Ultrasound-targeted Microbubble Research Articles

Ultrasound-targeted sirolimus-loaded microbubbles improves acute rejection of heart transplantation in rats by inhibiting TGF-β1-Smad signaling pathway, promoting autophagy and reducing inflammation

Acute rejection (AR) remains a pivotal complication and leading cause of mortality within the first year following heart transplantation (HT). In this study, we assessed the impact of ultrasound-targeted microbubbles loaded with sirolimus (SIR-MBs) on AR in a rat HT model and delved into the underlying mechanisms. We established a rat abdominal ectopic HT model, which was stratified into three groups receiveing the PBS, SIR-MBs + ultrasound-targeted microbubble destruction (UTMD), and sirolimus, respectively. The protective effects of each treatments on survival rate, inflammatory response, autophagy and TGF-β1-Smad signaling pathway-related proteins were evaluted. Additionally, rescue experiment was performed via adding the autophagy inhibitor or TGF-β1 agonist in combination therapy. UTMD combined SIR-MBs mediated 15-fold higher local drug concentration compared to direct sirolimus administration. The infiltration of inflammatory cells in the transplanted hearts indicated that SIR-MBs combined with UTMD were effective in mitigating the inflammatory response, achieving levels significantly lower than those observed in the sirolimus group. Furthermore, after SIR-MBs combined with UTMD treatment, the expression levels of TGF-β1-Smad signaling pathway-related proteins in heart tissues also showed a significant decrease compared to the model control group. Conversely, the expressions of autophagy proteins LC3-II, Beclin-1 and β-arrestin showed an up-regulated trend. Rescue experiments also revealed that the enhancement in survival trends was markedly suppressed following the administration of CsA or SRI-011381, respectively. Collectively, our findings suggest that SIR-MBs combined with UTMD augment the local treatment efficacy for AR in rat HT models by inhibiting the TGF-β1-Smad signaling pathway, promoting autophagy, and alleviating inflammation.

Experimental study on the treatment of diabetic cardiomyopathy in rats by using ultrasound-targeted microbubble destruction combined with coenzyme Q10 loaded long-circulating nanoliposomes

Objective: To investigate the therapeutic effects and mechanisms of Ultrasound-targeted microbubble destruction (UTMD) technology combined with CoQ10 loaded PEGylated nanoliposomes (CoQ10-PEG-lips) on diabetic cardiomyopathy (DCM) in rats. Methods: CoQ10-PEG-lips were prepared using the thin-film dispersion method combined with ultrasonic hydration, followed by quality assessment. Sixty healthy and clean male SD rats were selected, and 50 were randomly chosen using a random number table to establish a type 1 diabetes mellitus (DM) model via a single intraperitoneal injection of streptozotocin. The remaining 10 rats were assigned as the normal control group. A total of 47 rats successfully developed the DM model, and 40 were selected using the random number table method. Based on different intervention methods, these rats were then randomly divided into DM model group, CoQ10 solution group, CoQ10-PEG-Lips group, and CoQ10-PEG-Lips+UTMD group (n=10 per group). Normal control group and DM model group rats were injected with 1 ml of normal saline through caudal vein. CoQ10 solution group and CoQ10-PEG-Lips group were injected with 1 ml of CoQ10 solution or CoQ10-PEG-Lips solution containing 10 mg/kg of CoQ10 through caudal vein, respectively. Rats in the CoQ10-PEG-Lips+UTMD group were injected with 1 ml of CoQ10-PEG-Lips solution containing 10 mg/kg of CoQ10+100 mg of freeze-dried ultrasound microbubble powder through caudal vein and were given UTMD treatment at the same time, with the intervention given twice a week. After 12 weeks of intervention, cardiac function indexes [left ventricular end-systolic diameter (LVEDs), left ventricular end-diastolic diameter (LVEDd), and left ventricular ejection fraction (LVEF)]of each group were measured by ultrasonic cardiac function detection in vivo. Simultaneously, ex-vivo histopathological examination was conducted to assess myocardial cell morphology, cross-sectional area, collagen volume fraction (CVF), and apoptosis index (AI) in each group. Additionally, molecular biology techniques were employed to measure oxidative stress-related indicators and the expression of apoptosis-related pathway proteins. Results: The prepared CoQ10-PEG-lips had a well-rounded morphology, good dispersibility, and a high encapsulation efficiency of 87.45%±3.23%. After 12 weeks of intervention, the myocardial cell morphology in the CoQ10-PEG-Lips+UTMD group was intact, with orderly arrangement, closely resembling that of the normal control group. There were no statistically significant differences between the two groups in terms of LVEDs [(1.53±0.07) mm vs (1.42±0.04) mm], LVEDd [(2.93±0.15) mm vs (2.81±0.05) mm], or LVEF (80.76%±3.42% vs 84.60%±2.10%) (all P>0.05). Similarly, there were no significant differences between the two groups in myocardial cell cross-sectional area, CVF, or AI (all P>0.05). The CoQ10-PEG-Lips+UTMD group showed statistically significant differences in the above-mentioned indicators compared to the DM group, CoQ10 solution group, and CoQ10-PEG-Lips group (all P<0.05). In the CoQ10-PEG-Lips+UTMD group, the levels of myocardial superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and the expression of the anti-apoptotic protein B-cell lymphoma-2 (Bcl-2) were significantly higher compared to the DM model group, CoQ10 solution group, and CoQ10-PEG-Lips group (all P<0.05), while malondialdehyde levels and the expression of Bcl-2-associated X protein (Bax) and caspase-3 were lower (all P<0.05). Conclusions: Using PEG-lips to encapsulate the poorly soluble drug CoQ10 in combination with UTMD technology enables targeted delivery of the drug to the myocardium, which can help reduce myocardial cell damage, fibrosis, and apoptosis caused by diabetes mellitus (DM) by inhibiting oxidative stress damage and the Bcl-2/Bax/caspase-3 apoptosis signaling pathway, ultimately improving cardiac function in DCM rats.

Sonodynamic effect based on vancomycin-loaded microbubbles or meropenem-loaded microbubbles enhances elimination of different biofilms and bactericidal efficacy.

This study investigated vancomycin-microbubbles (Vm-MBs) and meropenem (Mp)-MBs with ultrasound-targeted microbubble destruction (UTMD) to disrupt biofilms and improve bactericidal efficiency, providing a new and promising strategy for the treatment of device-related infections (DRIs). A film hydration method was used to prepare Vm-MBs and Mp-MBs and examine their characterization. Biofilms of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli were treated with different groups. Biofilm biomass differences were determined by staining. Thickness and bacterial viability were observed with confocal laser scanning microscope (CLSM). Colony counts were determined by plate-counting. Scanning electron microscopy (SEM) observed bacterial morphology. The Vm-MBs and Mp-MBs met the experimental requirements. The biofilm biomass in the Vm, Vm-MBs, UTMD, and Vm-MBs + UTMD groups was significantly lower than in the control group. MRSA and E. coli biofilms were most notably damaged in the Vm-MBs + UTMD group and Mp-MBs + UTMD group, respectively, with mean 21.55% (SD 0.08) and 19.73% (SD 1.25) remaining in the biofilm biomass. Vm-MBs + UTMD significantly reduced biofilm thickness and bacterial viability (p = 0.005 and p < 0.0001, respectively). Mp-MBs + UTMD could significantly decrease biofilm thickness and bacterial viability (allp < 0.001). Plate-counting method showed that the numbers of MRSA and E. coli bacterial colonies were significantly lower in the Vm-MBs + UTMD group and the Mp, Mp-MBs, UTMD, Mp-MBs + UTMD groups compared to the control group (p = 0.031). SEM showed that the morphology and structure of MRSA and E. coli were significantly damaged in the Vm-MBs + UTMD and Mp-MBs + UTMD groups. Vm-MBs or Mp-MBs combined with UTMD can effectively disrupt biofilms and protectively release antibiotics under ultrasound mediation, significantly reducing bacterial viability and improving the bactericidal effect of antibiotics.

Ultrasound Controllable Release of Proteolysis Targeting Chimeras for Triple-Negative Breast Cancer Treatment.

Triple-negative breast cancer (TNBC) is a special subtype of breast cancer, which is highly aggressive and incurable. Here, we proposed an ultrasound activatable bromodomain-containing protein 4 (BRD4) proteolysis targeting chimera (PROTAC) release strategy for the first time for precisely controlled protein degradation in preclinical TNBC model. Through combination of PROTAC and ultrasound-targeted microbubble destruction (UTMD) technology, the present strategy also aims to concurrently solve the major limitations of poor loading capacity of microbubbles and undesirable targeting and membrane permeability of PROTAC. PROTAC (ARV-825)-encapsulated microbubbles, ARV-MBs, were developed for the efficacious treatment of TNBC invitro and invivo. The microbubbles we synthesized showed ultrasound-responsive drug release ability, which could effectively promote the penetration of PROTAC into tumor site and tumor cell. Under ultrasound, ARV-MBs could play an effective antitumor effect by potentiating the ubiquitination and degradation of BRD4 in tumor. The current study may provide a new idea for promoting clinical translation of drug-loaded microbubbles and PROTAC, and offer a new efficacious therapeutic modality for TNBC.

Progression in low-intensity ultrasound-induced tumor radiosensitization.

Radiotherapy (RT) is a widely utilized tumor treatment approach, while a significant obstacle in this treatment modality is the radioresistance exhibited by tumor cells. To enhance the effectiveness of RT, scientists have explored radiosensitization approaches, including the use of radiosensitizers and physical stimuli. Nevertheless, several approaches have exhibited disappointing results including adverse effects and limited efficacy. A safer and more effective method of radiosensitization involves low-intensity ultrasound (LIUS), which selectively targets tumor tissue and enhances the efficacy of radiation therapy. This review summarized the tumor radioresistance reasons and explored LIUS potential radiosensitization mechanisms. Moreover, it covered diverse LIUS application strategies in radiosensitization, including the use of LIUS alone, ultrasound-targeted intravascular microbubble destruction, ultrasound-mediated targeted radiosensitizers delivery, and sonodynamic therapy. Lastly, the review presented the limitations and prospects of employing LIUS-RT combined therapy in clinical settings, emphasizing the need to connect research findings with practical applications. LIUS employs cost-effective equipment to foster tumor radiosensitization, curtail radiation exposure, and elevate the quality of life for patients. This efficacy is attributed to LIUS's ability to utilize thermal, cavitation, and mechanical effects to overcome tumor cell resistance to RT. Multiple experimental analyses have underscored the effectiveness of LIUS in inducing tumor radiosensitization using diverse strategies. While initial studies have shown promising results, conducting more comprehensive clinical trials is crucial to confirm its safety and effectiveness in real-world situations.

Hydralazine loaded nanodroplets combined with ultrasound-targeted microbubble destruction to induce pyroptosis for tumor treatment

Pyroptosis, a novel type of programmed cell death (PCD), which provides a feasible therapeutic option for the treatment of tumors. However, due to the hypermethylation of the promoter, the critical protein Gasdermin E (GSDME) is lacking in the majority of cancer cells, which cannot start the pyroptosis process and leads to dissatisfactory therapeutic effects. Additionally, the quick clearance, systemic side effects, and low concentration at the tumor site of conventional pyroptosis reagents restrict their use in clinical cancer therapy. Here, we described a combination therapy that induces tumor cell pyroptosis via the use of ultrasound-targeted microbubble destruction (UTMD) in combination with DNA demethylation. The combined application of UTMD and hydralazine-loaded nanodroplets (HYD-NDs) can lead to the rapid release of HYD (a demethylation drug), which can cause the up-regulation of GSDME expression, and produce reactive oxygen species (ROS) by UTMD to cleave up-regulated GSDME, thereby inducing pyroptosis. HYD-NDs combined with ultrasound (US) group had the strongest tumor inhibition effect, and the tumor inhibition rate was 87.15% (HYD-NDs group: 51.41 ± 3.61%, NDs + US group: 32.73%±7.72%), indicating that the strategy had a more significant synergistic anti-tumor effect. In addition, as a new drug delivery carrier, HYD-NDs have great biosafety, tumor targeting, and ultrasound imaging performance. According to the results, the combined therapy reasonably regulated the process of tumor cell pyroptosis, which offered a new strategy for optimizing the therapy of GSDME-silenced solid tumors.

Ultrasound-targeted microbubble destruction rapidly improves left ventricular function in rats with ischemic cardiac dysfunction

BackgroundPrevious studies have demonstrated the efficacy of ultrasound-targeted microbubble destruction (UTMD) in the treatment of ischemic heart failure (HF). The purpose of this study was to explore the mechanism by which UTMD improves ischemic HF. MethodsAn ischemic heart failure model was established using Sprague-Dawley rats. Rats were randomly divided into 7 groups: sham group, HF group, HF + MB group, HF + ultrasound (US) group, HF + UTMD group, HF + UTMD+LY294002 group, and HF + LY294002 group. Serum BNP level and echocardiographic parameters were measured to evaluate cardiac function. PI3K/Akt/eNOS signaling pathway protein levels were detected by immunohistochemistry (IHC) and western blotting. The concentrations of nitrous oxide (NO) and ATP were detected by ELISA, and hematoxylin and eosin (HE) staining was used to evaluate myocardial tissue. ResultsUTMD rapidly improved ejection fraction (EF) (HF: 37.16 ± 1.21% vs. HF + UTMD: 46.31 ± 3.00%, P < 0.01) and fractional shortening (FS) (HF: 18.53 ± 0.58% vs. HF + UTMD: 24.05 ± 1.84%, P < 0.01) in rats with ischemic HF. UTMD activated the PI3K/AKT/eNOS signaling pathway (HF vs. HF + UTMD, P < 0.01) and promoted the release of NO and ATP (HF vs. HF + UTMD, both, P < 0.05). Inhibition of the PI3K/AKT/eNOS signaling pathway by LY294002 worsened EF (HF: 37.16 ± 1.21% vs. HF + LY294002: 32.73 ± 3.05%, P < 0.05), and the release of NO and ATP by UTMD (HF + UTMD vs. HF + UTMD+LY294002, P < 0.05). ConclusionsUTMD can rapidly improve cardiac function in ischemic HF by activating the PI3K/Akt/eNOS signaling pathway and promoting the release of NO and ATP.

Ultrasound Microbubble-Stimulated miR-145-5p Inhibits Malignant Behaviors of Breast Cancer Cells by Targeting ACTG1.

Ultrasound-targeted microbubble destruction (UTMD) technology combines ultrasound with a variety of functional microbubble vectors to enhance the transfection and expression of target genes, and has become a promising noninvasive method for localized gene transfer, which is widely used in gene therapy for cancer. This research aimed to explore the role of UTMD-mediated miR-145-5p on breast cancer (BC) tumorigenesis and the underlying mechanisms. To achieve UTMD-mediated miR-145-5p overexpression, BC cells were cotransfected with microbubbles (MBs) and miR-145-5p mimics. The BC cell malignant phenotypes were assessed through CCK-8, wound healing, and transwell assays. MiR-145-5p and actin gamma 1 (ACTG1) binding relationship was verified through luciferase reporter and RNA pull-down assays. MiR-145-5p and ACTG1 levels in BC cells and tissues were detected through RT-qPCR and Western blotting. ACTG1 was upregulated, whereas miR-145-5p was downregulated in BC cells and tissues. MiR-145-5p targeted ACTG1 and negatively regulated its level in BC cells. Overexpressing miR-145-5p restrained BC cell growth, migration, and invasion. Ultrasound-targeted microbubble destruction improved the overexpression efficiency of miR-145-5p and enhanced the suppressive influence on BC cell malignant phenotypes. In addition, ACTG1 overexpression compromises the repression of UTMD-mediated miR-145-5p on cellular behaviors in BC. Ultrasound-targeted microbubble destruction-delivered miR-145-5p hindered malignant behaviors of BC cells through downregulating ACTG1.

A combination of PD-L1-targeted IL-15 mRNA nanotherapy and ultrasound-targeted microbubble destruction for tumor immunotherapy

PD-1/PD-L1-based immune checkpoint blockade therapy has shown limited benefits in tumor patients, partially attributed to the inadequate infiltration of immune effector cells within tumors. Here, we established a nanoplatform named DPPA/IL-15 NPs to target PD-L1 for the tumor delivery of IL-15 messenger RNA (mRNA). DPPA/IL-15 NPs were endowed with ultrasound responsiveness and contrast-enhanced ultrasound (CEUS) imaging performance. They effectively protected IL-15 mRNA from degradation and specifically transfected it into tumor cells through the utilization of ultrasound-targeted microbubble destruction (UTMD). This resulted in the activation of IL-15-related immune effector cells while blocking the PD-1/PD-L1 pathway. In addition, UTMD could generate reactive oxygen species (ROS) that induce endoplasmic reticulum (ER) stress-driven immunogenic cell death (ICD), initiating anti-tumor immunity. In vitro and in vivo studies revealed that this combination therapy could induce a robust systemic immune response and enhance anti-tumor efficacy. Thus, this combination therapy has the potential for clinical translation through enhanced immunotherapy and provides real-time ultrasound imaging guidance.

Ultrasound-targeted microbubble technology facilitates SAHH gene delivery to treat diabetic cardiomyopathy by activating AMPK pathway

Diabetic cardiomyopathy (DCM) is a cardiovascular complication with no known cure. In this study, we evaluated the combination of ultrasound-targeted microbubble destruction (UTMD) and cationic microbubbles (CMBs) for cardiac S-adenosyl homocysteine hydrolase (SAHH) gene transfection as potential DCM therapy. Models of high glucose/fat (HG/HF)-induced H9C2 cells and streptozotocin-induced DCM rats were established. Ultrasound-mediated SAHH delivery using CMBs was a safe and noninvasive approach for spatially localized drug administration both invitro and invivo. Notably, SAHH overexpression increased cell viability and antioxidative stress and inhibited apoptosis of HG/HF-induced H9C2 cells. Likewise, UTMD-mediated SAHH delivery attenuated apoptosis, oxidative stress, cardiac fibrosis, and myocardial dysfunction in DCM rats. Activation of the AMPK/FOXO3/SIRT3 signaling pathway may be a key mechanism mediating the role of SAHH in regulating myocardial injury. Thus, UTMD-mediated SAHH transfection may be an important advancement in cardiac gene therapy for restoring ventricular function after DCM.

Ultrasound-targeted microbubble destruction improves the suppression and magnetic resonance imaging of pancreatic cancer with polyethyleneimine nanogels.

The chemoresistance of pancreatic cancer tumors urgently needs to be addressed. Pancreatic cancer is characterized by an abundant stroma, with significant fibrous connective tissue formation that encapsulates the tumor parenchyma and forms an interstitial microenvironment. Pancreatic stellate cells (PSCs) play a crucial role in this microenvironment and specially secrete periosteal protein (periostin), which can promote tumor growth, metastasis, and chemoresistance. Therefore, periostin has become a specific target of chemotherapy resistance intervention methods. The proposed polyethyleneimine (PEI) nanogels have multiple modification and efficient drug-loading properties. Additionally, ultrasound-targeted microbubble destruction (UTMD) supports the breakdown of the tough interstitial barrier of pancreatic cancer. A small interfering RNA (siRNA) can be used to downregulated the periostin gene, while sustained release of gemcitabine can promote killing of tumor cells. This method achieves a combination of gene silencing and chemotherapy. The imaging effect can be evaluated using magnetic resonance imaging (MRI). The ultimate goal of this work is to support individualized and effective therapeutic methods and help develop new strategies for pancreatic cancer treatment.

Ultrasound-Targeted Microbubble Destruction Increases BBB Permeability and Promotes Stem Cell-Induced Regeneration of Stroke by Downregulating MMP8.

The objective of this study was to evaluate the feasibility, safety, and effectiveness of intravenous stem cell delivery utilizing ultrasound-targeted microbubble destruction (UTMD) in a rat model of middle cerebral artery occlusion (MCAO), while investigating the underlying mechanisms. Acute cerebral infarction (ACI) was induced surgically in adult rats to create the MCAO rat model. Intravenous injection of SonoVue microbubbles and bone marrow-derived mesenchymal stem cells (BMSC) was performed concurrently, with or without ultrasound targeting the stroke. The animals were divided into four groups: sham-operated group, ACI-MCAO rats treated with phosphate-buffered saline (ACI+PBS), rats receiving intravenous delivery of BMSC expressing green fluorescent protein (GFP-BMSC; ACI+BMSC), and rats receiving intravenous GFP-BMSC with simultaneous UTMD exposure (ACI+BMSC+UTMD). The efficacy of the treatments was assessed by evaluating the animals' neurological function using the Longa score and examining histopathological changes such as cerebral infarct volume, cerebral edema, and cell apoptosis. A rat cytokine array was utilized to identify the potential cytokines that may be responsible for the therapeutic effect of UTMD-mediated BMSC treatment. Optimal UTMD parameters resulted in an increase in blood-brain barrier (BBB) permeability after 30 min, which returned to baseline 72 h later without causing any residual injury. UTMD application significantly increased the homing of intravenously delivered BMSC, resulting in a 2.2-fold increase in GFP-BMSC cell count on day 3 and a 2.6-fold increase on day 7 compared with intravenous delivery alone. This effect persisted for up to 6 weeks after injection. Intravenous BMSC delivery significantly reduced the volume of cerebral infarct and decreased cerebral edema, leading to a lower Longa score. Furthermore, this effect was further enhanced by UTMD. Acute cerebral infarction induced by MCAO led to elevated matrix metalloproteinase 8 (MMP8) levels in the cerebrospinal fluid, which were significantly reduced following UTMD-mediated BMSC treatment. Ultrasound-targeted microbubble destruction facilitates the migration and homing of BMSC into the brain, possibly by transiently increasing blood-brain barrier (BBB) permeability, thereby improving therapeutic outcomes in an ACI rat model. The observed effect may be partly attributed to modulation of MMP8 levels.Advances in knowledge: UTMD-mediated intravenously delivered BMSC transplantation led to a significant increase in cell homing and reduction of MMP8 levels, resulting in increased therapeutic effect in an acute ischemic cerebral infarction model.

Development of an In Vitro Model to Study Mechanisms of Ultrasound-Targeted Microbubble Cavitation–Mediated Blood–Brain Barrier Opening

Ultrasound-targeted microbubble cavitation (UTMC)-mediated blood-brain barrier (BBB) opening is being explored as a method to increase drug delivery to the brain. This strategy has progressed to clinical trials for various neurological disorders, but the underlying cellular mechanisms are incompletely understood. In the study described here, a contact co-culture transwell model of the BBB was developed that can be used to determine the signaling cascade leading to increased BBB permeability. This BBB model consists of bEnd.3 cells and C8-D1A astrocytes seeded on opposite sides of a transwell membrane. Pulsed ultrasound (US) is applied to lipid microbubbles (MBs), and the change in barrier permeability is measured via transendothelial electrical resistance and dextran flux. Live cell calcium imaging (Fluo-4 AM) is performed during UTMC treatment. This model exhibits important features of the BBB, including endothelial tight junctions, and is more restrictive than the endothelial cell (EC) monolayer alone. When US is applied to MBs in contact with the ECs, BBB permeability increases in this model by two mechanisms: UTMC induces pore formation in the EC membrane (sonoporation), leading to increased transcellular permeability, and UTMC causes formation of reversible inter-endothelial gaps, which increases paracellular permeability. Additionally, this study determines that calcium influx into ECs mediates the increase in BBB permeability after UTMC in this model. Both transcellular and paracellular permeability can be used to increase drug delivery to the brain. Future studies can use this model to determine how UTMC-induced calcium-mediated signaling increases BBB permeability.

Treatment of ischemic heart failure through ultrasound-targeted microbubble destruction and it's mechanism

Abstract Background The cavitation effect mediated by ultrasonic-targeted microbubble destruction (UTMD) can regulate the microenvironment and circulation of ischemic myocardium. The UTMD cavitation effect can rapidly enhance blood perfusion and improve cardiac function in patients with ischemic heart failure. However, the internal mechanism of this treatment has yet to be reported. Objective The objective of this study was to explore the underlying mechanism of UTMD-mediated cavitation effect to rapidly improve cardiac function in rats with ischemic heart failure. Methods In the first part of the study, the ischemic heart failure model was induced by ligation of the left anterior descending branch coronary in Sprague-Dawley rats, the rats were randomly divided into 7 groups: sham group, HF group, HF+MB(microbubble) group, HF+US(ultrasound) group, HF+UTMD group, HF+UTMD+LY294002(PI3K inhibitor) group, and HF+LY294002 group. Serum BNP level and echocardiographic parameters were measured to evaluate cardiac function. Thereafter, SD rats were treated with UTMD by specific ultrasonic parameters and microbubble concentration, cardiac function should be reassessed after treatment. Finally, the myocardial tissues were extracted for Western Blot and immunohistochemical analysis to detect the protein expression of the PI3K/Akt/eNOS signaling pathway, and the contents of serum nitric oxide(NO) and myocardial ATP were detected by Elisa. Results The application of UTMD resulted in significant improvements in ejection fraction (EF) and fractional shortening (FS) in rats with ischemic heart failure, as compared to the HF group (EF: 37.16 ± 1.21% vs. HF+UTMD: 46.31 ± 3.00%, P=0.0057; FS: 18.53 ± 0.58% vs. HF+UTMD: 24.05 ± 1.84%, P=0.0089). Additionally, UTMD treatment led to the activation of the PI3K/Akt/eNOS signaling pathway (HF vs. HF+UTMD, P &amp;lt; 0.01), and promoted the production of NO and ATP (HF vs. HF+UTMD, both, P&amp;lt; 0.05). However, when a PI3K inhibitor was used, the cardiac protective effects of UTMD treatment were largely eliminated. EF and FS deteriorated significantly (EF: HF+UTMD+LY294002: 42.84±2.88% vs. HF+LY294002: 32.73±3.05%, P&amp;lt;0.0001; FS: HF+UTMD+LY294002: 21.94±1.69% vs. HF+LY294002: 16.36±1.76%, P&amp;lt;0.0001), and the production of NO and ATP decreased significantly (HF+UTMD+LY294002 vs. HF+LY294002, both, P&amp;lt; 0.05). Conclusion The UTMD-mediated cavitation effect can rapidly improve the cardiac function of ischemic heart failure rats by activating PI3K/Akt/eNOS signaling pathway and promoting the release of NO and ATP.

Role of Ultrasonic Microbubbles in Treating Rheumatoid Arthritis: Enhancing the Efficacy of Tocilizumab via Contrast-Enhanced Ultrasound-Monitored, Ultrasound-Targeted Microbubble Destruction.

Our aim was to explore the feasibility of using ultrasound-targeted microbubble destruction (UTMD) to deliver tocilizumab and enhance its efficacy in treating rheumatoid arthritis (RA). Rats with adjuvant-induced arthritis were randomly assigned to one of five treatment groups: group 1, tocilizumab+microbubbles (MBs)+UTMD; group 2, tocilizumab+MBs; group 3, tocilizumab+saline; group 4, MBs+UTMD; group 5, no treatment. We employed a commercially available ultrasound (US) machine capable of performing contrast-enhanced ultrasound (CEUS) and UTMD simultaneously using a single probe. CEUS was performed to monitor the entry and collapse of MBs. After treatment, the rats' left hindlimb paws were harvested for immunohistochemical staining of interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α). After injection of the mixture of drugs and MBs with UTMD, significant enhancement was seen in the inflamed hindlimb paw regions, which subsided immediately on exposure to low-frequency US beams and re-appeared in the intervals between beam exposures. IL-6 expression was significantly lower in groups 1, 2 and 3 than in groups 4 and 5 (p < 0.01). Group 1 had the lowest level of IL-6 expression (p [G1 vs. G2] < 0.01, p [G1 vs. G3] < 0.01). The levels of TNF-α expression in groups 1, 2, and 3 were significantly lower than those in groups 4 and 5, but no difference was observed in these levels between groups 1-3. UTMD shows promise in enhancing the treatment efficacy of anti-IL-6 drugs for RA treatment.

O-27 - A kit-based approach to aluminium-[18F]fluoride-labelled microbubbles and their in vivo biodistribution following ultrasound-targeted microbubble destruction

O-27 - A kit-based approach to aluminium-[18F]fluoride-labelled microbubbles and their in vivo biodistribution following ultrasound-targeted microbubble destruction

Ultrasound-Targeted Microbubble Destruction Assisted Delivery of Platelet-Rich Plasma-Derived Exosomes Promoting Peripheral Nerve Regeneration.

Peripheral nerve injury is prevalent and has a high disability rate in clinical settings. Current therapeutic methods have not achieved satisfactory efficacy, underscoring the need for novel approaches to nerve restoration that remains an active area of research in neuroscience and regenerative medicine. In this study, we isolated platelet-rich plasma-derived exosomes (PRP-exos) and found that they can significantly enhance the proliferation, migration, and secretion of trophic factors by Schwann cells (SCs). In addition, there were marked changes in transcriptional and expression profiles of SCs, particularly via the upregulation of genes related to biological functions involved in nerve regeneration and repair. In the rat model of sciatic nerve crush injury, ultrasound-targeted microbubble destruction (UTMD) enhanced the efficiency of PRP-exos delivery to the injury site. This approach ensured a high concentration of PRP-exos in the injured nerve and improved the therapeutic outcomes. In conclusion, PRP-exos may promote nerve regeneration and repair, and UTMD may increase the effectiveness of targeted PRP-exos delivery to the injured nerve and enhance the therapeutic effect.

Ultrasound-targeted semaglutide-loaded PEG-nanoliposomes microbubble destruction protects diabetic cardiomyopathy by activating PI3K/Akt/Nrf2 signaling pathway

ObjectiveTo investigate the ameliorative effect of Semaglutide-loaded PEG-nanoliposomes (Sem-PEG-lips) combined with ultrasound-targeted microbubble destruction (UTMD) on streptozotocin (STZ)-induced diabetic cardiomyopathy (DCM) in rodents and its potential mechanisms. MethodsSem-PEG-lips were prepared by the reverse phase evaporation method. Fifty STZ-induced diabetic rats were randomly divided into DCM model group, Sem or Sem-PEG-lips alone treatment group, UTMD + Sem group and UTMD + Sem-PEG-lips group (n = 10), respectively, and used the healthy rats as normal control. During the 12-week intervention, the weight and blood glucose levels of all rats were recorded. Myocardial injury and fibrosis were observed by using H&E and Masson staining. The activity of antioxidant enzymes and the expression levels of oxidative stress-related signaling pathway markers in myocardial tissues were measured by ELISA and western blotting method, respectively. ResultsCompared with DCM rats, the body weight and blood glucose levels of those in the UTMD + Sem-PEG-lips group were significantly increased and decreased, respectively (both p < 0.05). The results of H&E and Masson staining showed that myocardial fibrosis and apoptosis were both significantly improved in combination group (both p < 0.001). Further results of ELISA and Western blot analysis showed that the activity of antioxidant enzymes in ones received combination therapy were significantly higher than that in DCM model group (all p < 0.001), and the expression of PI3K/Akt/Nrf2 signaling pathway related proteins were significantly up-regulated (all p < 0.001), and all these changes were reversed by the treatment of PI3K inhibitor. results ConclusionUTMD combined Sem-PEG-lips can reduce the oxidative stress of myocardial tissue in DCM rats by activating PI3K/Akt/Nrf2 signaling pathway, thereby improving diabetic myocardial injury.

Ultrasound-targeted microbubble destruction mediates PDE5i/NO integration for cavernosum remodeling and penile rehabilitation.

Erectile dysfunction (ED) caused by cavernous nerve injury (CNI) is refractory to heal mainly ascribed to the adverse remodeling of the penis induced by ineffectual microvascular perfusion, fibrosis, and neurotrophins scarcity in cavernosum. Phosphodiesterase type V inhibitors (PDE5i) have been regarded as an alternative candidate drug for avoiding penile neuropathy. However, the therapeutic efficacy is severely limited due to poor accumulation under systemic medication and endogenous nitric oxide (NO) deficiency in cavernosum. Herein, an innovative liposomal microbubble (MB) loaded with both Sildenafil (one of PDE5i) and NO was designed. Ultrasound-targeted MB destruction (UTMD)-mediated efficient release and integration erectogenic agents into corpus cavernosum with high biosafety. On a bilateral CNI rat model, the multifunctional MB-cooperated UTMD improved microvascular perfusion in penis, simultaneously, alleviated hypoxia and oxidative stress, indicating successful activation of NO-cyclic guanosine monophosphate pathway. Also, evaluation of the endothelial/muscular composition, intracavernosal pressure, and neural integrity in the penis proved that coordinated intervention reversed the abnormal structural remodeling and promoted the recovery of functional erection. Our work demonstrates that MB loading Sildenafil and NO combined with UTMD hold great promise to "awaken" the efficacy of PDE5i in neurogenic ED, which provided a superior option for ensuring penile rehabilitation.

Cardioprotective effect of ultrasound-targeted destruction of Sirt3-loaded cationic microbubbles in a large animal model of pathological cardiac hypertrophy.

Pathological cardiac hypertrophy occurs in response to numerous increased afterload stimuli and precedes irreversible heart failure (HF). Therefore, therapies that ameliorate pathological cardiac hypertrophy are urgently required. Sirtuin 3 (Sirt3) is a main member of histone deacetylase class III and is a crucial anti-oxidative stress agent. Therapeutically enhancing the Sirt3 transfection efficiency in the heart would broaden the potential clinical application of Sirt3. Ultrasound-targeted microbubble destruction (UTMD) is a prospective, noninvasive, repeatable, and targeted gene delivery technique. In the present study, we explored the potential and safety of UTMD as a delivery tool for Sirt3 in hypertrophic heart tissues using adult male Bama miniature pigs. Pigs were subjected to ear vein delivery of human Sirt3 together with UTMD of cationic microbubbles (CMBs). Fluorescence imaging, western blotting, and quantitative real-time PCR revealed that the targeted destruction of ultrasonic CMBs in cardiac tissues greatly boosted Sirt3 delivery. Overexpression of Sirt3 ameliorated oxidative stress and partially improved the diastolic function and prevented the apoptosis and profibrotic response. Lastly, our data revealed that Sirt3 may regulate the potential transcription of catalase and MnSOD through Foxo3a. Combining the advantages of ultrasound CMBs with preclinical hypertrophy large animal models for gene delivery, we established a classical hypertrophy model as well as a strategy for the targeted delivery of genes to hypertrophic heart tissues. Since oxidative stress, fibrosis and apoptosis are indispensable in the evolution of cardiac hypertrophy and heart failure, our findings suggest that Sirt3 is a promising therapeutic option for these diseases. STATEMENT OF SIGNIFICANCE: Pathological cardiac hypertrophy is a central prepathology of heart failure and is seen to eventually precede it. Feasible targets that may prevent or reverse disease progression are scarce and urgently needed. In this study, we developed surface-filled lipid octafluoropropane gas core cationic microbubbles that could target the release of human Sirt3 reactivating the endogenous Sirt3 in hypertrophic hearts and protect against oxidative stress in a pig model of cardiac hypertrophy induced by aortic banding. Sirt3-CMBs may enhance cardiac diastolic function and ameliorate fibrosis and apoptosis. Our work provides a classical cationic lipid-based, UTMD-mediated Sirt3 delivery system for the treatment of Sirt3 in patients with established cardiac hypertrophy, as well as a promising therapeutic target to combat pathological cardiac hypertrophy.