Nanostructured Micellar Films Formed via Layer-by-Layer Deposition of Photoactive Polymer

Photoactive nanostructured micellar films were prepared from the amphiphilic copolymer poly(sodium styrenesulfonate-stat-2-vinylnaphthalene) (PSSS-stat-VN) and cationic polyelectrolyte poly(diallyldimethylammonium chloride) (PDADMAC) or poly(allylamine hydrochloride) (PAH) on quartz and silicon substrates via layer-by-layer (LbL) electrostatic self-assembly. The macromolecules of this amphiphilic copolymer adopt a coiled micellar conformation in aqueous solution that is preserved in the films as evidenced by atomic force microscopy (AFM) and spectroscopic studies. The hydrophobic domains present in the film can serve as host sites for various organic molecules. The probe molecules reside in those isolated nanosize domains. Their aggregation and quenching of their emission is eliminated. The experiments showed a regular growth of multilayer thickness and the content of solubilized compounds in the films. Thus, a defined amount of the hydrophobic compounds of interest may be introduced into these water-processable polymeric films. Some stratification of the films was induced by the presence of stiff nanoparticle-like micelles. That makes these films an important new material for studies of photoinduced energy and electron transfer

Molecular Structure of the Dioctadecyldimethylammonium Bromide (DODAB) Bilayer

Dioctadecyldimethylammonium bromide (DODAB) is a double-chained quaternary ammonium surfactant that assembles in water into bilayer structures. This letter reports the molecular dynamics (MD) computer simulations of the DODAB bilayer at 25 °C. The simulations show that the surfactant membrane arranges spontaneously into the rippled phase (Pβ’) at that temperature. The ordering within the chain fragment closest to the hydrophilic head (carbon atoms 1−5) is relatively low. It grows significantly for the carbon atoms located in the center of the membrane (atoms 6−17). The C6−C17 chain fragments are well aligned and tilted by ca. 15° with respect to the bilayer normal

Sulfonated polymers limit the number of infected cells.

NSPAHs and carrageenans inhibit viral infection by hampering virus release from infected cells. Fluorescence images of LLC-MK2 cells (nuclei in blue) infected with hMPV B2 (green) were collected 5 days p.i. (scale bar = 100 μm).</p

Sulfonated polymers hamper hMPV A1 infection.

Inhibition of the infection was evaluated using RT-qPCR (black bars) and virus titration (grey bars). Polymers (1000 μg/ml) were present during the entire hMPV replication cycle. Data are shown as log reduction values (LRVs) normalized to the control samples. All experiments were performed in triplicate. The results are presented as average values with standard deviations (error bars). An asterisk (P < 0.05) indicates values that are significantly different from the control. ι-car: ι-carrageenan, λ-car: λ-carrageenan.</p

Porphyrin–Nanoclay Photosensitizers for Visible Light Induced Oxidation of Phenol in Aqueous Media

A new type of hybrid photosensitizer (Po–C30B) was obtained by efficient adsorption of a 5,10,15,20-tetrakis­(4-carboxyphenyl)­porphyrin (Po) by Cloisite 30B (C30B)a monotallow bis­(hydroxyethyl)­ammonium-modified montmorillonite clayfrom acidic solution in methanol. Structural and spectroscopic properties of Po-nanoclay photosensitizer were determined using X-ray diffraction, laser scanning fluorescence confocal microscopy, and electronic absorption/emission spectroscopies. Po is present not only at the surface of the nanoclay but also in the interior of the Po-C30B hybrid material. The obtained material was found to be an efficient photosensitizer for the oxidation of phenol in aqueous solution under irradiation with the visible light (λ > 470 nm). The mechanism and the quantum yield of that process were shown to be strongly pH-dependent. They were controlled by the acid–base equilibria of porphyrin associated with imine N-protonation as well as by the ionization of the phenol molecule. The quantitative information regarding these dependencies was obtained. The values of K3 and K4 acid–base equilibrium constants were determined (pK3 = 5.88 and pK4 = 2.46) from the absorption spectra recorded during acid–base titration and using an evolutionary factor analysis with the mathematical model including dicationic (H2Po2+), monocationic (HPo+), and neutral (Po) porphyrin forms. They were used to evaluate the importance of these forms in singlet oxygen generation by Po–C30B under defined pH conditions. Moreover, the hybrid photosensitizer can be used repeatedly, which makes it possible to use it in industrial applications

Adenine Molecularly Imprinted Polymer-Coated Submicrometer Silica Gel Particles

Adenine molecularly imprinted material was obtained. Well-defined silica gel particles of submicrometer size were coated with ultrathin polymeric layers, first with a polycationic poly(allylamine hydrochloride) layer that acted as a binder for the second outer layer of a photo-cross-linkable thymine-containing polyanion. Adenine template was adsorbed by the complementary thymine chromophores attached to the polymer and its imprints were created by photo-cross-linking of the outer polymer layer. The imprinted particles have shown the ability to recognize adenine and adenosine, an adenine-based nucleoside, whereas no imprinting effect was observed for purine

Sulfonated polymers do not inhibit HCoV-NL63 infection.

Inhibition of the infection was evaluated using RT-qPCR (black bars) and virus titration (grey bars). Polymers (1000 μg/ml) were present throughout the infection. Data are shown as log reduction values (LRVs) normalized to the control samples. All experiments were performed in triplicate. The results are presented as average values with standard deviations (error bars). An asterisk (P < 0.05) indicates values that are significantly different from the control. ι-car: ι-carrageenan, λ-car: λ-carrageenan.</p

Inhibition of hMPV B2 replication by sulfonated polymers during late steps of the virus replication cycle.

Inhibition of the infection was evaluated using RT-qPCR (black bars) and virus titration (grey bars). Polymers (1000 μg/ml) were added after infection of LLC-MK2 cells with hMPV for 2 h and supernatants were collected 6 days p.i. Data are shown as log reduction values (LRVs) normalized to the control samples. All experiments were performed in triplicate. The results are presented as average values with standard deviations (error bars). An asterisk (P < 0.05) indicates values that are significantly different from the control. ι-car: ι-carrageenan, λ-car: λ-carrageenan.</p

Nanoheterogeneous Multilayer Films with Perfluorinated Domains Fabricated Using the Layer-by-Layer Method

Nanoheterogenous ultrathin films containing perfluorinated domains were prepared via the layer-by-layer (LbL) electrostatic self-assembly method. The films are constructed from the amphiphilic cationic copolymer with perfluorinated side chains and poly(sodium styrenesulfonate) (PSS). The LbL process was optimized by the application of sonication which allowed linear growth of the film. The resulting film exhibited micellar structure with isolated fluorocarbon hydrophobic domains. The remarkable features of the films were their switchable wettability and friction properties. The obtained water-processable films can find a number of potential applications, e.g., as smart and low friction coatings

Sulfonated polymers do not inhibit intracellular hMPV B2 replication.

Inhibition of intracellular hMPV replication was tested using RT-qPCR (black bars) or titration (grey bars). Polymers (1000 μg/ml) were added 2 h after infection of LLC-MK2 with hMPV and lysates were prepared 6 days p.i. Data are shown as log reduction values (LRVs) normalized to the control samples. All experiments were performed in triplicate. The results are presented as average values with standard deviations (error bars). An asterisk (P < 0.05) indicates values that are significantly different from the control. ι-car: ι-carrageenan, λ-car: λ-carrageenan.</p