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Developing accurate electrophysiological recording platforms is crucial for investigating cellular electrical activities, understanding the mechanisms underlying cardiovascular disease, and advancing therapeutic strategies. While the successful recording of intracellular electrophysiological status has been achieved by 3D micro/nano devices, their preparation through demanding micro/nanofabrication and poorly controllable solvothermal synthesis is an impediment to widespread utilization. Easier‐to‐access recording electrodes are needed. To address this challenge, a simple and efficient supramolecular self‐assembly strategy that allows access to novel 3D electrodes is introduced. It relies on small organic molecules that can be self‐assembled efficiently into various 3D nanostructures, including lamellated nanosheets, thin nanobelts, and short rod‐like structures. Electrodes prepared through the present self‐assembly process are considerably simpler and more cost‐effective than conventional 3D micro/nanoelectrodes prepared through fabrication or solvothermal synthesis. It is demonstrated that the present electrodes allow for higher quality and prolonged intracellular recordings of action potentials as compared to similarly sized conventional planar electrodes. The noted improvements are attributed to the fact that 3D geometrical electrodes enhance the cell‐electrode interface, ensuring tight coupling and effective electroporation. This work showcases how supramolecular self‐assembly might emerge as a promising and powerful electrode preparation strategy that may facilitate low‐cost electrophysiological studies. [ABSTRACT FROM AUTHOR]

Bacterial evolution, particularly in hospital settings, is leading to an increase in multidrug resistance. Understanding the basis for this resistance is critical as it can drive discovery of new antibiotics while allowing the clinical use of known antibiotics to be optimized. Here, we report a photoactive chemical probe for superresolution microscopy that allows for the in situ probing of antibiotic-induced structural disruption of bacteria. Conjugation between a spiropyran (SP) and galactose via click chemistry produces an amphiphilic photochromic glycoprobe, which self-assembles into glycomicelles in water. The hydrophobic inner core of the glycomicelles allows encapsulation of antibiotics. Photoirradiation then serves to convert the SP to the corresponding merocyanine (MR) form. This results in micellar disassembly allowing for release of the antibiotic in an on-demand fashion. The glycomicelles of this study adhere selectively to the surface of a Gram-negative bacterium through multivalent sugar-lectin interaction. Antibiotic release from the glycomicelles then induces membrane collapse. This dynamic process can be imaged in situ by superresolution spectroscopy owing to the "fluorescence blinking" of the SP/MR photochromic pair. This research provides a high-precision imaging tool that may be used to visualize how antibiotics disrupt the structural integrity of bacteria in real time. [ABSTRACT FROM AUTHOR]

New stimulus‐responsive scaffolds are of interest as constituents of hierarchical supramolecular ensembles. 1,3,5–2,4,6‐Functionalized, facially segregated benzene moieties have a time‐honored role as building blocks for host molecules. However, their user as switchable motifs in the construction of multi‐component supramolecular structures remains poorly explored. Here, we report a molecular cage 1, which consists of a bent anthracene dimer 3 paired with 1,3,5‐tris(aminomethyl)‐2,4,6‐triethylbenzene 2. As the result of the pH‐induced ababab↔bababa isomerization of the constituent‐functionalized benzene units derived from 2, this cage can reversibly convert between an open state and a closed form, both in solution and in the solid state. Cage 1 was used to create stimuli‐responsive hierarchical superstructures, namely Russian doll‐like complexes with [K⊂18‐crown‐6⊂1]+ and [K⊂cryptand‐222⊂1]+. The reversible assembly and disassembly of these superstructures could be induced by switching cage 1 from its open to closed form. The present study thus provides an unusual example where pH‐triggered conformation motion within a cage‐like scaffold is used to control the formation and disassociation of hierarchical ensembles. [ABSTRACT FROM AUTHOR]

Developing anticancer drugs with low side effects is an ongoing challenge. Immunogenic cell death (ICD) has received extensive attention as a potential synergistic modality for cancer immunotherapy. However, only a limited set of drugs or treatment modalities can trigger an ICD response and none of them have cytotoxic selectivity. This provides an incentive to explore strategies that might provide more effective ICD inducers free of adverse side effects. Here, we report a metal-based complex (Cu-1) that disrupts cellular redox homeostasis and effectively stimulates an antitumor immune response with high cytotoxic specificity. Upon entering tumor cells, this Cu(II) complex enhances the production of intracellular radical oxidative species while concurrently depleting glutathione (GSH). As the result of heightening cellular oxidative stress, Cu-1 gives rise to a relatively high cytotoxicity to cancer cells, whereas normal cells with low levels of GSH are relatively unaffected. The present Cu(II) complex initiates a potent ferroptosis-dependent ICD response and effectively inhibits in vivo tumor growth in an animal model (c57BL/6 mice challenged with colorectal cancer). This study presents a strategy to develop metal-based drugs that could synergistically potentiate cytotoxic selectivity and promote apoptosis-independent ICD responses through perturbations in redox homeostasis. [ABSTRACT FROM AUTHOR]

Chemical tools that can report radioactive isotopes would be of interest to the defense community. Here we report ∼250 nm polymeric nanoparticles containing porphyrinoid macrocycles with and without pre-complexed depleted uranium and demonstrate that the latter species may be detected easily and with high sensitivity via photoacoustic imaging. The porphyrinoid macrocycles used in the present study are non-aromatic in the absence of the uranyl cation, but aromatic after cation complexation. We solubilized both the freebase and metalated forms of the macrocycles in poly(lactic-co-glycolic acid) and found a peak in the photoacoustic spectrum at 910 nm excitation in the case of the uranyl complex. The signal was stable for at least 15 minutes and allowed detection of uranium concentrations down to 6.2 ppb (5.7 nM) in vitro and 0.57 ppm (19 fCi; 0.52 μM) in vivo. To the best of our knowledge, this is the first report of a nanoparticle that detects an actinide cation via photoacoustic imaging.