Latest ArticlesHomogeneous gold catalysis has demonstrated the preponderant capability of realizing a broad range of synthetically versatile alkyne functionalization over the last two decades. Though catalytic asymmetric alkyne transformation has focused on the principle of using gold catalysts either associated with chiral phosphine ligand or combined with chiral counterion, a variety of breakthroughs have been reported with the application of gold-complex and chiral organocatalyst cooperative catalysis strategy, which could enable the challenging transformations that cannot be realized by mono-catalysis with excellent stereoselectivity. This review will cover two general protocols in this field, including relay catalysis and synergistic catalysis, with emphasis on the detailed cooperative catalysts models to illustrate the roles of the two catalysts and highlight the potential synthetic opportunities offered by asymmetric cooperative catalysis.
Target discovery, involving target identification and validation, is the prerequisite for drug discovery and screening. Novel methodologies and technologies for the precise discovery and confirmation of drug targets are powerful tools in understanding the disease, looking for a drug and elucidating the mechanism of drug treatment. Among the common target identification and confirmation methods, the modified method is time-consuming and laborious, which may reduce or change the activity of natural products. The unmodified methods developed in recent years without chemical modification have gradually become an important means of studying drug targets. A wide range of unmodified approaches have been reported, introducing and analyzing the recent emerging methodologies and technologies. This review highlights the advantages and limitations of these methods for the application of drug target discovery and presents an overview of their contributions to the target discovery of small molecule drugs. The application and future development trends of methodologies in target discovery are also prospected to provide a reference for drug target research.
Two-dimensional polymers (2DPs) are emerging crystalline 2D organic material comprising free-standing, single-atom/monomer-thick, planar, and covalent networks with long-ranging structural order. Benefiting from their intrinsic porosity, crystallinity, and electrical properties, 2DPs have displayed great potential for separation, energy conversion and electronic fields. In this mini review, we aim to provide the recent progress in crystalline 2DPs films form synthesis strategies to characterization methods, as well as the future trends. We first present the synthesis strategy of single-crystalline 2DPs films including crystal engineering approaches and surface science. Also, we summarize the characterization methods of 2DPs films and highlight the advantages and limitations of different methods focusing on chemical bonding, morphology, and crystal structure. Finally, we will present the current challenges and trends regarding the future developments of crystallinity, monomer design, synthesis strategy and characterization.
Graphene oxide (GO) has been widely used in the modification of membranes due to its excellent properties, i.e., huge specific surface area, good electrical conductivity, good hydrophilicity and various functional groups. The addition of GO in membranes were proved to exhibit improved properties in water permeability, molecular selectivity, membrane fouling mitigation and contaminants decomposition. Recently, the development of laminated GO in membranes achieved both high selectivity and high water permeability, conquering the limitations of conventional polymeric or inorganic membranes. By analyzing the separation mechanisms and the performance of GO composite membranes, this review systematically summarized the applications of GO composite membranes in three highlighted areas of environmental fields: desalination, gas separation and wastewater treatment, with challenges discussed faced with GO composite membranes.
Metal-organic frameworks (MOFs) materials with highly ordered and porous crystalline structure, have excellent performance in advanced oxidation progresses (AOPs) for organic contaminants degradation in water treatment. This review intends to summarize the timely references and insights for the recent advances in MOFs that are used in AOPs. Starting with the preparation methodologies, including conventional hydrothermal method, electrochemical method, sol-gel method, and emerging microwave and ultrasound assisted synthesis methods. Application and mechanism for MOFs using in various AOPs of Fenton-like, photocatalysis, catalytic ozonation, persulfate catalysis and other emerging oxidation methods are emphatically discussed. We hope this review can comprehensively summarize the research and application progress of MOFs in AOPs, deepen the understanding of the catalytic mechanisms.
Photoreduction of CO2 into value-added products offers a promising approach to overcome both climate change and energy crisis. However, low conversion efficiency, poor product selectivity, and unclear mechanism limit the further advancement of CO2 photoreduction. The development of two-dimensional (2D) materials and construction of single atom sites are two frontier research fields in catalysis. Combining the advantages of 2D materials and single atom sites is expected to make a breakthrough in CO2 photoreduction. In this review, we summarized the design and application, proposed challenges and opportunities, and laid a foundation for further research and application of 2D materials confining single atoms (SACs@2D) for CO2 photoreduction.
Diabetic wounds lead to a decrease in quality of life and an increase in mortality. Current treatment strategies include preventing bacterial adhesion while improving microcirculation. As a new type of wound dressing that imitates natural skin, hydrogel has gradually emerged with its excellent properties. However, existing hydrogels rarely achieve satisfactory results in promoting wound repair and antibacterial simultaneously. In this case, we prepared methacrylic anhydride chemically modified hyaluronic acid as a hydrogel matrix, added polyhexamethylene biguanide as an antibacterial component, and loaded sodium alginate/salidroside composite microspheres which could sustainably release salidroside and thus promote angiogenesis. Hybrid hydrogel (HAMA/PHMB-Ms) was synthesized via photocrosslinking, and its chemical structure, particle size distribution and microstructure were characterized. The satisfactory antibacterial properties of the HAMA/PHMB(15%)-Ms hydrogel were studied in vitro, and its antibacterial rates against E. coli and S. aureus were 97.85% and 98.56%, respectively. In addition, after demonstrating its good biocompatibility, we verified that the HAMA/PHMB-Ms hydrogel has increased granulation tissue formation, more collagen deposition, more subcutaneous capillary formation, and better wound healing than blank control, HAMA and HAMA/PHMB hydrogel on the back wound model of diabetic mice. The results confirmed that HAMA/PHMB-Ms hydrogel was a promising material for the treatment of the diabetic wounds.
Intelligent nanoplatform that combines multimodal imaging and therapeutic effects holds great promise for precise and efficient cancer therapy. Herein, folate-targeted polymersomes with stimuli-responsiveness were fabricated and evaluated by near-infrared fluorescence (NIRF) and optical coherence tomography angiography (OCTA) dual-imaging for photo-chemo-antiangiogenic therapy against cancer. The folate-targeted polymersomes (FA-MIT-SIPS) not only integrated ammonium bicarbonate (ABC) and mitoxantrone (MIT) into their hydrophilic cavity but also encapsulated indocyanine green (ICG) and sorafenib (SOR) within their hydrophobic layer. NIRF imaging demonstrated that FA-MIT-SIPS effectively accumulated and retained in the tumors. Upon 808 nm laser irradiation, the ICG produced hyperthermia and reactive oxygen species (ROS) for efficient photothermal and photodynamic therapy. In addition, the decomposition of ABC in responsive to acidic tumor environment and ICG-induced hyperthermia accelerated drug release. The released MIT accumulated in nucleus to inhibit DNA synthesis, while the released SOR destructed tumor vascularization. Notably, OCTA imaging was applied to observe the tumor blood flow upon the combination therapy, demonstrating that FA-MIT-SIPS obviously decreased the vessels area density. Moreover, the synergistic photo-chemo-antiangiogenic therapy of FA-MIT-SIPS achieved excellent antitumor effect with 40% of the 4T1 tumor-bearing mice being completely cured without recurrence. The multifunctional polymersomes provide a promising dual-modal imaging-evaluated synergistic strategy for tumor therapy.
The need for temporal resolution and long-term stability in super-resolution fluorescence imaging has motivated research to improve the photostability of fluorescent probes. Due to the inevitable photobleaching of fluorophores, it is difficult to obtain long-term super-resolution imaging regardless of the self-healing strategy of introducing peroxide scavengers or the strategy of fluorophore structure modification to suppress TICT formation. The buffered fluorogenic probe uses the intact probes in the buffer pool to continuously replace the photobleached ones in the target, which greatly improves the photostability and enables stable dynamic super-resolution imaging for a long time. But the buffering capacity comes at the expense of reducing the number of fluorescent probes in targets, resulting in low staining fluorescence intensity. In this paper, we selected BODIPY 493, a lipid droplet probe with high fluorescence brightness, to explore the dynamic process of lipid droplet staining of this probe in cells. We found that BODIPY 493 only needs very low laser power for lipid droplet imaging due to the high molecular accumulation in lipid droplets and the high brightness, and the spatiotemporal resolution is greatly improved. More importantly, we found that BODIPY 493 also has a certain buffering capacity, which enables BODIPY 493 to be used for super-resolution imaging of lipid droplet dynamics. This work reminds researchers to coordinate the buffering capacity and brightness of fluorogenic probes.
Two sulfonated diterpenoid alkaloids possessing different but related novel carbon skeletons, named aconidenusulfonine A (1) and 12, 16-secoaconidenusulfonine A (2), respectively, were isolated as minor components from an aqueous extract of the lateral roots of Aconitum carmichaelii ("Fu Zi"). The structures of 1 and 2, representing the first two C21-diterpenoid alkaloids from nature, were determined by analysis of various spectroscopic data and chemical transformation, of which 1 was further proved by single-crystal X-ray diffraction. Especially, 1 exhibited dose-depended analgesic activity consistent with the clinical function of Fu Zi.