Communications Chemistry最新文献

The emergence of molecular oxygen on early Earth is conventionally attributed to the evolution of oxygenic photosynthesis. A persistent challenge for early life, however, was the management of reactive oxygen species such as hydrogen peroxide (H₂O₂), which could arise through a variety of abiotic processes. Here we report that some RNA molecules, when coordinated with ferrous iron (Fe²⁺), catalyze the oxidation of H₂O₂ into O₂ and H₂O under anoxic conditions that mimic the early Earth environment. This previously unrecognized RNA-based redox activity suggests that ancient RNA-metal complexes may have contributed to the detoxification of H₂O₂ and the management of oxidative stress prior to the evolution of protein enzymes. Such RNA-Fe complexes provide a plausible molecular mechanism linking early geochemical oxidants to primitive biological redox chemistry.

The ability of biologically active molecules to access intracellular targets remains a critical barrier in drug development. While assays for measuring cellular uptake exist, they often fail to distinguish between membrane-associated or endosomal trapped compounds and those that successfully reach the cytosol. Here, we present the Chloroalkane HaloTag Azide-based Membrane Penetration (CHAMP) Assay, a high-throughput method that employs a minimally disruptive azide tag to report the cytosolic accumulation of diverse molecules in mammalian cells. The CHAMP assay utilizes HaloTag-expressing cells and strain-promoted azide-alkyne cycloaddition (SPAAC) chemistry to quantify the presence of azide-tagged test compounds in the cytosol. We demonstrate the versatility of this approach by evaluating the accumulation profiles of small molecules, peptides, and proteins, revealing how structural variations and stereochemical differences influence cytosolic penetration. Our findings with cell-penetrating peptides confirm established structure-activity relationships, with longer polyarginine sequences showing enhanced accumulation. Additionally, we observed that C-terminal amidation and D-amino acid substitutions significantly impact cellular penetration. When applied to supercharged proteins and antibiotics, CHAMP successfully discriminates between compounds with varying accumulation capabilities. This method provides a robust platform for screening cytosolic accumulation while minimizing the confounding effects of large tags on molecular permeability, potentially accelerating the development of therapeutics targeting intracellular pathways.

Stimuli-responsive supramolecular systems enable spatiotemporal control of nucleic acid (NA) delivery. To achieve precise and programmable vectors, we designed azobenzene-bridged ionizable amphiphilic Janus glycosides (IAJGs) as single-component, light-responsive DNA carriers. These glucopyranose-based dimers undergo reversible E/Z photoisomerization while forming stable nanocomplexes with plasmid DNA (pDNA). Photoisomerization alters nanocomplex size, surface charge, and internal order, resulting in distinct transfection outcomes. In vitro, O- and S-glycoside derivatives displayed isomer-dependent activity across COS-7, HepG2, and RAW264.7 cells, with pronounced switching effects specially in macrophages. In vivo, systemic administration revealed organ-selective responses: O-glycosides shifted expression from liver to lung upon E → Z conversion, whereas S-glycosides favored spleen targeting. All formulations maintained high cell viability. These results highlight photoswitchable IAJGs as structurally defined vectors for adjustable control over NA delivery and organ tropism.

Endometriosis is a chronic inflammatory gynecological condition that affects millions of women and people with uteri globally, with limited available treatments. In this work, we explore using ionic liquid (IL)-coated gold core polymeric nanoparticles (NPs), Au-PLGA-IL NPs, for selective neutrophil co-localization for the eventual development of targeted treatment of endometriosis via photothermal therapy. These NPs were synthesized by a modified solvent evaporation method and functionalized with ILs that confer neutrophil selectivity. In vitro biocompatibility was demonstrated using endometrial 12Z cells and a hemolysis assay with human female blood. Ex vivo studies confirmed superior neutrophil targeting ability in human female whole blood, quantified using fluorescence-activated cell sorting (FACS) and confocal laser scanning microscopy (CLSM) to visualize the NP co-localization. Upon near-infrared irradiation (1 W/cm², 5 min), the Au-PLGA-IL NPs induced significant apoptosis in 12Z cells through localized hyperthermia. This study introduces the first system integrating the plasmonic properties of AuNPs with PLGA's biocompatibility, enhanced by functional versatility of ILs, providing a promising platform for endometriosis treatment.

High-entropy metal sulfides (HEMSs) have emerged as a new class of electrocatalysts, but their synthesis often faces challenges due to their inherent complexity arising from multi-metal interactions, especially with elements having large differences in atomic/ionic sizes, such as the redox-active rare-earth elements. Here, we report a low-temperature (200°C) hydrothermal strategy to fabricate Ce-incorporated (CoFeNiCuCe)₉S₈ nanoballs by leveraging Cu²⁺ as a dynamic director for this phase evolution. Time-resolved studies reveal a multistage growth pathway involving cation exchange, lattice strain-driven reconstruction, and coalescence of various low and medium entropy intermediates (CoFeNi)₉S₈, CuS/(CoFeNi)₉S₈, (CoFeNiCu)₉S₈, Ce₂S₃, Ce₂S₃/(CoFeNi)₉S₈, (CoFeNiCuCe)/S nanoplates) into monodisperse (CoFeNiCuCe)₉S₈ HEMS nanoballs. By systematically varying Cu:Ce ratios, we obtain five distinct configurations, and Ce-rich HEMS-4 (Cu:Ce = 1:4) exhibits superior multifunctional electrocatalytic performance, outperforming a series of lower- (Co₉S₈, (NiFe)₉S₈, and (CoNiFe)₉S₈), medium-((CoNiFeCu)₉S₈), and high-entropy ((CoNiFeCuCe)₉S₈) analogues in the oxygen evolution reaction (OER; η₁₀ = 175 mV, η₁₀₀ = 260 mV), urea oxidation reaction (UOR; 1.277 V and 1.336 V at 10 and 100 mA.cm⁻²), hydrogen evolution reaction (HER; η₁₀ = 85 mV), and nitrite reduction (NO₂RR; 0.112 V at 100 mA.cm⁻²). Post-catalytic and in-situ Raman analyses, in conjunction with density functional theory (DFT), show that metal (oxy)hydroxides form during the reaction, while d-f orbital interactions protect the active sites from over-oxidation. This work establishes a paradigm for integrating rare-earth elements into HEMSs via controlled solution-phase synthesis, advancing the design of high-entropy electrocatalysts.

Photocatalysis research has evolved towards increasingly sophisticated structural regulation and material design. The synergistic enhancement of photocatalysis by multi-component semiconductors and biochar warrants detailed investigation. This study introduces an innovative biochar-based g-C₃N₄/Bi₂WO₆/Ag₃PO₄ nanocomposite (CN/Bi/Ag@ACB), which was applied to the efficient removal of antibiotic pollutants represented by tetracycline (TC). Findings reveal that CN/Bi/Ag@ACB forms a double Z-scheme heterojunction, significantly reducing photogenerated carrier recombination. It absorbs light in the 200-800 nm range, with a band gap of 1.91 eV. Under 120 min of illumination, the composite nearly completely removed 50 mg·L^-1 of TC, achieving a removal rate of 0.0351 min^-1, which is 8.56-13.50 times higher than that of the individual semiconductors. In real wastewater, TC removal exceeded 85.95%, with concurrent removal of other antibiotics, and achieved 99% sterilization of E. coli and S. aureus within 48 hours. The catalytic system was predominantly driven by ·O₂^-, h⁺, and ·OH radicals. The unique structure and surface characteristics of the composite, along with the incorporation of heteroatoms, substantially enhance photocatalytic activity. The TC degradation process is associated with the conversion of fulvic and humic acids, with three potential degradation pathways proposed. This study elucidates the synergistic mechanisms of photocatalysis enhancement by multi-component semiconductors and biochar.

Oxidative dehydrogenation of propane (ODHP) is a promising alternative route for producing light olefins, especially propene. Since the discovery of the exceptional activity of h-BN and other boron-based solids, their role in ODHP has attracted strong interest but remains insufficiently understood. Here, we provide the first direct experimental evidence of volatile boron oxide (BOₓ) species under ODHP conditions, revealed by TPD-MS and supported by XPS and solid-state NMR analyses. Advanced MAS ssNMR showed preferential coordination of BOₓ to Al in SiO₂-Al₂O₃ supports. BOₓ dispersion and stability were found to be strongly support-dependent: silica-supported BOₓ facilitates sublimation of boron oxides and propane activation at lower temperatures compared to γ-Al₂O₃ or SiO₂-Al₂O₃. Despite this, all systems follow identical selectivity-conversion trends. These results highlight a mechanistic pathway where volatile boron intermediates influence catalytic performance, advancing fundamental understanding and suggesting new strategies for designing selective, energy-efficient catalysts.

RegIIIα is an antibacterial protein primarily operating in the digestive tract to defend against bacterial infection through direct bactericidal activity. A previous study proposed that RegIIIα forms hexameric pores on the membrane of Gram-positive bacteria, leading to cell lysis. These RegIIIα hexamers can further assemble into filaments, diminishing RegIIIα activity. However, the high-resolution structure of RegIIIα assembly remains elusive, impeding the comprehension of the molecular mechanisms underlying RegIIIα function. In this study, we determined the cryo-electron microscopy (cryo-EM) structure of RegIIIα filaments formed in vitro at a resolution of 2.2 Å. Our structure reveals a similar subunit arrangement but a distinct subunit orientation compared to the previously reported low-resolution model of RegIIIα filaments. Through structural analysis and biochemical assays, we identified two essential interfaces for RegIIIα assembly, offered a potential explanation for the necessity of lipids in RegIIIα assembly, and elucidated the inhibitory mechanism of the pro-segment of RegIIIα. Collectively, our study presents the first near-atomic structure of filaments formed by C-tyle lectin containing proteins, providing structural insights into RegIIIα assembly that are closely related to its physiological functions and regulations.

Understanding how electrolyte-catalyst interactions govern reaction kinetics is crucial for advancing electrocatalytic hydrogen production. Here, we elucidate the atomic-scale synergy between alkali cations and platinum surface structure in accelerating the alkaline hydrogen evolution reaction (HER) through combined constant-potential density functional theory and ab initio molecular dynamics simulations. Our simulations demonstrate that stepped Pt(311) surfaces uniquely stabilize Na⁺ cations through formation of a Pt-H₂O-Na⁺(H₂O)ₓ adduct at step edges, positioning cations 2.3 Å closer to the surface than on Pt(111) terraces. This proximity creates a stronger interfacial electric field that polarizes adjacent water molecules, inducing partial O-H bond dissociation and lowering the Volmer step activation energy by 0.14 eV - threefold greater than the reduction observed on Pt(111). The stark facet dependence arises from fundamental differences in ion-surface coordination, with Pt(111) maintaining distant cation solvation that minimally perturbs HER kinetics. These findings establish cation-facet cooperativity as a key design principle, showing how atomic-scale control of both surface geometry and the electrochemical double layer can overcome intrinsic kinetic limitations of alkaline HER catalysis.