Latest ArticlesSinglet oxygen (1O2), as an electrophilic oxidant, is essential for the selective water decontamination of pollutants from water. Herein, we showcase a high-performing electrocatalytic filtration system composed of carbon nanotubes functionalized with CoFe alloy nanoparticles (CoFeCNT) to selectively facilitate the electrochemical activation of O2 to 1O2. Benefiting from the prominently featured bimetal active sites of CoFeCNT, nearly complete production of 1O2 is achieved by the electrocatalytic activation of O2. Additionally, the proposed system exhibits a consistent pollutant removal efficiency > 90% in a flow-through reactor over 48 h of continuous operation without a noticeable decline in performance, highlighting the dependable stability of the system for practical applications. The flow-through configuration demonstrates a striking 8-fold enhancement in tetracycline oxidation compared to a conventional batch reactor. This work provides a molecular level understanding of the oxygen reduction reaction, showing promising potential for the selective removal of emerging organic contaminants from water.
Perovskite oxides have been widely applied as an effective catalyst in heterogeneous catalysis. However, the rational design of active catalysts has been restricted by the lack of understanding of the electronic structure. The correlations between surface properties and bulk electronic structure have been ignored. Herein, a simple handler of LaFeO3 with diluted HNO3 was employed to tune the electronic structure and catalytic properties. Experimental analysis and theoretical calculations elucidate that acid etching could raise the Fe valence and enhance Fe–O covalency in the octahedral structure, thereby lessening charge transfer energy. Enhanced Fe–O covalency could lower oxygen vacancy formation energy and enhance oxygen mobility. In-situ DRIFTS results indicated the inherent adsorption capability of Toluene and CO molecules has been greatly improved owing to higher Fe–O covalency. As compared, the catalysts after acid etching exhibited higher catalytic activity, and the T90 had a great reduction of 45 and 58 ℃ for toluene and CO oxidation, respectively. A deeper understanding of electronic structure in perovskite oxides may inspire the design of high-performance catalysts.
Candida albicans is one of the most common pathogens causing invasive fungal infections, with a mortality rate of up to 20%–50%. Amphotericin B (AmB), a biopharmaceutics classification system (BCS) IV drug, significantly inhibits Candida albicans. AmB is primarily administered via oral and intravenous infusion, but severe infusion adverse effects, nephrotoxicity, and potential hepatotoxicity limit its clinical application. Deep eutectic solvents (DESs), with excellent solubilization ability and skin permeability, are attractive for transdermal delivery. Herein, we used DESs to deliver AmB for antifungal therapy transdermally. We first prepared and characterized DESs with different stoichiometric ratios of choline (Ch) and geranate (Ge). DESs increased the solubility of AmB by a thousand-fold. In vitro and in vivo, skin permeation studies indicated that DES1:2 (Ch and Ge in 1:2 ratio) had the most outstanding penetration and delivered fluorescence dye to the dermis layer. Then, DES1:2-AmB was prepared and in vitro antifungal tests demonstrated that DES1:2-AmB had superior antifungal effects compared to AmB and DES1:2. Furthermore, DES1:2-AmB was skin-irritating and biocompatible. In conclusion, DES-AmB provides a new and effective therapeutic solution for fungal infections.
An electronic circular dichroism (ECD)-based chiroptical sensing method has been developed for β- and γ-chiral primary amines via a C–H activation reaction. With the addition of Pd(OAc)2, the flexible remote chiral primary amine fragment in the bidentate ligand intermediate was fixed to form a cyclopalladium complex, producing an intense ECD response. The correlation between the sign of Cotton effects and the absolute configuration of substrates was proposed, together with theoretical verification using time-dependent density functional theory (TDDFT). Chiroptical sensing of an important drug raw material was performed to provide rapid and accurate information on the absolute optical purity. This work introduces an alternative perspective of C–H activation reaction as well as a feasible chiroptical sensing method of remote chiral amines.
Chirality, ubiquitous in living matter, plays vital roles in a series of physiological processes. The clarification of the multiple functions of chirality in bioapplications may provide innovative methodologies for engineering anti-tumor agents. Nevertheless, the related research has been rarely explored. In this study, the chiral supramolecular l/d-cysteine (Cys)-Zn2+-indocyanine green (ICG) nanoparticles were constructed through the coordination interaction between l/d-Cys and Zn2+, followed by the encapsulation of ICG. Experimental findings revealed that the d-Cys-Zn2+-ICG exhibited 17.31 times higher binding affinity toward phospholipid-composed liposomes compared to l-Cys-Zn2+-ICG. Furthermore, driven by chirality-specific interaction, a 2.07 folds greater cellular internalization of d-Cys-Zn2+-ICG than l-Cys-Zn2+-ICG was demonstrated. Additionally, the triple-level chirality-dependent photothermal, photodynamic and Zn2+ releasing anti-tumor effects of l/d Cys-Zn2+-ICG in vitro were verified. As a result, the d-formed nanoparticles achieved 1.93 times higher anti-tumor efficiency than the l-formed ones. The triple-level chirality-mediated anti-tumor effect highlighted in this study underscores the enormous potential of chirality in biomedicine and holds substantial significance in improving cancer therapeutic efficacy.
The continuous mutation and rapid spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have led to the ineffectiveness of many antiviral drugs targeting the original strain. To keep pace with the virus' evolutionary speed, there is a crucial need for the development of rapid, cost-effective, and efficient inhibitor screening methods. In this study, we created a novel approach based on fluorescence resonance energy transfer (FRET) technology for in vitro detection of inhibitors targeting the interaction between the SARS-CoV-2 spike protein RBD (s-RBD) and the virus receptor angiotensin-converting enzyme 2 (ACE2). Utilizing crystallographic insights into the s-RBD/ACE2 interaction, we modified ACE2 by fusing SNAP tag to its N-terminus (resulting in SA740) and Halo tag to s-RBD’s C-terminus (producing R525H and R541H), thereby ensuring the proximity (< 10 nm) of labeled FRET dyes. We found that relative to the R541H fusion protein, R525H exhibited higher FRET efficiency, which attributed to the shortened distance between FRET dyes due to the truncation of s-RBD. Utilizing the sensitive FRET effect between SA740 and R525H, we evaluated its efficacy in detecting inhibitors of SARS-CoV-2 entry in solution and live cells. Ultimately, this FRET-based detection method was demonstrated high sensitivity, rapidity, and simplicity in solution and held promise for high-throughput screening of SARS-CoV-2 inhibitors.
The radical difunctionalization of alkenes with sulfonyl bifunctional represents a powerful and straightforward approach to access functionalized alkane derivatives. However, both the mechanistic activation mode and the substrate scopes of this type of radical difunctionalizations are still limited. We demonstrate herein a modular photoredox strategy for the difunctionalization of alkenes, employing arylsulfonyl acetate as the bifunctional reagent. This approach involves a radical addition/Smiles rearrangement cascade process, offering a robust alternative for the synthesis of valuable γ,γ-diaryl and γ-aryl esters. A complementary oxidative bifunctional reagents activation mode is identified to govern the radical cascade reactions, facilitating the simultaneous incorporation of aryl and carboxylate-bearing alkyl groups into the alkenes with excellent diastereoselectivity. Noteworthy features of this method include mild reaction conditions, organophotocatalysis, high atom- and step-economy, excellent functional group compatibility and great structural diversity.
Traditional electrospray ionization tandem mass spectrometry (ESI-MSn) has been a powerful tool in diverse research areas, however, it faces great limitations in the study of protein-small molecule interactions. In this article, the state-of-the-art temperature-controlled electrospray ionization tandem mass spectrometry (TC-ESI-MSn) is applied to investigate interactions between ubiquitin and two flavonol molecules, respectively. The combination of collision-induced dissociation (CID) and MS solution-melting experiments facilitates the understanding of flavonol-protein interactions in a new dimension across varying temperature ranges. While structural changes of proteins disturbed by small molecules are unseen in ESI-MSn, TC-ESI-MSn allows a simultaneous assessment of the stability of the complex in both gas and liquid phases under various temperature conditions, meanwhile investigating the impact on the protein’s structure and tracking changes in thermodynamic data, and the characteristics of structural intermediates.
Hyperglycemia resulting from diabetes mellitus (DM) exacerbates osteoporosis and fractures, damaging bone regeneration due to impaired healing capacity. Stem cell therapy offers the potential for bone repair, accelerating the healing of bone defects by introducing stem cells with osteogenic differentiation ability. Dental follicle stem cells (DFSCs) are a newly emerging type of dental stem cells that not only have the potential for multipotent differentiation but also hold easy accessibility and can stand long-term storage. However, DM-associated oxidative stress and inflammation elevate the risk of DFSCs dysfunction and apoptosis, diminishing stem cell therapy efficacy. Recent nanomaterial advances, particularly in DNA nanostructures like tetrahedral framework nucleic acids (tFNAs), have been promising candidates for modulating cellular behaviors. Accumulating experiments have shown that tFNAs' cell proliferation and migration-promoting ability and induce osteogenic differentiation of stem cells. Meanwhile, tFNAs can scavenge reactive oxygen species (ROS) and downregulate the secretion of inflammatory factors by inhibiting various inflammation-related signaling pathways. Here, we applied tFNAs to modify DFSCs and observed enhanced osteogenic differentiation alongside ROS scavenging and anti-inflammatory effects mediated by suppressing the ROS/mitogen-activated protein kinases (MAPKs)/nuclear factor kappa-B (NF-κB) signaling pathway. This intervention reduced stem cell apoptosis, bolstering stem cell therapy efficacy in DM. Our study establishes a simple yet potent tFNAs-DFSCs system, offering potential as a bone repair agent for future DM treatment.
Self-assembled prodrug nanomedicine has emerged as an advanced platform for antitumor therapy, mainly comprise drug modules, response modules and modification modules. However, existing studies usually compare the differences between single types of modification modules, neglecting the impact of steric-hindrance effect caused by chemical structure. Herein, single-tailed modification module with low-steric-hindrance effect and two-tailed modification module with high-steric-hindrance effect were selected to construct paclitaxel prodrugs (P-LAC18 and P-BAC18), and the in-depth insights of the steric-hindrance effect on prodrug nanoassemblies were explored. Notably, the size stability of the two-tailed prodrugs was enhanced due to improved intermolecular interactions and steric hindrance. Single-tailed prodrug nanoassemblies were more susceptible to attack by redox agents, showing faster drug release and stronger antitumor efficacy, but with poorer safety. In contrast, two-tailed prodrug nanoassemblies exhibited significant advantages in terms of pharmacokinetics, tumor accumulation and safety due to the good size stability, thus ensuring equivalent antitumor efficacy at tolerance dose. These findings highlighted the critical role of steric-hindrance effect of the modification module in regulating the structure-activity relationship of prodrug nanoassemblies and proposed new perspectives into the precise design of self-assembled prodrugs for high-performance cancer therapeutics.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
