Effects of p38 inhibitor (SB203580, SB), NF-κB inhibitor (PDTC), and IL-17A on cell invasion and MMP2, MMP9 expression in cervical cancer cells.

<p>C33A(<b>A</b>) and Caski(<b>E</b>) cells were pretreated with SB (20 µM) and PDTC for 30 min, then incubated in the presence or absence of IL-17A (50 ng/mL) for 24 h. The cell invasive abilities were performed by Boyden chamber invasion assay. The percentage of invasive rate of C33A(<b>B</b>) and Caski(<b>F</b>) cells was expressed as a percentage of control. C33A(<b>C, D</b>) and Caski(<b>G, H</b>) cells were treated and then subjected to western blot to analyze the protein levels of MMP2, MMP 9. Values are represented as means ± SD of three independent experiments performed in triplicate. * <i>p</i><0.05 and ** <i>p</i><0.01 compared with control group respectively.</p

Correlation of IL-17A expression with clinicopathological features in 50 cervical cancer patients.

<p>*Partial data unavailable, statistics was done on the available data.</p><p>Correlation of IL-17A expression with clinicopathological features in 50 cervical cancer patients.</p

IL-17A can activate p38 and NF-κB signal pathways in cervical cancer cells.

<p>Expression of p38 and p-p38 were detected by western blot analysis in C33A(<b>A</b>) and Caski(<b>E</b>) cells treated with or without IL-17A for 24 hours. Quantification of the protein levels of p38 and p-p38 in C33A(<b>B</b>) and Caski(<b>F</b>). Values are represented as means ± SD of three independent experiments performed in triplicate. *p<0.05 and **p<0.01 compared with control group, respectively. Western blot analysis was used to detect nuclear p50 and p65 expression in C33A(<b>C</b>) and Caski(<b>G</b>) cells treated with IL-17A (50 ng/mL) at indicated time points. Quantification of the nuclear protein levels of p50 and p65 in C33A(<b>D</b>) and Caski(<b>H</b>) cells. Values are represented as means ± SD of three independent experiments performed in triplicate. * <i>p</i><0.05 and ** <i>p</i><0.01 compared with control group respectively.</p

IL-17A promoted cervical cancer cells migration and invasion.

<p>(<b>A, B</b>) Compared with control group cells, IL-17A treated cervical cancer cells (HeLa, C33 A, and Caski) showed higher motility in a wound-healing assay. (<b>C</b>) By cell invasive assay, the effect of IL-17A on cell invasion was detected (magnification 100×). (<b>D</b>) Total invasive cell number in each chamber was summarized. Values are represented as means ± SD of three independent experiments performed in triplicate. * <i>p</i><0.05 and ** <i>p</i><0.01 compared with control group respectively.</p

IL-17A upregulated MMPs expression and activity and downregulated TIMP expression.

<p>(<b>A</b>) MMPs expression was detected by real-time PCR analysis in the cervical cancer cells treated with and without IL-17A. (<b>B</b>) After treating with IL-17A for 24 hours, the expression of MMP2, MMP9, TIMP-1, and TIMP-2 were detected by western blot analysis in cervical cancer cells. (<b>C</b>) Quantification of the protein levels of MMP-2, MMP-9, TIMP-1, and TIMP-2. MMP2 (<b>D</b>) and MMP9 (<b>E</b>) concentrations in supernatants form cells treated with or without IL-17A were analyzed by ELISA. (<b>F</b>) The effects of IL-17A on the activities of MMP2 and MMP9 were analyzed by zymography assay. (<b>G</b>) Quantification of the activities of MMP-2 and MMP-9. Values are represented as means ± SD of three independent experiments performed in triplicate. * <i>p</i><0.05 and ** <i>p</i><0.01 compared with control group respectively.</p

PdCu Nanoalloy Electrocatalysts in Oxygen Reduction Reaction: Role of Composition and Phase State in Catalytic Synergy

The catalytic synergy of nanoalloy catalysts depends on the nanoscale size, composition, phase state, and surface properties. This report describes findings of an investigation of their roles in the enhancement of electrocatalytic activity of PdCu alloy nanoparticle catalysts for oxygen reduction reaction (ORR). Pd_<i>n</i>Cu_{100–<i>n</i>} nanoalloys with controlled composition and subtle differences in size and phase state were synthesized by two different wet chemical methods. Detailed electrochemical characterization was performed to determine the surface properties and the catalytic activities. The atomic-scale structures of these catalysts were also characterized by high-energy synchrotron X-ray diffraction coupled with atomic pair distribution function analysis. The electrocatalytic activity and stability were shown to depend on the size, composition, and phase structure. With Pd_<i>n</i>Cu_{100–<i>n</i>} catalysts from both methods, a maximum ORR activity was revealed at Pd/Cu ratio close to 50:50. Structurally, Pd₅₀Cu₅₀ nanoalloys feature a mixed phase consisting of chemically ordered (body-centered cubic type) and disordered (face-centered cubic type) domains. The phase-segregated structure is shown to change to a single phase upon electrochemical potential cycling in ORR condition. While the surface Cu dissolution occurred in PdCu catalysts from the two different synthesis methods, the PdCu with a single-phase character is found to exhibit a tendency of a much greater dissolution than that with the phase segregation. Analysis of the results, along theoretical modeling based on density functional theory calculation, has provided new insights for the correlation between the electrocatalytic activity and the catalyst structures

Composition–Structure–Activity Relationships for Palladium-Alloyed Nanocatalysts in Oxygen Reduction Reaction: An Ex-Situ/In-Situ High Energy X‑ray Diffraction Study

Understanding how the composition and atomic-scale structure of a nanocatalyst changes when it is operated under realistic oxygen reduction reaction (ORR) conditions is essential for enabling the design and preparation of active and robust catalysts in proton exchange membrane fuel cells (PEMFCs). This report describes a study of palladium-alloyed electrocatalysts (PdNi) with different bimetallic compositions, aiming at establishing the relationship between catalyst’s composition, atomic structure, and activity for ORR taking place at the cathode of an operating PEMFC. Ex-situ and in-situ synchrotron high-energy X-ray diffraction (HE-XRD) coupled to atomic pair distribution function (PDF) analysis are employed to probe the structural evolution of the catalysts under PEMFC operation conditions. The study reveals an intriguing composition–activity synergy manifested by its strong dependence on the fuel cell operation induced leaching process of base metals from the catalysts. In particular, the synergy sustains during electrochemical potential cycling in the ORR operation potential window. The alloy with Pd:Ni ratio of 50:50 atomic ratio is shown to exhibit the highest possible surface Pd–Pd and Pd–Ni coordination numbers, near which an activity is observed. The analysis of the Ni-leaching process in terms of atomic-scale structure evolution sheds further light on the activity–composition–structure correlation. The results not only show a sustainable alloy characteristic upon leaching of Ni consistent with catalytic synergy but also reveal a persistent fluctuation pattern of interatomic distances along with an atomic-level reconstruction under the ORR and fuel cell operation conditions. The understanding of this type of interatomic distance fluctuation in the catalysts in correlation with the base metal leaching and realloying mechanisms under the electrocatalytic operation conditions may have important implications in the design and preparation of catalysts with controlled activity and stability

Understanding Composition-Dependent Synergy of PtPd Alloy Nanoparticles in Electrocatalytic Oxygen Reduction Reaction

Gaining an insight into the relationship between the bimetallic composition and catalytic activity is essential for the design of nanoalloy catalysts for oxygen reduction reaction. This report describes findings of a study of the composition–activity relationship for PtPd nanoalloy catalysts in oxygen reduction reaction (ORR). Pt_<i>n</i>Pd_{100‑<i>n</i>} nanoalloys with different bimetallic compositions are synthesized by wet chemical method. While the size of the Pt₅₀Pd₅₀ nanoparticles is the largest among the nanoparticles with different compositions, the characterization of the nanoalloys using synchrotron high-energy X-ray diffraction (HE-XRD) coupled to atomic pair distribution function (PDF) analysis reveals that the nanoalloy with an atomic Pt:Pd ratio of 50:50 exhibits an intermediate lattice parameter. Electrochemical characterization of the nanoalloys shows a minimum ORR activity at Pt:Pd ratio close to 50:50, whereas a maximum activity is achieved at Pt:Pd ratio close to 10:90. The composition–activity correlation is assessed by theoretical modeling based on DFT calculation of nanoalloy clusters. In addition to showing an electron transfer from PtPd alloy to oxygen upon its adsorption on the nanoalloy, a relatively large energy difference between HOMO for nanoalloy and LUMO for oxygen is revealed for the nanoalloy with an atomic Pt:Pd ratio of 50:50. By analysis of the adsorption of OH species on PtPd (111) surfaces of different compositions, the strongest adsorption energy is observed for Pt₉₆Pd₁₀₅ (Pt:Pd ≈ 50:50) cluster, which is believed to be likely responsible for the reduced activity. Interestingly, the adsorption energy on Pt₂₄Pd₁₇₇ (Pt:Pd ≈ 10:90) cluster falls in between Pt₉₆Pd₁₀₅ and Pd₂₀₁ clusters, which is believed to be linked to the observation of the highest catalytic activity for the nanoalloy with an atomic Pt:Pd ratio of 10:90. These findings have implications for the design of composition-tunable nanoalloy catalysts for ORR

Composition Tunability and (111)-Dominant Facets of Ultrathin Platinum–Gold Alloy Nanowires toward Enhanced Electrocatalysis

The ability for tuning not only the composition but also the type of surface facets of alloyed nanomaterials is important for the design of catalysts with enhanced activity and stability through optimizing both ensemble and ligand effects. Herein we report the first example of ultrathin platinum–gold alloy nanowires (PtAu NWs) featuring composition-tunable and (111) facet-dominant surface characteristics, and the electrocatalytic enhancement for the oxygen reduction reaction (ORR). PtAu NWs of different bimetallic compositions synthesized by a single-phase and surfactant-free method are shown to display an alloyed, parallel-bundled structure in which the individual nanowires exhibit Boerdijk–Coxeter helix type morphology predominant in (111) facets. Results have revealed intriguing catalytic correlation with the binary composition, exhibiting an activity maximum at a Pt:Au ratio of ∼3:1. As revealed by high-energy synchrotron X-ray diffraction and atomic pair distribution function analysis, NWs of this ratio exhibit a clear shrinkage in interatomic bonding distances. In comparison with PtAu nanoparticles of a similar composition and degree of shrinking of atomic-pair distances, the PtAu NWs display a remarkably higher electrocatalytic activity and stability. The outperformance of NWs over nanoparticles is attributed to the predominant (111)-type facets on the surface balancing the contribution of ensemble and ligand effects, in addition to the composition synergy due to optimal adsorption energies for molecular and atomic oxygen species on the surface as supported by DFT computation of models of the catalysts. The findings open up a new pathway to the design and engineering of alloy nanocatalysts with enhanced activity and durability