Erratum: In vitro and in vivo antiangiogenic activity of desacetylvinblastine monohydrazide through inhibition of VEGFR2 and Axl pathways.

[This corrects the article on p. 843 in vol. 6, PMID: 27186435.].

Highly Dispersed Vanadia Anchored on Protonated g-C3N4 as an Efficient and Selective Catalyst for the Hydroxylation of Benzene into Phenol.

The direct hydroxylation of benzene is a green and economical-efficient alternative to the existing cumene process for phenol production. However, the undesired phenol selectivity at high benzene conversion hinders its wide application. Here, we develop a one-pot synthesis of protonated g-C3N4 supporting vanadia catalysts (V-pg-C3N4) for the efficient and selective hydroxylation of benzene. Characterizations suggest that protonating g-C3N4 in diluted HCl can boost the generation of amino groups (NH/NH2) without changing the bulk structure. The content of surface amino groups, which determines the dispersion of vanadia, can be easily regulated by the amount of HCl added in the preparation. Increasing the content of surface amino groups benefits the dispersion of vanadia, which eventually leads to improved H2O2 activation and benzene hydroxylation. The optimal catalyst, V-pg-C3N4-0.46, achieves 60% benzene conversion and 99.7% phenol selectivity at 60 oC with H2O2 as the oxidant.

Encapsulating Mn3O4 Nanorods in a Shell of SiO2 Nanobubbles for Confined Fenton-Type Catalysis.

Core-shell structured nanomaterials with delicate architectures have attracted considerable attention for realizing multifunctional responses and harnessing multiple interfaces for enhanced functionalities. Here, we report a controllable synthesis of core-shell structured Mn3O4@SiO2NB nanomaterials consisting of Mn3O4 nanorods covered with a shell of SiO2 nanobubbles. A series of Mn3O4@SiO2NB catalysts with tunable secondary structures can be synthesized by simply tuning the feeding ratio and the modification conditions. The as-synthesized Mn3O4@SiO2NB catalysts exhibit excellent catalytic performance in the degradation of methylene blue (MB) because the Fenton-type reaction between Mn3O4 and H2O2 is confined in an MB-rich environment created by the SiO2 nanobubble shell. The confined Fenton-type catalysis maximizes the contact of MB molecules with the reactive oxygen species and significantly promotes the degradation efficiency of MB. Under optimal conditions, Mn3O4@SiO2NB-0.4 can reach a degradation efficiency of 92% at room temperature and neutral pH within 12 min, which outperforms most reported Mn-based catalysts.

A vascular disrupting agent overcomes tumor multidrug resistance by skewing macrophage polarity toward the M1 phenotype.

Multidrug resistance (MDR) mediated by ATP-binding cassette (ABC) transporters is the major obstacle for chemotherapeutic success. Although attempts have been made to circumvent ABC transporter-mediated MDR in past decades, there is still no effective agent in clinic. Here, we identified a vascular disrupting agent, Z-GP-DAVLBH, that significantly inhibited the growth of multidrug-resistant human hepatoma HepG2/ADM and human breast cancer MCF-7/ADR tumor xenografts, although these cells were insensitive to Z-GP-DAVLBH in vitro. Z-GP-DAVLBH increased the secretion of granulocyte-macrophage colony-stimulating factor in tumor tissues and serum of tumor-bearing mice to skew tumor-associated macrophages from the pro-tumor M2 phenotype to the antitumor M1 phenotype, thereby contributing to the induction of HepG2/ADM and MCF-7/ADR cell apoptosis. Our findings shed new light on the underlying mechanisms of VDAs in the treatment of drug-resistant tumors and provide strong evidence that Z-GP-DAVLBH should be a promising agent for overcoming MDR.

Pericyte-targeting prodrug overcomes tumor resistance to vascular disrupting agents.

Blood vessels in the tumor periphery have high pericyte coverage and are resistant to vascular disrupting agents (VDAs). VDA treatment resistance leads to a viable peripheral tumor rim that contributes to treatment failure and disease recurrence. Here, we provide evidence to support a hypothesis that shifting the target of VDAs from tumor vessel endothelial cells to pericytes disrupts tumor peripheral vessels and the viable rim, circumventing VDA treatment resistance. Through chemical engineering, we developed Z-GP-DAVLBH (from the tubulin-binding VDA desacetylvinblastine monohydrazide [DAVLBH]) as a prodrug that can be selectively activated by fibroblast activation protein α (FAPα) in tumor pericytes. Z-GP-DAVLBH selectively destroys the cytoskeleton of FAPα-expressing tumor pericytes, disrupting blood vessels both within the core and around the periphery of tumors. As a result, Z-GP-DAVLBH treatment eradicated the otherwise VDA-resistant tumor rim and led to complete regression of tumors in multiple lines of xenografts without producing the drug-related toxicity that is associated with similar doses of DAVLBH. This study demonstrates that targeting tumor pericytes with an FAPα-activated VDA prodrug represents a potential vascular disruption strategy in overcoming tumor resistance to VDA treatments.

Effect of organic loading rate on dark fermentative hydrogen production in the continuous stirred tank reactor and continuous mixed immobilized sludge reactor from waste pastry hydrolysate.

Waste pastry (6%, w/v) was hydrolyzed by the produced glucoamylase and protease to obtain the glucose (19.8g/L) and free amino nitrogen (179mg/L) solution. Then, the effect of organic loading rate (OLR) (8-40kgCOD/(m3d)) on dark fermentative hydrogen production in the continuous stirred tank reactor (CSTR) and continuous mixed immobilized sludge reactor (CMISR) from waste pastry hydrolysate was investigated and compared. The maximum hydrogen production rate of CSTR (277.76mL/(hL)) and CMISR (320.2mL/(hL)) were achieved at OLR of 24kgCOD/(m3d) and 32kgCOD/(m3d), respectively. Carbon recovery ranged from 75.2-84.1% in the CSTR and CMISR with the balance assumed to be converted to biomass. One gram waste pastry could produce 0.33g (1.83mmol) glucose which could be further converted to 79.24mL (3.54mmol) hydrogen in the CMISR or 91.66mL (4.09mmol) hydrogen in the CSTR. This is the first study which reports dark fermentative hydrogen production from waste pastry.

In vitro and in vivo antiangiogenic activity of desacetylvinblastine monohydrazide through inhibition of VEGFR2 and Axl pathways.

Tumor angiogenic process is regulated by multiple proangiogenic pathways, such as vascular endothelial growth factor receptor 2 (VEGFR2) and Axl receptor tyrosine kinase (Axl). Axl is one of many important factors involved in anti-VEGF resistance. Inhibition of VEGF/VEGFR2 signaling pathway alone fails to block tumor neovascularization. Therefore, discovery of novel agents targeting multiple angiogenesis pathways is in demand. Desacetylvinblastine monohydrazide (DAVLBH), a derivative of vinblastine (VLB), has been reported exhibit an anticancer activity via its cytotoxic effect. However, little attention has been paid to the antiangiogenic properties of DAVLBH. Here, we firstly reported that DAVLBH exerted a more potent antiangiogenic effect than VLB in vitro and in vivo, which was associated with inactivation of VEGF/VEGFR2 and Gas6/Axl signaling pathways. We found that DAVLBH inhibited VEGF- and Gas6-induced HUVECs proliferation, migration, tube formation and vessel sprouts formation in vitro and ex vivo. It significantly inhibited in vivo tumor angiogenesis and tumor growth in HeLa xenografts. It also inhibited Gas6-induced pericytes recruitment to endothelial tubes accompanied with a decrease in expression and activation of Axl. Besides, it could block the compensatory up-regulating expression and activation of Axl in response to bevacizumab treatment in HUVECs. Taken together, our results suggest that DAVLBH potently inhibits angiogenesis-mediated tumor growth through blockage of the activation of VEGF/VEGFR2 and Gas6/Axl pathways and it might serve as a promising antiangiogenic agent for the cancer therapy.

Diaqua-bis[5-(5-carboxy-2-pyridyl)tetra-zolato-κN,N]cadmium(II) dihydrate.

In the title complex, [Cd(C(7)H(4)N(5)O(2))(2)(H(2)O)(2)]·2H(2)O, the water-coordinated Cd(II) atom ( symmetry) is coordinated by four N atoms from two symmetry-related 3-carboxy-pyidyl-6-tetra-zolato ligands, forming a distorted octa-hedral complex. The uncoordinated water mol-ecules connect the mononuclear units into a layer structure through O-H⋯N and O-H⋯O hydrogen bonds; similar hydrogen bonds between coordinated water mol-ecules and anionic groups result in a three-dimensional structure.

Bis[µ-5-(5-carboxyl-ato-3-pyrid-yl)tetra-zolato-κN,N:N]bis-[triaqua-zinc(II)].

In the title complex, [Zn(2)(C(7)H(3)N(5)O(2))(2)(H(2)O)(6)], the 5-(5-carboxyl-ato-3-pyrid-yl)tetra-zolate ligand chelates the Zn(II) center through one pyridyl N and one tetra-zolate N atom, and uses another N atom to bridge to the second Zn atom, forming a centrosymmetric dinuclear unit. Three coordinated water mol-ecules complete the distorted octa-hedral geometry of the Zn(II) atom. O-H⋯O and O-H⋯N hydrogen bonds involving the coordinated water mol-ecules, tetra-zolate N atoms and the carboxyl-ate group result in a three-dimensional structure.

[Hydrothermal synthesis and luminescence of one-dimensional Mn(2+)-doped CdS nanocrystals].

One-dimensional Mn(2+)-doped CdS nanocrystals were synthesized by the hydrothermal route. The products were characterized by SEM, EDS, XRD, TEM, HRTEM and PL, respectively. The results revealed that dopant Mn2+ completely substitutes Cd2+ in CdS nanocrystals, and the product was of good crystallite. Further more, a complete suppression of the emission from surface states at room temperature when doping with ions Mn2+ has been observed.

[Preparation and spectral properties of PVP-modified CdS nanorods].

Polyvinylpyrrolidone (PVP)-modified CdS nanorods were prepared by a hydrothermal reaction of CdCl2 2.5H2O and (NH4)2S with 10 wt% ethylenediamine aqueous solution as solvent and 1.0 wt% PVP as additives. The obtained products were characterized by means of XRD, TEM, IR, DTA-TG, UV-Vis and PL spectroscopies. The surface-modified CdS nanorods showed narrow size distribution and enhanced luminescence property compared with that of the unmodified ones. The UV-Vis spectra exhibited a structure peak. These results were attributed to the surface passivation of the CdS nanorods by the PVP molecules.