Electrical Manipulation of Orbital Current Via Oxygen Migration in Ni81 Fe19 /CuOx /TaN Heterostructure.

The orbital Hall effect and the interfacial Rashba effect provide new approaches to generate orbital current and spin-orbit torque (SOT) efficiently without the use of heavy metals. However, achieving efficient dynamic control of orbital current and SOT in light metal oxides has proven challenging. In this study, it is demonstrated that a sizable magnetoresistance effect related to orbital current and SOT can be observed in Ni81 Fe19 /CuOx /TaN heterostructures with various CuOx oxidization concentrations. The ionic liquid gating induces the migration of oxygen ions, which modulates the oxygen concentration at the Ni81 Fe19 /CuOx interface, leading to reversible manipulation of the magnetoresistance effect and SOT. The existence of a thick TaN capping layer allows for sophisticated internal oxygen ion reconstruction in the CuOx layer, rather than conventional external ion exchange. These results provide a method for the reversible and dynamic manipulation of the orbital current and SOT generation efficiency, thereby advancing the development of spin-orbitronic devices through ionic engineering.

Superhydrophobic Nanodiamond-Functionalized Melamine Sponge for Oil/Water Separation.

Fabrication of absorbent materials foroil/water separation is an important ecological pursuit for oil spill clean-up and organic pollutants' removal. In this study, nanodiamonds (NDs), a promising member of the carbon family, were functionally modified by the covalent linking of octadecylamine (ODA). Subsequently, the superhydrophobic sponge with hierarchical microstructures was fabricated by embedding ND-ODA into a melamine sponge (MS) skeleton via a simple immersion-drying process. The as-prepared sponge (ND-ODA@PDMS@MS) showed superhydrophobic properties with a water contact angle of 155 ± 2°. For various oils and organic solvents, ND-ODA@PDMS@MS possesses excellent absorption capacity (26.65-55.64 g/g) and oil/water separation efficiency (above 98.6%). Furthermore, the adsorption capacity to crude oil remained relatively stable in highly acidic, alkaline, and salty conditions, ensuring the application in the clean-up of industrial oily sewages and marine oil spills. Besides absorbing oil for a single time, ND-ODA@PDMS@MS also exhibited satisfactory performance in continuous oil/water separation. Therefore, this work provides a facile strategy to produce robust and efficient absorbent materials for oil/water separation in large-scale oil and organic solvent clean-ups.

Preclinical study of Shen Qi Li Xin formula in improving the development of chronic heart failure.

Chronic heart failure (CHF) is a common clinical heart disease. In recent years, traditional Chinese medicines have shown good outcomes in CHF treatment. We aimed to explore the therapeutic effect of Shen Qi Li Xin formula (SQLXF) in CHF. CHF rats were treated with SQLXF at the doses of 8.48, 16.96, and 33.92 g/kg/d once a day for 4 weeks by intragastric administration. The hemodynamic and cardiac function parameters of the rats were monitored by conduction echocardiography. In our results, SQLXF treatment at the doses of 16.96 and 33.92 g/kg/d significantly improved the haemodynamics and cardiac function of CHF rats by enhancing the levels of LVSP, +dp/dtmax, -dp/dtmax, LVEF and LVFS and reducing the levels of LVEDP, LVEDD and LVESD. SQLXF treatment at 16.96 and 33.92 g/kg/d also attenuated the damage of myocardial tissues in CHF rats. In addition, compared with normal rats, the number of pericytes was reduced in myocardial tissues of CHF rats. SQLXF treatment at the doses of 16.96 and 33.92 g/kg/d obviously increased the number of pericytes and proliferation of endothelial cells and promoted angiogenesis in myocardial tissues of CHF rats. In vitro, SQLXF impaired low-oxygen-induced inhibition of cell viability and promotion of apoptosis in primary pericytes. Importantly, SQLXF enhanced the adhesion ability of pericytes to endothelial cells. In conclusion, SQLXF improved myocardial injury in CHF rats by enhancing the interaction between pericytes and endothelial cells, suggesting that SQLXF may be a potential drug for CHF treatment.

Solution-based fabrication of mechanically transformative materials for implantable applications.

Implantable probes and needles represent multifunctional biomedical platforms by integrating sensing, stimulation, and drug delivery capabilities. Conventional rigid probes often result in inflammatory responses due to large mechanical mismatch with soft biological tissues, whereas soft probes with improved long-term performances are difficult to be inserted deep into the compliant biological tissues. An emerging class of mechanically transformative materials addresses the challenge by embedding a phase-change material of gallium within an elastomeric matrix. These materials exhibit high stiffness under ambient conditions to enable facile insertion and compliant mechanical properties after implantations. The widespread implementation of mechanically transformative materials is primarily hindered by the lack of facile fabrication techniques for delicate gallium features. In this study, we introduce a solution-based approach for scalable fabrication of gallium-based mechanically transformative materials, which exhibit bistable mechanical properties with large modulations in the modulus by five orders of magnitude. In a solution-based coating process, gallium features are created based on a patterned copper film and then encapsulated with elastomers to form mechanically transformative materials. The height profile of the gallium feature is controlled by the two-dimensional design of the copper pattern, which provides access to delicate and complex three-dimensional features as exemplified by mechanically transformative indwelling needles with sharp tips. The practical suitability is demonstrated by the in vivo implementation of the indwelling needles for long-term chemotherapy. The excellent biocompatibility enables applications of mechanically transformative biomedical devices in chronic implantable systems.

Stretchable and Superwettable Colorimetric Sensing Patch for Epidermal Collection and Analysis of Sweat.

Stretchable and wearable sensors allow intimate integration with the human body for health and fitness monitoring. In addition to the acquisition of various physical parameters, quantitative analysis of chemical biomarkers present in sweat may provide vital insights into the physiological state of an individual. A widely investigated system utilizes electrochemical techniques for continuous monitoring of these biomarkers. The required supporting electronics and batteries are often challenging to form a deformable system. In this study, an intrinsically stretchable sensing patch is developed with compliant mechanical properties for conformal attachment to the skin and reliable collection of sweat. In these patches, superhydrophilic colorimetric assays consisting of thermoplastic polyurethane nanofiber textiles decorated with silica nanoparticles are assembled over a styrene-ethylene-butylene-styrene-based superhydrophobic substrate, thereby generating a large wettability contrast to efficiently concentrate the sweat. The system supports multiplexed colorimetric analysis of sweat to quantify pH and ion concentrations with images acquired using smartphones, in which the influence of ambient lighting conditions is largely compensated with a set of reference color markers. Successful demonstrations of insitu analysis of sweat after physical exercises effectively illustrate the practical suitability of the sensing patch, which is attractive for advanced health monitoring, clinical diagnostics, and competitive sports.

Photosensitizer Functionalized Nanodiamonds for Raman Imaging and Photodynamic Therapy of Cancer Cells.

One novel nanoplatform with multiple functions including Raman imaging and photodynamic therapy (PDT) capacities was constructed through modifying nanodiamonds (NDs) with photosensitizer chlorin e6 (Ce6). The NDs-Ce6 nanoparticles show enhanced singlet oxygen generation efficiency relative to free Ce6. Cytotoxicity tests indicate that NDs-Ce6 have negligible influence toward HeLa cells vitality under dark condition but enhanced photodynamic ablation upon 660 nm laser irradiation in comparison with free Ce6. In addition, the NDs-Ce6 could be used as Raman imaging probes toward HeLa cells. These results demonstrate that the NDs-Ce6 multifunctional nanoplatform have attractive features using for Raman imaging and PDT. Additionally, a new idea could be provided for designing the multifunctional platform from the work.

The role of Nrf2 in astragaloside IV-mediated antioxidative protection on heart failure.

CONTEXT: Heart failure is one of the most serious diseases worldwide. Astragaloside IV (ASI) is widely used in the treatment of cardiovascular diseases. OBJECTIVE: To elucidate the antioxidative mechanism of ASI in a rat model of left coronary artery ligation. MATERIALS AND METHODS: Left coronary artery of Sprague-Dawley rats was ligated to establish the model of heart failure, and then vehicle (saline) or ASI (1 mg/kg/day) was orally administered to the rats (n = 15) for 6 weeks. Echocardiography was used to evaluate the cardiac function. Myocardial infarct size was measured by triphenyltetrazolium chloride staining. Oxidative stress in the ventricular myocardium was determined. Molecular mechanisms were investigated by Western blot and chromatin immunoprecipitation. RESULTS: ASI improved the cardiac function, especially ejection fraction (75.27 ± 5.75% vs. 36.26 ± 4.14%) and fractional shortening (45.39 ± 3.66% vs. 17.88 ± 1.32%), and reduced the infarct size of left ventricle (20.69 ± 2.98% vs. 39.11 ± 3.97%). ASI maintained the levels of glutathione, catalase and superoxide dismutase and prevented the leakage of creatine kinase. In addition, ASI induced the protein expression of Nrf2 (1.97-fold) and HO-1 (2.79-fold), while reduced that of Keap-1 (0.77-fold) in the ventricular myocardium. In H9c2 cells, a rat cardiomyocyte cell line, ASI induced the translocation of Nrf2 from cytoplasm to nucleus, followed by transcriptional activation of NQO-1 (8.27-fold), SOD-2 (3.27-fold) and Txn-1 (9.83-fold) genes. DISCUSSION AND CONCLUSIONS: ASI prevented heart failure by counteracting oxidative stress through the Nrf2/HO-1 pathway. Application in clinical practice warrants further investigation.

Soft elastomeric composite materials with skin-inspired mechanical properties for stretchable electronic circuits.

The stretchable version of electronic circuits harnesses commercial chip scale components to achieve complex functionality and mechanical deformability, which represents an emerging technology to expand the application of conventional electronics on rigid wafers. The bottleneck lies in the lack of a robust approach for the collective integration of off-the-shelf components into a reliable system. In this study, an elastomeric composite material with skin-like mechanical responses and spatially heterogeneous rigidity is reported as an attractive platform for stretchable circuit systems. The approach utilizes a high modulus microstructure embedded in the matrix of a soft elastomer to achieve programmable mechanical properties, thereby offering selective strain isolation for fragile components and overall protection against excessive loads. A low cost procedure involving laser ablation and blade coating is established to create the composite material matching with the circuit design. In addition, ultrasonic atomization of liquid metal into microparticles allows flexible preparations of deformable conductors in the forms of interconnects and contacts. An LED matrix is demonstrated as a prototype circuit system with excellent durability to withstand repetitive stretching and external impacts. Stretchable circuit systems based on soft elastomeric composite materials may find potential uses in health monitoring, mechatronic prosthetics, and soft robotics.

Omnidirectional Printing of Soft Elastomer for Liquid-State Stretchable Electronics.

Stretchable electronics has emerged as a new class of electronic technology to expand the applications of conventional electronics built on rigid wafers. Among various systems, liquid-state devices utilize electronically active liquids to achieve excellent stretchability and durability. The widespread adaption to such attractive form of device is hindered by the lack of robust fabrication approach to precisely and efficiently assemble liquid-state materials into functional systems. In this study, an additive manufacturing platform for digital fabrication of three-dimensional elastomeric structures is reported. The shear-thinning ink is formulated to enable omnidirectional printing process. Various elastic features with complex architectures are generated without using sacrificial materials, which consist of overhanging parts, suspended structures, and embedded channels. Harnessing the unique printability allows facile creation of elastomeric sensors with strain- and pressure-sensing capabilities by simply filling the embedded microchannels with liquid metal. A smart glove to capture hand gestures is also demonstrated as a fully integrated electronic system with liquid-state components. The liquid-state stretchable electronics developed here may find potential applications in biomedical instruments, wearable devices, and soft robotics.

A self-calibrated luminescent thermometer based on nanodiamond-Eu/Tb hybrid materials.

Luminescent hybrid materials based on nanodiamonds (NDs) and rare earth ions have been successfully synthesized by covalently modifying NDs with pyromellitic acid (PMA) which is capable of coordinating to Eu3+ and Tb3+ ions. With NDs acting as a host matrix, the PMA and rare earth ions serve as an organic sensitizer and activator, respectively, yielding a highly bright hybrid composite. Interestingly, for the co-doped hybrid composites ND-PMA-Eu/Tb, the intensity ratio of the two emissions, 5D4→7F5 transition (Tb3+) to 5D0→7F2 transition (Eu3+), is linearly related to temperature in the range from 77 K to 277 K. Therefore, the hybrid could be developed as a self-calibrated ratiometric luminescent thermometer due to its temperature-dependent luminescence performance.

Adeno-associated Virus 9-mediated Small RNA Interference of TLR4 Alleviates Myocardial Ischemia and Reperfusion Injury by Inhibition of the NF-κB and MAPK Signaling Pathways in Rats.

BACKGROUND: Despite intensive investigation, effective therapeutic procedures for myocardial I/R injury are still in demand. OBJECTIVE: To explore the effect of adeno-associated virus 9 (AAV9)-mediated small interfering RNA targeting TLR4 in the treatment of myocardial ischemia and reperfusion (I/R) injury and its influence on the NF-κB and MAPK signaling pathways. METHODS: Rats were divided into 3 groups, namely, the sham, AAV9-siRNA control, and AAV9-TLR4 siRNA groups. siRNA solution or normal saline was injected through the tail vain. The rat myocardial I/R injury model was then established. HE staining and TUNEL staining were applied to compare the pathological changes in cardiomyocytes in the three groups. Immunohistochemical staining and western blotting were utilized to detect TLR4 expression under siRNA interference. Serum inflammatory factor (IL-1ß, TNF-α) expression was determined by an ELISA commercial kit. Key proteins in the MAPK (p38, JNK 1/2) and NF-κB (p65) signaling pathways were determined to identify the TLR4 siRNA functional mechanism. RESULTS: Fluorescence microscopic images of the myocardium indicated that AAV9- mediated siRNA was efficiently transfected into the myocardium, and the infarcted size after I/R injury was decreased by AAV9-TLR4 siRNA when compared with negative control rats (P<0.05). TLR4 protein expression was significantly decreased by siRNA interference (P<0.001). Apoptosis-related factor BCL-2 expression was increased in the TLR4 gene silencing group, whereas Bax expression was decreased. The Bax/BCL-2 ratio was also decreased, demonstrating a protective effect for cardiomyocytes. Inflammatory factors were lower in the TLR4 gene silencing group than in the siRNA control group (P<0.001). The MAPK and NF-κB signaling pathways were activated in myocardial I/R injury; however, the primary proteins in these two signaling pathways were downregulated upon interference of TLR4 siRNA, with significant differences (P<0.05). CONCLUSION: AAV9-TLR4 siRNA has a positive effect on myocardial I/R injury by inhibiting the MAPK and NF-κB signaling pathways and can be used as a potential therapeutic method for myocardial I/R injury.

Exosomal microRNA-29a mediates cardiac dysfunction and mitochondrial inactivity in obesity-related cardiomyopathy.

PURPOSE: Present study aims to explore the pathophysiological role of microRNA (miR)-29a in the process of obesity-related cardiomyopathy in human subjects and mice. METHODS: The expression level of circulating exosomal miR-29a was measured in 37 lean and 30 obese human subjects, and correlated with cardiac parameters. The effects of miR-29a on mitochondrial activity and cardiac function were investigated by treatment of miR-29a sponge in primary mouse cardiomyocytes and diet-induced obesity-related cardiomyopathy in mice. RESULTS: The increased circulating miR-29a level was closely associated with impaired human cardiac function, including ejection fraction (r = -0.2663, p < 0.05) and NT-proBNP levels (r = 0.4270, p < 0.001). Exosomes from obese human plasma mediated cardiomyocyte mitochondrial inactivity, but pre-treatment with miR-29a sponge attenuated the exosomal miR-29a-induced reduction of ATP production (p < 0.001), basal oxygen consumption (p < 0.01) and mitochondrial complex I activity (p < 0.01). In vivo mouse study, high fat diet damaged cardiac function, normal structure, and mitochondrial activity, whereas miR-29a sponge improved the cardiac status. CONCLUSIONS: Present study uncovered the correlation between circulating miR-29a and cardiac parameters in human subjects, and provided solid evidence of the therapeutic application of miR-29a sponge in combating obesity-mediated cardiac dysfunction.

Nanodiamonds conjugated upconversion nanoparticles for bio-imaging and drug delivery.

A multifunctional nanoplatform with simultaneous imaging and therapeutic capacities has been fabricated by covalently conjugating nanodiamonds (NDs) with upconversion NaYF4:Yb,Er nanoparticles (UCNPs). Green emission can be observed for the UCNP-NDs composites under 980 nm excitation, and in vitro imaging was carried out towards HeLa cells. The UCNP-NDs also shows good drug storage capability toward anticancer drug doxorubicin (Dox) and exhibits significant pH-dependent drug-release behavior. Dox-loaded UCNP-NDs shows higher therapy efficiency towards Hela cells than free Dox when the equivalent concentration of the Dox is more than 10 µg/mL. Thus, a favorable strategy may be provided to decrease the side effects of Dox, minimize drug dose, and improve its efficacy. These findings highlight the fascinating features of UCNP-NDs nanocomposites as upconversion fluorescence imaging contrast agents and doxorubicin loading carrier. In addition, this work may also provide a novel strategy for the design of multifunctional nanoplatforms.

A feedback regulatory loop between HIF-1α and miR-21 in response to hypoxia in cardiomyocytes.

Accumulating evidence suggests that hypoxia-inducible factor 1α (HIF-1α) regulates numerous miRNAs and is crucial for cellular response to hypoxia. However, the relationship between HIF-1α and miR-21 in hypoxic cardiomyocytes is little known. We found that hypoxia induced HIF-1α and miR-21 expression. HIF-1α knockdown increased cell apoptosis and reduced miR-21 expression. Furthermore, we found that HIF-1α transcriptionally enhanced miR-21 promoter activity by binding to its promoter, which required the recruitment of CBP/p300. In addition, we found that miR-21 inhibition increased cell apoptosis and reduced HIF-1α expression, and modulated the PTEN/Akt pathway. Our results indicate that HIF-1α-miR-21 feedback contributes to the adaptation of cardiomyocytes to hypoxia, and has potential as therapeutic target for myocardial ischemia.