Latest ArticlesMolecular networking-guided chemical investigation of the Euphorbia endophyte Malbranchea umbrina D16 led to the isolation of 14 novel unusually cyclized triterpenoids (UCT) involving three different skeletal types. Compounds 1–10 are tricyclic triterpenoids featuring a 1-cyclohexyloctahydro-1H-indene core, in which 1 incoporates an unusual 7,7-dimethyl-6,8-dioxabicyclo[3.1.2]octane motif. Compounds 11–13 represent a rare class of bicyclic triterpenes (6/5 ring system) containing various O-heterocycles at the side chain. Compound 14 is an acyclic triterpenoid with O-heterocycles at both ends. Their structures were assigned by spectroscopic, chemical, computational, and crystallographic means, which also allowed the stereochemical revisions of three previously reported analogues. Compound 1 significantly inhibited the adipogenesis in 3T3-L1 adipocytes via activating the AMP-activated protein kinase (AMPK) signalling.
Ferroptosis is a cell death pathway that plays a crucial role in numerous biological processes. Although closely related to ferrous ion, the execution of ferroptosis was found to be impacted by zinc ion (Zn2+) in recent years. However, most of the related researches focused on the effects of exogenously added Zn2+, while the fundamental understanding of endogenous Zn2+ during ferroptosis still needs further exploration. Herein, a ratiometric fluorescent probe based on pyridine-substituted boron dipyrromethene (BODIPY) fluorophore (BDP-p) was designed to track the endogenous Zn2+ in cells during ferroptosis process. Zn2+ coordination induced an enhancement on the intramolecular charge transfer (ICT), leading to an obvious red shift from 563 nm to 594 nm. In A549 cells, we found fluorescence ratio of the probe elevated in some discrete regions during erastin induced ferroptosis, and this change followed the same trend as the reactive oxygen species (ROS) level. The results suggested that the Zn2+ would be localized in some discrete areas in A549 cells during ferroptosis. This work not only provided a reliable design strategy for developing ratiometric probes of Zn2+, but also supplemented the current understanding of the non-negligible role of Zn2+ in ferroptosis.
Bacteria and stains on tooth and various dental materials severely harm dental health and beauty and require feasible solutions. In this study, a simple strategy was developed to produce nano-coating on different substrates for persistent antibacterial and whitening. The coating is formed by the lysozyme (Lys), hemoglobin (Hb), and glucose oxidase (GOD) via co-assembly, in which the phase transition of Lys initiated the co-assembly to anchor other two proteins. During therapy, the GOD continuously oxidizes glucose in the oral environment to cut off the nutrition of bacteria meanwhile generating H2O2, which would be further catalyzed by the ferrous ions in Hb to produce reactive oxygen species (ROS) for effective decomposition of surrounding bacteria and stains. Moreover, the Hb can perform persistent release of oxygen, which not only enhances the efficiency of glucose oxidation to produce more ROS but directly suppresses anaerobic bacteria via reversing the local hypoxia environment in the mouth. The experimental results indicated that our strategy is able to form nano-film of proteins both on the surface of dental orthosis and human tooth, which further causes obvious reduction of the bacteria not only on the coated substrate but in the surrounding tissue with up to 100% of the bacteriostatic rate. In addition, both the dental orthosis and human tooth were also rapidly cleaned due to the local ROS generation, leading to a sustained anti-staining property in the long term.
Molecular glass refers to amorphous rigid small molecules with certain polymer-like properties. Herein, spirobixanthene is first adopted as the backbone to develop negative photoresist X4Ep with four epoxy moieties. F4Ep based on classical spirobifluorene is also synthesized as a benchmark against X4Ep. Both exhibit good thermostability and similar sensitivity. However, in e-beam lithography, performances of X4Ep completely surpass F4Ep. F4Ep lithography shows inevitably minor bridges no matter how we optimize process conditions. The relatively poor performances of F4Ep may be probably ascribed to its partial crystallization tendency inducing uneven photoacid generator (PAG) distribution and uneven acid diffusion, which thus promotes nonuniform epoxy crosslink to form rough patterns. X4Ep readily achieves dense lines without any defects. The superiority of X4Ep to F4Ep can be ascribed to the exceptional yet apparent structural distortion and asymmetry of spirobixanthene, which guarantees a perfect amorphous state and uniform crosslink. Finally, the optimal line/space (L/S) pattern with half pitch (HP) of 25 nm and line edge roughness (LER) of 2.7 nm is achieved. Therefore, spirobixanthene is a valuable molecular glass backbone for high-performance photoresists in the future.
Layered double hydroxides (LDHs) hold great promise for flexible solid-state supercapacitors owing to their high theoretical capacitance and distinctive architecture. However, their proneness to agglomeration and poor electrical conductivity have long hindered the manifestation of outstanding electrochemical performance. In a groundbreaking approach, we have engineered a hierarchical carbon nanofiber-based NiCo2S4/NiCo-LDH/C nanostructure array. The meticulously crafted hierarchical structure not only imparts remarkable stability to the electrode but also ingeniously harnesses the synergistic interplay among materials. Through density functional theory calculations, we have precisely identified and verified the active sites for charge transfer, unveiling a new understanding of the underlying mechanisms. This unique structure significantly facilitates ion transfer in the vicinity of NiCo-LDH, substantially elevates electrical conductivity, and notably increases the adsorption capacity of OH-. Moreover, it gives a substantial boost to the quantum capacitance. As a result, the electrode showcases a high specific capacitance of 1838.3 F/g. This research pioneers an effective and versatile strategy that can be readily applied to the majority of LDHs, opening up new avenues for enhancing their efficiency of supercapacitor materials.
The advent of the most representative commercially available formulations of paclitaxel, Taxol and Abraxane®, resolved the intravenous challenge of paclitaxel by increasing the water solubility. However, the severe excipient-related toxicity and poor stability of Taxol, along with the low drug loading (10%), complex preparation processes, and poor tumor selectivity of Abraxane®, present significant clinical dilemma. To overcome the challenges, 16-methylheptadecanoic acid (16-MH), with excellent biocompatibility was selected as the assembly module. The paclitaxel-16-MH prodrug nanoassemblies (PSSMH NPs) were constructed by conjugating 16-MH with redox-sensitive disulfide bonds and paclitaxel through an ethylene glycol. PSSMH NPs featured the advantages of easy preparation, high drug loading (> 50%) and superior stability (stable storage for 60 days at 25 ℃). Notably, the area under the concentration−time curve (AUC0–24 h) of PSSMH NPs was 14.95-fold compared with Taxol, indicating a significant improvement in the in vivo fate of paclitaxel. Moreover, the existence of redox-sensitive disulfide bonds endowed PSSMH NPs with increased tumor selectivity, resulting in exceptional tolerance and antitumor efficacy. Overall, the redox-triggered prodrug nano-system with high tumor selectivity and biocompatibility exhibits substantial potential for clinical translation.
The escalating threat of antimicrobial resistance necessitates advanced tools for rapid and selective antibiotic detection in environmental systems. Herein, we report polyphenol-derived carbon dots (P-CDs) synthesized via a one-step solvothermal method using polyphenols and citric acid, enabling dual-mode detection of tetracyclines and quinolones through pH-tunable fluorescence. The P-CDs exhibit distinct fluorescence quenching for tetracyclines (e.g., oxytetracycline (OTC)) and enhancement for quinolones (e.g., norfloxacin (NOR)), driven by synergistic multiple molecular interactions facilitated by surface phenolic groups. With detection limits of 8.19 µmol/L (OTC) and 5.27 µmol/L (NOR), P-CDs achieve 6-fold higher sensitivity compared to conventional carbon dots. Their pH adaptability (pH 2–12), specificity (> 90% selectivity against seven antibiotic classes), and robust performance in real water matrices (e.g., river water and wastewater) underscore their potential as eco-friendly sensors for on-site environmental monitoring. This work highlights a versatile platform to address antibiotic contamination and advance public health safety.
Natural products bearing a bicyclo[3.2.2]nonane motif pose a considerable challenge to chemical synthesis. We developed a europium-promoted inverse-electron-demand Diels–Alder reaction of benzo[2,3]tropone derivatives with electron-rich olefins, which offers an expeditious approach to densely substituted bicyclo[3.2.2]nonanes. This method enabled the concise synthesis of a tetracyclic amine, subsequently identified as a downstream suppressor of autophagy.
Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and is among the leading causes of cancer-related mortality. Immunotherapy strategies targeting HCC are widely used in clinical practice. However, the pronounced immunosuppressive characteristics of the tumor microenvironment in HCC significantly hinder the efficacy of immunotherapy, often leading to suboptimal therapeutic outcomes. Innovative immunomodulatory delivery systems offer a promising path for HCC therapy by enabling precise targeting of tumor sites and significantly reducing the chances of systemic toxicity and side effects. This study describes the immune microenvironment of HCC and the mechanisms leading to immune evasion. This study then explores the issues and restrictions of current mainstream immunotherapies, highlighting the breakthroughs achieved through drug delivery systems crafted with innovative micro-nanomaterials for HCC immunotherapy. Besides, the application scenarios and challenges encountered by micro-nanomaterials in clinical translational applications were also discussed, and future development trends in this field were prospected, offering a theoretical foundation for the design of efficient HCC treatment strategies.
Ocular posterior segment diseases (OPSDs), including uveitis, glaucoma, retinitis pigmentosa (RP), fundus neovascular diseases (FNDs), and age-related macular degeneration (AMD), are major causes of global blindness. The eye's biological barriers often prevent conventional drugs from reaching the posterior segment effectively, while potentially causing adverse effects. Nanocarrier-based drug delivery systems (DDS) offer promising solutions, with their small size, tunable properties, and high biocompatibility enhancing drug permeability, stability, and targeted delivery. These systems may reduce administration frequency, prolong therapeutic effects, minimize side effects, and improve patient compliance. Unlike previous reviews, this article comprehensively examines novel nanocarriers for OPSD treatment. We first analyze small molecules, their nanocarriers, and administration methods based on recent two-decade research. Next, we compare nanocarrier stability, biocompatibility, ocular penetration, drug release kinetics, and formulation ease, emphasizing recent advances in design, preparation, and functional modification. Finally, by evaluating clinical applications and challenges, we discuss translational hurdles and future prospects for OPSD nanotherapeutics. Greater research efforts are needed to realize nanocarriers' full potential in OPSD treatment.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
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
