Sonoporation, drug delivery, and gene therapy

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.

Ultrasound-controllable dexamethasone-loaded nanobubbles for highly effective rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is an autoimmune disease that seriously threatens human health and affects the quality of life of patients. At present, pharmacotherapy is still the mainstream treatment for RA, but most methods have shortcomings, such as poor drug targeting, a low effective drug dosage at the inflammatory site, and high systemic toxicity. The combined application of drug-loaded nanobubbles and ultrasound technology provides a new technique for the treatment of RA. Low-intensity focused ultrasound (LIFU) traces the transmission of drug-loaded nanobubbles in the body, and high-intensity focused ultrasound (HIFU) causes the nanobubbles to rupture to release drugs at the inflammatory site, thereby reducing their toxicity to normal tissues. In this study, a drug-loaded nanobubble delivery system (DEXsp@Liposomes/C3F8) with ultrasonic response characteristics was successfully constructed, and its therapeutic effect was evaluated for the treatment of RA in vitro and in vivo. DEXsp@Liposomes/C3F8 + LIFU had good biocompatibility and excellent ultrasound imaging ability. DEXsp@Liposomes/C3F8 +HIFU distinctly increased the cellular uptake of DEXsp and significantly reduced the secretion of related inflammatory factors in RAW264.7 cells. Moreover, DEXsp@Liposomes/C3F8 + HIFU effectively alleviated the symptoms of RA in model rats and significantly improved their exercise capacity. In conclusion, the prepared ultrasound-mediated DEXsp@Liposomes/C3F8 system exhibits good imaging, monitoring and therapeutic effects, and the results of this study provide a new direction for the diagnosis and treatment of RA.

Drug Release via Ultrasound-Activated Nanocarriers for Cancer Treatment: A Review

Conventional cancer chemotherapy often struggles with safely and effectively delivering anticancer therapeutics to target tissues, frequently leading to dose-limiting toxicity and suboptimal therapeutic outcomes. This has created a need for novel therapies that offer greater efficacy, enhanced safety, and improved toxicological profiles. Nanocarriers are nanosized particles specifically designed to enhance the selectivity and effectiveness of chemotherapy drugs while reducing their toxicity. A subset of drug delivery systems utilizes stimuli-responsive nanocarriers, which enable on-demand drug release, prevent premature release, and offer spatial and temporal control over drug delivery. These stimuli can be internal (such as pH and enzymes) or external (such as ultrasound, magnetic fields, and light). This review focuses on the mechanics of ultrasound-induced drug delivery and the various nanocarriers used in conjunction with ultrasound. It will also provide a comprehensive overview of key aspects related to ultrasound-induced drug delivery, including ultrasound parameters and the biological effects of ultrasound waves.

A, Nayak UY. Low-Frequency Sonophoresis: A Promising Strategy for Enhanced Transdermal Delivery

Sonophoresis is the most approachable mode of transdermal drug delivery system, wherein low-frequency sonophoresis penetrates the drug molecules into the skin. It is an alternative method for an oral system of drug delivery and hypodermal injections. The cavitation effect is thought to be the main mechanism used in sonophoresis. The cavitation process involves forming a gaseous bubble and its rupture, induced in the coupled medium. Other mechanisms used are thermal effects, convectional effects, and mechanical effects. It mainly applies to transporting hydrophilic drugs, macromolecules, gene delivery, and vaccine delivery. It is also used in carrier-mediated delivery in the form of micelles, liposomes, and dendrimers. Some synergistic effects of sonophoresis, along with some permeation enhancers, such as chemical enhancers, iontophoresis, electroporation, and microneedles, increased the effectiveness of drug penetration. Sonophoresis-mediated ocular drug delivery, nail drug delivery, gene delivery to the brain, sports medicine, and sonothrombolysis are also widely used. In conclusion, while sonophoresis offers promising applications in diverse fields, further research is essential to comprehensively elucidate the biophysical mechanisms governing ultrasound-tissue interactions. Addressing these gaps in understanding will enable the refinement and optimization of sonophoresis-based therapeutic strategies for enhanced clinical efficacy.

Microfluidic Mechanoporation: Current Progress and Applications in Stem Cells

Intracellular delivery, the process of transporting substances into cells, is crucial for various applications, such as drug delivery, gene therapy, cell imaging, and regenerative medicine. Among the different approaches of intracellular delivery, mechanoporation stands out by utilizing mechanical forces to create temporary pores on cell membranes, enabling the entry of substances into cells. This method is promising due to its minimal contamination and is especially vital for stem cells intended for clinical therapy. In this review, we explore various mechanoporation technologies, including microinjection, micro-nano needle arrays, cell squeezing through physical confinement, and cell squeezing using hydrodynamic forces. Additionally, we highlight recent research efforts utilizing mechanoporation for stem cell studies. Furthermore, we discuss the integration of mechanoporation techniques into microfluidic platforms for high-throughput intracellular delivery with enhanced transfection efficiency. This advancement holds potential in addressing the challenge of low transfection efficiency, benefiting both basic research and clinical applications of stem cells. Ultimately, the combination of microfluidics and mechanoporation presents new opportunities for creating comprehensive systems for stem cell processing.

Ultrasound-mediated nano-sized drug delivery systems for cancer treatment: Multi-scale and multi-physics computational modeling

Computational modeling enables researchers to study and understand various complex biological phenomena in anticancer drug delivery systems (DDSs), especially nano-sized DDSs (NSDDSs). The combination of NSDDSs and therapeutic ultrasound (TUS), that is, focused ultrasound and low-intensity pulsed ultrasound, has made significant progress in recent years, opening many opportunities for cancer treatment. Multiple parameters require tuning and optimization to develop effective DDSs, such as NSDDSs, in which mathematical modeling can prove advantageous. In silico computational modeling of ultrasound-responsive DDS typically involves a complex framework of acoustic interactions, heat transfer, drug release from nanoparticles, fluid flow, mass transport, and pharmacodynamic governing equations. Owing to the rapid development of computational tools, modeling the different phenomena in multi-scale complex problems involved in drug delivery to tumors has become possible. In the present study, we present an in-depth review of recent advances in the mathematical modeling of TUS-mediated DDSs for cancer treatment. A detailed discussion is also provided on applying these computational models to improve the clinical translation for applications in cancer treatment. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

The Evolution and Recent Trends in Acoustic Targeting of Encapsulated Drugs to Solid Tumors: Strategies beyond Sonoporation

Despite recent advancements in ultrasound-mediated drug delivery and the remarkable success observed in pre-clinical studies, no delivery platform utilizing ultrasound contrast agents has yet received FDA approval. The sonoporation effect was a game-changing discovery with a promising future in clinical settings. Various clinical trials are underway to assess sonoporation's efficacy in treating solid tumors; however, there are disagreements on its applicability to the broader population due to long-term safety issues. In this review, we first discuss how acoustic targeting of drugs gained importance in cancer pharmaceutics. Then, we discuss ultrasound-targeting strategies that have been less explored yet hold a promising future. We aim to shed light on recent innovations in ultrasound-based drug delivery including newer designs of ultrasound-sensitive particles specifically tailored for pharmaceutical usage.

Focused ultrasound for treatment of peripheral brain tumors

Malignant brain tumors are the leading cause of cancer-related death in children and remain a significant cause of morbidity and mortality throughout all demographics. Central nervous system (CNS) tumors are classically treated with surgical resection and radiotherapy in addition to adjuvant chemotherapy. However, the therapeutic efficacy of chemotherapeutic agents is limited due to the blood-brain barrier (BBB). Magnetic resonance guided focused ultrasound (MRgFUS) is a new and promising intervention for CNS tumors, which has shown success in preclinical trials. High-intensity focused ultrasound (HIFU) has the capacity to serve as a direct therapeutic agent in the form of thermoablation and mechanical destruction of the tumor. Low-intensity focused ultrasound (LIFU) has been shown to disrupt the BBB and enhance the uptake of therapeutic agents in the brain and CNS. The authors present a review of MRgFUS in the treatment of CNS tumors. This treatment method has shown promising results in preclinical trials including minimal adverse effects, increased infiltration of the therapeutic agents into the CNS, decreased tumor progression, and improved survival rates.

Immunomodulation and targeted drug delivery with high intensity focused ultrasound (HIFU): Principles and mechanisms

High intensity focused ultrasound (HIFU) is a non-invasive and non-ionizing sonic energy-based therapeutic technology for inducing thermal and non-thermal effects in tissues. Depending on the parameters, HIFU can ablate tissues by heating them to >55 °C to induce denaturation and coagulative necrosis, improve radio- and chemo-sensitizations and local drug delivery from nanoparticles at moderate hyperthermia (~41-43 °C), and mechanically fragment cells using acoustic cavitation (also known as histotripsy). HIFU has already emerged as an attractive modality for treating human prostate cancer, veterinary cancers, and neuromodulation. Herein, we comprehensively review the role of HIFU in enhancing drug delivery and immunotherapy in soft and calcified tissues. Specifically, the ability of HIFU to improve adjuvant treatments from various classes of drugs is described. These crucial insights highlight the opportunities and challenges of HIFU technology and its potential to support new clinical trials and translation to patients.

Ultrasound-mediated nano drug delivery for treating cancer: Fundamental physics to future directions

The application of biocompatible nanocarriers in medicine has provided several benefits over conventional treatment methods. However, achieving high treatment efficacy and deep penetration of nanocarriers in tumor tissue is still challenging. To address this, stimuli-responsive nano-sized drug delivery systems (DDSs) are an active area of investigation in delivering anticancer drugs. While ultrasound is mainly used for diagnostic purposes, it can also be applied to affect cellular function and the delivery/release of anticancer drugs. Therapeutic ultrasound (TUS) has shown potential as both a stand-alone anticancer treatment and a method to induce targeted drug release from nanocarrier systems. TUS approaches have been used to overcome various physiological obstacles, including endothelial barriers, the tumor microenvironment (TME), and immunological hurdles. Combining nanomedicine and ultrasound as a smart DDS can increase in situ drug delivery and improve access to impermeable tissues. Furthermore, smart DDSs can perform targeted drug release in response to distinctive TMEs, external triggers, or dual/multi-stimulus. This results in enhanced treatment efficacy and reduced damage to surrounding healthy tissue or organs at risk. Integrating DDSs and ultrasound is still in its early stages. More research and clinical trials are required to fully understand ultrasound's underlying physical mechanisms and interactions with various types of nanocarriers and different types of cells and tissues. In the present review, ultrasound-mediated nano-sized DDS, specifically focused on cancer treatment, is presented and discussed. Ultrasound interaction with nanoparticles (NPs), drug release mechanisms, and various types of ultrasound-sensitive NPs are examined. Additionally, in vitro, in vivo, and clinical applications of TUS are reviewed in light of the critical challenges that need to be considered to advance TUS toward an efficient, secure, straightforward, and accessible cancer treatment. This study also presents effective TUS parameters and safety considerations for this treatment modality and gives recommendations about system design and operation. Finally, future perspectives are considered, and different TUS approaches are examined and discussed in detail. This review investigates drug release and delivery through ultrasound-mediated nano-sized cancer treatment, both pre-clinically and clinically.

Combinatorial physical methods for cellular therapy: Towards the future of cellular analysis?

The physical energy activated techniques for cellular delivery and analysis is one of the most rapidly expanding research areas for a variety of biological and biomedical discoveries. These methods, such as electroporation, optoporation, sonoporation, mechanoporation, magnetoporation, etc., have been widely used in delivering different biomolecules into a range of primary and patient-derived cell types. However, the techniques when used individually have had limitations in delivery and co-delivery of diverse biomolecules in various cell types. In recent years, a number of studies have been performed by combining the different membrane disruption techniques, either sequentially or simultaneously, in a single study. The studies, referred to as combinatorial, or hybrid techniques, have demonstrated enhanced transfection, such as efficient macromolecular and gene delivery and co-delivery, at lower delivery parameters and with high cell viability. Such studies can open up new and exciting avenues for understanding the subcellular structure and consequently facilitate the development of novel therapeutic strategies. This review consequently aims at summarising the different developments in hybrid therapeutic techniques. The different methods discussed include mechano-electroporation, electro-sonoporation, magneto-mechanoporation, magnetic nanoparticles enhanced electroporation, and magnetic hyperthermia studies. We discuss the clinical status of the different methods and conclude with a discussion on the future prospects of the combinatorial techniques for cellular therapy and diagnostics.

Dual-frequency ultrasound enhances functional neuron differentiation from neural stem cells by modulating Ca2+ dynamics and the ERK1/2 signaling pathway

Our previous study demonstrated that ultrasound is able to promote differentiation on neural stem cells (NSCs), and dual-frequency ultrasound promotes this effect due to enhanced acoustic cavitation compared with single-frequency ultrasound. However, the underlying biological reasons have not been well disclosed. The purpose of this study was to investigate the underlying bioeffects, mechanisms and signaling pathways of dual-frequency ultrasound on NSC differentiation. The morphology, neurite outgrowth, and differentiation percentages were investigated under various dual-frequency simulation parameters with exposure periods varying from 5 to 15 min. Morphological observations identified that dual-frequency ultrasound stimulation promoted ultrasound dose-dependent neurite outgrowth. In particular, cells exposed for 10 min/2 days showed optimal neurite outgrowth and neuron differentiation percentages. In addition, live cell calcium images showed that dual-frequency ultrasound enhanced the internal calcium content of the cells, and calcium ions entering cells from the extracellular environment could be observed. Dual frequency ultrasound exposure enhanced extracellular calcium influx and upregulated extracellular signal-regulated kinases 1/2 (ERK1/2) expression. Observations from immunostaining and protein expression examinations also identified that dual-frequency ultrasound promoted brain-derived neurotrophic factor (BDNF) secretion from astrocytes derived from NSCs. In summary, evidence supports that dual-frequency ultrasound effectively enhances functional neuron differentiation via calcium channel regulation via the downstream ERK1/2 pathway and promotes BDNF secretion to serve as feedback to cascade neuron differentiation. The results may provide an alternative for cell-based therapy in brain injury.

Appraisal for the Potential of Viral and Nonviral Vectors in Gene Therapy: A Review

Over the past few decades, gene therapy has gained immense importance in medical research as a promising treatment strategy for diseases such as cancer, AIDS, Alzheimer's disease, and many genetic disorders. When a gene needs to be delivered to a target cell inside the human body, it has to pass a large number of barriers through the extracellular and intracellular environment. This is why the delivery of naked genes and nucleic acids is highly unfavorable, and gene delivery requires suitable vectors that can carry the gene cargo to the target site and protect it from biological degradation. To date, medical research has come up with two types of gene delivery vectors, which are viral and nonviral vectors. The ability of viruses to protect transgenes from biological degradation and their capability to efficiently cross cellular barriers have allowed gene therapy research to develop new approaches utilizing viruses and their different genomes as vectors for gene delivery. Although viral vectors are very efficient, science has also come up with numerous nonviral systems based on cationic lipids, cationic polymers, and inorganic particles that provide sustainable gene expression without triggering unwanted inflammatory and immune reactions, and that are considered nontoxic. In this review, we discuss in detail the latest data available on all viral and nonviral vectors used in gene delivery. The mechanisms of viral and nonviral vector-based gene delivery are presented, and the advantages and disadvantages of all types of vectors are also given.

Pancreatic Ductal Adenocarcinoma: Current and Emerging Therapeutic Uses of Focused Ultrasound

Pancreatic ductal adenocarcinoma (PDAC) diagnosis accompanies a somber prognosis for the patient, with dismal survival odds: 5% at 5 years. Despite extensive research, PDAC is expected to become the second leading cause of mortality by cancer by 2030. Ultrasound (US) has been used successfully in treating other types of cancer and evidence is flourishing that it could benefit PDAC patients. High-intensity focused US (HIFU) is currently used for pain management in palliative care. In addition, clinical work is being performed to use US to downstage borderline resectable tumors and increase the proportion of patients eligible for surgical ablation. Focused US (FUS) can also induce mechanical effects, which may elicit an anti-tumor response through disruption of the stroma and can be used for targeted drug delivery. More recently, sonodynamic therapy (akin to photodynamic therapy) and immunomodulation have brought new perspectives in treating PDAC. The aim of this review is to summarize the current state of those techniques and share our opinion on their future and challenges.

Delivery of astragalus polysaccharide by ultrasound microbubbles attenuate doxorubicin-induced cardiomyopathy in rodent animals

The aim of this study was to investigate the cardioprotective effects and probable mechanism of ultrasound-targeted microbubble destruction (UTMD) combined with astragalus polysaccharide (APS) on diabetic cardiomyopathy (DCM) model rats. The DCM rats with diabetes and cardiomyopathy were induced via chronic treatment of doxorubicin and then randomly divided into the (1) DCM model group; (2) APS microbubble group; (3) UTMDgroup; and (4) APS microbubbles combined with UTMD group. After 4-week intervention, the fasting blood glucose levels, body weight, %HbA1c level and glucose tolerance of DCM rats received combination therapy were significantly improved as compared with those of UTMD or saline-treated ones. Moreover, the heart/body weight ratio, and myocardial contractility were all improved after receiving combination therapy groups compared with others. In addition, significantly upregulated activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) as well as significantly downregulated malondialdehyde (MDA) levels were all observed in the ones received combined treatment compared to others. Furthermore, the lipid accumulation and the expression levels of inflammatory factors were all significantly down-regulated in those ones received combination therapy compared with others (all P < 0.05). Further pathological analysis demonstrated that combination therapy effectively ameliorated fibrosis and myocardial morphological changes of DCM rats via activating the upregulation of AMPK and PPAR-γ signaling pathway, and inhibiting NF-κB activity in myocardial tissues of DCM rats. In conclusion, APS microbubbles combined with UTMD effectively protect the myocardial injury of DCM rats via activating AMPK signaling pathway to alleviate inflammation response, fibrosis and oxidative stress in myocardial tissues.

Gene Therapy of Chronic Limb-Threatening Ischemia: Vascular Medical Perspectives

A decade ago, gene therapy seemed to be a promising approach for the treatment of chronic limb-threatening ischemia, providing new perspectives for patients without conventional, open or endovascular therapeutic options by potentially enabling neo-angiogenesis. Yet, until now, the results have been far from a safe and routine clinical application. In general, there are two approaches for inserting exogenous genes in a host genome: transduction and transfection. In case of transduction, viral vectors are used to introduce genes into cells, and depending on the selected strain of the virus, a transient or stable duration of protein production can be achieved. In contrast, the transfection of DNA is transmitted by chemical or physical processes such as lipofection, electro- or sonoporation. Relevant risks of gene therapy may be an increasing neo-vascularization in undesired tissue. The risks of malignant transformation and inflammation are the potential drawbacks. Additionally, atherosclerotic plaques can be destabilized by the increased angiogenesis, leading to arterial thrombosis. Clinical trials from pilot studies to Phase II and III studies on angiogenic gene therapy show mainly a mixed picture of positive and negative final results; thus, the role of gene therapy in vascular occlusive disease remains unclear.

Microfluidic mechanoporation for cellular delivery and analysis

Highly efficient intracellular delivery strategies are essential for developing therapeutic, diagnostic, biological, and various biomedical applications. The recent advancement of micro/nanotechnology has focused numerous researches towards developing microfluidic device-based strategies due to the associated high throughput delivery, cost-effectiveness, robustness, and biocompatible nature. The delivery strategies can be carrier-mediated or membrane disruption-based, where membrane disruption methods find popularity due to reduced toxicity, enhanced delivery efficiency, and cell viability. Among all of the membrane disruption techniques, the mechanoporation strategies are advantageous because of no external energy source required for membrane deformation, thereby achieving high delivery efficiencies and increased cell viability into different cell types with negligible toxicity. The past two decades have consequently seen a tremendous boost in mechanoporation-based research for intracellular delivery and cellular analysis. This article provides a brief review of the most recent developments on microfluidic-based mechanoporation strategies such as microinjection, nanoneedle arrays, cell-squeezing, and hydroporation techniques with their working principle, device fabrication, cellular delivery, and analysis. Moreover, a brief discussion of the different mechanoporation strategies integrated with other delivery methods has also been provided. Finally, the advantages, limitations, and future prospects of this technique are discussed compared to other intracellular delivery techniques.

Ultrasound-targeted simvastatin-loaded microbubble destruction promotes OA cartilage repair by modulating the cholesterol efflux pathway mediated by PPARγ in rabbits

Aims

To evaluate the effect of ultrasound-targeted simvastatin-loaded microbubble destruction (UTMD_SV) for alleviation of the progression of osteoarthritis (OA) in rabbits through modulation of the peroxisome proliferator-activated receptor (PPARγ).

Methods

In vitro, OA chondrocytes were treated with ultrasound (US), US-targeted microbubble destruction (UTMD), simvastatin (SV), and UTMD_SV on alternate days for four weeks. Chondrocytes were also treated with PPARγ inhibitor, PPARγ inhibitor+ UTMD_SV, and UTMD_SV. The cholesterol efflux rate and triglyceride levels were measured using an assay kit and oil red O staining, respectively. In vivo, the OA rabbits were treated with a single intra-articular injection of UTMD, SV, and UTMD_SV every seven days for four weeks. Cartilage histopathology was assessed by safranin-O staining and the Mankin score. Total cholesterol (TC) and high-density lipoprotein-cholesterol (HDL-C) in rabbit knee synovial fluid were detected by enzyme-marker assay. Aggrecan, collagen II, and PPARγ expression levels were analyzed by Western blotting (WB).

Results

In vitro, UTMD_SV significantly increased the cholesterol efflux rate and aggrecan, collagen II, and PPARγ levels in OA chondrocytes; these effects were blocked by the PPARγ inhibitor. In vivo, UTMD_SV significantly increased aggrecan, collagen II, PPARγ, and HDL-C levels, while TC levels and Mankin scores were decreased compared with the UTMD, SV, OA, and control groups.

Conclusion

UTMD_SV promotes cartilage extracellular matrix synthesis by modulating the PPARγ-mediated cholesterol efflux pathway in OA rabbits.

Cite this article: Bone Joint Res 2021;10(10):693–703.

A Comparison of Focused and Unfocused Ultrasound for Microbubble-Mediated Gene Delivery

We compared focused and unfocused ultrasound-targeted microbubble destruction (UTMD) for delivery of reporter plasmids to the liver and heart in mice. Optimal hepatic expression was seen with double-depth targeting at 5 and 13 mm in vivo, incorporating a low pulse repetition frequency and short pulse duration. Reporter expression was similar, but the transfection patterns were distinct, with intense foci of transfection using focused UTMD (F-UTMD). We then compared both approaches for cardiac delivery and found 10-fold stronger levels of reporter expression for F-UTMD and observed small areas of intense luciferase expression in the left ventricle. Non-linear contrast imaging of the liver before and after insonation also showed a substantially greater change in signal intensity for F-UTMD, suggesting distinct cavitation mechanisms for both approaches. Overall, similar levels of hepatic transgene expression were observed, but cardiac-directed F-UTMD was substantially more effective. Focused ultrasound presents a new frontier in UTMD-directed gene therapy.

Repurposed drug against COVID-19: nanomedicine as an approach for finding new hope in old medicines

The coronavirus disease 2019 (COVID-19) has become a threat to global public health. It is caused by the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) and has triggered over 17 lakh causalities worldwide. Regrettably, no drug or vaccine has been validated for the treatment of COVID-19 and standard treatment for COVID-19 is currently unavailable. Most of the therapeutics moieties which were originally intended for the other disease are now being evaluated for the potential to be effective against COVID-19 (re-purpose). Nanomedicine has emerged as one of the most promising technologies in the field of drug delivery with the potential to deal with various diseases efficiently. It has addressed the limitations of traditional repurposed antiviral drugs including solubility and toxicity. It has also imparted enhanced potency and selectivity to antivirals towards viral cells. This review emphasizes the scope of repositioning of traditional therapeutic approaches, in addition to the fruitfulness of nanomedicine against COVID-19.

Passive Cavitation Mapping by Cavitation Source Localization From Aperture-Domain Signals-Part I: Theory and Validation Through Simulations

Passive cavitation mapping (PCM) algorithms for diagnostic ultrasound arrays based on time exposure acoustics (TEA) exhibit poor axial resolution, which is in part due to the diffraction-limited point spread function of the imaging system and poor rejection by the delay-and-sum beamformer. In this article, we adapt a method for speed of sound estimation to be utilized as a cavitation source localization (CSL) approach. This method utilizes a hyperbolic fit to the arrival times of the cavitation signals in the aperture domain, and the coefficients of the fit are related to the position of the cavitation source. Wavefronts exhibiting poor fit to the hyperbolic function are corrected to yield improved source localization. We demonstrate through simulations that this method is capable of accurate estimation of the origin of coherent spherical waves radiating from cavitation/point sources. The average localization error from simulated microbubble sources was 0.12 ± 0.12mm ( 0.15 ± 0.14λ₀ for a 1.78-MHz transmit frequency). In simulations of two simultaneous cavitation sources, the proposed technique had an average localization error of 0.2mm ( 0.23λ₀ ), whereas conventional TEA had an average localization error of 0.81mm ( 0.97λ₀ ). The reconstructed PCM-CSL image showed a significant improvement in resolution compared with the PCM-TEA approach.

Modifications of Plasma Membrane Organization in Cancer Cells for Targeted Therapy

Modifications of the composition or organization of the cancer cell membrane seem to be a promising targeted therapy. This approach can significantly enhance drug uptake or intensify the response of cancer cells to chemotherapeutics. There are several methods enabling lipid bilayer modifications, e.g., pharmacological, physical, and mechanical. It is crucial to keep in mind the significance of drug resistance phenomenon, ion channel and specific receptor impact, and lipid bilayer organization in planning the cell membrane-targeted treatment. In this review, strategies based on cell membrane modulation or reorganization are presented as an alternative tool for future therapeutic protocols.

A fiber optoacoustic emitter with controlled ultrasound frequency for cell membrane sonoporation at submillimeter spatial resolution

Focused ultrasound has attracted great attention in minimally invasive therapeutic and mechanism studies. Frequency below 1 MHz is identified preferable for high-efficiency bio-modulation. However, the poor spatial confinement of several millimeters and large device diameter of ∼25 mm of typical sub-MHz ultrasound technology suffered from the diffraction limit, severely hindering its further applications. To address it, a fiber-based optoacoustic emitter (FOE) is developed, serving as a miniaturized ultrasound point source, with sub-millimeter confinement, composed of an optical diffusion layer and an expansion layer on an optical fiber. By modifying acoustic damping and light absorption performance, controllable frequencies in the range of 0.083 MHz-5.500 MHz are achieved and further induce cell membrane sonoporation with frequency dependent efficiency. By solving the problem of compromise between sub-MHz frequency and sub-millimeter precision via breaking the diffraction limit, the FOE shows a great potential in region-specific drug delivery, gene transfection and neurostimulation.

Overcoming anticancer resistance by photodynamic therapy-related efflux pump deactivation and ultrasound-mediated improved drug delivery efficiency

One of the major obstacles to successful chemotherapy is multi-drug resistance (MDR). A multi-drug resistant cancerous cell abnormally overexpresses membrane transporters that pump anticancer drugs out of the cell, resulting in low anticancer drug delivery efficiency. To overcome the limitation, many attempts have been performed to inhibit the abilities of efflux receptors chemically or genetically or to increase the delivery efficiency of anticancer drugs. However, the results have not yet been satisfactory. In this study, we developed nanoparticle-microbubble complexes (DOX-NPs/Ce6-MBs) by conjugating doxorubicin loaded human serum albumin nanoparticles (DOX-NPs) onto the surface of Chlorin e6 encapsulated microbubbles (Ce6-MBs) in order to maximize anticancer efficiency by overcoming MDR. Under the ultrasound irradiation, DOX-NPs and Ce6 encapsulating self-assembled liposomes or micelles were effectively delivered into the cells due to the sonoporation effect caused by the microbubble cavitation. At the same time, reactive oxygen (ROS) generated from intracellularly delivered Ce6 by laser irradiation arrested the activity of ABCG2 efflux receptor overexpressed in doxorubicin-resistant breast cancer cells (MCF-7/ADR), resulting in increased the chemotherapy efficacy. In addition, the total number of side population cells that exhibit the properties of cancer stem-like cells were also reduced by the combination of photodynamic therapy and chemotherapy. In conclusion, DOX-NPs/Ce6-MBs will provide a platform for simultaneously overcoming MDR and increasing drug delivery and therefore, treatment efficiency, under ultrasound irradiation.

A review of ultrasound-mediated microbubbles technology for cancer therapy: a vehicle for chemotherapeutic drug delivery

Background:

The unique behaviour of microbubbles under ultrasound acoustic pressure makes them useful agents for drug and gene delivery. Several studies have demonstrated the potential application of microbubbles as a non-invasive, safe and effective technique for targeted delivery of drugs and genes. The drugs can be incorporated into the microbubbles in several different approaches and then carried to the site of interest where it can be released by destruction of the microbubbles using ultrasound to achieve the required therapeutic effect.

Methods:

The objective of this article is to report on a review of the recent advances of ultrasound-mediated microbubbles as a vehicle for delivering drugs and genes and its potential application for the treatment of cancer.

Conclusion:

Ultrasound-mediated microbubble technology has the potential to significantly improve chemotherapy drug delivery to treatment sites with minimal side effects. Moreover, the technology can induce temporary and reversible changes in the permeability of cells and vessels, thereby allowing for drug delivery in a spatially localised region which can improve the efficiency of drugs with poor bioavailability due to their poor absorption, rapid metabolism and rapid systemic elimination.

On-Chip Sonoporation-Based Flow Cytometric Magnetic Labeling

Tracing magnetically labeled cells with magnetic resonance imaging (MRI) is an emerging and promising approach to uncover in vivo behaviors of cells in cell therapy. Today, existing methods for the magnetic labeling of cells are cumbersome and time-consuming, which has greatly limited the progress of such studies on cell therapy. Thus, in this study, using the flow cytometric loading technology, we develop a sonoporation-based microfluidic chip (i.e., a microfluidic chip integrated with ultrasound; MCU), to achieve the safe, instant, convenient, and continuous magnetic labeling of cells. For the MCU we designed, a suitable group of operating conditions for safely and efficiently loading superparamagnetic iron oxide (SPIO) nanoparticles into DC2.4 cells was identified experimentally. Under the identified operating conditions, the DC2.4 cells could be labeled in approximately 2 min with high viability (94%) and a high labeling quantity of SPIO nanoparticles (19 pg of iron per cell). In addition, the proliferative functions of the cells were also well maintained after labeling. Furthermore, the in vivo imaging ability of the DC2.4 cells labeled using the MCU was verified by injecting the labeled cells into the leg muscle of the C57BL/6 mice. The results show that the excellent imaging outcome can be continuously achieved for 7 days at a density of 10⁶ cells/mL. This work can provide insight for the design of magnetic cell labeling devices and promote the MRI-based study of cell therapies.

A review of emerging physical transfection methods for CRISPR/Cas9-mediated gene editing

Gene editing is a versatile technique in biomedicine that promotes fundamental research as well as clinical therapy. The development of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) as a genome editing machinery has accelerated the application of gene editing. However, the delivery of CRISPR components often suffers when using conventional transfection methods, such as viral transduction and chemical vectors, due to limited packaging size and inefficiency toward certain cell types. In this review, we discuss physical transfection methods for CRISPR gene editing which can overcome these limitations. We outline different types of physical transfection methods, highlight novel techniques to deliver CRISPR components, and emphasize the role of micro and nanotechnology to improve transfection performance. We present our perspectives on the limitations of current technology and provide insights on the future developments of physical transfection methods.

Micro-Particle Image Velocimetry Investigation of Flow Fields of SonoVue Microbubbles Mediated by Ultrasound and Their Relationship With Delivery

The flow fields generated by the acoustic behavior of microbubbles can significantly increase cell permeability. This facilitates the cellular uptake of external molecules in a process known as ultrasound-mediated drug delivery. To promote its clinical translation, this study investigated the relationships among the ultrasound parameters, acoustic behavior of microbubbles, flow fields, and delivery results. SonoVue microbubbles were activated by 1 MHz pulsed ultrasound with 100 Hz pulse repetition frequency, 1:5 duty cycle, and 0.20/0.35/0.70 MPa peak rarefactional pressure. Micro-particle image velocimetry was used to detect the microbubble behavior and the resulting flow fields. Then HeLa human cervical cancer cells were treated with the same conditions for 2, 4, 10, 30, and 60 s, respectively. Fluorescein isothiocyanate and propidium iodide were used to quantitate the rates of sonoporated cells with a flow cytometer. The results indicate that (1) microbubbles exhibited different behavior in ultrasound fields of different peak rarefactional pressures. At peak rarefactional pressures of 0.20 and 0.35 MPa, the dispersed microbubbles clumped together into clusters, and the clusters showed no apparent movement. At a peak rarefactional pressure of 0.70 MPa, the microbubbles were partially broken, and the remainders underwent clustering and coalescence to form bubble clusters that exhibited translational oscillation. (2) The flow fields were unsteady before the unification of the microbubbles. After that, the flow fields showed a clear pattern. (3)The delivery efficiency improved with the shear stress of the flow fields increased. Before the formation of the microbubble/bubble cluster, the maximum shear stresses of the 0.20, 0.35, and 0.70 MPa groups were 56.0, 87.5 and 406.4 mPa, respectively, and the rates of the reversibly sonoporated cells were 2.4% ± 0.4%, 5.5% ± 1.3%, and 16.6% ± 0.2%. After the cluster formation, the maximum shear stresses of the three groups were 9.1, 8.7, and 71.7 mPa, respectively. The former two could not mediate sonoporation, whereas the last one could. These findings demonstrate the critical role of flow fields in ultrasound-mediated drug delivery and contribute to its clinical applications.

Cellular Bioeffect Investigations on Low-Intensity Pulsed Ultrasound and Sonoporation: Platform Design and Flow Cytometry Protocol

At low-intensity levels, ultrasound can potentially generate therapeutic effects on living cells, and it can trigger sonoporation when microbubbles (MBs) are present to facilitate drug delivery. Yet, our foundational knowledge of low-intensity pulsed ultrasound (LIPUS) and sonoporation remains to be critically weak because the pertinent cellular bioeffects have not been rigorously studied. In this article, we present a population-based experimental protocol that can effectively foster investigations on the mechanistic bioeffects of LIPUS and sonoporation over a cell population. Walkthroughs of different methodological details are presented, including the fabrication of the ultrasound exposure platform and its calibration, as well as the design of a bioassay procedure that uses fluorescent tracers and flow cytometry to isolate sonicated cells with similar characteristics. An application example is also presented to illustrate how our protocol can be used to investigate the downstream cellular bioeffects of leukemia cells. We show that, with 1-MHz LIPUS exposure (with 29.1 J/cm² delivered acoustic energy density), variations in viability and morphology would be found among different types of sonicated leukemia cells (HL-60, Molt-4) in the absence and presence of MBs. Taken altogether, this article provides a reference on how cellular bioeffect experiments on LIPUS and sonoporation can be planned meticulously to acquire strong observations that are critical to establish the biological foundations for therapeutic applications.

Nanoparticle-Coated Microbubbles for Combined Ultrasound Imaging and Drug Delivery

Biomedical microbubbles stabilized by a coating of magnetic or drug-containing nanoparticles show great potential for theranostics applications. Nanoparticle-coated microbubbles can be made to be stable, to be echogenic, and to release the cargo of drug-containing nanoparticles with an ultrasound trigger. This Article reviews the design principles of nanoparticle-coated microbubbles for ultrasound imaging and drug delivery, with a particular focus on the physical chemistry of nanoparticle-coated interfaces; the formation, stability, and dynamics of nanoparticle-coated bubbles; and the conditions for controlled nanoparticle release in ultrasound. The emerging understanding of the modes of nanoparticle expulsion and of the transport of expelled material by microbubble-induced flow is paving the way toward more efficient nanoparticle-mediated drug delivery. This Article highlights the knowledge gap that still remains to be addressed before we can control these phenomena.

Acoustofluidic methods in cell analysis

Cellular analysis is a central concept for both biology and medicine. Over the past two decades, acoustofluidic technologies, which marry acoustic waves with microfluidics, have significantly contributed to the development of innovative approaches for cellular analysis. Acoustofluidic technologies enable precise manipulations of cells and the fluids that confine them, and these capabilities have been utilized in many cell analysis applications. In this review article, we examine various applications where acoustofluidic methods have been implemented, including cell imaging, cell mechanotyping, circulating tumor cell phenotyping, sample preparation in clinics, and investigation of cell-cell interactions and cell-environment responses. We also provide our perspectives on the technological advantages, limitations, and potential future directions for this innovative field of methods.

Very low intensity ultrasounds as a new strategy to improve selective delivery of nanoparticles-complexes in cancer cells

Background

The possibility to combine Low Intensity UltraSound (LIUS) and Nanoparticles (NP) could represent a promising strategy for drugs delivery in tumors difficult to treat overcoming resistance to therapies. On one side the NP can carry drugs that specifically target the tumors on the other the LIUS can facilitate and direct the delivery to the tumor cells. In this study, we investigated whether Very Low Intensity UltraSound (VLIUS), at intensities lower than 120 mW/cm², might constitute a novel strategy to improve delivery to tumor cells. Thus, in order to verify the efficacy of this novel modality in terms of increase selective uptake in tumoral cells and translate speedily in clinical practice, we investigated VLIUS in three different in vitro experimental tumor models and normal cells adopting three different therapeutic strategies.

Methods

VLIUS at different intensities and exposure time were applied to tumor and normal cells to evaluate the efficiency in uptake of labeled human ferritin (HFt)-based NP, the delivery of NP complexed Firefly luciferase reported gene (lipoplex-LUC), and the tumor-killing of chemotherapeutic agent.

Results

Specifically, we found that specific VLIUS intensity (120 mW/cm²) increases tumor cell uptake of HFt-based NPs at specific concentration (0.5 mg/ml). Similarly, VLIUS treatments increase significantly tumor cells delivery of lipoplex-LUC cargos. Furthermore, of interest, VLIUS increases tumor killing of chemotherapy drug trabectedin in a time dependent fashion. Noteworthy, VLIUS treatments are well tolerated in normal cells with not significant effects on cell survival, NPs delivery and drug-induced toxicity, suggesting a tumor specific fashion.

Conclusions

Our data shed novel lights on the potential application of VLIUS for the design and development of novel therapeutic strategies aiming to efficiently deliver NP loaded cargos or anticancer drugs into more aggressive and unresponsive tumors niche.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-1018-6) contains supplementary material, which is available to authorized users.

Enhanced shRNA delivery by the combination of polyethylenimine, ultrasound, and nanobubbles in liver cancer

BACKGROUND

Traditional cancer treatments such as surgery, radiation, and chemotherapy destroy both cancer and normal cells, which limit their clinical application. It is difficult to achieve the best results for any liver cancer patients using any single treatment method. Gene therapy for HCC demands non-invasive, efficient, targeted and safe gene transfection strategies.

OBJECTIVE

In this study, a nonviral shRNA gene delivery system utilizing a combination of PEI, US, and NBs was developed for targeting survivin in liver Cancer.

METHODS AND RESULTS

The PEI-shRNA-NBs cumulated in the tumor tissue because of the EPR effect. By exposure to the US, micelles shRNA may be released from PEI-shRNA-NBs in tumor tissues and the shRNA then transmitted efficiently to cancer cells. Considerably enhanced therapeutic outcome was obtained with the gene silencing effect enhanced.

CONCLUSIONS

PEI-shRNA-NBs possess the potential to become promising tools intended for shRNA delivery.

Applications of Focused Ultrasound in Cerebrovascular Diseases and Brain Tumors

Oncology and cerebrovascular disease constitute two of the most common diseases afflicting the central nervous system. Standard of treatment of these pathologies is based on multidisciplinary approaches encompassing combination of interventional procedures such as open and endovascular surgeries, drugs (chemotherapies, anti-coagulants, anti-platelet therapies, thrombolytics), and radiation therapies. In this context, therapeutic ultrasound could represent a novel diagnostic/therapeutic in the armamentarium of the surgeon to treat these diseases. Ultrasound relies on mechanical energy to induce numerous physical and biological effects. The application of this technology in neurology has been limited due to the challenges with penetrating the skull, thus limiting a prompt translation as has been seen in treating pathologies in other organs, such as breast and abdomen. Thanks to pivotal adjuncts such as multiconvergent transducers, magnetic resonance imaging (MRI) guidance, MRI thermometry, implantable transducers, and acoustic windows, focused ultrasound (FUS) is ready for prime-time applications in oncology and cerebrovascular neurology. In this review, we analyze the evolution of FUS from the beginning in 1950s to current state-of-the-art. We provide an overall picture of actual and future applications of FUS in oncology and cerebrovascular neurology reporting for each application the principal existing evidences.

Weighting the Passive Acoustic Mapping Technique With the Phase Coherence Factor for Passive Ultrasound Imaging of Ultrasound-Induced Cavitation

Ultrasound (US) cavitation is currently being explored for low-invasive therapy techniques applied to a wide panel of pathologies. Because of the random behavior of cavitation, a real-time spatial monitoring system may be required. For this purpose, the US passive imaging techniques have been recently investigated. In particular, the passive acoustic mapping (PAM) beamforming method enables the reconstruction of cavitation activity maps by beamforming acoustic signals passively recorded by an array transducer. In this paper, an optimized version of PAM, PAM weighted with a phase coherence factor (PAM-PCF), is considered. A general validation process is developed including simulations on a point source and experiments on a wire. Furthermore, using a focused regulated US-induced cavitation generator, reproducible cavitation experiments are conducted in water and in agar gel. The spatial behavior of a bubble cavitation cloud is determined using the PAM-PCF beamforming method to localize the focal cavitation point in two perpendicular imaging planes.

Ultrasound-Mediated Gene Therapy in Swine Livers Using Single-Element, Multi-lensed, High-Intensity Ultrasound Transducers

We have achieved significant enhancement of gene delivery into livers of large animals using ultrasound (US)-targeted microbubble (MB) destruction methods. An infusion of pGL4 (encoding a luciferase reporter gene) plasmid DNA (pDNA) and MBs into a portal-vein segmental branch of a porcine liver was exposed to US for 4 min. Therapeutic US induced cavitation of MBs to temporarily permeabilize the vascular endothelium and cell membranes, allowing entry of pDNA. We obtained a 64-fold enhancement in luciferase expression in pig livers compared to control without US using an unfocused, dual-element transducer (H105, center frequency [f_c] = 1.10 MHz) at 2.7 MPa peak negative pressure (PNP). However, input electrical energy was limited, and modified transducers were designed to have spherical (H185A, f_c = 1.10 MHz) or cylindrical foci (H185B, f_c = 1.10 MHz; H185D, f_c = 1.05 MHz) to enhance PNP output. The revised transducers required less electrical input to achieve 2.7 MPa PNP compared to H105, thereby allowing PNP outputs of up to 6.2 MPa without surpassing the piezo-material limitations. Subsequently, luciferase expression significantly improved up to 9,000-fold compared to controls with minor liver damage. These advancements will allow us to modify our current protocols toward minimally invasive US gene therapy.

Combination of chemotherapy and photodynamic therapy for cancer treatment with sonoporation effects

To overcome the limitations of single therapy, chemotherapy has been studied to be combined with photodynamic therapy. However, nanomedicine combining anticancer drug and photosensitizer still cannot address the insufficiency of drug delivery and the off-targeting effect. To address drug delivery issue, we have developed a doxorubicin encapsulating human serum albumin nanoparticles/chlorin e6 encapsulating microbubbles (DOX-NPs/Ce6-MBs) complex system. Microbubbles enable ultrasound-triggered local delivery via sonoporation for maximizing the drug delivery to a target site. In both in vitro and in vivo experiments, the developed DOX-NPs/Ce6-MBs drug delivery complex could be confirmed to transfer drugs deeply and effectively into cancerous tumors through the following three steps; (1) the local release of nanoparticles due to the cavitation of DOX-NPs/Ce6-MBs; (2) the enhanced extravasation of DOX-NPs and Ce6-liposome/micelle due to the sonoporation phenomenon; (3) the improved penetration of extravasated nanomedicines into the deep tumor region due to the mechanical energy of ultrasound. As a result, the developed DOX-NPs/Ce6-MBs complex with ultrasound irradiation showed increased therapeutic effects compared to the case where no ultrasound irradiation was applied. The DOX-NPs/Ce6-MBs was concluded from this study to be the optimal drug delivery system for external-stimuli local combination (chemotherapy + PDT) therapy.

Ultrasound Combined with Microbubbles Enhances the Effects of Methylprednisolone in Lipopolysaccharide-Induced Human Mesangial Cells

A novel drug delivery system mediated by ultrasound (US) combined with microbubbles (MBs) (US+MB) could improve local drug concentration to enhance its efficacy. To investigate the influence of US+MB on methylprednisolone (MP), the effect of US+MB combined with MP (US+MB+MP) on lipopolysaccharide (LPS)-induced human mesangial cells (HMCs) and the underlying mechanism were explored in this study. The results revealed that HMCs treated with LPS underwent significant proliferation and exhibited an increase in nuclear transcription factor-κB (NF-κB) and transforming growth factor-β1 (TGF-β1) expression and a decrease in cellular apoptosis. This effect was significantly inhibited by MP (30-100 μg/ml), US combined with MBs (3.22 × 107 and 8.05 × 107 bubbles/ml), and US combined with both MBs (1.29 × 107 bubbles/ml) and MP (12 μg/ml) (US+MB1+MP12). The effect of US+MB1+MP12 was better than the effect of 12 μg/ml of MP alone and was similar to the effect of 100 μg/ml of MP. Additionally, the intracellular free MP content was significantly higher in the US+MB1+MP12 group than in the MP12 group. US combined with MBs not only inhibited LPS-induced HMC proliferation and NF-κB and TGF-β1 expression and increased cellular apoptosis but also synergized with the pharmacologic effect of MP. The mechanism is partially due to the US-assisted MB local drug delivery and the anti-inflammatory effect induced by US combined with MBs.

Localized delivery of curcumin into brain with polysorbate 80-modified cerasomes by ultrasound-targeted microbubble destruction for improved Parkinson's disease therapy

Rationale: Treatment for Parkinson's disease (PD) is challenged by the presence of the blood-brain barrier (BBB) that significantly limits the effective drug concentration in a patient's brain for therapeutic response throughout various stages of PD. Curcumin holds the potential for α-synuclein clearance to treat PD; however, its applications are still limited due to its low bioavailability and poor permeability through the BBB in a free form.

Methods: Herein, this paper fabricated curcumin-loaded polysorbate 80-modified cerasome (CPC) nanoparticles (NPs) with a mean diameter of ~110 nm for enhancing the localized curcumin delivery into the targeted brain nuclei via effective BBB opening in combination with ultrasound-targeted microbubble destruction (UTMD).

Results: The liposomal nanohybrid cerasome exhibited superior stability towards PS 80 surfactant solubilization and longer circulation lifetime (t_1/2 = 6.22 h), much longer than free curcumin (t_1/2 = 0.76 h). The permeation was found to be 1.7-fold higher than that of CPC treatment only at 6 h after the systemic administration of CPC NPs. Notably, motor behaviors, dopamine (DA) level and tyrosine hydroxylase (TH) expression all returned to normal, thanks to α-synuclein (AS) removal mediated by efficient curcumin delivery to the striatum. Most importantly, the animal experiment demonstrated that the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice had notably improved behavior disorder and dopamine depletion during two-week post-observation after treatment with CPC NPs (15 mg curcumin/kg) coupled with UTMD.

Conclusion: This novel CPC-UTMD formulation approach could be an effective, safe and amenable choice with higher therapeutic relevance and fewer unwanted complications than conventional chemotherapeutics delivery systems for PD treatment in the near future.

Ultrasound-based triggered drug delivery to tumors

Over the past few decades, applications of ultrasound (US) in drug delivery have been documented widely for local and site-specific release of bioactives in a controlled manner, after acceptable use in mild physical therapy for tendinitis and bursitis, and for high-energy applications in fibroid ablation, cataract removal, bone fracture healing, etc. US is a non-invasive, efficient, targetable and controllable technique. Drug delivery can be enhanced by applying directed US in terms of targeting and intracellular uptake. US cannot only provide local hyperthermia but can also enhance local extravasations and permeability of the cell membrane for delivery of cell-impermeable and poorly permeable drugs. It is also found to increase the anticancer efficacy of drug against solid tumors by facilitating uniform drug delivery throughout the tumor mass. This review summarizes the mechanism of US; various drug delivery systems like microbubbles, liposomes, and micelles; and biological manifestations employed for improving treatment of cancer, i.e., hyperthermia and enhanced extravasation. Safety issues are also discussed for better therapeutic outcomes of US-assisted drug delivery to tumors. This review can be a beneficial asset to the scientists looking at non-invasive techniques (externally guided) for improving the anticancer potential of drug delivery systems.

High-Intensity Focused Ultrasound for Pain Management in Patients with Cancer

Cancer-related pain affects up to 80% of patients with malignancies. Pain is an important distressing symptom that diminishes the quality of life and negatively affects the survival of patients. Opioid analgesics are generally the primary therapy for cancer-related pain, with surgery, radiation therapy, chemotherapy, and other interventions used in cases of treatment-resistant pain. These treatments, which can be associated with substantial side effects and systemic toxicity, may not be effective. High-intensity focused ultrasound is an entirely noninvasive technique that is approved for treatment of uterine fibroids, bone metastases, and essential tremors. With magnetic resonance imaging or ultrasonographic guidance, high-intensity ultrasound waves are focused on a small well-demarcated region to result in precise localized ablation. This treatment may represent a multimodality approach to treating patients with malignant diseases-facilitating pain palliation, enhanced local drug delivery and radiation therapy effects, and stimulation of anticancer specific immune responses, and potentially facilitating local tumor control. Focused ultrasound can be used to achieve pain palliation by producing several effects, including tissue denervation, tumor mass reduction, and neuromodulation, that can influence different pathways at the origin of the pain. This technology has several key advantages compared with other analgesic therapies: It is completely noninvasive, might be used to achieve rapid pain control, can be safely repeated, and can be used in combination with chemotherapy and radiation therapy to enhance their effects. Online supplemental material is available for this article. ^©RSNA, 2018.

Differential effects on membrane permeability and viability of human keratinocyte cells undergoing very low intensity megasonic fields

Among different therapeutic applications of Ultrasound (US), transient membrane sonoporation (SP) - a temporary, non-lethal porosity, mechanically induced in cell membranes through US exposure - represents a compelling opportunity towards an efficient and safe drug delivery. Nevertheless, progresses in this field have been limited by an insufficient understanding of the potential cytotoxic effects of US related to the failure of the cellular repair and to the possible activation of inflammatory pathway. In this framework we studied the in vitro effects of very low-intensity US on a human keratinocyte cell line, which represents an ideal model system of skin protective barrier cells which are the first to be involved during medical US treatments. Bioeffects linked to US application at 1 MHz varying the exposure parameters were investigated by fluorescence microscopy and fluorescence activated cell sorting. Our results indicate that keratinocytes undergoing low US doses can uptake drug model molecules with size and efficiency which depend on exposure parameters. According to sub-cavitation SP models, we have identified the range of doses triggering transient membrane SP, actually with negligible biological damage. By increasing US doses we observed a reduced cells viability and an inflammatory gene overexpression enlightening novel healthy relevant strategies.