Latest ArticlesNeutrophil extracellular traps (NETs) formation (NETosis), is a crucial immune system mechanism mediated by neutrophils, measuring the capacity to induce NETosis is proposed as a clinical biomarker indicating the severity of COVID-19 and long COVID. Azvudine (FNC), has shown efficacy in treating SARS-CoV-2 infection and potential for alleviating inflammation. However, the molecular mechanism underlying its anti-inflammatory effects has not been extensively investigated. Therefore, a series of experiments were conducted on SARS-CoV-2 infected rhesus macaques (RMs) to investigate the anti-inflammatory effects of FNC. The experiments involved HE staining, mass spectrometry-based proteomics, validation experiments conducted in vivo using RMs tissues and in vitro differentiation of HL-60 cells. Additionally, interaction investigations were carried out utilizing LiP-MS, CETSA, Co-IP along with molecular docking. The results demonstrated that FNC treatment effectively alleviated neutrophil infiltration and attenuated inflammatory injury following infection. In addition to exhibiting antiviral effects, FNC treatment exhibited a reduction in inflammation-associated proteins and pathways such as myeloperoxidase (MPO) and the formation of NETs, respectively. Validation experiments confirmed the impact of FNC on regulating NETs formation, interaction experiments suggested that MPO may serves as a therapeutic target. The multifaceted properties of FNC, including its antiviral and anti-inflammatory characteristics, highlight the therapeutic potential in diseases associated with NETosis, particularly those involving concurrent SARS-CoV-2 infection, providing insights for drug development targeting MPO and NETosis-associated diseases.
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.
Traditional Pt/C electrode materials are prone to corrosion and detachment during H2S detection, leading to a decrease in fuel cell-type sensor performance. Here, a high-performance H2S sensor based on Pt loaded Ti3C2 electrode material with -O/-OH terminal groups was designed and prepared. Experimental tests showed that the Pt/Ti3C2 sensor has good sensitivity (0.162 µA/ppm) and a very low detection limit to H2S (10 ppb). After 90 days of stability testing, the response of the Pt/Ti3C2 sensor shows a smaller decrease of 2% compared to that of the Pt/C sensor (22.9%). Meanwhile, the sensor also has high selectivity and repeatability. The density functional theory (DFT) calculation combined with the experiment results revealed that the improved H2S sensing mechanism is attributed to the fact that the strong interaction between Pt and Ti3C2 via the Pt-O-Ti bonding can reduce the formation energy of Pt and Ti3C2, ultimately prolonging the sensor’s service life. Furthermore, the catalytic property of Pt can decrease the adsorption energy and dissociation barrier of H2S on Pt/Ti3C2 surface, greatly enhance the ability to generate protons and effectively transfer charges, realizing good sensitivity and high selectivity of the sensor. The sensor works at room temperature, making it very promising in the field of H2S detection in future.
The development of general and practical strategies toward the construction of medium-sized rings is still challenging in organic synthesis, especially for the multiple stereocenters control of substituted groups on the ring owing to the long distance between groups. Thus, stereoselective synthesis of multi-substituted ten-membered rings is attractive. Herein, a rapid assembly of various highly substituted ten-membered nitrogen heterocycles between two 1,3-dipoles through a tandem [3 + 3] cycloaddition/aza-Claisen rearrangement of N-vinyl-α,β-unsaturated nitrones and aza-oxyallyl or oxyallyl cations are disclosed. Products containing two or multiple stereocenters could be obtained in up to 96% yield with high regioselectivity and diastereoselectivity. Selective N-O bond cleavages of ten-membered nitrogen heterocycles lead to various novel 5,6,6-perifused benzofurans, bicyclo[4.4.0] or bicyclo[5.3.0] skeletons containing three or multiple continuous stereocenters in good yields and high diastereoselectivity. Biological tests show that the obtained ten-membered N-heterocycles and bicyclo[4.4.0] skeletons inhibited nitric oxide generation in LPS-stimulated RAW264.7 cells and might serve as good anti-inflammatory agents.
As a renovator in the field of gene editing, CRISPR-Cas9 has demonstrated immense potential for advancing next-generation gene therapy owing to its simplicity and precision. However, this potential faces significant challenges primarily stemming from the difficulty in efficiently delivering large-sized genome editing system (including Cas9 protein and sgRNA) into targeted cells and spatiotemporally controlling their activity in vitro and in vivo. Therefore, the development of CRISPR/Cas9 nanovectors that integrate high loading capacity, efficient encapsulation and spatiotemporally-controlled release is highly desirable. Herein, we have engineered a near-infrared (NIR) light-activated upconversion-DNA nanocapsule for the remote control of CRISPR-Cas9 genome editing. The light-responsive upconversion-DNA nanocapsules consist of macroporous silica (mSiO2) coated upconversion nanoparticles (UCNPs) and photocleavable o-nitrobenzyl-phosphate-modified DNA shells. The UCNPs act as a "nanotransducers" to convert NIR light (980 nm) into local ultraviolet light, thereby facilitating the cleavage of photosensitive DNA nanocapsules and enabling on-demand release of CRISPR-Cas9 encapsuled in the macroporous silica. Furthermore, by formulating a sgRNA targeted to a tumor gene (polo-like kinase-1, PLK-1), the CRISPR-Cas9 loaded UCNP-DNA nanocapsules (crUCNP-DNA nanocapsules) have effectively suppressed the proliferation of tumor cells through NIR light-activated gene editing both in vitro and in vivo. Overall, this UCNP-DNA nanocapsule holds tremendous potential for CRISPR-Cas9 delivery and remote-controlled gene editing in deep tissues, as well as the treatment of diverse diseases.
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.
Bridged bicyclic cores have been recognized as valuable bioisosteres of benzene ring, which are of great value in medicinal chemistry. However, the development of fluorinated bicyclic skeletons, which encompass two privileged elements widely acknowledged for fine tuning the working effect of target molecules, are far less common. Herein, we present a general and practical synthesis of gem–difluorobicyclo[2.1.1]hexanes (diF-BCHs) from readily available difluorinated hexa-1,5-dienes through energy transfer photocatalysis. By taking advantage of an efficient Cope rearrangement, the preparation of both constitutional isomers of diF-BCHs is readily achieved under identical conditions. The operational simplicity, mild conditions and wide scope further highlight the potential application of this protocol. Moreover, computational studies indicated a positive effect of fluorine atoms in lowering either the triplet or FMO energies of the hexa-1,5-diene substrates, thus promoting the present photoinduced [2 + 2] cycloaddition.
As a versatile and environmentally benign oxidant, hydrogen peroxide (H2O2) is highly desired in sanitation, disinfection, environmental remediation, and the chemical industry. Compared with the conventional anthraquinone process, the electrosynthesis of H2O2 through the two-electron oxygen reduction reaction (2e− ORR) is an efficient, competitive, and promising avenue. Electrocatalysts and devices are two core factors in 2e− ORR, but the design principles of catalysts for different pH conditions and the development trends of relevant synthesis devices remain unclear. To this end, this review adopts a multiscale perspective to summarize recent advancements in the design principles, catalytic mechanisms, and application prospects of 2e− ORR catalysts, with a particular focus on the influence of pH conditions, aiming at providing guidance for the selective design of advanced 2e− ORR catalysts for highly-efficient H2O2 production. Moreover, in response to diverse on-site application demands, we elaborate on the evolution of H2O2 electrosynthesis devices, from rotating ring-disk electrodes and H-type cells to diverse flow-type cells. We elaborate on their characteristics and shortcomings, which can be beneficial for their further upgrades and customized applications. These insights may inspire the rational design of innovative catalysts and devices with high performance and wide serviceability for large-scale implementations.
The enantioselective separation of racemate, particularly those containing C(sp3)-H bonds knowns for their high bond dissociation energies and significant polarity, presents a significant challenge in pharmaceutical synthesis. Recent advances have witnessed the fusion of photocatalysis with hydrogen atom transfer (HAT) methodologies, marking a notable trend in synthesis of chiral molecules. This technique uses the excitation of a catalyst to activate substrates, enabling the selective isomerization of chiral centers containing C(sp3) configurations. This process distinctively facilitates the direct activation of the C(sp3)-H bond in targeted reagents. This review systematically discusses the photocatalytic isomerization of various chiral molecule featuring C(sp3)-H centers, capable of undergoing deracemization through two primary HAT mechanisms: direct and indirect pathways. From the perspective of synthetic organic chemistry, this field has progressed towards the development of isomerization strategies for molecules that incorporate an activating group at the α-position adjacent to the C(sp3) chiral center. Moreover, it covers methodologies applicable to molecules characterized by specific C-C and C-S bond configurations. The integration of photocatalysis with HAT technology thus provides valuable strategies for the synthesis of enantiopure compounds with enhanced selectivity and efficiency.
Carbon dots (CDs) are an emerging class of zero-dimensional carbon nano optical materials that are as promising candidates for various applications. Through the exploration of scientific researchers, the optical band gap of CDs has been continuously regulated and red-shifted from the initial blue-violet light to longer wavelengths. In recent years, CDs with near-infrared (NIR) absorption/emission have been gradually reported. Because NIR light has deeper penetration and lower scattering and is invisible to the human eye, it has great application prospects in the fields of biological imaging and treatment, information encryption, optical communications, etc. Although there are a few reviews on deep red to NIR CDs, they only focus on the single biomedical direction. There is still a lack of comprehensive reviews focusing on NIR (≥700 nm) absorption and luminescent CDs and their multifunctional applications. Based on our research group’s findings on NIR CDs, this review summarizes recent advancements in their preparation strategies and applications, points out the current shortcomings and challenges, and anticipates future development trajectories.