Search

To develop new anti-metastasis chemotherapeutic drugs, a series of flurbiprofen (FLP) and zaltoprofen (ZTP) platinum(IV) complexes targeting COX-2, PD-L1 and DNA was prepared and investigated. Complex 2 with dual FLP ligands displays promising antitumor activities

Cycloxygenases (COXs) and matrix metalloproteinases (MMPs) in the tumor microenvironment (TME) are tightly related to the progression of cancers. Here, naproxen as a potent inhibitor of both COX and MMP was combined with platinum(iv) to construct hybrids as antitumor agents. Compound 2 with comparable or even superior activities to that of cisplatin, oxaliplatin, and carboplatin, great potential for reversing drug resistance, and superior tumor targeting properties was screened out as a lead compound. Moreover, compound 2 possessed potent tumor growth inhibition capability in vivo, which was comparable to that of oxaliplatin, and displayed rather lower side effects than the platinum(ii) reference drugs. The naproxen platinum(iv) complex could easily undergo reduction and liberate the platinum(ii) complex and naproxen as well as exert a multifunctional antitumor mechanism: (i) the liberated platinum(ii) fragment would cause serious DNA injury; (ii) naproxen would inhibit COX-2 and decrease tumor-associated inflammation; and (iii) the naproxen platinum(iv) complex exhibited remarkable MMP-9 inhibition in tumor tissues. These antitumor functions can help reduce the growth and metastasis of malignancy.

Composites with reduced graphene oxide (rGO) modification or carbon-coated structures are usually constructed to enhance the electrochemical performance of electrode materials. Herein, we develop a sequential freeze-drying, calcination and sulfidation strategy to prepare dual carbon-modified nickel sulfide composites (Ni3S2@C/rGO). Owing to the ultrasmall particle size, stable structure and high electrical conductivity, the as-prepared composites exhibit enhanced performance with high specific capacitance (1023.44 F g−1 at a current density of 5 A g−1), good rate capability (848 F g−1 at a current density of 20 A g−1) and long-term cycling stability (70.1% retention over 5000 cycles) as electrode materials for supercapacitors. Moreover, the asymmetric supercapacitor displays a good cycle life and a superior energy density of 52.5 W h kg−1 at a power density of 750 W kg−1. The facile fabrication and excellent electrochemical performances of Ni3S2@C/rGO demonstrate that constructing dual carbon-modified composites is a promising strategy for high-performance electrode materials.

Natural polyphenols showing a variety of beneficial effects will interact with multiple proteases after administration. The interactions of oxyresveratrol and piceatannol with trypsin and lysozyme were investigated using fluorescence spectroscopy, UV-vis absorption spectroscopy, circular dichroism spectroscopy, differential scanning calorimetry and molecular docking. Fluorescence quenching results and UV-vis absorption difference spectra revealed that the quenching process was a static mode initiated by ground-state complex formation. The different binding ability of oxyresveratrol and piceatannol with trypsin and lysozyme was discussed based on their different molecular structures. Moreover, the major driving force for the binding process was elucidated as hydrogen bonding and van der Waals forces by the negative enthalpy and entropy changes. Synchronous fluorescence, three-dimensional fluorescence and circular dichroism spectral analysis suggested that the binding of oxyresveratrol and piceatannol to trypsin and lysozyme induced some microenvironmental and conformational changes of the two enzymes. The thermal stability of the enzymes in the presence of polyphenols was studied based on the change in melting temperature by differential scanning calorimetry. The above experimental results were validated by the protein-ligand docking studies which showed the location of the two ligands in the enzymes and the surrounding amino acid residues. Furthermore, enzyme activity assays indicated that the enzymatic activity of trypsin and lysozyme was inhibited by oxyresveratrol and piceatannol. The effect of trypsin and lysozyme on the antioxidant activity and stability of oxyresveratrol and piceatannol was also investigated. In conclusion, the comparative study on the interaction of oxyresveratrol and piceatannol with trypsin and lysozyme showed that the positions of hydroxyl groups of the polyphenols had an important influence on their interaction with enzymes and their antioxidant activity and stability as well as the enzyme activities. The obtained results are expected to provide a theoretical basis for the application of polyphenols in functional foods and pharmaceuticals.

Nickel phosphides are considered to be a promising lithium storage host due to their high theoretical capacities. However, the volume change during the charge-discharge process and inherent poor reaction kinetics limit their electrochemical performance. To solve these problems, Ni/Ni2P heterostructures encapsulated in 3D porous carbon networks are fabricated. The macro/micro-pores-rich carbon networks are in situ constructed via a freeze-drying method and subsequent pyrolysis route using NaCl as a template. In the following phosphorization process, Ni/Ni2P nanoparticles are homogenously embedded in the carbon matrix. When used as anodes for lithium ion batteries, the Ni/Ni2P/porous carbon networks deliver high discharge capacity, good cycling stability as well as good rate performance. It is believed that metallic Ni and porous carbon networks significantly improve the conductivity of electrodes. Moreover, the 3D conductive matrix can not only alleviate the volume change, but also prevent the aggregation and pulverization of Ni2P nanoparticles during the charge-discharge process.