Ultrasound/microbubble-mediated targeted delivery of anticancer microRNA-loaded nanoparticles to deep tissues in pigs

Ultrasound nanobubble-based combinational strategies of loaded miR-107-3p and CD133 Ab for anti-PD-L1 and anti-hepatocellular cancer stem cells

BACKGROUND

CD133 is regarded as a marker and target for cancer stem cells (CSCs) in various types of tumors, including hepatocellular carcinoma (HCC). The expressions of CD133 and programmed cell death ligand 1 (PD-L1) in CSCs exhibit a positive feedback regulatory effect. This effect promotes CSC proliferation and immune escape, ultimately leading to tumor progression and poor prognosis.

METHODS

CD133-specific antibodies and miR-107-3p loaded nanobubbles (miR-107-3p/CD133 Ab-NBs) were assembled using various techniques, such as the biotin-avidin system and cationic lipid nanobubbles. The relationship between miR-107-3p and PD-L1 was established via a miR-107-3p mimic/inhibitor using RT-qPCR and Western blot methods. The miR-107-3p/CD133 Ab-NBs were characterized, and their pharmacokinetic attributes were studied in combination with ultrasound-targeted microbubble destruction (UTMD). Subsequently, the anti-tumor efficacy and mechanism were scrutinized both in vitro and in vivo.

RESULTS

miR-107-3p/CD133Ab NBs were successfully prepared through CD133Ab conjugation and miR-107-3p loading, yielding an average particle size of 342.0 ± 26.3 nm, and presenting as spherical particles with uniform size and distribution. By using a mouse subcutaneous transplanted tumor model, paired with UTMD, we found that miR-107-3p/CD133Ab-NBs could significantly accumulate at the tumor site, as observed through the IVIS Spectrum system. These nanoparticles showed considerable anti-tumor activity against HCC, both in vitro and in the xenograft mouse model. Further findings indicated that miR-107-3p/CD133Ab-NBs promoted lymphocyte proliferation enhanced the cytotoxic T lymphocyte (CTL) killing activity, and increased cytokine gene expression. This suggests that the combination of miR-107-3p/CD133Ab-NBs with UTMD could enhance anti-cancer immune responses by inhibiting PD-L1 with miR-107-3p and targeting CD133 on the CSCs of HCC.

CONCLUSIONS

Our study introduces a novel strategy for ultrasound-targeted microbubbles containing miR-107-3p and CD133Ab. This strategy demonstrated substantial anti-tumor activity against HCC by blocking the positive feedback of CD133 and PD-L1 expression in CSCs. Thus, it reveals a potential advantage of combined miR-107-3p/CD133 Ab-NBs therapy for HCC.

Synergistic Ultrasound-Activable Artificial Enzyme and Precision Gene Therapy to Suppress Redox Homeostasis and Malignant Phenotypes for Controllably Combating Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) remains one of the most lethal malignant tumors. Multimodal therapeutics with synergistic effects for treating HCC have attracted increasing attention, for instance, designing biocompatible porphyrin-based nanomedicines for enzyme-mimetic and ultrasound (US)-activable reactive oxygen species (ROS) generation. Despite the promise, the landscape of such advancements remains sparse. Here, we propose the de novo design of a π-conjugated, osmium (Os)-coordinated polyporphyrin (P-Por-Os) nanovesicle to serve as an ultrasound-activable artificial enzyme for synergistic therapies to suppress redox homeostasis and malignant phenotypes for controllably combating HCC. Our findings reveal that the P-Por-Os with US showed superior, multifaceted, and controllable ROS-generating activities. This system not only subverts the redox balance within HCC cells but also achieves precise and controlled tumor ablation at remarkably low concentrations, as evidenced across cellular assays and animal models. In the liver orthotopic model, US not only activates the artificial enzyme to catalyze ROS but also facilitates remote-controlled ablation of HCC through precise US positioning. Moreover, the P-Por-Os + US can assist the precision gene therapy by knocking down the ROS resistance factor, MT2A, and down-regulating its downstream oncogene IGFBP2 to attenuate ROS resistance, proliferation, and migration of HCC efficiently. We suggest that the design of this ultrasound-activable artificial enzyme presents a promising avenue for the engineering of innovative tumoricidal materials, offering a synergistic therapeutic approach with high biosecurity for HCC treatment.

Neutrophil membrane-coated nanoparticles for targeted delivery of toll-like receptor 4 siRNA ameliorate LPS-induced acute lung injury

Pulmonary delivery of small interfering RNAs (siRNAs) is an effective treatment for acute lung injury (ALI), which can modulate the expression of pro-inflammatory cytokines and alleviate the symptoms of ALI. However, the rapid degradation of siRNA in vivo and its limited ability to target and validate cells are important challenges it faces in clinical practice. In this work, we developed neutrophil membrane-coated Poly (lactic-co-glycolic acid) nanoparticles loaded with TLR4 siRNA (si-TLR4) (Neutrophil-NP-TLR4), which can target both inflammatory and macrophage cells to alleviate the pulmonary inflammation in lipopolysaccharide (LPS)-induced ALI mice. These Neutrophil-NP-TLR4 effectively reduce the TNF-α and IL-1β expressions both in vitro and in vivo. Meanwhile, they also reduced the expression of TLR4, and its downstream genes including TNF receptor-associated factor 6 (TRAF6), X-linked inhibitor of apoptosis protein (XIAP), and Nuclear Factor kappa-B (NF-κB), but elevated the levels of Aquaporin 1 (AQP1) and Aquaporin 5 (AQP5). Moreover, the Neutrophil-NP-TLR4 precisely targets the inflammatory site to attenuate the lung injury without causing toxicity to normal tissue. This system provides a promising approach to effective delivery of siRNA to precisely treat the ALI.

Ultrasound-Controlled Prodrug Activation: Emerging Strategies in Polymer Mechanochemistry and Sonodynamic Therapy

Ultrasound has gained prominence in biomedical applications due to its noninvasive nature and ability to penetrate deep tissue with spatial and temporal resolution. The burgeoning field of ultrasound-responsive prodrug systems exploits the mechanical and chemical effects of ultrasonication for the controlled activation of prodrugs. In polymer mechanochemistry, materials scientists exploit the sonomechanical effect of acoustic cavitation to mechanochemically activate force-sensitive prodrugs. On the other hand, researchers in the field of sonodynamic therapy adopt fundamentally distinct methodologies, utilizing the sonochemical effect (e.g., generation of reactive oxygen species) of ultrasound in the presence of sonosensitizers to induce chemical transformations that activate prodrugs. This cross-disciplinary review comprehensively examines these two divergent yet interrelated approaches, both of which originated from acoustic cavitation. It highlights molecular and materials design strategies and potential applications in diverse therapeutic contexts, from chemotherapy to immunotherapy and gene therapy methods, and discusses future directions in this rapidly advancing domain.

miRNAs in HCC, pathogenesis, and targets

Liver cancer is the third leading cause of cancer-related mortality worldwide. HCC, the most common type of primary liver cancer, is driven by complex genetic, epigenetic, and environmental factors. MicroRNAs, a class of naturally occurring small noncoding RNAs, play crucial roles in HCC by simultaneously modulating the expression of multiple genes in a fine-tuning manner. Significant progress has been made in understanding how miRNAs influence key oncogenic pathways, including cell proliferation, apoptosis, angiogenesis, and epithelial-mesenchymal transition (EMT), as well as their role in modulating the immune microenvironment in HCC. Due to the unexpected stability of miRNAs in the blood and fixed HCC tumors, recent advancements also highlight their potential as noninvasive diagnostic tools. Restoring or inhibiting specific miRNAs has offered promising strategies for targeted HCC treatment by suppressing malignant hepatocyte growth and enhancing antitumor immunity. In this comprehensive review, we consolidate previous research and provide the latest insights into how miRNAs regulate HCC and their therapeutic and diagnostic potential. We delve into the dysregulation of miRNA biogenesis in HCC, the roles of miRNAs in the proliferation and apoptosis of malignant hepatocytes, angiogenesis and metastasis of HCC, the immune microenvironment in HCC, and drug resistance. We also discuss the therapeutic and diagnostic potential of miRNAs and delivery approaches of miRNA drugs to overcome the limitations of current HCC treatment options. By thoroughly summarizing the roles of miRNAs in HCC, our goal is to advance the development of effective therapeutic drugs with minimal adverse effects and to establish precise tools for early diagnosis of HCC.

Recent Advancements in Ultrasound Contrast Agents Based on Nanomaterials for Imaging

Ultrasound (US) is a type of mechanical wave that is capable of transmitting energy through biological tissues. By utilization of various frequencies and intensities, it can elicit specific biological effects. US imaging (USI) technology has been continuously developed with the advantages of safety and the absence of radiation. The advancement of nanotechnology has led to the utilization of various nanomaterials composed of both organic and inorganic compounds as ultrasound contrast agents (UCAs). These UCAs enhance USI, enabling real-time monitoring, diagnosis, and treatment of diseases, thereby facilitating the widespread adoption of UCAs in precision medicine. In this review, we introduce various UCAs based on nanomaterials for USI. Their principles can be roughly divided into the following categories: carrying and transporting gases, endogenous gas production, and the structural characteristics of the nanomaterial itself. Furthermore, the synergistic benefits of US in conjunction with various imaging modalities and their combined application in disease monitoring and diagnosis are introduced. In addition, the challenges and prospects for the development of UCAs are also discussed.

Integrated organosilica nanomedicine enables sonoimaging, sonochemistry and antitumor sonodynamic therapy

Sonography with its non-invasive and deep tissue-penetrating characteristics, not only contributes to promising developments in clinical disease diagnosis but also obtains acknowledgments as a prospective therapeutic approach in the field of tumor treatment. However, it remains a challenge for sonography simultaneously to achieve efficient imaging and therapeutic functionality. Here, we present an innovative integrated diagnosis and treatment paradigm by developing the nanomedicine of percarbamide-bromide-mesoporous organosilica spheres (MOS) with RGD peptide modification (PBMR) by loading percarbamide and bromide in MOS which were prepared by a one-step O/W microemulsion method. The PBMR nanomedicine effectively modifies the tumor acoustic environment to improve sonoimaging efficacy and induces sonochemical reactions to enhance the production of reactive oxygen species (ROS) for tumor treatment efficiency under sonography. The combination of PBMR nanomedicine and SDT achieved multiple ROS generation through the controlled sonochemical reactions and significantly boosted the potency of sonodynamic therapy and induced significant tumor regression with non-invasive tissue penetrability and minimizing damage to healthy tissues. Simultaneously, the generation of oxygen gas in the sonochemical process augments ultrasound reflection, resulting in a 4.9-fold increase in imaging grayscale. Our research establishes an effective platform for the synergistic integration of sonoimaging and sonodynamic antitumor therapy, offering a novel approach for precise antitumor treatment in the potential clinical applications.

Recent Review on Biological Barriers and Host-Material Interfaces in Precision Drug Delivery: Advancement in Biomaterial Engineering for Better Treatment Therapies

Preclinical and clinical studies have demonstrated that precision therapy has a broad variety of treatment applications, making it an interesting research topic with exciting potential in numerous sectors. However, major obstacles, such as inefficient and unsafe delivery systems and severe side effects, have impeded the widespread use of precision medicine. The purpose of drug delivery systems (DDSs) is to regulate the time and place of drug release and action. They aid in enhancing the equilibrium between medicinal efficacy on target and hazardous side effects off target. One promising approach is biomaterial-assisted biotherapy, which takes advantage of biomaterials' special capabilities, such as high biocompatibility and bioactive characteristics. When administered via different routes, drug molecules deal with biological barriers; DDSs help them overcome these hurdles. With their adaptable features and ample packing capacity, biomaterial-based delivery systems allow for the targeted, localised, and prolonged release of medications. Additionally, they are being investigated more and more for the purpose of controlling the interface between the host tissue and implanted biomedical materials. This review discusses innovative nanoparticle designs for precision and non-personalised applications to improve precision therapies. We prioritised nanoparticle design trends that address heterogeneous delivery barriers, because we believe intelligent nanoparticle design can improve patient outcomes by enabling precision designs and improving general delivery efficacy. We additionally reviewed the most recent literature on biomaterials used in biotherapy and vaccine development, covering drug delivery, stem cell therapy, gene therapy, and other similar fields; we have also addressed the difficulties and future potential of biomaterial-assisted biotherapies.

Ultrasound-Based Micro-/Nanosystems for Biomedical Applications

Due to the intrinsic non-invasive nature, cost-effectiveness, high safety, and real-time capabilities, besides diagnostic imaging, ultrasound as a typical mechanical wave has been extensively developed as a physical tool for versatile biomedical applications. Especially, the prosperity of nanotechnology and nanomedicine invigorates the landscape of ultrasound-based medicine. The unprecedented surge in research enthusiasm and dedicated efforts have led to a mass of multifunctional micro-/nanosystems being applied in ultrasound biomedicine, facilitating precise diagnosis, effective treatment, and personalized theranostics. The effective deployment of versatile ultrasound-based micro-/nanosystems in biomedical applications is rooted in a profound understanding of the relationship among composition, structure, property, bioactivity, application, and performance. In this comprehensive review, we elaborate on the general principles regarding the design, synthesis, functionalization, and optimization of ultrasound-based micro-/nanosystems for abundant biomedical applications. In particular, recent advancements in ultrasound-based micro-/nanosystems for diagnostic imaging are meticulously summarized. Furthermore, we systematically elucidate state-of-the-art studies concerning recent progress in ultrasound-based micro-/nanosystems for therapeutic applications targeting various pathological abnormalities including cancer, bacterial infection, brain diseases, cardiovascular diseases, and metabolic diseases. Finally, we conclude and provide an outlook on this research field with an in-depth discussion of the challenges faced and future developments for further extensive clinical translation and application.

Metal-organic frameworks as candidates for tumor sonodynamic therapy: Designable structures for targeted multifunctional transformation

Sonodynamic therapy (SDT), utilizing ultrasound (US) as the trigger, has gained popularity recently as a therapeutic approach with significant potential for treating various diseases. Metal-organic frameworks (MOFs), characterized by structural flexibility, are prominently emerging in the SDT realm as an innovative type of sonosensitizer, offering functional tunability and biocompatibility. However, due to the inherent limitations of MOFs, such as low reactivity to reactive oxygen species and challenges posed by the complex tumor microenvironment, MOF-based sonosensitizers with singular functions are unable to demonstrate the desired therapeutic efficacy and may pose risks of toxicity, limiting their biological applications to superficial tissues. MOFs generally possess distinctive crystalline structures and properties, and their controlled coordination environments provide a flexible platform for exploring structure-effect relationships and guiding the design and development of MOF-based nanomaterials to unlock their broader potential in biological fields. The primary focus of this paper is to summarize cases involving the modification of different MOF materials and the innovative strategies developed for various complex conditions. The paper outlines the diverse application areas of functionalized MOF-based sonosensitizers in tumor synergistic therapies, highlighting the extensive prospects of SDT. Additionally, challenges confronting SDT are briefly summarized to stimulate increased scientific interest in the practical application of MOFs and the successful clinical translation of SDT. Through these discussions, we strive to foster advancements that lead to early-stage clinical benefits for patients. STATEMENT OF SIGNIFICANCE: 1. An overview for the progresses in SDT explored from a novel and fundamental perspective. 2. Different modification strategies to improve the MOFs-mediated SDT efficacy are provided. 3. Guidelines for the design of multifunctional MOFs-based sonosensitizers are offered. 4. Powerful tumor ablation potential is reflected in SDT-led synergistic therapies. 5. Future challenges in the field of MOFs-based SDT in clinical translation are suggested.

Passive Acoustic Mapping for Convex Arrays With the Helical Wave Spectrum Method

Passive acoustic mapping (PAM) has emerged as a valuable imaging modality for monitoring the cavitation activity in focused ultrasound therapies. When it comes to imaging in the human abdomen, convex arrays are preferred due to their large acoustic window. However, existing PAM methods for convex arrays rely on the computationally expensive delay-and-sum (DAS) operation limiting the image reconstruction speed when the field-of-view (FOV) is large. In this work, we propose an efficient and frequency-selective PAM method for convex arrays. This method is based on projecting the helical wave spectrum (HWS) between cylindrical surfaces in the imaging field. Both the in silico and in vitro experiments showed that the HWS method has comparable image quality and similar acoustic cavitation source localization accuracy as the DAS-based methods. Compared to the frequency-domain and time-domain DAS methods, the time-complexity of the HWS method is reduced by one order and two orders of magnitude, respectively. A parallel implementation of the HWS method realized millisecond-level image reconstruction speed. We also show that the HWS method is inherently capable of mapping microbubble (MB) cavitation activity of different status, i.e., no cavitation, stable cavitation, or inertial cavitation. After compensating for the lens effects of the convex array, we further combined PAM formed by the HWS method and B-mode imaging as a real-time dual-mode imaging approach to map the anatomical location where MBs cavitate in a liver phantom experiment. This method may find use in applications where convex arrays are required for cavitation activity monitoring in real time.

Local Renal Treatments for Acute Kidney Injury: A Review of Current Progress and Future Translational Opportunities

Acute kidney injury (AKI) constitutes a significant public health concern, with limited therapeutic options to mitigate injury or expedite recovery. A novel therapeutic approach, local renal treatment, encompassing pharmacotherapy and surgical interventions, has exhibited positive outcomes in AKI management. Peri-renal administration, employing various delivery routes, such as the renal artery, intrarenal, and subcapsular sites, has demonstrated superiority over peripheral intravenous infusion. This review evaluates different drug delivery methods, analyzing their benefits and limitations, and proposes potential improvements. Renal decapsulation, particularly with the availability of minimally invasive techniques, emerges as an effective procedure warranting renewed consideration for AKI treatment. The potential synergistic effects of combined drug delivery and renal decapsulation could further advance AKI therapies. Clinical studies have already begun to leverage the benefits of local renal treatments, and with ongoing technological advancements, these modalities are expected to increasingly outperform systemic intravenous therapy.

Bridging Smart Nanosystems with Clinically Relevant Models and Advanced Imaging for Precision Drug Delivery

Intracellular delivery of nano-drug-carriers (NDC) to specific cells, diseased regions, or solid tumors has entered the era of precision medicine that requires systematic knowledge of nano-biological interactions from multidisciplinary perspectives. To this end, this review first provides an overview of membrane-disruption methods such as electroporation, sonoporation, photoporation, microfluidic delivery, and microinjection with the merits of high-throughput and enhanced efficiency for in vitro NDC delivery. The impact of NDC characteristics including particle size, shape, charge, hydrophobicity, and elasticity on cellular uptake are elaborated and several types of NDC systems aiming for hierarchical targeting and delivery in vivo are reviewed. Emerging in vitro or ex vivo human/animal-derived pathophysiological models are further explored and highly recommended for use in NDC studies since they might mimic in vivo delivery features and fill the translational gaps from animals to humans. The exploration of modern microscopy techniques for precise nanoparticle (NP) tracking at the cellular, organ, and organismal levels informs the tailored development of NDCs for in vivo application and clinical translation. Overall, the review integrates the latest insights into smart nanosystem engineering, physiological models, imaging-based validation tools, all directed towards enhancing the precise and efficient intracellular delivery of NDCs.

Nanobubble-mediated cancer cell sonoporation using low-frequency ultrasound

Ultrasound insonation of microbubbles can form transient pores in cell membranes that enable the delivery of non-permeable extracellular molecules to the cells. Reducing the size of microbubble contrast agents to the nanometer range could facilitate cancer sonoporation. This size reduction can enhance the extravasation of nanobubbles into tumors after an intravenous injection, thus providing a noninvasive sonoporation platform. However, drug delivery efficacy depends on the oscillations of the bubbles, the ultrasound parameters and the size of the target compared to the membrane pores. The formation of large pores is advantageous for the delivery of large molecules, however the small size of the nanobubbles limit the bioeffects when operating near the nanobubble resonance frequency at the MHz range. Here, we show that by coupling nanobubbles with 250 kHz low frequency ultrasound, high amplitude oscillations can be achieved, which facilitate low energy sonoporation of cancer cells. This is beneficial both for increasing the uptake of a specific molecule and to improve large molecule delivery. The method was optimized for the delivery of four fluorescent molecules ranging in size from 1.2 to 70 kDa to breast cancer cells, while comparing the results to targeted microbubbles. Depending on the fluorescent molecule size, the optimal ultrasound peak negative pressure was found to range between 300 and 500 kPa. Increasing the pressure to 800 kPa reduced the fraction of fluorescent cells for all molecules sizes. The optimal uptake for the smaller molecule size of 4 kDa resulted in a fraction of 19.9 ± 1.8% of fluorescent cells, whereas delivery of 20 kDa and 70 kDa molecules yielded 14 ± 0.8% and 4.1 ± 1.1%, respectively. These values were similar to targeted microbubble-mediated sonoporation, suggesting that nanobubbles can serve as noninvasive sonoporation agents with a similar potency, and at a reduced bubble size. The nanobubbles effectively reduced cell viability and may thus potentially reduce the tumor burden, which is crucial for the success of cancer treatment. This method provides a non-invasive and low-energy tumor sonoporation theranostic platform, which can be combined with other therapies to maximize the therapeutic benefits of cancer treatment or be harnessed in gene therapy applications.

Remote Loading: The Missing Piece for Achieving High Drug Payload and Rapid Release in Polymeric Microbubbles

The use of drug-loaded microbubbles for targeted drug delivery, particularly in cancer treatment, has been extensively studied in recent years. However, the loading capacity of microbubbles has been limited due to their surface area. Typically, drug molecules are loaded on or within the shell, or drug-loaded nanoparticles are coated on the surfaces of microbubbles. To address this significant limitation, we have introduced a novel approach. For the first time, we employed a transmembrane ammonium sulfate and pH gradient to load doxorubicin in a crystallized form in the core of polymeric microcapsules. Subsequently, we created remotely loaded microbubbles (RLMBs) through the sublimation of the liquid core of the microcapsules. Remotely loaded microcapsules exhibited an 18-fold increase in drug payload compared with physically loaded microcapsules. Furthermore, we investigated the drug release of RLMBs when exposed to an ultrasound field. After 120 s, an impressive 82.4 ± 5.5% of the loaded doxorubicin was released, demonstrating the remarkable capability of remotely loaded microbubbles for on-demand drug release. This study is the first to report such microbubbles that enable rapid drug release from the core. This innovative technique holds great promise in enhancing drug loading capacity and advancing targeted drug delivery.

A novel convex acoustic lens-attached ultrasound drug delivery system and its testing in a murine melanoma subcutaneous modelo

Target-specific drug release is indispensable to improve chemotherapeutic efficacy as it enhances drug uptake and penetration into tumors. Sono-responsive drug-loaded nano-/micro-particles are a promising solution for achieving target specificity by exposing them to ultrasound near tumors. However, the complicated synthetic processes and limited ultrasound (US) exposure conditions, such as limited control of ultrasound focal depth and acoustic power, prevent the practical application of this approach in clinical practice. Here, we propose a convex acoustic lens-attached US (CALUS) as a simple, economic, and efficient alternative of focused US for drug delivery system (DDS) application. The CALUS was characterized both numerically and experimentally using a hydrophone. In vitro, microbubbles (MBs) inside microfluidic channels were destroyed using the CALUS with various acoustic parameters (acoustic pressure [P], pulse repetition frequency [PRF], and duty cycle) and flow velocity. In vivo, tumor inhibition was evaluated using melanoma-bearing mice by characterizing tumor growth rate, animal weight, and intratumoral drug concentration with/without CALUS DDS. US beams were measured to be efficiently converged by CALUS, which was consistent with our simulation results. The acoustic parameters were optimized through the CALUS-induced MB destruction test (P = 2.34 MPa, PRF = 100 kHz, and duty cycle = 9%); this optimal parameter combination successfully induced MB destruction inside the microfluidic channel with an average flow velocity of up to 9.6 cm/s. The CALUS also enhanced the therapeutic effects of an antitumor drug (doxorubicin) in vivo in a murine melanoma model. The combination of the doxorubicin and the CALUS inhibited tumor growth by ∼55% more than doxorubicin alone, clearly indicating synergistic antitumor efficacy. Our tumor growth inhibition performance was better than other methods based on drug carriers, even without a time-consuming and complicated chemical synthesis process. This result suggests that our novel, simple, economic, and efficient target-specific DDS may offer a transition from preclinical research to clinical trials and a potential treatment approach for patient-centered healthcare.

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.

Mesocrystalline ZnS nanoparticles-augmented sonocatalytic full water splitting into H2/O2 for immunoactivating deep tumor

Therapeutic gas molecules have high tissue penetrability, but their sustainable supply and controlled release in deep tumor is a huge challenge. In this work, a concept of sonocatalytic full water splitting for hydrogen/oxygen immunotherapy of deep tumor is proposed, and a new kind of ZnS nanoparticles with a mesocrystalline structure (mZnS) is developed to achieve highly efficient sonocatalytic full water splitting for sustainable supply of H₂ and O₂ in tumor, achieving a high efficacy of deep tumor therapy. Mechanistically, locally generated hydrogen and oxygen molecules exhibit a tumoricidal effect as well as the co-immunoactivation of deep tumors through inducing the M2-to-M1 repolarization of intratumoral macrophages and the tumor hypoxia relief-mediated activation of CD8⁺ T cells, respectively. The proposed sonocatalytic immunoactivation strategy will open a new window to realize safe and efficient treatment of deep tumors.

Ultrasound and microbubble-mediated delivery of miR-424-5p has a therapeutic effect in preeclampsia

OBJECTIVE

To determine the influence of ultrasound/microbubble-mediated miR-424-5p delivery on trophoblast cells and the underlying mechanism.

METHODS

Blood pressure and 24-h proteinuria of patients with preeclampsia (PE) were measured as well as the levels of miR-424-5p and amine oxidase copper containing 1 (AOC1) in placental tissues. HTR-8/Svneo and TEV-1 cells were subjected to cell transfection or ultrasonic microbubble transfection for determination of the expression of miR-424-5p, AOC1, β-catenin and c-Myc as well as cell proliferation, apoptosis, migration and invasiveness. The concentrations of placental growth factor (PLGF), human chorionic gonadotropin (β-hCG) and tumor necrosis factor-α (TNF-α) were measured in HTR-8/Svneo and TEV-1 cells. RNA immunoprecipitation (RIP) and dual luciferase reporter assay detected the binding of miR-424-5p to AOC1. A PE mouse model was induced by subcutaneous injection of L-NAME, where the influence of ultrasound/microbubble-mediated miR-424-5p delivery was evaluated.

RESULTS

miR-424-5p was downregulated while AOC1 was upregulated in the placental tissues from PE patients. Overexpression of miR-424-5p activated Wnt/β-catenin signaling pathway and promoted the proliferation of HTR-8/Svneo and TEV-1 cells as well as enhanced the migratory and invasive behaviors. AOC1 overexpression partly eliminated the effects of miR-424-5p on HTR-8/Svneo and TEV-1 cells. Ultrasound and microbubble mediated gene delivery enhanced the transfection efficiency of miR-424-5p and further promoted the effects of miR-424-5p in trophoblast cells. Ultrasound/microbubble-mediated miR-424-5p delivery alleviated experimental PE in mice.

CONCLUSION

Ultrasound and microbubble-mediated miR-424-5p delivery targets AOC1 and activates Wnt/β-catenin signaling pathway, thus promoting the aggressive phenotype of trophoblast cells, which indicating that miR-424-5p/AOC1 axis might be involved with PE pathogenesis.

Recent advances of polymer based nanosystems in cancer management

Cancer is still one of the leading causes of death worldwide. Nanotechnology, particularly nanoparticle-based platforms, is at the leading edge of current cancer management research. Polymer-based nanosystems have piqued the interest of researchers owing to their many benefits over other conventional drug delivery systems. Polymers derived from both natural and synthetic sources have various biomedical applications due to unique qualities like porosity, mechanical strength, biocompatibility, and biodegradability. Polymers such as poly(lactic-co-glycolic acid) (PLGA), polycaprolactone (PCL), and polyethylene glycol (PEG) have been approved by the USFDA and are being researched for drug delivery applications. They have been reported to be potential carriers for drug loading and are used in theranostic applications. In this review, we have primarily focused on the aforementioned polymers and their conjugates. In addition, the therapeutic and diagnostic implications of polymer-based nanosystems have been briefly reviewed. Furthermore, the safety of the developed polymeric formulations is crucial, and we have discussed their biocompatibility in detail. This article also discusses recent developments in block co-polymer-based nanosystems for cancer treatment. The review ends with the challenges of clinical translation of polymer-based nanosystems in drug delivery for cancer therapy.

Microbubble–Nanoparticle Complexes for Ultrasound-Enhanced Cargo Delivery

Targeted delivery of therapeutics to specific tissues is critically important for reducing systemic toxicity and optimizing therapeutic efficacy, especially in the case of cytotoxic drugs. Many strategies currently exist for targeting systemically administered drugs, and ultrasound-controlled targeting is a rapidly advancing strategy for externally-stimulated drug delivery. In this non-invasive method, ultrasound waves penetrate through tissue and stimulate gas-filled microbubbles, resulting in bubble rupture and biophysical effects that power delivery of attached cargo to surrounding cells. Drug delivery capabilities from ultrasound-sensitive microbubbles are greatly expanded when nanocarrier particles are attached to the bubble surface, and cargo loading is determined by the physicochemical properties of the nanoparticles. This review serves to highlight and discuss current microbubble–nanoparticle complex component materials and designs for ultrasound-mediated drug delivery. Nanocarriers that have been complexed with microbubbles for drug delivery include lipid-based, polymeric, lipid–polymer hybrid, protein, and inorganic nanoparticles. Several schemes exist for linking nanoparticles to microbubbles for efficient nanoparticle delivery, including biotin–avidin bridging, electrostatic bonding, and covalent linkages. When compared to unstimulated delivery, ultrasound-mediated cargo delivery enables enhanced cell uptake and accumulation of cargo in target organs and can result in improved therapeutic outcomes. These ultrasound-responsive delivery complexes can also be designed to facilitate other methods of targeting, including bioactive targeting ligands and responsivity to light or magnetic fields, and multi-level targeting can enhance therapeutic efficacy. Microbubble–nanoparticle complexes present a versatile platform for controlled drug delivery via ultrasound, allowing for enhanced tissue penetration and minimally invasive therapy. Future perspectives for application of this platform are also discussed in this review.

Biomaterial-assisted biotherapy: A brief review of biomaterials used in drug delivery, vaccine development, gene therapy, and stem cell therapy

Biotherapy has recently become a hotspot research topic with encouraging prospects in various fields due to a wide range of treatments applications, as demonstrated in preclinical and clinical studies. However, the broad applications of biotherapy have been limited by critical challenges, including the lack of safe and efficient delivery systems and serious side effects. Due to the unique potentials of biomaterials, such as good biocompatibility and bioactive properties, biomaterial-assisted biotherapy has been demonstrated to be an attractive strategy. The biomaterial-based delivery systems possess sufficient packaging capacity and versatile functions, enabling a sustained and localized release of drugs at the target sites. Furthermore, the biomaterials can provide a niche with specific extracellular conditions for the proliferation, differentiation, attachment, and migration of stem cells, leading to tissue regeneration. In this review, the state-of-the-art studies on the applications of biomaterials in biotherapy, including drug delivery, vaccine development, gene therapy, and stem cell therapy, have been summarized. The challenges and an outlook of biomaterial-assisted biotherapies have also been discussed.

Immunotheranostic microbubbles (iMBs) - a modular platform for dendritic cell vaccine delivery applied to breast cancer immunotherapy

BACKGROUND

Therapeutic strategies engaging the immune system against malignant cells have revolutionized the field of oncology. Proficiency of dendritic cells (DCs) for antigen presentation and immune response has spurred interest on DC-based vaccines for anti-cancer therapy. However, despite favorable safety profiles in patients, current DC-vaccines have not yet presented significant outcome due to technical barriers in active DC delivery, tumor progression, and immune dysfunction. To maximize the therapeutic response, we present here a unique cell-free DC-based vaccine capable of lymphoid organ targeting and eliciting T-cell-mediated anti-tumor effect.

METHODS

We developed this novel immunotheranostic platform using plasma membranes derived from activated DCs incorporated into ultrasound contrast microbubbles (MBs), thereby offering real-time visualization of MBs' trafficking and homing in vivo. Human PBMC-derived DCs were cultured ex vivo for controlled maturation and activation using cell membrane antigens from breast cancer cells. Following DC membrane isolation, immunotheranostic microbubbles, called DC-iMBs, were formed for triple negative breast cancer treatment in a mouse model harboring a human reconstituted immune system.

RESULTS

Our results demonstrated that DC-iMBs can accumulate in lymphoid organs and induce anti-tumor immune response, which significantly reduced tumor growth via apoptosis while increasing survival length of the treated animals. The phenotypic changes in immune cell populations upon DC-iMBs delivery further confirmed the T-cell-mediated anti-tumor effect.

CONCLUSION

These early findings strongly support the potential of DC-iMBs as a novel immunotherapeutic cell-free vaccine for anti-cancer therapy.

Glucose Metabolism Intervention-Facilitated Nanomedicine Therapy

Ordinarily, cancer cells possess features of abnormally increased nutrient intake and metabolic pathways. The disorder of glucose metabolism is the most important among them. Therefore, starvation therapy targeting glucose metabolism specifically, which results in metabolic disorders, restricted synthesis, and inhibition of tumor growth, has been developed for cancer therapy. However, issues such as inadequate targeting effectiveness and drug tolerance impede their clinical transformation. In recent years, nanomaterial-assisted starvation treatment has made significant progress in addressing these challenges, whether as a monotherapy or in combination with other medications. Herein, representative researches on the construction of nanosystems conducting starvation therapy are introduced. Elaborate designs and interactions between different treatment mechanisms are meticulously mentioned. Not only are traditional treatments based on glucose oxidase involved, but also newly sprung small molecule agents targeting glucose metabolism. The obstacles and potential for advancing these anticancer therapies were also highlighted in this review.

A theranostic 3D ultrasound imaging system for high resolution image-guided therapy

Microbubble contrast agents are a diagnostic tool with broad clinical impact and an increasing number of indications. Many therapeutic applications have also been identified. Yet, technologies for ultrasound guidance of microbubble-mediated therapy are limited. In particular, arrays that are capable of implementing and imaging microbubble-based therapy in three dimensions in real-time are lacking. We propose a system to perform and monitor microbubble-based therapy, capable of volumetric imaging over a large field-of-view. To propel the promise of the theranostic treatment strategies forward, we have designed and tested a unique array and system for 3D ultrasound guidance of microbubble-based therapeutic protocols based on the frequency, temporal and spatial requirements. Methods: Four 256-channel plane wave scanners (Verasonics, Inc, WA, USA) were combined to control a 1024-element planar array with 1.3 and 2.5 MHz therapeutic and imaging transmissions, respectively. A transducer aperture of ~40×15 mm was selected and Field II was applied to evaluate the point spread function. In vitro experiments were performed on commercial and custom phantoms to assess the spatial resolution, image contrast and microbubble-enhanced imaging capabilities. Results: We found that a 2D array configuration with 64 elements separated by λ-pitch in azimuth and 16 elements separated by 1.5λ-pitch in elevation ensured the required flexibility. This design, of 41.6 mm × 16 mm, thus provided both an extended field-of-view, up to 11 cm x 6 cm at 10 cm depth and steering of ±18° in azimuth and ±12° in elevation. At a depth of 16 cm, we achieved a volume imaging rate of 60 Hz, with a contrast ratio and resolution, respectively, of 19 dB, 0.8 mm at 3 cm and 20 dB and 2.1 mm at 12.5 cm. Conclusion: A single 2D array for both imaging and therapeutics, integrated with a 1024 channel scanner can guide microbubble-based therapy in volumetric regions of interest.

Non-Coding RNAs as Novel Regulators of Neuroinflammation in Alzheimer's Disease

Alzheimer’s disease (AD) is one of the most common causes of dementia. Although significant breakthroughs have been made in understanding the progression and pathogenesis of AD, it remains a worldwide problem and a significant public health burden. Thus, more efficient diagnostic and therapeutic strategies are urgently required. The latest research studies have revealed that neuroinflammation is crucial in the pathogenesis of AD. Non-coding RNAs (ncRNAs), including long noncoding RNAs (lncRNAs), microRNAs (miRNAs), circular RNAs (circRNAs), PIWI-interacting RNAs (piRNAs), and transfer RNA-derived small RNAs (tsRNAs), have been strongly associated with AD-induced neuroinflammation. Furthermore, several ongoing pre-clinical studies are currently investigating ncRNA as disease biomarkers and therapeutic interventions to provide new perspectives for AD diagnosis and treatment. In this review, the role of different types of ncRNAs in neuroinflammation during AD are summarized in order to improve our understanding of AD etiology and aid in the translation of basic research into clinical practice.

MicroRNAs and their delivery in diabetic fibrosis

The global prevalence of diabetes mellitus was estimated to be 463 million people in 2019 and is predicted to rise to 700 million by 2045. The associated financial and societal costs of this burgeoning epidemic demand an understanding of the pathology of this disease, and its complications, that will inform treatment to enable improved patient outcomes. Nearly two decades after the sequencing of the human genome, the significance of noncoding RNA expression is still being assessed. The family of functional noncoding RNAs known as microRNAs regulates the expression of most genes encoded by the human genome. Altered microRNA expression profiles have been observed both in diabetes and in diabetic complications. These transcripts therefore have significant potential and novelty as targets for therapy, therapeutic agents and biomarkers.

Engineered Cell-Derived Vesicles Displaying Targeting Peptide and Functionalized with Nanocarriers for Therapeutic microRNA Delivery to Triple-Negative Breast Cancer in Mice

Polymeric nanocarriers (PNCs) can be used to deliver therapeutic microRNAs (miRNAs) to solid cancers. However, the ability of these nanocarriers to specifically target tumors remains a challenge. Alternatively, extracellular vesicles (EVs) derived from tumor cells show homotypic affinity to parent cells, but loading sufficient amounts of miRNAs into EVs is difficult. Here, it is investigated whether uPAR-targeted delivery of nanococktails containing PNCs loaded with therapeutic antimiRNAs, and coated with uPA engineered extracellular vesicles (uPA-eEVs) can elicit synergistic antitumor responses. The uPA-eEVs coating on PNCs increases natural tumor targeting affinities, thereby enhancing the antitumor activity of antimiRNA nanococktails. The systemic administration of uPA-eEV-PNCs nanococktail shows a robust tumor tropism, which significantly enhances the combinational antitumor effects of antimiRNA-21 and antimiRNA-10b, and leads to significant tumor regression and extension of progression free survival for syngeneic 4T1 tumor-bearing mice. In addition, the uPA-eEV-PNCs-antimiRNAs nanococktail plus low dose doxorubicin results in a synergistic antitumor effect as evidenced by inhibition of tumor growth, reduction of lung metastases, and extension of survival of 4T1 tumor-bearing mice. The targeted combinational nanococktail strategy could be readily translated to the clinical setting by using autologous cancer cells that have flexibility for ex vivo expansion and genetic engineering.

Smart Strategies for Precise Delivery of CRISPR/Cas9 in Genome Editing

The emergence of CRISPR/Cas technology has enabled scientists to precisely edit genomic DNA sequences. This approach can be used to modulate gene expression for the treatment of genetic disorders and incurable diseases such as cancer. This potent genome-editing tool is based on a single guide RNA (sgRNA) strand that recognizes the targeted DNA, plus a Cas nuclease protein for binding and processing the target. CRISPR/Cas has great potential for editing many genes in different types of cells and organisms both in vitro and in vivo. Despite these remarkable advances, the risk of off-target effects has hindered the translation of CRISPR/Cas technology into clinical applications. To overcome this hurdle, researchers have devised gene regulatory systems that can be controlled in a spatiotemporal manner, by designing special sgRNA, Cas, and CRISPR/Cas delivery vehicles that are responsive to different stimuli, such as temperature, light, magnetic fields, ultrasound (US), pH, redox, and enzymatic activity. These systems can even respond to dual or multiple stimuli simultaneously, thereby providing superior spatial and temporal control over CRISPR/Cas gene editing. Herein, we summarize the latest advances on smart sgRNA, Cas, and CRISPR/Cas nanocarriers, categorized according to their stimulus type (physical, chemical, or biological).

Controlled Transdermal Iontophoresis of Insulin from Water-Soluble Polypyrrole Nanoparticles: An In Vitro Study

The iontophoresis delivery of insulin (INS) remains a serious challenge due to the low permeability of the drug through the skin. This work aims to investigate the potential of water-soluble polypyrrole nanoparticles (WS-PPyNPs) as a drug donor matrix for controlled transdermal iontophoresis of INS. WS-PPyNPs have been prepared via a simple chemical polymerization in the presence of sodium dodecyl sulfate (SDS) as both dopant and the stabilizing agent. The synthesis of the soluble polymer was characterized using field emission scanning electron microscopy (FESEM), dynamic light scattering (DLS), fluorescence spectroscopy, and Fourier transform infrared (FT–IR) spectroscopy. The loading mechanism of INS onto the WS-PPyNPs is based on the fact that the drug molecules can be replaced with doped dodecyl sulfate. A two-compartment Franz-type diffusion cell was employed to study the effect of current density, formulation pH, INS concentration, and sodium chloride concentration on anodal iontophoresis (AIP) and cathodal iontophoresis (CIP) of INS across the rat skin. Both AIP and CIP delivery of INS using WS-PPyNPs were significantly increased compared to passive delivery. Furthermore, while the AIP experiment (60 min at 0.13 mA cm^–2) show low cumulative drug permeation for INS (about 20.48 µg cm⁻²); the CIP stimulation exhibited a cumulative drug permeation of 68.29 µg cm⁻². This improvement is due to the separation of positively charged WS-PPyNPs and negatively charged INS that has occurred in the presence of cathodal stimulation. The obtained results confirm the potential applicability of WS-PPyNPs as an effective approach in the development of controlled transdermal iontophoresis of INS.

Safety of Image-Guided Treatment of the Liver with Ultrasound and Microbubbles in an in Vivo Porcine Model

Ultrasound and microbubbles are useful for both diagnostic imaging and targeted drug delivery, making them ideal conduits for theranostic interventions. Recent reports have indicated the preclinical success of microbubble cavitation for enhancement of chemotherapy in abdominal tumors; however, there have been limited studies and variable efficacy in clinical implementation of this technique. This is likely because in contrast to the high pressures and long cycle lengths seen in successful preclinical work, current clinical implementation of microbubble cavitation for drug delivery generally involves low acoustic pressures and short cycle lengths to fit within clinical guidelines. To translate the preclinical parameter space to clinical adoption, a relevant safety study in a healthy large animal is required. Therefore, the purpose of this work was to evaluate the safety of ultrasound cavitation treatment (USCTx) in a healthy porcine model using a modified Philips EPIQ with S5-1 as the focused source. We performed USCTx on eight healthy pigs and monitored health over the course of 1 wk. We then performed an acute study of USCTx to evaluate immediate tissue damage. Contrast-enhanced ultrasound exams were performed before and after each treatment to investigate perfusion changes within the treated areas, and blood and urine were evaluated for liver damage biomarkers. We illustrate, through quantitative analysis of contrast-enhanced ultrasound data, blood and urine analyses and histology, that this technique and the parameter space considered are safe within the time frame evaluated. With its safety confirmed using a clinical-grade ultrasound scanner and contrast agent, USCTx could be easily translated into clinical trials for improvement of chemotherapy delivery. This represents the first safety study assessing the bio-effects of microbubble cavitation from relevant ultrasound parameters in a large animal model.

DNA Based and Stimuli-Responsive Smart Nanocarrier for Diagnosis and Treatment of Cancer: Applications and Challenges

The rapid development of multidrug co-delivery and nano-medicines has made spontaneous progress in tumor treatment and diagnosis. DNA is a unique biological molecule that can be tailored and molded into various nanostructures. The addition of ligands or stimuli-responsive elements enables DNA nanostructures to mediate highly targeted drug delivery to the cancer cells. Smart DNA nanostructures, owing to their various shapes, sizes, geometry, sequences, and characteristics, have various modes of cellular internalization and final disposition. On the other hand, functionalized DNA nanocarriers have specific receptor-mediated uptake, and most of these ligand anchored nanostructures able to escape lysosomal degradation. DNA-based and stimuli responsive nano-carrier systems are the latest advancement in cancer targeting. The data exploration from various studies demonstrated that the DNA nanostructure and stimuli responsive drug delivery systems are perfect tools to overcome the problems existing in the cancer treatment including toxicity and compromised drug efficacy. In this light, the review summarized the insights about various types of DNA nanostructures and stimuli responsive nanocarrier systems applications for diagnosis and treatment of cancer.

Sonodynamic antimicrobial chemotherapy: An emerging alternative strategy for microbial inactivation

Sonodynamic antimicrobial chemotherapy (SACT), which relies on a combination of low-intensity ultrasound and chemotherapeutic agents termed sonosensitizers, has been explored as a promising alternative for microbial inactivation. Such treatment has superior penetration ability, high target specificity, and can overcome resistance conferred by the local microenvironment. Taken of these advantages, SACT has been endowed with an extensive application prospect in the past decade and attracted more and more attention. This review focusses on the current understanding of the mechanism of SACT, the interaction of sonodynamic action on different microbes, the factors affecting the efficacy of SACT, discusses the findings of recent works on SACT, and explores further prospects for SACT. Thus, a better understanding of sonodynamic killing facilitates the scientific community and industry personnel to establish a novel strategy to combat microbial burden.

Minoxidil-Coated Lysozyme-Shelled Microbubbes Combined With Ultrasound for the Enhancement of Hair Follicle Growth: Efficacy In Vitro and In Vivo

Lysozyme (Lyz) is an antimicrobial peptide, a safe adjunct, and it has been indicated that Lyz can promote vibrissae follicle growth by enhancing the hair-inductive capacity of dermal papilla cells in mice. The present study produced a new type of minoxidil (Mx)-coated antifungal Lyz-shelled microbubble (LyzMB) for inhibiting bacteria and allergies on the oily scalp. The potential of Mx-coated LyzMBs (Mx-LyzMBs) combined with ultrasound (US) and the role of LyzMB fragments in enhancing hair follicle growth were investigated. Mx grafted with LyzMBs were synthesized and the loading efficiency of Mx on cationic LyzMBs was 20.3%. The biological activity of Lyz in skin was determined using an activity assay kit and immunohistochemistry expression, and the activities in the US+Mx-LyzMBs group were 65.8 and 118.5 μU/mL at 6 and 18 h, respectively. In hair follicle cell culture experiments, the lengths of hair follicle cells were significantly enhanced in the US+Mx-LyzMBs group (108.2 ± 11.6 μm) compared to in the US+LyzMBs+Mx group (44.3 ± 9.8 μm) and the group with Mx alone (79.6 ± 12.0 μm) on day 2 (p < 0.001). During 21 days of treatment in animal experiments, the growth rates at days 10 and 14 in the US+Mx-LyzMBs group increased by 19.4 and 65.7%, respectively, and there were significant differences (p < 0.05) between the US+Mx-LyzMBs group and the other four groups. These findings indicate that 1-MHz US (applied at 3 W/cm², acoustic pressure = 0.266 MPa) for 1 min combined with Mx-LyzMBs can significantly increase more penetration of Mx and LyzMB fragments into skin and enhance hair growth than Mx alone.

Bibliometric Analysis of Global Research Trends on Ultrasound Microbubble: A Quickly Developing Field

Background: Microbubbles are widely used as highly effective contrast agents to improve the diagnostic capability of ultrasound imaging. Mounting evidence suggests that ultrasound coupled with microbubbles has promising therapeutic applications in cancer, cardiovascular, and neurological disorders by acting as gene or drug carriers. The aim of this study was to identify the scientific output and activity related to ultrasound microbubble through bibliometric approaches. Methods: The literature related to ultrasound microbubble published between 1998 and 2019 was identified and selected from the Science Citation Index Expanded of Web of Science Core Collection on February 21, 2021. The Scopus database was also searched to validate the results and provided as supplementary material. Quantitative variables including number of publications and citations, H-index, and journal citation reports were analyzed by using Microsoft Excel 2019 and GraphPad Prism 8.0 software. VOS viewer and CiteSpace V were used to perform coauthorship, citation, co-citation, and co-occurrence analysis for countries/regions, institutions, authors, and keywords. Results: A total of 6088 publications from the WoSCC were included. The United States has made the largest contribution in this field, with the majority of publications (2090, 34.3%), citations (90,741, 46.6%), the highest H-index (138), and close collaborations with China and Canada. The most contributive institution was the University of Toronto. Professors De Jong N and Dayton P A have made great achievements in this field. However, the research cooperation between institutions and authors was relatively weak. All the studies could be divided into four clusters: "ultrasound diagnosis study," "microbubbles' characteristics study," "gene therapy study," and "drug delivery study." The average appearing years (AAY) of keywords in the cluster "drug delivery study" was more recent than other clusters. For promising hot spots, "doxorubicin" showed a relatively latest AAY of 2015.49, followed by "nanoparticles" and "breast cancer." Conclusion: There has been an increasing amount of scientific output on ultrasound microbubble according to the global trends, and the United States is staying ahead in this field. Collaboration between research teams still needs to be strengthened. The focus gradually shifts from "ultrasound diagnosis study" to "drug delivery study." It is recommended to pay attention to the latest hot spots, such as "doxorubicin," "nanoparticles," and "breast cancer."

Therapeutic efficacy and cardioprotection of nucleolin-targeted doxorubicin-loaded ultrasound nanobubbles in treating triple-negative breast cancer

Targeted lipid nanobubbles as theranostic ultrasound molecular probes with both targeted contrast-enhanced ultrasound molecular imaging and synergistic treatment capabilities are expected to overcome severe challenges in the diagnosis and treatment of refractory triple-negative breast cancer (TNBC). In this study, AS1411 aptamer-functionalised nucleolin-targeted doxorubicin-loaded lipid nanobubbles (AS1411-DOX-NBs) were constructed, and their physicochemical properties as well as anti-tumour and cardioprotective efficacies were systematically tested and evaluated. The results showed that AS1411-DOX-NBs can carry and maintain the physicochemical and pharmacodynamic properties of doxorubicin (DOX) and show stronger tumour cell-killing abilityin vitroby increasing the active uptake of drugs. AS1411-DOX-NBs also significantly inhibited the growth of TNBC xenografts while maintaining the weight and health of the mice. Echocardiography and pathological examination further confirmed that AS1411-DOX-NBs effectively caused tumour tissue apoptosis and necrosis while reducing DOX-induced cardiotoxicity. The AS1411-DOX-NBs constructed in this study enable both targeted contrast-enhanced ultrasound molecular imaging and synergistic therapeutic efficacy and can be used as safe and efficient theranostic ultrasound molecular probes for the diagnosis and treatment of TNBC.

Ultrasound-responsive polymer-based drug delivery systems

Ultrasound-responsive polymeric materials have received a tremendous amount of attention from scientists for several decades. Compared to other stimuli-responsive materials (such as UV-, thermal-, and pH-responsive materials), these smart materials are more applicable since they allow more efficient drug delivery and targeted treatment by fairly non-invasive means. This review describes the recent advances of such ultrasound-responsive polymer-based drug delivery systems and illustrates various applications. More specifically, the mechanism of ultrasound-induced drug delivery, typical formulations, and biomedical applications (tumor therapy, disruption of blood-brain barrier, fighting infectious diseases, transdermal drug delivery, and enhanced thrombolysis) are summarized. Finally, a perspective on the future research directions for the development of ultrasound-responsive polymeric materials to facilitate a clinical translation is given.

Therapeutic Ultrasound Parameter Optimization for Drug Delivery Applied to a Murine Model of Hepatocellular Carcinoma

Ultrasound and microbubble (USMB)-mediated drug delivery is a valuable tool for increasing the efficiency of the delivery of therapeutic agents to cancer while maintaining low systemic toxicity. Typically, selection of USMB drug delivery parameters used in current research settings are either based on previous studies described in the literature or optimized using tissue-mimicking phantoms. However, phantoms rarely mimic in vivo tumor environments, and the selection of parameters should be based on the application or experiment. In the following study, we optimized the therapeutic parameters of the ultrasound drug delivery system to achieve the most efficient in vivo drug delivery using fluorescent semiconducting polymer nanoparticles as a model nanocarrier. We illustrate that voltage, pulse repetition frequency and treatment time (i.e., number of ultrasound pulses per therapy area) delivered to the tumor can successfully be optimized in vivo to ensure effective delivery of the semiconducting polymer nanoparticles to models of hepatocellular carcinoma. The optimal in vivo parameters for USMB drug delivery in this study were 70 V (peak negative pressure = 3.4 MPa, mechanical index = 1.22), 1-Hz pulse repetition frequency and 100-s therapy time. USMB-mediated drug delivery using in vivo optimized ultrasound parameters caused an up to 2.2-fold (p < 0.01) increase in drug delivery to solid tumors compared with that using phantom-optimized ultrasound parameters.

Acoustically Driven Microbubbles Enable Targeted Delivery of microRNA-Loaded Nanoparticles to Spontaneous Hepatocellular Neoplasia in Canines

Spatially localized microbubble cavitation by ultrasound offers an effective means of altering permeability of natural barriers (i.e. blood vessel and cell membrane) in favor of nanomaterials accumulation in the target site. In this study, a clinically relevant, minimally invasive ultrasound guided therapeutic approach is investigated for targeted delivery of anticancer microRNA loaded PLGA-b-PEG nanoparticles to spontaneous hepatocellular neoplasia in a canine model. Quantitative assessment of the delivered microRNAs revealed prominent and consistent increase in miRNAs levels (1.5-to 2.3-fold increase (p<0.001)) in ultrasound treated tumor regions compared to untreated control regions. Immunohistology of ultrasound treated tumor tissue presented a clear evidence for higher amount of nanoparticles extravasation from the blood vessels. A distinct pattern of cytokine expression supporting CD8+ T cells mediated "cold-to-hot" tumor transition was evident in all patients. On the outset, proposed platform can enhance delivery of miRNA-loaded nanoparticles to deep seated tumors in large animals to enhance chemotherapy.

Molecular micromanagement: DNA nanotechnology establishes spatio-temporal control for precision medicine

Current advances in DNA nanotechnology pinpoint exciting perspectives for the design of customized, patient-specific treatments. This advance is made possible by the exceptionally high precision and specificity that are typical for DNA base pairing on the one hand and our growing ability to harness those features in synthetic, DNA-based constructs on the other hand. Modern medicine may soon benefit from recent developments in this field, especially regarding the targeted delivery of drugs and the rational interference of synthetic DNA strands with cellular oligonucleotides. In this Review, we summarize selected examples from the area of DNA nanotechnology, where the development of precisely controlled, advanced functional mechanisms was achieved. To demonstrate the high versatility of these rationally designed structures, we categorize the dynamic DNA-based materials suggested for precision medicine according to four fundamental tasks: "hold & release," "heal," "detect & measure," as well as "guide & direct." In all the biomedical applications we highlight, DNA strands not only constitute structural building blocks but allow for creating stimuli-responsive objects, serve as an active cargo, or act as molecular control/guidance tools. Moreover, we discuss several issues that need to be considered when DNA-based structures are designed for applications in the field of precision medicine. Even though the majority of DNA-based objects have not been used in clinical settings yet, recent progress regarding the stability, specificity, and control over the dynamic behavior of synthetic DNA structures has advanced greatly. Thus, medical applications of those nanoscopic objects should be feasible in the near future.

Recent Advances in Nanomaterial-Assisted Combinational Sonodynamic Cancer Therapy

Ultrasound (US)-triggered sonodynamic therapy (SDT), as a promising noninvasive therapeutic modality, has received ever-increasing attention in recent years. Its specialized chemical agents, named sonosensitizers, are activated by low-intensity US to produce lethal reactive oxygen species (ROS) for oncotherapy. Compared with phototherapeutic strategies, SDT provides many noteworthy opportunities and benefits, such as deeper penetration depth, absence of phototoxicity, and fewer side effects. Nevertheless, previous studies have also demonstrated its intrinsic limitations. Thanks to the facile engineering nature of nanotechnology, numerous novel nanoplatforms are being applied in this emerging field to tackle these intrinsic barriers and achieve continuous innovations. In particular, the combination of SDT with other treatment strategies has demonstrated a superior efficacy in improving anticancer activity relative to that of monotherapies alone. Therefore, it is necessary to summarize the nanomaterial-assisted combinational sonodynamic cancer therapy applications. Herein, the design principles in achieving synergistic therapeutic effects based on nanomaterial engineering methods are highlighted. The ultimate goals are to stimulate the design of better-quality combined sonodynamic treatment schemes and provide innovative ideas for the perspectives of SDT in promoting its future transformation to clinical application.

SARS-CoV-2 Vaccine Development: An Overview and Perspectives

Coronavirus disease 2019, abbreviated as COVID-19, is caused by a new strain of coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It started in late December 2019 in Wuhan, China, and by mid-March 2020, the disease had spread globally. As of July 17, 2020, this pandemic virus has infected 13.9 million people and claimed the life of approximately 593 000 people globally, and the numbers continue to climb. An unprecedented effort is underway to develop therapeutic and prophylactic strategies against this disease. Various drugs and vaccines are undergoing rapid development, and some of these are already in phase III clinical trials. Although Russia was the first to release a vaccine by skipping phase III clinical trials, there is no evidence of large-scale clinical trials, and the safety and efficacy of the vaccine are still a concern. Nevertheless, critical lessons can be learned and data garnered for developing promising vaccines against this rapidly emerging virus or other similar pathogens in the future. In this overview, we cover the available information on the various vaccine development initiatives by different companies, the potential strategies adopted for vaccine design, and the challenges and clinical impact expected from these vaccines. We also briefly discuss the possible role of these vaccines and the specific concerns for their use in patients with pre-existing disease conditions such as cardiovascular, lung, kidney, and liver diseases, cancer patients who are receiving immunosuppressive medications, including anticancer chemotherapies, and many other sensitive populations, such as children and the elderly.

Image-Guided Treatment of Primary Liver Cancer in Mice Leads to Vascular Disruption and Increased Drug Penetration

Despite advances in interventional procedures and chemotherapeutic drug development, hepatocellular carcinoma (HCC) is still the fourth leading cause of cancer-related deaths worldwide with a <30% 5-year survival rate. This poor prognosis can be attributed to the fact that HCC most commonly occurs in patients with pre-existing liver conditions, rendering many treatment options too aggressive. Patient survival rates could be improved by a more targeted approach. Ultrasound-induced cavitation can provide a means for overcoming traditional barriers defining drug uptake. The goal of this work was to evaluate preclinical efficacy of image-guided, cavitation-enabled drug delivery with a clinical ultrasound scanner. To this end, ultrasound conditions (unique from those used in imaging) were designed and implemented on a Philips EPIQ and S5-1 phased array probe to produced focused ultrasound for cavitation treatment. Sonovue^® microbubbles which are clinically approved as an ultrasound contrast agent were used for both imaging and cavitation treatment. A genetically engineered mouse model was bred and used as a physiologically relevant preclinical analog to human HCC. It was observed that image-guided and targeted microbubble cavitation resulted in selective disruption of the tumor blood flow and enhanced doxorubicin uptake and penetration. Histology results indicate that no gross morphological damage occurred as a result of this process. The combination of these effects may be exploited to treat HCC and other challenging malignancies and could be implemented with currently available ultrasound scanners and reagents.

Highly penetrating nanobubble polymer enhances LINC00511-siRNA delivery for improving the chemosensitivity of triple-negative breast cancer

Ultrasound-mediated nanobubble destruction (UMND), which can utilize the physical energy of ultrasound irradiation to improve the transfer efficiency to target cells is becoming one of the most promising carriers for gene delivery. The purpose of this study was to establish cell-penetrating peptide (CPP)-loaded nanobubbles (CNBs) connected with long intergenic nonprotein coding RNA 00511-small interfering RNA (LINC00511-siRNA) and evaluate its feasibility for improving the chemosensitivity of triple-negative breast cancer in vitro. First, fluorescence imaging confirmed the loading of siLINC00511 on CNBs, and the CNBs-siLINC00511 were characterized by the Zetasizer Nano ZS90 analyzer and transmission electron microscopy. Next, cell counting kit 8 assay was used to detect the inhibitory activity of cisplatin on the proliferation of MDA-MB-231 cells, and the 50% inhibition concentration value before and after transfer was calculated. Finally, the silencing effect of siLINC00511 was evaluated in vitro using an apoptosis assay, transwell assay, real time-PCR and western blotting. UMND combined with CNBs could effectively transfer the siRNA to MDA-MB-231 cells, thus evidently reducing the expression of LINC00511. Furthermore, inhibitory activity of cisplatin on MDA-MB-231 cells was enhanced after downregulation of LINC00511 expression. Downregulation of LINC00511 alters expression of cell cycle-related (CDK 6) and apoptosis-related (Bcl-2 and Bax) proteins in MDA-MB-231 cells. These results suggested that siRNA-CNBs may be an ideal vector for the treatment of tumors, with high efficiency RNA interference under the combined action of UMND. It may provide a new therapeutic method for triple negative breast cancer.

Integration of microbubbles with biomaterials in tissue engineering for pharmaceutical purposes

Tissue engineering with the aid of biomaterials is a novel and promising knowledge aiming at improving human life expectancy. Besides, microbubbles are increasingly employed in biomedical applications due to their capability as a reservoir of therapeutic agents and oxygen molecules. In the present study, Microbubbles as the backbone of the research are produced as one of the potent devices in tissue engineering approaches, including drug delivery, wound healing, 3D printing, and scaffolding. It was shown that microbubbles are capable of promoting oxygen penetration and boosting the wound healing process by supplying adequate oxygen. Microbubbles also demonstrated their strength and potency in advancing drug delivery systems by reinforcing mass transfer phenomena. Furthermore, microbubbles developed the mechanical and biological characteristics of engineered scaffolds by manipulating the pores. Increasing cell survival, the biological activity of cells, angiogenesis, cell migration, and also nutrient diffusion into the inner layers of the scaffold were other achievements by microbubbles. In conclusion, the interest of biomedical communities in simultaneous usage of microbubbles and biomaterials under tissue engineering approaches experiences remarkable growth in Pharmaceutical studies.

The opposite functions of miR-24 in the osteogenesis and adipogenesis of adipose-derived mesenchymal stem cells are mediated by the HOXB7/β-catenin complex

Adipose-derived mesenchymal stem cells (ADMSCs) used in combination with nanoparticles or scaffolds represent promising candidates for bone engineering. Compared to bone marrow-derived MSCs (BMMSCs), ADMSCs show a relatively low capacity for osteogenesis. In the current study, miR-24 was identified as an osteogenesis- and adipogenesis-related miRNA that performs opposing roles (inhibition in osteogenesis and promotion in adipogenesis) during these two differentiation processes. Through bioinformatics analysis and luciferase reporter assays, homeobox protein Hox-B7 (HOXB7) was identified as a potential novel downstream target of miR-24 that contains a miR-24 binding site in the 3'-UTR of its mRNA. Overexpression of HOXB7 could partly halt the inhibitory effect of miR-24 on osteogenesis, and downregulation of HOXB7 could also partly suppress the positive effect of miR-24 on adipogenesis. Furthermore, immunoprecipitation experiments found that HOXB7 and β-catenin formed a functional complex that acted as an essential modulator during osteogenesis and adipogenesis of ADMSCs. After transfecting ADMSCs with an MSNs-PEI-miR-24 agomir or antagomir and loading the cells onto gelatin-chitosan scaffolds, the compounds were assessed for their abilities to repair the critical-sized calvarial defects in rats. Comprehensive evaluation, including micro-CT, sequential fluorescent labeling, and immunohistochemistry analysis, revealed that silencing miR-24 distinctly promoted in vivo bone remolding, whereas overexpression of miR-24 significantly repressed bone formation. Taken together, our findings demonstrated opposite roles for the miR-24/HOXB7/β-catenin signaling pathway in the osteogenesis and adipogenesis of ADMSCs, which may provide a novel mechanism for determining the balance between these two biological processes.