Crowded Bis-(M-salphen) [M = Pt(II), Zn(II)] Coordination Architectures: Luminescent Properties and Ion-Selective Responses

For binuclear luminescent host systems, cooperativity between metal–organic moieties becomes feasible with regards to photophysical properties and sensing behavior. A new class of conformationally rigid binuclear platinum­(II) and zinc­(II) complexes bearing tetradentate aromatic Schiff base (salphen) ligands with limited rotational freedom has been prepared and characterized, and the molecular structure of a (Pt-salphen)₂ derivative has been determined by X-ray crystallography. Their UV–vis absorption and emission properties have been investigated and are tentatively ascribed to different excited states depending on the metal and the extent of intramolecular π-stacking interactions. Colorimetric and phosphorescent responses by the bis-Pt­(II) complexes in the presence of selected metal ions have been observed. The nature of the host–guest interactions has been examined by quantitative binding studies, mass spectrometry and DFT calculations, and through comparisons with control complexes

Crowded Bis-(M-salphen) [M = Pt(II), Zn(II)] Coordination Architectures: Luminescent Properties and Ion-Selective Responses

For binuclear luminescent host systems, cooperativity between metal–organic moieties becomes feasible with regards to photophysical properties and sensing behavior. A new class of conformationally rigid binuclear platinum­(II) and zinc­(II) complexes bearing tetradentate aromatic Schiff base (salphen) ligands with limited rotational freedom has been prepared and characterized, and the molecular structure of a (Pt-salphen)₂ derivative has been determined by X-ray crystallography. Their UV–vis absorption and emission properties have been investigated and are tentatively ascribed to different excited states depending on the metal and the extent of intramolecular π-stacking interactions. Colorimetric and phosphorescent responses by the bis-Pt­(II) complexes in the presence of selected metal ions have been observed. The nature of the host–guest interactions has been examined by quantitative binding studies, mass spectrometry and DFT calculations, and through comparisons with control complexes

Poly(Zn-salphen)-<i>alt</i>-(<i>p</i>‑phenyleneethynylene)s as Dynamic Helical Metallopolymers: Luminescent Properties and Conformational Behavior

The synthesis of soluble, conjugated poly­(Zn-salphen)-<i>alt</i>-(<i>p</i>-phenyleneethynylene)­s with a coilable structure and bearing acetylated sugar substituents is described, and their photophysical properties and conformational behavior have been investigated. Their CD spectra confirm that these systems are chiral, and signify ordered (helical) coiling of the polymer backbone arising from chirality transfer from the β-d-glucopyranosyl groups. The consequences of varying side-chain substituents as well as the extent of inter- and intrachain [π-stacking and Zn···O­(salphen)] interactions have been studied, and comparisons with the corresponding linear-rod and Pt-based congeners have been made. Analysis of the effects of different solvents on these systems by UV–vis absorption, emission, and CD spectroscopy indicates that low-polarity solvents give a tighter, more compressed helical structure with increased CD intensities, while coordinating solvents can perturb the folded conformation to afford a more extended coiled structure with decreased Cotton effects. These observations, together with variable-temperature CD experiments, point to the flexibility and dynamic nature of the helical conformation

Cytokine and chemokine secretion from mouse bone marrow derived macrophages after influenza A virus infection.

<p>(A) TNF-α (B) IP-10 protein secreted by the mouse bone marrow derived macrophages after influenza A viruses infection (as denoted in legend). Mean and standard error of duplicate assays are shown. All influenza A virus infected mouse macrophages secrete significantly higher concentration of TNF-α than mock infected cells (<i>p</i><0.05).</p

Viral matrix (M) gene expression copy number normalized to β-actin gene expression (10⁵ copies) by quantitative RT-PCR in influenza virus infected mouse bone marrow derived macrophages.

<p>Matrix gene mRNA copy number was assayed 3 h, 6 h and 24 h post-infection and normalized to those of β-actin mRNA in the corresponding sample. Means of triplicate assays are shown with standard error. Asterisk indicates statistical difference (<i>p</i><0.05).</p

Virus titer detected in the supernatant of influenza A virus infected mouse bone marrow derived macrophages.

<p>Virus titer of various (A) influenza H1N1, and (B) H5N1 influenza viruses was determined at 3, 24, 48 and 72 h post-influenza virus infection of mouse bone marrow derived macrophages. Means and standard error of triplicate assays were shown. Dotted line represents the lowest detection limit of the TCID₅₀ assay. The thermal inactivation (serial dilution of influenza virus was incubated in the cell-free culture medium alone at the corresponding time points) curves (dotted line) of influenza H1N1 and H5N1 viruses at 37°C were determined from culture wells without macrophages.</p

Cell characterization and lectin profile of the mouse bone marrow derived macrophages.

<p>Histogram showing the percentage of positive stained mouse bone marrow derived macrophages by flow cytometry (open peak-blue line). Isotype control (open peak-black line) and non-stained cells as negative control (shaded peak) of bone marrow derived macrophages stained with (A) CD14 and (B) F4/80. Lectin immune-staining assay to determine the sialic acid (SA) distribution on mouse bone marrow derived macrophages. (C) <i>Maackia amurensis</i> lectin (MAA) conjugated with FITC (the lectin that binds SA-α2,3Gal linked sialic acid) and (D) with <i>Sambucus nigra</i> lectin (SNA) conjugated with FITC (the lectin that binds SA-α2,6GalNAc).</p

Lectin binding: MAL-I binds to Sia-α2-3Galβ1-4GlcNAc (Panel A, D, G and J), MAL-II binds to Sia-α2-3Galβ1-3GalNAc (Panel B, E, H and K) and SNA binds to Sia-α2-6-linkage (Panel C, F, I and L) to determine the Sias distribution on the ud- and wd-NHBE cells.

<p>MAL-I, MAL-II and SNA bindings presented on the (A-C) <i>en face</i> staining of ud-NHBE, (D-F) cross-section staining of ud-NHBE, (G-I) cross-section staining of wd-NHBE cells <i>in vitro</i> cultures and (J-L) the human bronchial biopsy in reddish brown.</p

Wd-NHBE cells <i>in vitro</i> cultured in ALI (A) for 7 days and for (B) 21 days show the pseudostratified columnar type epithelium by H&E staining.

<p>(C) Positive staining of FITC-conjugated β-tubulin on apical surface of epithelium confirms the presence of cilia and (E) positive staining of biotinylated MUC5AC indicates the presence of mucin secreting goblet cells. Human bronchus stained with (D) FITC-conjugated β-tubulin and (F) biotinylated MUC5AC showed the presence of both ciliated and mucus secreting goblet cells along the epithelium. (G) Transepithelial resistance and (H) HAT mRNA expression by of the differentiating NHBE culture from D1 to D21 ALI culture.</p

Immunofluorescence staining of (A–C) ud-NHBE cells and (D–F) wd-NHBE cells at 16 h post infection with (A and D) mock infection, (B and E) HK98/H1N1 and (C and F) VN04/H5N1.

<p>Influenza nucleoprotein and matrix protein was stained in green with FITC-conjugated mouse antibody.</p