Ultrasound-Targeted Microbubble Destruction Mediates Gene Transfection for Beta-Cell Regeneration and Glucose Regulation

A Ratiometric Gene-Switch System for miRNA Sensing and Gene Regulation

microRNAs (miRNAs) are a class of non-coding, small RNAs that play an important role in diverse biological processes and diseases. By regulating the expression of eukaryotic genes post-transcriptionally in a sequence-specific manner, miRNAs are widely used to design synthetic RNA switches. However, most of the RNA switches are often dependent on the corresponding ligand molecules, whose specificity and concentration would affect the efficiency of synthetic RNA circuits. Here, a fused transcriptional repressor Gal4BD-Rluc based gene-switch system Gal-miR for miRNA visualization and gene regulation is described. By placing a luciferase downstream gene under the control of endogenous miRNA machinery, the Gal-miR system makes the conversion of miRNA-mediated gene silencing into a ratiometric bioluminescent signal, which quantitatively reflected miRNA-206 activity during myogenic differentiation. Moreover, it demonstrates that this gene-switch system can effectively inhibit breast cancer cell viability, migration and invasion under the control of specific miRNAs by replacing the downstream gene with melittin functional gene. The study proposes a powerful modular genetic design for achieving precise control of transgene expression in a miRNA responsive way, as well as visualizing the dynamics of miRNA activity.

Fully Active Delivery of Nanodrugs In Vivo via Remote Optical Manipulation

The active delivery of nanodrugs has been a bottleneck problem in nanomedicine. While modification of nanodrugs with targeting agents can enhance their retention at the lesion location, the transportation of nanodrugs in the circulation system is still a passive process. The navigation of nanodrugs with external forces such as magnetic field has been shown to be effective for active delivery, but the existing techniques are limited to specific materials like magnetic nanoparticles. In this study, an alternative actuation method is proposed based on optical manipulation for remote navigation of nanodrugs in vivo, which is compatible with most of the common drug carriers and exhibits significantly higher manipulation precision. By the programmable scanning of the laser beam, the motion trajectory and velocity of the nanodrugs can be precisely controlled in real time, making it possible for intelligent drug delivery, such as inverse-flow transportation, selective entry into specific vascular branch, and dynamic circumvention across obstacles. In addition, the controlled mass delivery of nanodrugs can be realized through indirect actuation by the microflow field. The developed optical manipulation method provides a new solution for the active delivery of nanodrugs, with promising potential for the treatment of blood diseases such as leukemia and thrombosis.

Nature-Inspired Thylakoid-Based Photosynthetic Nanoarchitectures for Biomedical Applications

"Drawing inspiration from nature" offers a wealth of creative possibilities for designing cutting-edge materials with improved properties and performance. Nature-inspired thylakoid-based nanoarchitectures, seamlessly integrate the inherent structures and functions of natural components with the diverse and controllable characteristics of nanotechnology. These innovative biomaterials have garnered significant attention for their potential in various biomedical applications. Thylakoids possess fundamental traits such as light harvesting, oxygen evolution, and photosynthesis. Through the integration of artificially fabricated nanostructures with distinct physical and chemical properties, novel photosynthetic nanoarchitectures can be catalytically generated, offering versatile functionalities for diverse biomedical applications. In this article, an overview of the properties and extraction methods of thylakoids are provided. Additionally, the recent advancements in the design, preparation, functions, and biomedical applications of a range of thylakoid-based photosynthetic nanoarchitectures are reviewed. Finally, the foreseeable challenges and future prospects in this field is discussed.

Metformin Reduces the Risk of Total Hip Arthroplasty in Elderly Patients with Hip Osteoarthritis and Type 2 Diabetes Mellitus

Purpose

To assess if metformin could reduce the risk of total hip arthroplasty (THA) in elderly patients with hip osteoarthritis and type 2 diabetes (T2DM).

Patients and Methods

It is a retrospective study among elderly patients (≥65 years) with hip osteoarthritis and T2DM. All included patients were divided into metformin group and non-metformin group, then propensity-score match (PSM) was performed to control potential confounding factors. The primary endpoint was the incidence of the first THA during the study period. Multivariate Cox regression analysis was employed to evaluate the association of metformin with the risk of THA.

Results

A matched cohort of 716 patients were finally included, with 308 metformin users and 308 metformin non-users. During a maximum follow-up of 10 years, the incidence of THA in metformin users was significantly lower than that in non-users (4.9% vs 25.0%, P<0.01). Multivariate Cox regression analysis indicated that metformin users were significantly associated with a lower risk of THA compared with non-users (HR = 0.17, 95% CI: 0.10-0.30; P<0.01). In addition, further analyses indicated that participants with long-term metformin use (HR = 0.10, 95% CI: 0.02-0.46; P<0.01) or high metformin dosage (HR = 0.15, 95% CI: 0.04-0.57; P<0.01) had a lower risk of THA.

Conclusion

Metformin use could reduce the risk of THA in patients with hip osteoarthritis and T2DM, and the effect is accumulative and dose dependent.

Advanced Materials and Delivery Systems for Enhancement of Chimeric Antigen Receptor Cells

Chimeric antigen receptor (CAR) cell therapy is a great success and breakthrough in immunotherapy. However, there are still lots of barriers to its wide use in clinical, including long time consumption, high cost, and failure against solid tumors. For these challenges, researches are deplored to explore CAR cells to more appliable products in clinical. This minireview focuses on the advanced non-viral materials for CAR-T transfection ex vivo with better performance, delivery systems combined with other therapy for enhancement of CAR-T therapy in solid tumors. In addition, the targeted delivery platform for CAR cells in vivo generation as a breakthrough technology as its low cost and convenience. In the end, the prospective direction and future of CAR cell therapy are discussed.

Cardiac-targeted delivery of nuclear receptor RORα via ultrasound targeted microbubble destruction optimizes the benefits of regular dose of melatonin on sepsis-induced cardiomyopathy

BACKGROUND

Large-dose melatonin treatment in animal experiments was hardly translated into humans, which may explain the dilemma that the protective effects against myocardial injury in animal have been challenged by clinical trials. Ultrasound-targeted microbubble destruction (UTMD) has been considered a promising drug and gene delivery system to the target tissue. We aim to investigate whether cardiac gene delivery of melatonin receptor mediated by UTMD technology optimizes the efficacy of clinically equivalent dose of melatonin in sepsis-induced cardiomyopathy.

METHODS

Melatonin and cardiac melatonin receptors in patients and rat models with lipopolysaccharide (LPS)- or cecal ligation and puncture (CLP)-induced sepsis were assessed. Rats received UTMD-mediated cardiac delivery of RORα/cationic microbubbles (CMBs) at 1, 3 and 5 days before CLP surgery. Echocardiography, histopathology and oxylipin metabolomics were assessed at 16-20 h after inducing fatal sepsis.

RESULTS

We observed that patients with sepsis have lower serum melatonin than healthy controls, which was observed in the blood and hearts of Sprague-Dawley rat models with LPS- or CLP-induced sepsis. Notably, a mild dose (2.5 mg/kg) of intravenous melatonin did not substantially improve septic cardiomyopathy. We found decreased nuclear receptors RORα, not melatonin receptors MT1/2, under lethal sepsis that may weaken the potential benefits of a mild dose of melatonin treatment. In vivo, repeated UTMD-mediated cardiac delivery of RORα/CMBs exhibited favorable biosafety, efficiency and specificity, significantly strengthening the effects of a safe dose of melatonin on heart dysfunction and myocardial injury in septic rats. The cardiac delivery of RORα by UTMD technology and melatonin treatment improved mitochondrial dysfunction and oxylipin profiles, although there was no significant influence on systemic inflammation.

CONCLUSIONS

These findings provide new insights to explain the suboptimal effect of melatonin use in clinic and potential solutions to overcome the challenges. UTMD technology may be a promisingly interdisciplinary pattern against sepsis-induced cardiomyopathy.

Formulation strategies to provide oxygen-release to contrast local hypoxia for transplanted islets

Islet transplantation refers to the transfusion of healthy islet cells into the diabetic recipients and reconstruction of their endogenous insulin secretion to achieve insulin independence. It is a minimally invasive surgery that holds renewed prospect as a therapeutic method for type 1 diabetes mellitus. However, poor oxygenation in the early post-transplantation period is considered as one of the major causes of islet loss and dysfunction. Due to the metabolism chacteristics, islets required a high supply of oxygen for cell survival while a hypoxia environment would lead to severe islet loss and graft failure. Emerging strategies have been proposed, including providing external oxygen and speeding up revascularization. From the perspective of formulation science, it is feasible and practical to protect transplanted islets by oxygen-release before revascularization as opposed to local hypoxia. In this study, we review the potential formulation strategies that could provide oxygen-release by either delivering external oxygen or triggering localized oxygen generation for transplanted islets.

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.

Photoacoustic/ultrasound-guided gene silencing: Multifunctional microbubbles for treating adjuvant-induced arthritis

AIMS

To effectively deliver small interfering RNA (siRNA) to inflammatory tissues for treating rheumatoid arthritis (RA), we developed the multifunctional microbubbles (MBs) to perform photoacoustic/ultrasound-guided gene silencing.

METHODS

Fluorescein amidite (FAM)-labelled tumour necrosis factor-α (TNF-α)-siRNA and cationic MBs were mixed to fabricate FAM-TNF-α-siRNA-cMBs. The cell transfection efficacy of FAM-TNF-α-siRNA-cMBs was evaluated in vitro on RAW264.7 cells. Subsequently, wistar rats with adjuvant-induced arthritis (AIA) were injected intravenously with MBs and simultaneously subjected to low-frequency ultrasound for ultrasound-targeted microbubble destruction (UTMD). Photoacoustic imaging (PAI) was utilized to visualize the distribution of siRNA. And the clinical and pathological changes of AIA rats was estimated.

RESULTS

FAM-TNF-α-siRNA-cMBs were evenly distributed within the RAW264.7 cells and significantly reduced TNF-α mRNA levels of the cells. For AIA rats, the entering and collapsing of MBs was visualized by contrast-enhanced ultrasound (CEUS). Photoacoustic imaging showed markedly enhanced signals following injection, indicating localization of the FAM-labelled siRNA. The articular tissues of the AIA rats treated with TNF-α-siRNA-cMBs and UTMD showed decreased TNF-α expression levels.

CONCLUSIONS

The theranostic MBs exhibited a TNF-α gene silencing effect under the guidance of CEUS and PAI. The theranostic MBs served as vehicles for delivering siRNA as well as contrast agents for CEUS and PAI.

Targeted microbubbles combined with low-power focused ultrasound promote the thrombolysis of acute deep vein thrombosis

Introduction: The side effects of conventional therapy for acute deep vein thrombosis (DVT) are severe, with inflammatory reactions playing a pivotal role. It is particularly important to explore new ways of treatment thrombosis by targeting inflammatory factors.

Methods: A targeted microbubble contrast agent was prepared using the biotin-avidin method. The 40 DVT model rabbits were established and divided into four groups according to different treatment regimens. The four coagulation indexes, TNF-α, and D-dimer content of experimental animals were measured before modeling and before and after treatment, and the thrombolysis was assessed by ultrasound imaging. Finally, the results were verified by pathology.

Results and Discussion: Fluorescence microscopy verified the successful preparation of targeted microbubbles. Among the groups, PT, APTT, and TT in Group II-IV were longer than those in Group I (all p &lt; 0.05). FIB and D-dimer content were lower than those in Group I (all p &lt; 0.05), and TNF-α content in Group IV was lower than that in Group I-III (all p &lt; 0.05). Pairwise comparison before modeling and before treatment and after treatment showed that, after treatment, the PT, APTT, and TT in Group II-IV were longer than those before modeling (all p &lt; 0.05). The contents of FIB and D-dimer were lower than those before modeling and before treatment (all p &lt; 0.05). The content of TNF-α decreased significantly only in Group IV, but increased in the other three groups. Targeted microbubbles combined with Low-power focused ultrasound can reduce inflammation, significantly promote thrombolysis, and provide new ideas and methods for the diagnosis and treatment of acute DVT.

Magnetic Nanodroplets for Enhanced Deep Penetration of Solid Tumors and Simultaneous Magnetothermal-Sensitized Immunotherapy against Tumor Proliferation and Metastasis

The central cells of solid tumors are more proliferative and metastatic than the marginal cells. Therefore, more intelligent strategies for targeting cells with deep spatial distributions in solid tumors remain to be explored. In this work, a biocompatible nanotheranostic agent with a lipid membrane-coated, Fe₃ O₄ and perfluoropentane (PFP)-loaded, cRGD peptide (specifically targeting the integrin αvβ3 receptor)-grafted, magnetic nanodroplets (MNDs) is developed. The MNDs exhibit excellent magnetothermal conversion and controllable magnetic hyperthermia (MHT) through alternating magnetic field regulation. Furthermore, MHT-mediated magnetic droplet vaporization (MDV) induces the expansion of the MNDs to transform them into ultrasonic microbubbles, increasing the permeability of tissue and the cell membrane via the ultrasound-targeted microbubble destruction (UTMD) technique and thereby promoting the deep penetration of MNDs in solid tumors. More importantly, MHT not only causes apoptotic damage by downregulating the expression of the HSP70, cyclin D1, and Bcl-2 proteins in tumor cells but also improves the response rate to T-cell-related immunotherapy by upregulating PD-L1 expression in tumor cells, thus inhibiting the growth of both primary and metastatic tumors. Overall, this work introduces a distinct application of nanoultrasonic biomedicine in cancer therapy and provides an attractive immunotherapy strategy for preventing the proliferation and metastasis of deeply distributed cells in solid tumors.

Controllable and Directional Transportation of Bubbles on Asymmetric Hexagonal Cage Substrate in Aqueous Environment

Controllable and directional bubble transport is usually the critical step in applications involving bubbles. However, current bubble transport strategies either are limited in controllability and transport distance or require the assistance of a specific external field. Here, we propose a strategy for bubble transport in an asymmetric hexagonal cage (ASHC), which works smoothly even under antibuoyancy conditions. The transport efficiency of bubbles can be greatly improved by adjusting the structural parameters of the cage. The control of the bubble depends only on the change of the bubble's volume, so there is no strict restriction on the driving force, which can be pressure, photothermal, electrothermal, and even acoustic-thermal forces. Moreover, we demonstrate that long-distance transport and controllable merging of bubbles can be easily achieved by cascading multistage ASHC structures. This investigation offers a simple, low-cost, extensible, and versatile construction for bubble transport for fundamental research and practical applications.

Glaucoma Characterization by Machine Learning of Tear Metabolic Fingerprinting

Glaucoma is a common optic neuropathy disease affecting over 76 million people. Both timely diagnosis and progression monitoring are critical but challenging. Conventional characterization of glaucoma needs a combination of methods, calling for tedious procedures and experienced doctors. Herein, a platform through machine learning of tear metabolic fingerprinting (TMF) using nanoparticle enhanced laser desorption-ionization mass spectrometry is built. Direct TMF is obtained noninvasively, with fast speed and high reproducibility, using trace tear samples (down to 10 nL). Consequently, glaucoma patients are screened against healthy controls with the area under the curve (AUC) of 0.866, through machine learning of TMF. Further, primary open-angle glaucoma (POAG) is differentiated from primary angle-closure glaucoma (PACG) and an early-stage POAG is identified. Finally, a biomarker panel of six metabolites for glaucoma characterization (including screening, subtyping, and early diagnosis) with AUC of 0.827-0.891 is constructed, showing related metabolic pathways. The work will provide insights into eye diseases not limited to glaucoma.