Latest ArticlesA novel class of chiral spiro-fused bisoxazoline ligands possessing a deep chiral pocket was prepared. The developed ligands have been employed in the nickel-catalyzed highly enantioselective Michael-type Friedel-Crafts reaction, affording the products bearing a trifluoromethylated all-carbon quaternary stereocenter with moderate to excellent yields (up to 99%) and good to excellent enantioselectivies (up to > 99.9% ee). Moreover, a proposed model of chiral pocket revealed that the attack of indole from the Re-face of β-CF3-β-disubstituted nitroalkene was favorable.
Highly efficient removal of tumor necrosis factor-α (TNF-α) from plasma by hemoperfusion for autoimmune disease therapy remains a challenge in the clinical field owing to the low adsorption capacity and poor blood compatibility of adsorbents. In this work, a new class of nanobody (Nb)-coupled antifouling polyvinyl alcohol (PVA) beads was constructed as an immunosorbent for the selective removal of TNF-α from plasma. Notably, our immunosorbent exhibited an exceptionally high specific TNF-α adsorption capacity of 416.9 ng/g in human plasma (at a plasma-to-adsorbent ratio of 300). More importantly, the obtained adsorbent beads showed outstanding blood compatibility. In addition, during in vivo experiments, the blood circulation device was constructed to remove TNF-α in rat models, proving that the beads had good removal performance (~85%/60 min). Furthermore, 95% of the original capacity was retained after 6-month storage, showed strong stability and prolonged storage of PVA-Nb. Above all, the results indicate that the novel PVA-Nb immunosorbent has possible clinical applications for treating autoimmune diseases in the clinic.
Stimuli-responsive hydrogels hold an irreplaceable statue in intelligent actuation materials because of their reversible stretchability and excellent biocompatibility. However, the poor mechanical performance and complicated fabrication process of anisotropic structures severely limit their further applications. Herein, we report a high-strength thermoresponsive wood-PNIPAM composite hydrogel actuator with complex deformations, through a simple in-situ polymerization. In this composite hydrogel actuator, the anisotropic wood and the thermoresponsive PNIPAM hydrogel hydroel can work together to provide bending and even other complex deformations. Owing to strong interfacial interaction, this actuator perfectly realized the combination of good mechanical properties (~1.1 MPa) and fast actuation speed (~0.9 s). In addition, by adjusting the orientation direction of wood, this actuator can achieve various complex deformations. Such composite hydrogel actuator could be a good candidate for intelligent applications, such as intelligent actuators, smart valves, manipulators and even soft robots.
Among the large energy storage batteries, the sodium ion batteries (SIBs) are attracted huge interest due to the fact of its abundant raw materials and low cost, and has become the most promising secondary battery. Tunnel-type sodium manganese oxides (TMOs) are industrialized cathode materials because of their simple synthesis method and proficient electrochemical performance. Na0.44MnO2 (NMO) is considered the best candidate material for all tunnel-type structural materials. In this paper, the research progress in charge and discharge of cathode materials for tunnel-type structural SIBs is reviewed, the redox mechanism and all sorts of synthesis methods and different coating methods lead to different morphology and electrochemical properties of materials and the classification of electrolytes and non-aqueous electrolytes. The development and utility of aqueous solutions are discussed, and the mechanism is analyzed. Summarized the cationic potential of the transition metal oxide for tunnel structure, plays a vital role in predicting and designing the cathode material of this structure. In addition, the future opportunities and challenges for such tunnel-type SIBs in this field are described in detail.
Self-assembly is a powerful approach in molecular engineering for biomedical applications, in particular for creating self-assembling prodrugs. Here, we report a self-assembling prodrug of the anticancer drug gemcitabine (Gem) based on amphiphilic dendrimer approach. The prodrug reported in this study demonstrates high drug loading (40%) and robust ability to self-assemble into small nanomicelles, which increase the metabolic stability of Gem and enable entry into cells via endocytosis, hence bypassing transport-mediated uptake. In addition, this prodrug nanosystem exhibited an effective pH- and enzyme-responsive release of Gem, resulting in enhanced anticancer activity and reduced toxicity. Harboring advantageous features of both prodrug- and nanotechnology-based drug delivery, this self-assembling Gem prodrug nanosystem constitutes a promising anticancer candidate. This study also offers new perspectives of the amphiphilic dendrimer nanoplatforms for the development of self-assembling prodrugs.
Gold nanorods (AuNRs), as relatively common materials used in biomedical areas, have been synthesized by means of many methods. However, the conventional seed-mediated method is limited by complex operations and low yield. Besides, for further applications of AuNRs, well monodispersed AuNRs and tunable longitudinal surface plasmon resonance (LSPR) remain to be improved. Herein, we report a one-pot method for synthesizing AuNRs without seeding agents. In this method, we use phenols as reducing agents and hydrochloric acid and nitric acid are used to regulate the pH of the growth solution. AuNRs with the longest LSPR peak position reaching 1340 nm are prepared. Furthermore, by systematically optimizing concentrations of the reagents involved in the growth solution, different aspect ratios of AuNRs are synthesized. The facile synthesis, controllability aspect ratio, and long LSPR peak make our method promising for wider applications of AuNRs.
Glutathione (GSH) is a key maintainer of cellular redox balance and plays an important role in many physiological effects. For example, GSH has been widely implicated in cancer initiation, progression and metastasis. Moreover, the concentrations of GSH in tumor cells can influence drug resistance. Given the serious harmfulness of cancer and the important roles of GSH in cancer, it has great significance to development probes for screening of tumor cells and real-time monitoring of GSH fluctuations in tumor cells. However, no targetable probe for reversible imaging of GSH in tumor cells has been reported. Herein, we constructed a melatonin-based targetable and reversible fluorescent probe (GR-MT) for screening of tumor cells and real-time imaging of GSH fluctuations in tumor cells. The probe uses coumarin as the skeleton, Michael addition reaction as the reaction mechanism, and melatonin as the targeted groups of tumor cells. The experimental results demonstrate this probe has many advantages including high selectivity, satisfactory sensitivity, excellent reversible ability, rapid reaction speed, and outstanding targetability of tumor cells. Therefore, this study provides a promising tool for tumor cells screening and real-time detection of GSH fluctuations in specific tumor cells.
DNA-encoded chemical library (DEL) represents an emerging drug discovery technology to construct compound libraries with abundant chemical combinations. While drug-like small molecule DELs facilitate the discovery of binders against targets with defined pockets, macrocyclic DELs harboring extended scaffolds enable targeting of the protein–protein interaction (PPI) interface. We previously demonstrated the design of the first-generation DNA-encoded multiple display based on a constant macrocyclic scaffold, which harvested binders against difficult targets such as tumor necrosis factor-α (TNF-α). Here, we developed a novel strategy which utilized four orthogonal amine-protecting groups on DNA, to explore larger chemical combinations on the same constant macrocyclic scaffold, following the parallel paradigm to mimic the versatile antibody-like multivalent epitope recognition patterns. We successfully integrated these orthogonal protecting groups with acylation and made a mock second-generation DNA-encoded display combination. This work illustrates a strategy to produce larger encoded multiple display on a constant macrocyclic scaffold, which could facilitate potential binder discovery with enhanced affinity to clinically significant PPI targets.
In this study, SB216763 and cyclosporine A were identified as anti-influenza A virus (IAV) agents by transcriptome signature reversion (TSR) analysis through deep mining of the cellular transcriptome of human airway and lung cell lines infected with 3 strains of IAV and the chemical perturbations library. A synergistic effect of SB216763 and cyclosporine A against influenza A was disclosed by quantification of the network-based relationship, which was validated in vitro. Along with burgeoning omics approaches, transcriptome-based drug development is flourishing, which provides a novel insight into antivirals discovery with comprehensive cellular transcriptional information of disease and chemical perturbations in multicomponent intervention. This strategy can be applied as a new approach in discovering multitarget antiviral agents from approved drugs, clinical compounds, natural products or other known bioactive compounds.
The increase of atmospheric CO2 concentration has caused many environmental issues. Electrochemical CO2 reduction reaction (CO2RR) has been considered as a promising strategy to mitigate these challenges. The electrocatalysts with a low overpotential, high Faradaic efficiency, and excellent selectivity are of great significance for the CO2RR. Carbon-based materials including metal-free carbon catalysts and metal-based carbon catalysts have shown great potential in the CO2RR, owing to the tailorable porous structures, abundant natural resources, resistance to acids and bases, high-temperature stability, and environmental friendliness. In this review, various carbon materials including graphene, carbon nanotubes, quantum dots, porous carbon, and MOF-derived catalysts, etc., for the CO2RR have been summarized. Particularly, recent progress in terms of the mechanism and pathway of CO2 conversion has been comprehensively reviewed. Finally, the opportunities and challenges of carbon-based electrocatalysts for the CO2RR are proposed.