Biomechanical Response of Cancer Stem Cells to Low-Intensity Ultrasound.

The presence of stem cells in cancer may increase the chances of drug resistance and invasiveness. Low-intensity ultrasound (LIUS) can regulate the biological and mechanical properties of cells and participate in cellular migration and differentiation. Although LIUS has shown significant potential in cancer treatment, the effects of LIUS on migration and drug resistance of cancer stem cells (CSCs) are unclear from a biomechanical perspective. Hence, the objective of this work is to analyze the biomechanical response of LIUS to CSCs. In this study, we selected human ovarian cancer cell line A2780 and ovarian cancer stem cells (OCSCs) were enriched from A2780 cells and observed that OCSCs had higher drug sensitivity and lower invasiveness than A2780 cells after LIUS exposure. Furthermore, we further analyzed the changes in cell morphology, cytoskeleton, and membrane stiffness of A2780 cells and OCSCs at various intensities of LIUS, these results showed that LIUS could induce morphological changes, F-actin formation and increase membrane stiffness, which could help to suppress migration and reduce the drug resistance of OCSCs. Our findings will help establish a better understanding of the biomechanical response to LIUS in CSCs, and future studies on cancer will benefit from the careful consideration of the cellular response of CSCs to LIUS stimulation, ultimately allowing for the development of more effective therapies.

Progress in the Application of Ultrasound Elastography for Brain Diseases.

Ultrasound (US) can be used to evaluate the brain structure and nervous system damage. Patients with neurologic symptoms need rapid, noninvasive imaging with high spatial resolution and tissue contrast. Magnetic resonance imaging is currently the most sensitive and specific imaging method for evaluating neuropathologic conditions. This approach does present some challenges, such as the need to transport patients who may be seriously ill to the magnetic resonance imaging suite and the need for patients to remain for a considerable time. Cranial US provides a very valuable imaging method for clinicians, which can make a rapid diagnosis and evaluation without ionizing radiation. The main disadvantage of cranial US is its low sensitivity and specificity for subtle/early lesions. In recent years, with the rapid development of anatomic and functional US technology, the practicability of US diagnosis and intervention has been greatly improved. Ultrasound elastography may have the potential to improve the sensitivity and specificity of various cranial nerve conditions. Ultrasound elastography has received considerable critical attention, and an increasing number of studies have recognized its critical role in evaluating brain diseases. At present, US elastography has been applied to the evaluation of traumatic brain injury, ischemic stroke, intraoperative brain tumors, and hypoxic ischemic encephalopathy. The latest animal experiments and human clinical trial developments in the applications of US elastography for brain diseases are summarized in this review.

Development of an auxiliary device for ultrasound-guided aspiration of pelvic cystic masses: a simulation study.

BACKGROUND: Pelvic cystic masses are a common gynecological condition. Ultrasound-guided aspiration is a minimally invasive surgical technique for the treatment of pelvic cystic masses. However, further developments to improve its stability and safety are wanting. This study evaluated the application and safety of a self-developed auxiliary device for pelvic cystic masses' ultrasound-guided aspiration through phantom testing. METHODS: Saline and coupling agents were used at different viscosity levels to simulate simple cysts, medium viscosity cysts (such as pelvic effusions), and ovarian, endometrial cysts. An auxiliary device consisting of a three-way valve, a negative pressure aspirator, and a pressurized infusion bag was developed. Phantom testing was performed to evaluate the application of this device in ultrasound-guided aspiration of pelvic cystic masses. The indicators, including the time of aspiration, time of injection, and the incidence of complications, were compared to cases in which ultrasound-guided aspiration was performed manually with a syringe. RESULTS: The incidence of complications in the auxiliary device group was significantly lower compared to the manual operation group (P<0.05). The ovarian cystic aspiration times and operation times were significantly shorter in the auxiliary device group compared to the traditional manual puncture group (P<0.05). CONCLUSIONS: Ultrasound-guided aspiration is repeatable and minimally invasive for the treatment of pelvic cystic masses. Using the auxiliary device designed in this report resulted in shorter operation times, definite needle fixation, and fewer complications, which may allow for a more stable and safer aspiration procedure for the treatment of pelvic cystic masses.

Convolutional Neural Network for Breast and Thyroid Nodules Diagnosis in Ultrasound Imaging.

OBJECTIVE: The incidence of superficial organ diseases has increased rapidly in recent years. New methods such as computer-aided diagnosis (CAD) are widely used to improve diagnostic efficiency. Convolutional neural networks (CNNs) are one of the most popular methods, and further improvements of CNNs should be considered. This paper aims to develop a multiorgan CAD system based on CNNs for classifying both thyroid and breast nodules and investigate the impact of this system on the diagnostic efficiency of different preprocessing approaches. METHODS: The training and validation sets comprised randomly selected thyroid and breast nodule images. The data were subgrouped into 4 models according to the different preprocessing methods (depending on segmentation and the classification method). A prospective data set was selected to verify the clinical value of the CNN model by comparison with ultrasound guidelines. Diagnostic efficiency was assessed based on receiver operating characteristic (ROC) curves. RESULTS: Among the 4 models, the CNN model using segmented images for classification achieved the best result. For the validation set, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and area under the curve (AUC) of our CNN model were 84.9%, 69.0%, 62.5%, 88.2%, 75.0%, and 0.769, respectively. There was no statistically significant difference between the CNN model and the ultrasound guidelines. The combination of the two methods achieved superior diagnostic efficiency compared with their use individually. CONCLUSIONS: The study demonstrates the probability, feasibility, and clinical value of CAD in the ultrasound diagnosis of multiple organs. The use of segmented images and classification by the nature of the disease are the main factors responsible for the improvement of the CNN model. Moreover, the combination of the CNN model and ultrasound guidelines results in better diagnostic performance, which will contribute to the improved diagnostic efficiency of CAD systems.

Synergistic ultrasonic biophysical effect-responsive nanoparticles for enhanced gene delivery to ovarian cancer stem cells.

Ovarian cancer stem cells (OCSCs) that are a subpopulation within bulk tumor survive chemotherapy and conduce to chemo-resistance and tumor relapse. However, conventional gene delivery is unsuitable for the on-demand content release, which limits OCSCs therapeutic utility. Here, we reported ultrasound-targeted microbubble destruction (UTMD)-triggerable poly(ethylene glycol)-disulfide bond-polyethylenimine loaded microbubble (PSP@MB). Taking advantage of glutathione (GSH) responsiveness, ultrasound triggering and spatiotemporally controlled release manner, PSP@MB is expected to realize local gene delivery for OCSCs treatment. But the biophysical mechanisms of gene delivery via PSP@MB and ultrasound remain unknown. The aim of this study is to determine the potential of gene delivery to OCSCs via ultrasonic synergistic biophysical effects and GSH-sensitive PSP@MB. The GSH-sensitive disulfide bond cleavable properties of PSP@MB were confirmed by 1H NMR spectra and infrared spectroscopy. The biophysical mechanisms between PSP@MB and cells were confirmed by scanning electron microscopy (SEM) and confocal laser scanning microscope (CLSM) to optimize the ultrasonic gene delivery system. The gene transfection via ultrasound and PSP@MB was closely related to the biophysical mechanisms (sonoporation, enhanced-endocytosis, sonoprinting, and endosomal escape). Ultrasound combined with PSP@MB successfully delivered aldehyde dehydrogenase 1 (ALDH1) short hairpin RNA (shRNA) plasmid to OCSCs and promoted apoptosis of OCSCs. The gene transfection rate and apoptosis rate were (18.41 ± 2.41)% and (32.62 ± 2.36)% analyzed by flow cytometry separately. This study showed that ultrasound triggering and GSH responsive PSP@MB might provide a novel strategy for OCSCs treatment via sonoporation and enhanced-endocytosis.

Ultrasound Responsive Magnetic Mesoporous Silica Nanoparticle-Loaded Microbubbles for Efficient Gene Delivery.

Purpose: Gene therapy is an important therapeutic strategy for cancer. Nanoparticles are used for noninvasive gene delivery, which has great potential in tumor therapy. However, it is a challenge to construct a targeted gene delivery vector with high gene delivery efficiency, good biocompatibility, and multiple functions. Method: Herein, we designed magnetic mesoporous silica nanoparticle loading microbubbles (M-MSN@MBs) for ultrasound-mediated imaging and gene transfection. The plasmid DNA (pDNA) was encapsulated into the pores of M-MSNs. Also, the pDNA-carrying M-MSNs were loaded in the lipid microbubbles. Results: The gene vector presented good biocompatibility, DNA binding stability, ultrasound imaging performance, and magnetic responsiveness. The polyethyleneimine (PEI)-modified M-MSNs effectively protected the loaded pDNA from enzyme degradation. The cytotoxicity of M-MSNs was significantly reduced via encapsulating in lipid microbubbles. Upon the magnetic field, M-MSN@MBs were attracted to the tumor area. Then, ultrasound-targeted microbubble destruction (UTMD) not only released loaded M-MSNs but also facilitated M-MSNs delivery to tumor tissue by opening blood-tumor barrier and increasing the cytomembrane permeability, and ultimately improved the pDNA delivery efficiency. Conclusion: Our findings suggested that the developed ultrasound-responsive gene delivery system was a promising platform for gene therapy, which could noninvasively enhance tumor gene transfection.

Advances in mechanism studies on ultrasonic gene delivery at cellular level.

Ultrasound provides a means for intracellular gene delivery, contributing to a noninvasive and spatiotemporally controllable strategy suitable for clinical applications. Many studies have been done to provide mechanisms of ultrasound-mediated gene delivery at the cellular level. This review summarizes the studies on the important aspects of the mechanisms, providing an overview of recent progress in cellular experiment of ultrasound-mediated gene delivery.

Update on thyroid ultrasound: a narrative review from diagnostic criteria to artificial intelligence techniques.

OBJECTIVE: Ultrasound imaging is well known to play an important role in the detection of thyroid disease, but the management of thyroid ultrasound remains inconsistent. Both standardized diagnostic criteria and new ultrasound technologies are essential for improving the accuracy of thyroid ultrasound. This study reviewed the global guidelines of thyroid ultrasound and analyzed their common characteristics for basic clinical screening. Advances in the application of a combination of thyroid ultrasound and artificial intelligence (AI) were also presented. DATA SOURCES: An extensive search of the PubMed database was undertaken, focusing on research published after 2001 with keywords including thyroid ultrasound, guideline, AI, segmentation, image classification, and deep learning. STUDY SELECTION: Several types of articles, including original studies and literature reviews, were identified and reviewed to summarize the importance of standardization and new technology in thyroid ultrasound diagnosis. RESULTS: Ultrasound has become an important diagnostic technique in thyroid nodules. Both standardized diagnostic criteria and new ultrasound technologies are essential for improving the accuracy of thyroid ultrasound. In the standardization, since there are no global consensus exists, common characteristics such as a multi-feature diagnosis, the performance of lymph nodes, explicit indications of fine needle aspiration, and the diagnosis of special populations should be focused on. Besides, evidence suggests that AI technique has a good effect on the unavoidable limitations of traditional ultrasound, and the combination of diagnostic criteria and AI may lead to a great promotion in thyroid diagnosis. CONCLUSION: Standardization and development of novel techniques are key factors to improving thyroid ultrasound, and both should be considered in normal clinical use.

Echogenic PEGylated PEI-Loaded Microbubble As Efficient Gene Delivery System.

BACKGROUND: Cancer stem cells (CSCs) are responsible for cancer therapeutic resistance and metastasis. To date, in addition to surgery, chemotherapy, and radiotherapy, gene delivery has emerged as a potential therapeutic modality for ovarian cancer. Efficient and safe targeted gene delivery is complicated due to the tumor heterogeneity barrier. Ultrasound (US)-stimulated microbubbles (MBs) have demonstrated a method of enabling non-invasive targeted gene delivery. PURPOSE: The purpose of our study was to show the utility of poly(ethylene glycol)-SS-polyethylenimine-loaded microbubbles (PSP@MB) as an ultrasound theranostic and redox-responsive agent in a gene delivery system. PATIENTS AND METHODS: PSP nanoparticles were conjugated to the MB surface through biotin-avidin linkage, increasing the gene-loading efficiency of MB. The significant increase in the release of genes from the PSP@MB complexes was achieved upon ultrasound exposure. The positive surface charge in PSP@MB can condense the plasmid through electrostatic interactions; agarose-gel electrophoresis further confirmed the ability of PSP@MB to condense plasmids. The morphology, particle sizes and zeta potential of PSP@MB were characterized by transmission electron microscopy and dynamic light scattering. RESULTS: Laser confocal microscopy showed that the combination of ultrasound with PSP@MB could promote the cellular uptake of plasmids. Plasmids which encode enhanced green fluorescence protein (EGFP) reporter genes or luciferase reporter genes were delivered to CSCs in vitro and to subcutaneous xenografts in vivo via the combination of ultrasound with PSP@MB. Gene transfection efficiency was evaluated by fluorescence microscopy and In Vivo Imaging Systems. This study demonstrated that the combination of ultrasound with PSP@MB can remarkably promote gene delivery to solid tumors as well as diminishing the toxicity towards normal tissues in vivo. The combination of PSP@MB and the use of ultrasound can efficiently enhance accumulation, extravasation and penetration into solid tumors. CONCLUSION: Taken together, our study showed that this novel PSP@MB and ultrasound-mediated gene delivery system could efficiently target CSCs.

Ultrasound microbubbles mediated miR-let-7b delivery into CD133+ ovarian cancer stem cells.

Ovarian cancer stem cells (OCSCs) are considered the reason for ovarian cancer's emergence and recurrence. Ultrasound-targetted microbubble destruction (UTMD), a non-vial, safe, and promising delivery method for miRNA, is reported to transfect cancer stem cells (CSCs). In the present study, we investigated to transfect miR-let-7b into OCSCs using UTMD. The CD133+ OCSCs, accounted for only 0.1% of ovarian cancer cell line A2780, were separated by flow cytometry, and the CSC characteristics of CD133+ OCSCs have been proved by spheroid formation and self-renewal assay. The miR-let-7b transfection efficiency using UTMD was significantly higher than other groups except lipofectamine group through flow cytometry. The cell viability of all groups decreased after transfection, and the late apoptosis rate of CD133+ OCSCs after miR-let7b transfection induced by UTMD was 2.62%, while that of non-treated cells was 0.02% (P<0.05). Furthermore, the Western blot results demonstrated that the stem cells surface marker of CD133 expression has decreased. Therefore, our results indicated that UTMD-mediated miRNA delivery could be a promising platform for CSC therapy.

Echogenic Chitosan Nanodroplets for Spatiotemporally Controlled Gene Delivery.

To attain attractive ultrasound-responsive gene delivery, a new kind of echogenic chitosan nanodroplets (CND) was developed to explore the potential to deliver genes in a spatiotemporally controlled manner. Self-assembled amphiphilic chitosan micelles of nanoscale size were fabricated to encapsulate hydrophobic perfluoropentane into the inner cores. The resulting CND presented a positive surface charge, enabling the formation of nano-complexes with genetic cargo through electrostatic interactions. Agarose-gel electrophoresis further confirmed the ability of CND to bind DNA. CND was also observed to protect DNA from degradation by nucleases. A temperature-dependent droplet-to-bubble conversion was also demonstrated. More importantly, our study revealed that CND in combination with ultrasound could significantly enhance gene delivery. In conclusion, our study demonstrated a novel carrier with great potential for efficient ultrasound-mediated gene delivery to specific tissues in a spatiotemporally controlled manner.

Ultrasound-mediated microbubble destruction: a new method in cancer immunotherapy.

Immunotherapy provides a new treatment option for cancer. However, it may be therapeutically insufficient if only using the self-immune system alone to attack the tumor without any aiding methods. To overcome this drawback and improve the efficiency of therapy, new treatment methods are emerging. In recent years, ultrasound-mediated microbubble destruction (UMMD) has shown great potential in cancer immunotherapy. Using the combination of ultrasound and targeted microbubbles, molecules such as antigens or genes encoding antigens can be efficiently and specifically delivered into the tumor tissue. This review focuses on the recent progress in the application of UMMD in cancer immunotherapy.

Ultrasound in neonatal lung disease.

Lung diseases in neonates can be life-threatening condition and may result in respiratory failure and death. Chest X-ray is a traditional diagnostic technique that results in radiation exposure to patients. Lung ultrasound is a user-friendly imaging technique that has been increasingly used in clinical practice in recent years and presents the advantages of real-time imaging and without radiation. Here we review the sonographic appearances of common neonatal lung diseases and present demonstration of typical cases.

Microbubbles: A Novel Strategy for Chemotherapy.

BACKGROUND: Ultrasound microbubbles have conventionally been used for diagnostic purposes. In recent years, however, new types of microbubbles have emerged as important carriers for drug delivery. Moreover, studies have shown that ultrasound microbubbles can serve as valuable and noninvasive tools in cancer therapy; thus the use of ultrasound microbubbles to deliver chemotherapeutic drugs to malignant tissues is a promising possibility. METHODS: In this review, we briefly describe the status of ultrasound microbubbles in clinical practice and then discuss the development of targeted microbubbles. Finally, we consider novel strategies for the use of microbubbles in cancer therapy. RESULTS: Many different kinds of microbubbles are emerged. Novel strategies of ultrasound microbubble have been shown to be effective in cancer therapy. CONCLUSION: Although many problems need to be solved in the future, the ultrasound drugs loaded microbubbles still have strong potential for the use in clinical cancer therapy.