Latest ArticlesOsteoarthritis (OA) is the most prevalent joint disease and icariin is a promising drug for its treatment. However, the clinical use of icariin is hindered by poor water solubility, low bioavailability, and non-specific release and biological distribution. Herein, sulfonated azocalix[4]arene (SAC4A) with enhanced water solubility, recognition capacity, and designed responsiveness was used to improve the efficiency of icariin for OA therapy. SAC4A, a macrocycle with well-defined molecular weight and structure, could encapsulate and enhance water solubility of various drugs. In addition, SAC4A enables hypoxia-responsive release of loaded drug. Compared with icariin treatment, supramolecular complex icariin@SAC4A significantly relieved OA symptoms of rats, including more regular bone morphology and structure, and lower degree of cartilage damage. Moreover, the supramolecular formulation demonstrated various advantages, including easy preparation, hypoxia-triggered release, and small size that conducive to drug penetration.
A transition-metal- and oxidant-free amination/cyclization reaction to access 1,2,4-triazolo[1,5-a]pyridines was realized in water by using amino diphenylphosphinate as amino source. A broad array of readily accessible N-(pyridyl)amides could be converted into the products featuring a diverse set of functional groups. The sustainable methodology was successfully applied to the late-stage functionalization of natural products and drugs.
Immunotherapy offers significant potential but is often hampered by the immunosuppressive environment in oral squamous cell carcinoma (OSCC). To address this, we propose an enhanced immunotherapeutic strategy that revitalizes the tumor immune microenvironment (TIME) in OSCC by integrating upconversion-based photodynamic therapy (PDT) with chemotherapy. Using a red blood cell membrane-inspired biomimetic nanoplatform, our approach concurrently delivers chlorin e6@upconversion nanoparticles (Ce6@UCNP) and doxorubicin (DOX). By leveraging fluorescence resonance energy transfer (FRET) for 980 nm to 660 nm upconversion excitation, we address challenges such as limited tissue penetration and tissue damage, as well as nanoplatform issues including immunogenicity and targeting inaccuracy Our integrated approach enhances PDT and chemotherapy with the goal of transforming immunologically "cold" tumors into "hot" ones through a cascaded therapy, thereby revitalizing the tumor immune microenvironment in OSCC.
The treatment of skin wounds, especially chronic wounds, remains a critical clinical challenge and places a heavy burden on patients and healthcare systems. In recent years, the engineering strategy of using biomaterial-assisted exosomes has emerged as a powerful tool for skin repair. Compared to treatments such as debridement and regular dressing changes, the design of biomaterial-assisted exosomes not only maintains the bioactivity of exosomes at the wound site but also provides an appropriate microenvironment for the repair of complex tissues, thereby accelerating wound healing. This review systematically introduces the general characteristics of exosomes and their functions in skin wound healing, highlights recent advances in classification of natural exosomes and engineering methods which enriching their functions in intercellular communication. Then, various emerging and innovative approaches based on biomaterials delivery of exosomes are comprehensively discussed. The review seeks to bring an in-depth understanding of bioactive dressings based on exosomes therapeutic strategies, aiming to facilitate new clinical application value.
Intracellular redox homeostasis is of indispensable importance in pathophysiology. In order to maintain the balance of the redox state within the cell, reactive oxygen species (ROS) and reactive sulfur species (RSS) react and transform with each other, and their levels also directly reflect the degree of oxidative stress and disease. Hypochlorous acid (HClO) and cysteine (Cys) usually co-exist in organisms, interacting with each other in many important physiological processes and synergistically maintaining the dynamic redox balance in the body. To understand the relevance and pathophysiological effects of these two signaling molecules in oxidative stress, unique fluorescence imaging tools are required. Herein, we designed and developed a dual-channel fluorescent probe HP, for the individual and continuous detection of HClO and Cys. This probe could simultaneously monitor the changes in the concentrations of HClO and Cys in cells, and was characterized by a fast response, high sensitivity and high selectivity, especially compared with glutathione (GSH) and homocysteine (Hcy), the probe had a good specificity for Cys. Importantly, probe HP successfully observed dynamic changes in HClO- and Cys-mediated redox status in the oxygen-glucose deprivation/reperfusion (OGD/R) model of HeLa cells and dynamically monitored fluctuations in endogenous HClO levels in lipopolysaccharides (LPS)-induced peritonitis mice.
Herein, we report the dynamic kinetic resolution asymmetric acylation of γ-hydroxy-γ-perfluoroalkyl butenolides/phthalides catalyzed by amino acid-derived bifunctional organocatalysts, and a series of ketals were obtained in high yields (up to 95%) and excellent enantioselectivities (up to 99%). In terms of synthetic utility, the reaction can be performed on a gram scale, and the product can be converted into potential biological nucleoside analog.
Aflatoxins B1 (AFB1) contamination in agro-food holds great threaten to human and animal health. Conventional test strips for rapid AFB1 visualized monitoring remains challenged by improvement of sensitivity and matrix interference resistance. In this case, we developed a portable electrochemiluminescence (ECL) imaging test strip with dual-signal outputs for AFB1 quantification in corn samples. Ru-PEI@SiO2@Au nanospheres were synthesized for bonding with anti-AFB1 antibody and then colorimetrical signal-reported on test line through the capillary flow at strips. Meanwhile, ECL imaging signal of the constructed carbon-ink-based working electrode on polyvinyl chloride substrate of strips was exported under an applied potential of 1.25 V. The whole ECL test strips not only endowed convenient colorimetric responses but guaranteed quick-witted ECL image distinguishment even at extremely low AFB1 content. The detection limit of this ECL imaging-integrated mode was 10-fold lower than that of only colorimetric mode. Furthermore, satisfactory selectivity, reliability and practicability of the as-proposed ECL test strips were demonstrated. This work offered a promising platform for on-site, accurate and sensitive detection of pollutants in foods.
The demand for enhanced optical properties in advanced fluorescence technologies has driven research into the structure-property relationship of fluorophores. In this paper, we use naphthalene fluorophores NaDC-Aze and PhDO-Aze as a case study to emphasize the pivotal role of cross conjugation in tuning the optical structure-property relationship. NaDC-Aze and PhDO-Aze, formed by hybridizing two distinct conjugated systems in a single naphthalene molecule, exhibit spectral characteristics from both conjugated systems. Experimental data and theoretical calculations demonstrate the coexistence of two electron-delocalization systems in a cross-conjugation manner in both NaDC-Aze and PhDO-Aze. The cross-conjugation fluorophores exhibit high brightness, large Stokes shift, and a broad absorption wavelength range by combining distinct spectral properties from its parent fluorophores. These spectral properties will be advantageous for certain applications (i.e., panchromatic absorption in organic solar cells, and fluorophores compatible with a wide range of excitation wavelengths).
An N-heterocyclic carbene (NHC) catalyzed enantioselective cyclisation and trifluoromethylation of olefins with cinnamaldehydes via radical relay cross-coupling in the presence of Togni reagent is reported and δ-lactones tolerated with stereogenic centers at β- and γ-positions are obtained in moderate to high yields and with high enantioselectivities. Further computational studies explain that the radical cross-coupling step is the key to determining the enantioselectivity. Energy analysis of key transition states and intermediates also provides a reasonable explanation for the difficulty of diastereoselective control. DFT calculations also reveal that the hydrogen-bonding interaction plays a vital role in the promotion of this chemistry.
PBQ [1-(4-chlorophenyl)-3-(pyridin-3-yl)urea], an enormous potent molluscicide, showed excellent Pomacea canaliculata (P. canaliculata) control activity and low toxicity for other aquatic organisms, but its snail-killing mechanisms are still not fully understood. We employed an optical method to elucidate PBQ action via a novel fluorescent viscosity probe, NCV. As the viscosity in the test solutions increased, compared with that in pure ethanol, a 54-fold fluorescence intensity enhancement of NCV was observed in 310 cP of 90% glycerol. Furthermore, NCV successfully exhibited a selective fluorescence response towards monensin-induced cellular viscosity changes in HepG2 cells. The liver, stomach, and foot plantar of the tested snails were frozen and sectioned for fluorescent imaging experiments after the treatment with different PBQ concentrations over various times. A significant fluorescent increase in the snail's liver was observed upon exposure to 0.75 mg/L PBQ for 72 h, which highlighted an increase in viscosity. Hematoxylin and eosin (HE) staining further supported PBQ-induced liver damage with a viscosity increase in P. canaliculata. Our study provides a new rapid optical visualization method to study the killing mechanisms of PBQ and may help discover new chemicals that control snail populations.