Latest ArticlesGallstones are a common disease worldwide, often leading to obstruction and inflammatory complications, which seriously affect the quality of life of patients. Research has shown that gallstone disease is associated with ferroptosis, lipid droplets (LDs), and abnormal levels of nitric oxide (NO). Fluorescent probes provide a sensitive and convenient method for detecting important substances in life systems and diseases. However, so far, no fluorescent probes for NO and LDs in gallstone disease have been reported. In this work, an effective ratiometric fluorescent probe LR-NH was designed for the detection of NO in LDs. With an anthracimide fluorophore and a secondary amine as a response site for NO, LR-NH exhibits high selectivity, sensitivity, and attractive ratiometric capability in detecting NO. Importantly, it can target LDs and shows excellent imaging ability for NO in cells and ferroptosis. Moreover, LR-NH can target the gallbladder and image NO in gallstone disease models, providing a unique and unprecedented tool for studying NO in LDs and gallbladder.
Boron neutron capture therapy (BNCT) has emerged as a promising treatment for cancers, offering a unique approach to selectively target tumor cells while sparing healthy tissues. Despite its clinical utility, the widespread use of fructose-BPA (F-BPA) has been hampered by its limited ability to penetrate the blood-brain barrier (BBB) and potential risks for patients with certain complications such as diabetes, hyperuricemia, and gout, particularly with substantial dosages. Herein, a series of novel BPA derivatives were synthesized. After the primary screening, geniposide-BPA (G-BPA) and salidroside-BPA (S-BPA) exhibited high water solubility, low cytotoxicity and safe profiles for intravenous injection. Furthermore, both G-BPA and S-BPA had demonstrated superior efficacy in vitro against the 4T1 cell line compared with F-BPA. Notably, S-BPA displayed optimal BBB penetration capability, as evidenced by in vitro BBB models and glioblastoma models in vivo, surpassing all other BPA derivative candidates. Meanwhile, G-BPA also exhibited enhanced performance relative to the clinical drug F-BPA. In brief, G-BPA and S-BPA, as novel BPA derivatives, demonstrated notable safety profiles and remarkable boron delivery capabilities, thereby offering promising therapeutic options for BNCT in the clinic.
Photodynamic therapy (PDT) has received much attention in recent years. However, traditional photosensitizers (PSs) applied in PDT usually suffer from aggregation-caused quenching (ACQ) effect in H2O, single and inefficient photochemical mechanism of action (MoA), poor cancer targeting ability, etc. In this work, two novel Ru(Ⅱ)-based aggregation-induced emission (AIE) agents (Ru1 and Ru2) were developed. Both complexes exhibited long triplet excited lifetimes and nearly 100% singlet oxygen quantum yields in H2O. In addition, Ru1 and Ru2 displayed potent photo-catalytic reduced nicotinamide adenine dinucleotide (NADH) oxidation activity with turnover frequency (TOF) values of about 1779 and 2000 h−1, respectively. Therefore, both Ru1 and Ru2 showed efficient PDT activity towards a series of cancer cells. Moreover, Ru2 was further loaded in bovine serum albumin (BSA) to enhance the tumor targeting ability in vivo, and the obtained Ru2@BSA could selectively accumulate in tumor tissues and effectively inhibit tumor growth on a 4T1 tumor-bearing mouse model. So far as we know, this work represents the first report about Ru(Ⅱ) AIE agents that possess high singlet oxygen quantum yields and also potent photo-catalytic NADH oxidation activity, and may provide new ideas for rational design of novel PSs with efficient PDT activity.
Tumor blockade therapy inhibits tumor progression by cutting off essential supplies of nutrients, oxygen, and biomolecules from the surrounding microenvironments. Inspired by natural processes, tumor biomineralization has evolved due to its biocompatibility, self-reinforcing capability, and penetration-independent mechanism. However, the selective induction of tumor biomineralization using synthetic tools presents a significant challenge. Herein, a metabolic glycoengineering-assistant tumor biomineralization strategy was developed. Specifically, the azido group (N3) was introduced onto the cytomembrane by incubating tumor cells with glycose analog Ac4ManNAz. In addition, a bisphosphonate-containing polymer, dibenzocyclooctyne-poly(ethylene glycol)-alendronate (DBCO-PEG-ALN, DBPA) was synthesized, which attached to the tumor cell surface via "click chemistry" reaction between DBCO and N3. Subsequently, the bisphosphonate group on the cell surface chelated with positively charged ions in the microenvironments, triggering a consecutive process of biomineralization. This physical barrier significantly reduced tumor cell viability and mobility in a calcium ion concentration-dependent manner, suggesting its potential as an effective anti-tumor strategy for in vivo applications.
Lipids serve as fundamental constituents of cell membranes and organelles. Recent studies have highlighted the significance of lipids as biomarkers in the diagnosis of breast cancer. Although liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) is widely employed for lipid analysis in complex samples, it suffers from limitations such as complexity and time-consuming procedures. In this study, we have developed dopamine-modified TiO2 nanoparticles (TiO2-DA) and applied the materials to assist the analysis of lipids by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The TiO2-DA can provide large specific surface area and acidic environment, well suited for lipid analysis. The method was initially validated using standard lipid molecules. Good sensitivity, reproducibility and quantification performance was observed. Then, the method was applied to the analysis of 90 serum samples from 30 patients with breast cancer, 30 patients with benign breast disease and 30 healthy controls. Five lipid molecules were identified as potential biomarkers for breast cancer. We constructed a classification model based on the MALDI-TOF MS signal of the 5 lipid molecules, and achieved high sensitivity, specificity and accuracy for the differentiation of breast cancer from benign breast disease and healthy control. We further collected another 60 serum samples from 20 healthy controls, 20 patients with benign breast disease and 20 patients with breast cancer for MALDI-TOF MS analysis to verify the accuracy of the classification model. This advancement holds great promise for the development of diagnostic models for other lipid metabolism-related diseases.
Chemodynamic therapy (CDT), using Fenton agents to generate highly cytotoxic •OH from H2O2 has been demonstrated as a powerful anticancer method. However, the insufficient endogenous H2O2 in tumor cells greatly limited its therapeutic effect. Herein, we prepared a pH-responsive β-lapachone-loaded iron-polyphenol nanocomplex (LIPN) through a one-pot method. β-Lapachone in LIPN selectively enhanced H2O2 concentration in tumor cells, and ferrous ions cascadely generated abundant cytotoxic •OH. Therefore, LIPN with cascade amplification of reactive oxygen species (ROS) showed high chemodynamic cytotoxicity in tumor cells, efficiently improving the expression of damage-associated molecular patterns (DAMPs), and exerting strong immunogenic cell death (ICD). As a result, LIPN exhibited efficient tumor inhibition ability in 4T1 subcutaneous tumor model in vivo with great biocompatibility. Additionally, the infiltration of cytotoxic CD8+ T lymphocytes and inhibition of regulatory CD4+ FoxP3+ T lymphocytes in tumors demonstrated the activation of immunosuppressive tumor microenvironment by LIPN-induced ICD. Therefore, this work provided a new approach to enhance ICD of chemodynamic therapy through selective cascade amplification of ROS in cancer cells.
Simultaneous degradation and detoxification during pharmaceutical and personal care product removal are important for water treatment. In this study, sodium niobate nanocubes decorated with graphitic carbon nitride (NbNC/g-C3N4) were fabricated to achieve the efficient photocatalytic degradation and detoxification of ciprofloxacin (CIP) under simulated solar light. NaNbO3 nanocubes were in-situ transformed from Na2Nb2O6·H2O via thermal dehydration at the interface of g-C3N4. The optimized NbNC/g-C3N4–1 was a type-Ⅰ heterojunction, which showed a high conduction band (CB) level of −1.68 eV, leading to the efficient transfer of photogenerated electrons to O2 to produce primary reactive species, •O2−. Density functional theory (DFT) calculations of the density of states indicated that C 2p and Nb 3d contributed to the CB, and 0.37 e– transferred from NaNbO3 to g-C3N4 in NbNC/g-C3N4 based on the Mulliken population analysis of the built-in electric field intensity. NbNC/g-C3N4–1 had 3.3- and 2.3-fold of CIP degradation rate constants (k1 = 0.173 min−1) compared with those of pristine g-C3N4 and NaNbO3, respectively. In addition, N24, N19, and C5 in CIP with a high Fukui index were reactive sites for electrophilic attack by •O2−, resulting in the defluorination and ring-opening of the piperazine moiety of the dominant degradation pathways. Intermediate/product identification, integrated with computational toxicity evaluation, further indicated a substantial detoxification effect during CIP degradation in the photocatalysis system.
[2+2]-Type cyclobutane derivatives comprise a large family of natural products with diverse molecular architectures. However, the structure elucidation of the cyclobutane ring, including its connection mode and stereochemistry, presents a significant challenge. Plumerubradins A–C (1–3), three novel iridoid glycoside [2+2] dimers featuring a highly functionalized cyclobutane core and multiple stereogenic centers, were isolated from the flowers of Plumeria rubra. Through biomimetic semisynthesis and chemical degradation of compounds 1–3, synthesis of phenylpropanoid-derived [2+2] dimers 7–10, combined with extensive spectroscopic analysis, single-crystal X-ray crystallography, and microcrystal electron diffraction experiments, the structures with absolute configurations of 1–3 were unequivocally elucidated. Furthermore, quantum mechanics-based 1H NMR iterative full spin analysis successfully established the correlations between the signal patterns of cyclobutane protons and the structural information of the cyclobutane ring in phenylpropanoid-derived [2+2] dimers, providing a diagnostic tool for the rapid structural elucidation of [2+2]-type cyclobutane derivatives.
The selective conversion of CO2 and NH3 into valuable nitriles presents significant potential for CO2 utilization. In this study, we exploited the synergistic interplay between silicon and fluoride to augment the nickel-catalyzed reductive cyanation of aryl pseudohalides containing silyl groups, utilizing CO2 and NH3 as the CN source. Our methodology exhibited exceptional compatibility with diverse functional groups, such as alcohols, ketones, ethers, esters, nitriles, olefins, pyridines, and quinolines, among others, as demonstrated by the successful synthesis of 58 different nitriles. Notably, we achieved high yields in the preparation of bifunctionalized molecules, including intermediates for perampanel, derived from o-silylaryl triflates, which are well-known as aryne precursors. Remarkably, no degradation of substrates or formation of aryne intermediates were observed. Mechanistic studies imply that the formation of penta-coordinated silyl isocyanate intermediates is crucial for the key C–C coupling step and the presence of vicinal silyl group in the substrate is beneficial to further make this step kinetically favorable.
The addition of cold flow improvers (CFIs) is considered as the optimum strategy to improve the cold flow properties (CFPs) of diesel fuels, but this strategy is always limited by the required large dosage. To obtain low-dosage and high-efficiency CFIs for diesel, 1,2,3,6-tetrahydrophthalic anhydride (THPA) was introduced as a third and polar monomer to enhance the depressive effects of alkyl methacrylate-trans anethole copolymers (C14MC-TA). The terpolymers of alkyl methacrylate-trans anethole-1,2,3,6-tetrahydrophthalic anhydride (C14MC-TA-THPA) were synthesized and compared with the binary copolymers of C14MC-TA and alkyl methacrylate-1,2,3,6-tetrahydrophthalic anhydride (C14MC-THPA). Results showed that C14MC -THPA achieved the best depressive effects on the cold filter plugging point (CFPP) and solid point (SP) by 11 ℃ and 16 ℃ at a dosage of 1250 mg/L and monomer ratio of 6:1, while 1500 mg/L C14MC-TA (1:1) reached the optimal depressive effects on the CFPP and SP by 12 ℃ and 18 ℃. THPA introduction significantly improved the depressive effects of C14MC-TA. Lower dosages of C14MC-TA-THPA in diesel exerted better improvement effects on the CFPP and SP than that of C14MC-TA and C14MC-THPA. When the monomer ratio and dosage were 6:0.6:0.4 and 1000 mg/L, the improvement effect of C14MC-TA-THPA on diesel reached the optimum level, and the CFPP and SP were reduced by 13 ℃ and 19 ℃, respectively. A 3D nonlinear surface diagram fitted by a mathematical model was also used for the first time to better understand the relationships of monomer ratios, dosages, and depressive effects of CFIs in diesel. Surface analysis results showed that C14MC-TA-THPA achieved the optimum depressive effects at a monomer ratio of 6:0.66:0.34 and dosage of 1000 mg/L, and the CFPP and SP decreased by 14 ℃ and 19 ℃, respectively. The predicted results were consistent with the actual ones. Additionally, the improvement mechanism of these copolymers in diesel was also explored.