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Intracellular viscosity plays an important role in regulating cellular morphology and physiology and is closely related to a host of diseases. Especially, the changes in mitochondrial viscosity will cause some common diseases such as hyperlipidemia, Alzheimer's disease and cancer. In this work, we report the design of a red-emissive molecular rotor for the detection of mitochondrial viscosity in live cells. The probe showed fascinating performance, such as specific targeting to mitochondria, high sensitivity to viscosity, and rapid fluorescence response, especially the dual response mode of fluorescence intensity and fluorescence lifetime. By using this probe, we realized monitoring of the mitochondrial viscosity variations in live cells under different physiological processes. Our study offers an opportunity to discover potential tools for mitochondria-related physiology and pathology investigation. [ABSTRACT FROM AUTHOR]

Integrating imaging and therapeutic capabilities into a single entity can offer enhanced diagnostic accuracy and treatment efficacy in clinically effective formulations. Due to the diversity of chemical structures and/or limited solubility of inhibitors or fluorophores, it is essential to employ a robust delivery carrier that can facilitate drug absorption and distribution during its circulation in the blood. This study explores the potential of hollow gadolinium oxide (Gd2O3) nanocarriers in imaging and drug delivery applications. The citric acid (CA)-capped hollow gadolinium oxide nanocarriers were synthesized via urea-assisted precipitation and hydrothermal methods using carbon spheres as sacrificial templates. The resulting nanosized hollow spheres displayed a spherical morphology and demonstrated relaxation rates in the longitudinal and transverse directions, as indicated by their r1 and r2 values of 1.8 and 5.3 s–1 mM–1, respectively. To mimic the physiological conditions, the hollow gadolinium oxide spheres were loaded separately with antibiotic sparfloxacin and the azo dye Congo red at neutral pH (7.4) and body temperature (37 °C). The CR-loaded nanospheres exhibited a time-dependent internalization behavior with HeLa cells, suggesting their imaging potential for intracellular drug delivery. Furthermore, the SP-loaded nanospheres demonstrated antimicrobial activity against both Gram-positive and Gram-negative bacteria, demonstrating their therapeutic potential against bacterial infections. To mitigate the risk of leaching of Gd3+ ions and their inherent toxicity, a CA coating was applied to hollow gadolinium oxide surface which resulted in outstanding cell viability of the surface functionalized nanocarriers. In addition, the CA coating offered additional support for the increased encapsulation and continuous release of drug molecules until 1 week (168 h). The characterization data provide evidence for the potential of CA-capped hollow gadolinium oxide spheres as positive MR contrast agents and their applicability as safe and controlled drug carriers. [ABSTRACT FROM AUTHOR]

As one of the major causes of antimicrobial resistance, β‐lactamase develops rapidly among bacteria. Detection of β‐lactamase in an efficient and low‐cost point‐of‐care testing (POCT) way is urgently needed. However, due to the volatile environmental factors, the quantitative measurement of current POCT is often inaccurate. Herein, we demonstrate an artificial intelligence (AI)‐assisted mobile health system that consists of a paper‐based β‐lactamase fluorogenic probe analytical device and a smartphone‐based AI cloud. An ultrafast broad‐spectrum fluorogenic probe (B1) that could respond to β‐lactamase within 20 s was first synthesized, and the detection limit was determined to be 0.13 nmol/L. Meanwhile, a three‐dimensional microfluidic paper‐based analytical device was fabricated for integration of B1. Also, a smartphone‐based AI cloud was developed to correct errors automatically and output results intelligently. This smart system could calibrate the temperature and pH in the β‐lactamase level detection in complex samples and mice infected with various bacteria, which shows the problem‐solving ability in interdisciplinary research, and demonstrates potential clinical benefits. [ABSTRACT FROM AUTHOR]

Electrochemical impedance spectroscopy was employed to explore the possibility of relating the permeation of electrolyte ions in [omega]-functionalized self-assembled monolayers to structural or polarity changes induced by interaction with metal ions. The monolayers were based on aikanethiols modified with a phosphorylated tyrosine analogue, which from previous work are known to drastically change their organization on gold surfaces upon interaction with aluminum and magnesium ions. The ion permeation was evaluated by using relatively low excitation frequencies, 1000 to 2 Hz, and quantified by an extra resistive component in the equivalent circuit ([R.sub.SAM]). The extent of ion permeation influenced by the dc potential, the electrolyte concentration, the functional group, and the thiol length were also investigated. It was, for example, found that [R.sub.SAM] decreased ~20% when the thiol organization collapsed and that [R.sub.SAM] increased ~4-5 times when the electrolyte concentration was decreased by 1 order of magnitude. Interesting observations were also made regarding the potential dependence of [R.sub.SAM] and the double layer capacitance. The evaluation of the ion permeation can be used to indirectly detect whether the organization of a SAM is influenced by, for example, electric fields or chemical and biological interactions. This analysis can be performed without addition of redox species, but is on the other hand complicated by the fact that other factors also influence the presence of ions within the monolayer. In addition, a second parallel RC process was obtained in some of the impedance spectra when using even lower frequencies, and its resistive component revealed different results compared to [R.sub.SAM]. Such data may be useful for the understanding of complex double layer phenomena at modified electrodes.

Monolayers of tert-butyl carbamate-terminated thiol are formed by adsorption of the molecules onto polycrystalline gold substrate. The electronic structure, composition, characteristic fingerprint and orientation of the molecular absorbate are obtained.

The structure of a 3,4-dihydroxyphenyalanine(DOPA)-derived thiol self-assembled on a gold surface is investigated using X-ray photoelectron spectroscopy (XPS), infrared reflection-absorption spectroscopy (IRAS) and near-edge X-ray absorption fine structure spectroscopy (NEXAFS). Strong molecular binding of DOPA-PT on gold through the sulphur atom is achieved.

Cerium oxide nanoparticles with integrated gadolinium have been proved to be useful as contrast agents in magnetic resonance imaging. Of question is their performance in dual-energy computed tomography. The aims of this work are to determine (1) the relation between the computed tomography number and the concentration of the I, Gd or Ce contrast agent and (2) under what conditions it is possible to resolve the type of contrast agent. Hounsfield values of iodoacetic acid, gadolinium acetate and cerium acetate dissolved in water at molar concentrations of 10, 50 and 100 mM were measured in a water phantom using the Siemens SOMATOM Definition Force scanner; gadolinium- and cerium acetate were used as substitutes for the gadolinium-integrated cerium oxide nanoparticles. The relation between the molar concentration of the I, Gd or Ce contrast agent and the Hounsfield value was linear. Concentrations had to be sufficiently high to resolve the contrast agents. [ABSTRACT FROM AUTHOR]

Metal oxide nanoparticles are widely used in both consumer products and medical applications, but the knowledge regarding exposure-related health effects is limited. However, it is challenging to investigate nanoparticle interaction processes with biological systems. The overall aim of this project was to improve the possibility to predict exposure-related health effects of metal oxide nanoparticles through interdisciplinary collaboration by combining workflows from the pharmaceutical industry, nanomaterial sciences, and occupational medicine. Specific aims were to investigate nanoparticle-protein interactions and possible adverse immune reactions. Four different metal oxide nanoparticles; CeOx nanocrystals with 5% or 14% Gd, Co3O4, and Fe2O3, were characterized by dynamic light scattering and high-resolution transmission electron microscopy. Nanoparticle-binding proteins were identified and screened for HLA-binding peptides in silico. Monocyte interaction with nanoparticle–protein complexes was assessed in vitro. Herein, for the first time, immunogenic properties of nanoparticle-binding proteins have been characterized. The present study indicates that especially Co3O4-protein complexes can induce both 'danger signals', verified by the production of inflammatory cytokines and simultaneously bind autologous proteins, which can be presented as immunogenic epitopes by MHC class II. The clinical relevance of these findings should be further evaluated to investigate the role of metal oxide nanoparticles in the development of autoimmune disease. The general workflow identified experimental difficulties, such as nanoparticle aggregate formation and a lack of protein-free buffers suitable for particle characterization, protein analyses, as well as for cell studies. This confirms the importance of future interdisciplinary collaborations. [ABSTRACT FROM AUTHOR]