications of LIPUS in regenerative medicine and the in vivo and in vitro studies that have confirmed the unbounded clinical potential of this platform. We highlight the latest developments aimed at investigating the physical and biological mechanisms of action of LIPUS, outlining the most recent efforts in using this technology to aid tissue engineering strategies for repairing tissue or modelling specific diseases. Ultimately, we detail tissue-specific applications harnessing LIPUS stimuli, offering insights over the engineering of new constructs and therapeutic modalities. Overall, we aim to lay the foundation for a deeper understanding of the mechanisms governing LIPUS-based therapy, to inform the development of safer and more effective tissue regeneration strategies in the field of regenerative medicine.

Bone and Joint-on-Chip Platforms: Construction Strategies and Applications

Organ-on-a-chip, also known as "tissue chip," is an advanced platform based on microfluidic systems for constructing miniature organ models in vitro. They can replicate the complex physiological and pathological responses of human organs. In recent years, the development of bone and joint-on-chip platforms aims to simulate the complex physiological and pathological processes occurring in human bones and joints, including cell-cell interactions, the interplay of various biochemical factors, the effects of mechanical stimuli, and the intricate connections between multiple organs. In the future, bone and joint-on-chip platforms will integrate the advantages of multiple disciplines, bringing more possibilities for exploring disease mechanisms, drug screening, and personalized medicine. This review explores the construction and application of Organ-on-a-chip technology in bone and joint disease research, proposes a modular construction concept, and discusses the new opportunities and future challenges in the construction and application of bone and joint-on-chip platforms.

Low-Intensity Continuous Ultrasound Enhances the Therapeutic Efficacy of Curcumin-Encapsulated Exosomes Derived from Hypoxic Liver Cancer Cells via Homotropic Drug Delivery Systems

Exosomes are extracellular nanovesicles secreted by cells that efficiently deliver therapeutic cargo for cancer treatment. However, because exosomes are present in low quantities and have limited target specificity, internal and external stress stimulation has been studied to increase exosome efficiency. Inspired by these studies, the uptake efficiency of cobalt chloride-induced hypoxic cancer cell-secreted exosomes was evaluated. Western blotting and RT-PCR data revealed increased exosome secretion and different protein compositions exhibited by hypoxic exosomes (H-Exos) compared to natural normoxic exosomes (N-Exos). Furthermore, these H-Exos were continuously stimulated using low-intensity ultrasound (LICUS) at an intensity of 360 mW/cm2 and a frequency of 3 MHz in vitro and 1 MHz in vivo. Hyperthermic and mechanical stress caused by ultrasound successfully improved exosome uptake via clathrin-mediated pathways, and confocal laser microscopy showed strong internal localization near the target cell nuclei. Finally, LICUS-equipped H-Exos were loaded with hydrophobic curcumin (H-Exo-Cur) and used to treat parent HepG2 liver cancer cells. The UV-Vis spectrophotometer displayed enhanced stability, solubility, and concentration of the encapsulated drug molecules. In MTT and FACS studies, approximately 40 times higher cell death was induced, and in animal studies, approximately 10 times higher tumor sizes were suppressed by LICUS-assisted H-Exo-Cur compared to the control. In this study, the delivery platform constructed demonstrated enormous potential for liver cancer therapy.

Age-related testosterone decline: mechanisms and intervention strategies

Contemporary societies exhibit delayed reproductive age and increased life expectancy. While the male reproductive system demonstrates relatively delayed aging compared to that of females, increasing age substantially impacts its function. A characteristic manifestation is age-induced testosterone decline. Testosterone, a crucial male sex hormone, plays pivotal roles in spermatogenesis and sexual function, and contributes significantly to metabolism, psychology, and cardiovascular health. Aging exerts profound effects on the hypothalamic-pituitary-gonadal axis and Leydig cells, precipitating testosterone reduction, which adversely affects male health. Exogenous testosterone supplementation can partially ameliorate age-related testosterone deficiency; however, its long-term safety remains contentious. Preserving endogenous testosterone production capacity during the aging process warrants further investigation as a potential intervention strategy.

Anti-inflammatory role of low-intensity pulsed ultrasound in inhibiting lipopolysaccharide-induced M1 polarization of RAW264.7 cells via Wnt2b/AXIN/β-catenin

Background

Low-intensity pulsed ultrasound (LIPUS) is a special type of low-intensity ultrasound. In periodontal disease, LIPUS is applied as an adjuvant and non-invasive treatment. It has been reported that LIPUS significantly shifts the macrophage phenotype from M1 to M2, but the specific mechanism behind this shift is still unknown.

Methods

RAW264.7 cells were induced to M1/M2 polarization with lipopolysaccharide (LPS)/interleukin-4 (IL4). LIPUS was performed for 25 min two times, 24 h apart, at an intensity of 45 mW/cm2 to stimulate RAW264.7 cells. PolyA mRNA sequencing was conducted of both the LPS-induced RAW264.7 cells and the LPS-induced RAW264.7 cells with LIPUS treatment. The expression of Wnt2b in RAW264.7 cells was downregulated by siRNA. The macrophage surface markers and downstream inflammatory cytokines were detected using flow cytometry. The relative expression of proteins in the Wnt2b/AXIN/β-catenin pathway was assessed using reverse transcription real-time polymerase chain reaction (RT-qPCR) and Western blot.

Results

LIPUS reversed the M1 polarization of RAW264.7 cells, with decreased expression of CD80 and CD86. In addition, LIPUS enhanced the M2 polarization of RAW264.7 cells, with upregulated expression of CD163 and CD206. The polyA mRNA sequencing results indicated that the Wnt signaling pathway participated in the M1 polarization of LIPUS-treated RAW264.7. The results of the RT-qPCR showed a higher expression of Wnt2b in LIPUS-treated and M1- or M2-polarized RAW264.7 cells. Knocking down Wnt2b was shown to reverse the inhibitory effect of LIPUS on M1 polarization and increase the expression of CD80 and CD86. Wnt2b knockdown also regulated downstream AXIN, β-catenin, and inflammatory factors such as tumor necrosis factor alpha (TNFα) and interleukin-6 (IL6).

Conclusions

LIPUS plays an anti-inflammatory role by inhibiting LPS-induced M1 polarization of RAW264.7 cells in a Wnt2b/AXIN/β-catenin-dependent way. LIPUS may play a therapeutic role in periodontal diseases by inhibiting inflammation through the regulation of macrophage differentiation.

Dynamic reorganization of multivesicular bodies and exosome production impacted by sonoporation

Naturally occurring cell-derived extracellular vesicles (EVs) have emerged as attractive nanocarriers for drug delivery. However, production of large quantities of EVs for clinical applications in a scalable manner remains a significant challenge. This study investigated at the single cell level how sonoporation, or membrane poration produced by ultrasound-induced microbubble cavitation, impacts EV production using mouse macrophage RAW 264.7 cells stably expressing CD63-GFP as a model system. Real-time fluorescence videomicroscopy detected rapid changes in CD63-GFP, a tetraspanin family member highly enriched in intraluminal vesicles tagged with GFP, to track changes in multivesicular bodies (MVBs), which are the cellular compartments where exosomes originate within the cells. Our results revealed distinct dynamic changes in CD63-GFP intensity and distribution in RAW 264.7 cells in terms of response time and duration depending on whether the cells were directly or indirectly impacted by sonoporation, suggesting reorganization of MVBs in response to direct and indirect mechanisms resulted from the mechanical impact of ultrasound pulse on the cells. Analysis of the supernatant from sonoporation-treated RAW 264.7 cells expressing CD63-GFP demonstrated a delayed and sustained increase in the production of CD63-GFP-positive EVs. These results show the robust and detailed effect of sonoporation and reveal insights into sonoporation-induced EV release useful for guiding the application of sonoporation to enhance large-scale EV production.

Low-intensity pulsed ultrasound combined with microbubble mediated JNK/c-Jun pathway to reverse multidrug resistance in triple-negative breast cancer

To investigate the effects of low-intensity pulsed ultrasound combined with microbubble (LIPUS-MB) mediated JNK/c-Jun pathway reversal on multidrug resistance in triple-negative breast cancer and the underlying mechanisms. An orthogonal experiment was designed to screen for the optimal parameters of LIPUS-MB in MDA-MB-231/DOX cells. The CCK-8 assay was used to determine the drug resistance of the cells and to measure their proliferation activity and resistance reversal efficiency at the optimal parameters. Hoechst 33,342 staining and Annexin V-FITC/PI staining were employed to detect cell morphological changes and apoptosis, respectively. The MDA-MB-231/DOX models of transplanted tumor were established in BALB/c. The impact of LIPUS-MB on allograft tumor growth was observed in vivo. Immunohistochemistry was employed to investigate the expression of P-gp, ABCG2, and Ki-67 in tumor tissues, while western blot was utilized to assess the protein expression of P-gp, ABCG2, JNK, p-JNK, c-Jun, p-c-Jun, Bcl-2 and Bax in both MDA-MB-231/DOX cells and allograft tumor tissues. The optimal LIPUS-MB parameters for MDA-MB-231/DOX cells are the microbubble concentration of 20%, ultrasound intensity of 1.0 W/cm2, and irradiation time of 60 s. The drug resistance index of MDA-MB-231/DOX cells is 19.17. Following the optimal parameter application, the IC50 value of the cells decreases by 5.71-fold, with a reversal efficiency of 87.03%, and a simultaneous decrease in cell proliferation activity. Compared with other groups, the DOX + LIPUS-MB group displayed the highest incidence of apoptotic nuclear morphology, and the greatest quantity of cellular apoptosis and the most pronounced decrease in the expression levels of P-gp, ABCG2, p-JNK, p-c-Jun, and Bcl-2 proteins within the cells. Conversely, the expression levels of Bax proteins reach the highest levels (all P < 0.05). Furthermore, in vivo subcutaneous tumor transplantation experiments in nude mice revealed that the DOX + LIPUS-MB group exhibited smaller tumor growth rate, volume and the expression of P-gp, ABCG2, and Ki-67 compared to the DOX + LIPUS group, indicating the most pronounced inhibitory effect on tumor growth and it significantly inhibited tumor proliferation, promoted its apoptosis. In conclusion, following parameter optimization, LIPUS-MB was found to reduce the drug resistance of MDA-MB-231/DOX cells. The underlying mechanism may involve the downregulation of P-gp and ABCG2 proteins expression through the modulation of the JNK/c-Jun pathway by LIPUS-MB, thereby inhibiting cell proliferation activity and promoting apoptosis, and enhancing the in vivo anti-tumor effect of DOX, thus reversing multidrug resistance in triple-negative breast cancer.

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 recruited 56 patients with PD-CI who were continuously treated with LIPUS for 8 wk, and observed the clinical efficacy of LIPUS on patients with PD-CI by comparing with the Sham stimulation continuous treatment. Fifty-six patients with PD-CI 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 wk. 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 aforementioned 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.NEW & NOTEWORTHY This paper provides some data to inform the potential of LIPUS in the treatment of PD-CI.

Cellular signaling pathways in the nervous system activated by various mechanical and electromagnetic stimuli

Mechanical stimuli, such as stretch, shear stress, or compression, activate a range of biomolecular responses through cellular mechanotransduction. In the nervous system, studies on mechanical stress have highlighted key pathophysiological mechanisms underlying traumatic injury and neurodegenerative diseases. However, the biomolecular pathways triggered by mechanical stimuli in the nervous system has not been fully explored, especially compared to other body systems. This gap in knowledge may be due to the wide variety of methods and definitions used in research. Additionally, as mechanical stimulation techniques such as ultrasound and electromagnetic stimulation are increasingly utilized in psychological and neurorehabilitation treatments, it is vital to understand the underlying biological mechanisms in order to develop accurate pathophysiological models and enhance therapeutic interventions. This review aims to summarize the cellular signaling pathways activated by various mechanical and electromagnetic stimuli with a particular focus on the mammalian nervous system. Furthermore, we briefly discuss potential cellular mechanosensors involved in these processes.

Mechanical strategies to promote vascularization for tissue engineering and regenerative medicine

Vascularization is a major challenge in the field of tissue engineering and regenerative medicine. Mechanical factors have been demonstrated to play a fundamental role in vasculogenesis and angiogenesis and can affect the architecture of the generated vascular network. Through the regulation of mechanical factors in engineered tissues, various mechanical strategies can be used to optimize the preformed vascular network and promote its rapid integration with host vessels. Optimization of the mechanical properties of scaffolds, including controlling scaffold stiffness, increasing surface roughness and anisotropic structure, and designing interconnected, hierarchical pore structures, is beneficial for the in vitro formation of vascular networks and the ingrowth of host blood vessels. The incorporation of hollow channels into scaffolds promotes the formation of patterned vascular networks. Dynamic stretching and perfusion can facilitate the formation and maturation of preformed vascular networks in vitro. Several indirect mechanical strategies provide sustained mechanical stimulation to engineered tissues in vivo, which further promotes the vascularization of implants within the body. Additionally, stiffness gradients, anisotropic substrates and hollow channels in scaffolds, as well as external cyclic stretch, boundary constraints and dynamic flow culture, can effectively regulate the alignment of vascular networks, thereby promoting better integration of prevascularized engineered tissues with host blood vessels. This review summarizes the influence and contribution of both scaffold-based and external stimulus-based mechanical strategies for vascularization in tissue engineering and elucidates the underlying mechanisms involved.

Low-intensity pulsed ultrasound modulates disease progression in the SOD1G93A mouse model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterized by the progressive loss of motor neurons in the brain and spinal cord, and there are no effective drug treatments. Low-intensity pulsed ultrasound (LIPUS) has garnered attention as a promising noninvasive neuromodulation method. In this study, we investigate its effects on the motor cortex and underlying mechanisms using the SOD1G93A mouse model of ALS. Our results show that LIPUS treatment delays disease onset and prolongs lifespan in ALS mice. LIPUS significantly increases cerebral blood flow in the motor cortex by preserving vascular endothelial cell integrity and increasing microvascular density, which may be mediated via the ion channel TRPV4. RNA sequencing analysis reveals that LIPUS substantially reduces the expression of genes associated with neuroinflammation. These findings suggest that LIPUS applied to the motor cortex may represent a potentially effective therapeutic tool for the treatment of ALS.

Regenerative Medicine in Orthopedic Surgery: Expanding Our Toolbox

Regenerative medicine leverages the body's inherent regenerative capabilities to repair damaged tissues and address organ dysfunction. In orthopedics, this approach includes a variety of treatments collectively known as orthoregeneration, encompassing modalities such as prolotherapy, extracorporeal shockwave therapy, pulsed electromagnetic field therapy, therapeutic ultrasound, and photobiomodulation therapy, and orthobiologics like platelet-rich plasma and cell-based therapies. These minimally invasive techniques are becoming prominent due to their potential for fewer complications in orthopedic surgery. As regenerative medicine continues to advance, surgeons must stay informed about these developments. This paper highlights the current state of regenerative medicine in orthopedics and advocates for further clinical research to validate and expand these treatments to enhance patient outcomes.

Recent advancement of sonogenetics: A promising noninvasive cellular manipulation by ultrasound

Recent advancements in biomedical research have underscored the importance of noninvasive cellular manipulation techniques. Sonogenetics, a method that uses genetic engineering to produce ultrasound-sensitive proteins in target cells, is gaining prominence along with optogenetics, electrogenetics, and magnetogenetics. Upon stimulation with ultrasound, these proteins trigger a cascade of cellular activities and functions. Unlike traditional ultrasound modalities, sonogenetics offers enhanced spatial selectivity, improving precision and safety in disease treatment. This technology broadens the scope of non-surgical interventions across a wide range of clinical research and therapeutic applications, including neuromodulation, oncologic treatments, stem cell therapy, and beyond. Although current literature predominantly emphasizes ultrasonic neuromodulation, this review offers a comprehensive exploration of sonogenetics. We discuss ultrasound properties, the specific ultrasound-sensitive proteins employed in sonogenetics, and the technique's potential in managing conditions such as neurological disorders, cancer, and ophthalmic diseases, and in stem cell therapies. Our objective is to stimulate fresh perspectives for further research in this promising field.

Ultrasound therapy for pain reduction in musculoskeletal disorders: a systematic review and meta-analysis

Background

Ultrasound therapy is a non-invasive technique used to address a variety of health issues.

Objectives

This systematic review and meta-analysis aim to assess the effectiveness of ultrasound therapy in alleviating pain associated with musculoskeletal diseases.

Design

This study was conducted following PRISMA guidelines, with relevant articles identified through comprehensive searches in electronic databases.

Data sources and methods

We conducted searches across multiple databases, including Scopus, PubMed, MEDLINE, ProQuest, Science Direct, CINAHL, AIM, and ELDIS. Two independent reviewers screened the titles and abstracts of the retrieved articles. We included randomized controlled trials (RCTs) and observational cohort studies published between 2010 and 2023 that evaluated ultrasound therapy for knee and shoulder skeletal disorders. The selected data were analyzed qualitatively and synthesized, with the risk of bias assessed using the RoB2 tool.

Results

Initially, 117 articles were reviewed using the search strategy, and 10 trials that met the inclusion criteria were identified. In seven of these studies, the primary musculoskeletal disorder was osteoarthritis, while three studies focused on shoulder pain and impingement. Most studies indicated that ultrasound therapy significantly reduced pain. The meta-analysis showed that ultrasound therapy was significantly more effective than other interventions for knee disorders (I 2 = 51%, Z = 2.65, p = 0.008). However, for shoulder disorders, both ultrasound and other intervention methods were found to be ineffective (I 2 = 93%, Z = 0.73, p = 0.46).

Conclusion

The current evidence supports the effectiveness of ultrasound therapy in reducing pain and aiding rehabilitation for knee conditions. However, there are mixed results regarding its efficacy for shoulder conditions, highlighting the need for further research in this area.

Effect of low-intensity pulsed ultrasound on postoperative rehabilitation of rotator cuff tears: Protocol for a systematic review and meta-analysis

BACKGROUND

Rotator cuff tears are a common shoulder injury that significantly impacts patients' daily lives and work abilities. Although surgical treatment methods for rotator cuff tears have been continuously improved with advances in medical technology, postoperative rehabilitation remains challenging. Therefore, finding effective rehabilitation treatments is crucial for improving patient prognosis and enhancing quality of life. This study will aim to systematically evaluate the impact of low-intensity pulsed ultrasound (LIPUS) on postoperative rehabilitation of rotator cuff tears, comprehensively assessing the efficacy and safety of LIPUS in postoperative recovery.

METHODS

This protocol will search multiple databases including PubMed/MEDLINE, Embase, Cochrane Library, CNKI, Scopus, and Web of Science to identify randomized controlled trials related to LIPUS for postoperative rehabilitation of rotator cuff tears. The search will encompass literature published from the inception of the databases up to April 2024. Methodological quality assessment and data extraction will be conducted using the Cochrane Handbook for Systematic Reviews of Interventions and PRISMA guidelines. Meta-analysis will be performed on appropriate studies using either random-effects or fixed-effects models, and subgroup analyses will be conducted to explore potential heterogeneity. Studies meeting the inclusion criteria will be included in the analysis. All analyses will be performed using Stata version 16.0.

RESULTS

The incidence of rotator cuff tear rates will be assessed by imaging techniques such as MRI or ultrasound. Pain intensity will be scored using standardized pain assessment scales, such as the Visual Analog Scale (VAS). Improved range of motion (ROM) in shoulder flexion, abduction, and rotation. Functional outcomes will be evaluated using effective measures such as Constant-Murley scores (CMS) and shoulder joint scores by American Shoulder and Elbow Surgeons (ASES). Adverse events associated with LIPUS therapy, including skin irritation, increased pain, or any other complications. Subgroup analysis will also be carried out if possible.

DISCUSSION AND CONCLUSION

Following the meta-analysis, we will assess the overall effect of LIPUS on postoperative rehabilitation of rotator cuff tears, and further explore its impact on aspects such as pain relief, functional improvement, and postoperative complications. It is anticipated that this study will provide comprehensive evidence regarding the role of LIPUS in postoperative rehabilitation of rotator cuff tears, guiding clinical practice and future research. The resultant manuscript will be submitted for publication in a peer-reviewed journal.

PROTOCOL REGISTRATION NUMBER

CRD42024530798.

Low-Intensity Pulsed Ultrasound: A Physical Stimulus with Immunomodulatory and Anti-inflammatory Potential

Ultrasound has expanded into the therapeutic field as a medical imaging and diagnostic technique. Low-intensity pulsed ultrasound (LIPUS) is a kind of therapeutic ultrasound that plays a vital role in promoting fracture healing, wound repair, immunomodulation, and reducing inflammation. Its anti-inflammatory effects are manifested by decreased pro-inflammatory cytokines and chemokines, accelerated regression of immune cell invasion, and accelerated damage repair. Although the anti-inflammatory mechanism of LIPUS is not very clear, many in vitro and in vivo studies have shown that LIPUS may play its anti-inflammatory role by activating signaling pathways such as integrin/Focal adhesion kinase (FAK)/Phosphatidylinositol 3-kinase (PI3K)/Serine threonine kinase (Akt), Vascular endothelial growth factor (VEGF)/endothelial nitric oxide synthase (eNOS), or inhibiting signaling pathways such as Toll-like receptors (TLRs)/Nuclear factor kappa-B (NF-κB) and p38-Mitogen-activated protein kinase (MAPK). As a non-invasive physical therapy, the anti-inflammatory and immunomodulatory effects of LIPUS deserve further exploration.

Synergistic effect of ultrasound and reinforced electrical environment by bioinspired periosteum for enhanced osteogenesis via immunomodulation of macrophage polarization through Piezo1

The periosteum plays a vital role in repairing bone defects. Researchers have demonstrated the existence of electrical potential in the periosteum and native bone, indicating that electrical signals are essential for functional bone regeneration. However, the clinical use of external electrical treatments has been limited due to their inconvenience and inefficacy. As an alternative, low-intensity pulsed ultrasound (LIPUS) is a noninvasive form of physical therapy that enhances bone regeneration. Furthermore, the wireless activation of piezoelectric biomaterials through ultrasound stimulation would generate electric charges precisely at the defect area, compensating for the insufficiency of external electrical stimulation and potentially promoting bone regeneration through the synergistic effect of mechanical and electrical stimulation. However, the optimal integration of LIPUS with an appropriate piezoelectric periosteum is yet to be explored. Herein, the BaTiO3/multiwalled-carbon nanotubes/collagen (BMC) membranes have been fabricated, possessing physicochemical properties including improved surface hydrophilicity, enhanced mechanical performance, ideal piezoelectricity, and outstanding biocompatibility, all of which are conducive to bone regeneration. When combined with LIPUS, the endogenous electrical microenvironment of native bone was recreated. After that, the wireless-generated electrical signals, along with the mechanical signals induced by LIPUS, were transferred to macrophages and activated Ca2+ influx through Piezo1. Ultimately, the regenerative effect of the BMC membrane with LIPUS stimulation (BMC + L) was confirmed in a mouse cranial defect model. Together, this research presents a co-engineering strategy that involves fabricating a novel biomimetic periosteum and utilizing the synergistic effect of ultrasound to enhance bone regeneration, which is achieved through the reinforcement of the electrical environment and the immunomodulation of macrophage polarization.

Effects of Low-Intensity Pulsed Ultrasound on the Regulation of Free Fatty Acid Release in 3T3-L1 Cells

OBJECTIVES

To investigate the effects of low-intensity pulsed ultrasound (LIPUS) on the proliferation, differentiation, and tumor necrosis factor-α (TNF-α)-induced lipolysis of 3T3-L1 cells, and to explore the feasibility of regulating the release of free fatty acids (FFA) to prevent lipotoxicity.

METHODS

Different intensities (30, 60, 90, and 120 mW/cm2) of LIPUS were applied to 3T3-L1 preadipocytes for different durations (5, 10, 15, 20, 25, and 30 minutes). Appropriate parameters for subsequent experiments were selected by assessing cell viability. The effect of LIPUS on the proliferation and differentiation of 3T3-L1 cells was evaluated by microscope observation, flow cytometry, and lipid content determination. After treated with LIPUS and TNF-α (50 ng/mL), the degree of lipolysis was assessed by measuring the extracellular FFA content. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the mRNA expression of relevant genes.

RESULTS

Different parameters of LIPUS significantly enhance the viability of 3T3-L1 cells (P < .05), with 20 minutes and 30 mW/cm2 as the most suitable settings. After LIPUS treatment, 3T3-L1 cell proliferation accelerated, apoptosis rate and G1 phase cell proportion decreased, the content of lipid droplets and TG was increased in differentiated cells, while FFA release decreased (P < .05). The expression of PCNA, PPARγ, C/EBPα, Perilipin A mRNA increased, and the expression of TNF-α, ATGL, HSL mRNA decreased (P < .05).

CONCLUSIONS

LIPUS could promote the proliferation and differentiation of 3T3-L1 cells and inhibit TNF-α-induced lipolysis, indicating its potential as a therapy for mitigating lipotoxicity caused by decompensated adipocytes.

Triggerable Patches for Medical Applications

Medical patches have garnered increasing attention in recent decades for several diagnostic and therapeutic applications. Advancements in material science, manufacturing technologies, and bioengineering have significantly widened their functionalities, rendering them highly versatile platforms for wearable and implantable applications. Of particular interest are triggerable patches designed for drug delivery and tissue regeneration purposes, whose action can be controlled by an external signal. Stimuli-responsive patches are particularly appealing as they may enable a high level of temporal and spatial control over the therapy, allowing high therapeutic precision and the possibility to adjust the treatment according to specific clinical and personal needs. This review aims to provide a comprehensive overview of the existing extensive literature on triggerable patches, emphasizing their potential for diverse applications and highlighting the strengths and weaknesses of different triggering stimuli. Additionally, the current open challenges related to the design and use of efficient triggerable patches, such as tuning their mechanical and adhesive properties, ensuring an acceptable trade-off between smartness and biocompatibility, endowing them with portability and autonomy, accurately controlling their responsiveness to the triggering stimulus and maximizing their therapeutic efficacy, are reviewed.

Flexible Sono-Piezo Patch for Functional Sweat Gland Repair through Endogenous Microenvironmental Remodeling

Remodeling the endogenous regenerative microenvironment in wounds is crucial for achieving scarless, functional tissue regeneration, especially the functional recovery of skin appendages such as sweat glands in burn patients. However, current approaches mostly rely on the use of exogenous materials or chemicals to stimulate cell proliferation and migration, while the remodeling of a pro-regenerative microenvironment remains challenging. Herein, we developed a flexible sono-piezo patch (fSPP) that aims to create an endogenous regenerative microenvironment to promote the repair of sweat glands in burn wounds. This patch, composed of multifunctional fibers with embedded piezoelectric nanoparticles, utilized low-intensity pulsed ultrasound (LIPUS) to activate electrical stimulation of the target tissue, resulting in enhanced pro-regenerative behaviors of niche tissues and cells, including peripheral nerves, fibroblasts, and vasculatures. We further demonstrated the effective wound healing and regeneration of functional sweat glands in burn injuries solely through such physical stimulation. This noninvasive and drug-free therapeutic approach holds significant potential for the clinical treatment of burn injuries.

Effects of insonification on repairing the renal injury of diabetic nephropathy rats

INTRODUCTION

Prolonged hyperglycemia in diabetes mellitus can result in the development of diabetic nephropathy (DN) and increase the susceptibility to kidney failure. Low-intensity pulsed ultrasound (LIPUS) is a non-invasive modality that has demonstrated effective tissue repair capabilities. The objective of this study was to showcase the reparative potential of LIPUS on renal injury at both animal and cellular levels, while also determining the optimal pulse length (PL).

RESEARCH DESIGN AND METHODS

We established a rat model of DN, and subsequently subjected the rats' kidneys to ultrasound irradiation (PL=0.2 ms, 10 ms, 20 ms). Subsequently, we assessed the structural and functional changes in the kidneys. Additionally, we induced podocyte apoptosis and evaluated its occurrence following ultrasound irradiation.

RESULTS

Following irradiation, DN rats exhibited improved mesangial expansion and basement membrane thickening. Uric acid expression increased while urinary microalbumin, podocalyxin in urine, blood urea nitrogen, and serum creatinine levels decreased (p<0.05). These results suggest that the optimal PL was 0.2 ms. Using the optimal PL further demonstrated the reparative effect of LIPUS on DN, it was found that LIPUS could reduce podococyte apoptosis and alleviate kidney injury. Metabolomics revealed differences in metabolites including octanoic acid and seven others and western blot results showed a significant decrease in key enzymes related to lipolysis (p<0.05). Additionally, after irradiating podocytes with different PLs, we observed suppressed apoptosis (p<0.05), confirming the optimal PL as 0.2 ms.

CONCLUSIONS

LIPUS has been demonstrated to effectively restore renal structure and function in DN rats, with an optimal PL of 0.2 ms. The mechanism underlying the alleviation of DN by LIPUS is attributed to its ability to improve lipid metabolism disorder. These findings suggest that LIPUS may provide a novel perspective for future research in this field.