Identification of Synergies in Fe, Co-Coordinated Polyphthalocyanines Scaffolds for Electrochemical CO2 Reduction Reaction.

The synergistic interaction between the isolated metal sites promoted the electrocatalytic activity of the catalysts. However, the structural heterogeneity of the isolated sites makes it challenging to evaluate this effect accurately. In this work, metal-coordinated polyphthalocyanine molecules (Fe-PPc, Co-PPc, FeCo-PPc) with long-range ordered and precise coordination structures are used as a platform to study the synergies of different isolated metal sites in the electrochemical CO2 reduction reaction. The combination means of experimental and theoretical calculation clearly reveal that the coexistence of Fe and Co sites in PPc significantly enhances the conjugation effect of the macrocycle. This enhancement subsequently causes the metal sites to lose more electrons, thereby improving their adsorption of CO2 and facilitating the formation of intermediate *COOH on them. As a result, FeCo-PPc achieves a CO partial current density of about 57.4 mA/cm2 with a high turnover frequency of over 49000 site-1 h-1 at -0.9 V (vs RHE).

Carbon-Doped Nickle Via a Fast Decarbonization Route for Enhanced Hydrogen Oxidation Reaction in Alkaline Media.

Nickel (Ni) based materials with non-metal heteroatom doping are competitive substitutes for platinum group catalyst toward alkaline hydrogen oxidation reaction (HOR). However, the incorporation of non-metal atom into the lattice of conventional fcc phase Ni can easily trigger a structural phase transformation, forming hcp phase nonmetallic intermetallic compounds. Such tangle phenomenon makes it difficult to uncover the relationship between HOR catalytic activity and doping effect on fcc phase Ni. Herein, taking trace carbon doped Ni (C-Ni) nanoparticles as an example, a new nonmetal doped Ni nanoparticles synthesized by a simple fast decarbonization route using Ni3 C as precursor is presented, which provides an ideal platform to study the structure-activity relationship between alkaline HOR performance and non-metal doping effect toward fcc phase Ni. The obtained C-Ni exhibits an enhanced alkaline HOR catalytic activity compared with pure Ni, approaching to commercial Pt/C. X-ray absorption spectroscopy confirms that the trace carbon doping can modulate the electronic structure of conventional fcc phase nickel. Besides, theoretical calculations suggest that the introducing of C atoms can effectively regulate the d-band center of Ni atoms, resulting in the optimized hydrogen absorption, thereby improving the HOR activity.

[Preparation of humanized anti-tissue factor antibody and its mechanism of killing colon cancer cells and inhibiting cell migration].

Objective To investigate the killing effect of humanized antibodies targeting tissue factors on colon cancer cells as well as migration-inhibiting effect. Methods Humanized anti-tissue factor antibody was purified by Protein A and gel filtration chromatography from cultured CHO-5G4.1 cells that highly express the antibody. The purity was detected by capillary SDS-PAGE. Anticoagulant activity was assessed using the prothrombin time test. Killing effect of the antibody on SW620 and SW480 colorectal cancer cells was tested using antibody-dependent cell-mediated cytotoxicity (ADCC). The effect of antibodies on cell migration was investigated using TranswellTM assay. Gelatin zymography and Western blotting were used to detect the changes of matrix metalloproteinase 2 (MMP2), MMP9, focal adhesion kinase (FAK) and phosphorylated FAK (p-FAK) after treatment with humanized anti-tissue factor antibody. Results The purity of the humanized anti-tissue factor antibody was estimated 96.9% by the two-step method. The purified antibody showed an obvious anticoagulant activity. The antibody treatment had a significant killing effect on colorectal cancer cells through ADCC and a significant inhibiting effect (99%) on cell migration. The antibody significantly inhibited expression of MMP2 and p-FAK. Conclusion The humanized anti-tissue factor antibody can effectively kill tumor cells through ADCC and inhibit cancer cell migration, which is possibly mediated by MMP2 expression through suppression of FAK signaling.

Design, Synthesis, and Preliminary Bioactivity Evaluation of 2,7-Substituted Carbazole Derivatives as Potent Autotaxin Inhibitors and Antitumor Agents†.

BACKGROUND: Autotaxin-LPA signaling has been implicated in cancer progression, and targeted for the discovery of cancer therapeutic agents. OBJECTIVE: Potential ATX inhibitors were synthesized to develop novel leading compounds and effective anticancer agents. METHODS: The present work designs and synthesizes a series of 2,7-subsitituted carbazole derivatives with different terminal groups R [R = -Cl (I), -COOH (II), -B(OH)2 (III), or -PO(OH)2 (I-IV)]. The inhibition of these compounds on the enzymatic activity of ATX was measured using FS-3 and Bis-pNpp as substrates, and the cytotoxicity of these compounds was evaluated using SW620, SW480, PANC-1, and SKOV-3 human carcinoma cells. Furthermore, the binding of leading compound with ATX was analyzed by molecular docking. RESULTS: Compound III was shown to be a promising antitumor candidate by demonstrating both good inhibition of ATX enzymatic activity and high cytotoxicity against human cancer cell lines. Molecular docking study shows that compound III is located in a pocket, which mainly comprises amino acids 209 to 316 in domain 2 of ATX, and binds with these residues of ATX through van der Waals, conventional hydrogen bonds, and hydrophobic interactions. CONCLUSION: Compound III with the terminal group R = -B(OH)2 has the most potent inhibitory effect with the greatest cytotoxicity to cancer cells. Moreover, the docking model provides a structural basis for the future optimization of promising antitumor compounds.

[Preparation and characterization of a monoclonal antibody against human tissue factor with anticoagulation activity].

OBJECTIVE: To prepare and characterize a monoclonal antibody (mAb) against human tissue factor (hTF) with anticoagulation activity. METHODS: BALB/c mice were immunized with truncated recombinant protein (rhTF243). Hybridoma cell lines were generated from cell fusion, and screened using indirect ELISA and prothrombin time (PT). After ascites was developed in BALB/c mice, antibody titers were determined using indirect ELISA. Western blotting was performed to study the antibody specificity. Anticoagulant activity of the antibody was detected by PT assay. RESULTS: A mAb to hTF with excellent anticoagulation activity was identified. Its immunoglobulin subclass belonged to IgG1. Titer of ascites fluid was 1:200 000. Western blotting and PT analysis confirmed the specificity and anticoagulant activity of the antibody. The mAb reacted specifically to both recombinant hTF243 and natural TF on SW620 colon cancer cell surface. CONCLUSION: A hTF mAb with anticoagulation activity and high specificity has been successfully prepared.