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Due to their unique microphase structure copolymer systems have become important potential candidates for nanolitographic purposes. In order to properly design copolymeric templates a complete characterization of the phase separated system is required. Due to the fact that structural analysis of organic compounds remains demanding, especially when it comes to nanometer scale features such as interfacial spaces, there are very often at least two complementary experimental techniques employed to fully characterize observed morphologies. In this work diblock copolymers of poly (styrene)-b-poly (ethylene oxide) (PS-PEO) with three different molecular weights were investigated. Two different experimental methods were used: nuclear magnetic resonance spectroscopy (NMR) and atomic force microscopy (AFM). AFM topographic images of self-assembled polymer films enabled estimation of average interdomain distances, whereas the NMR spin diffusion experiment provided structural parameters related to stiff PS domains and interfacial space thickness. An application of two complementary methods enabled complete description of the studied morphologies and revealed substantial differences in polymer chain mobility between two distinct phases. [ABSTRACT FROM AUTHOR]

We report the observations of electronic properties of graphene oxide and reduced graphene oxide, performed with electron paramagnetic resonance technique in a broad temperature range. Both materials were examined in pure form and saturated with air, helium, and heavy water molecules. We show that spin localization strongly depends on the type and amount of molecules adsorbed at the graphene layer edges (and possible in-plane defects). Physical and chemical states of edges play crucial role in electrical transport within graphene-based materials, with hopping as the leading mechanism of charge carrier transport. Presented results are a good basis to understand the electronic properties of other carbon structures made of graphene-like building blocks. Most active carbons show some degree of functionalization and are known of having good adsorptive properties; thus, controlling both phenomena is important for many applications. Sample treatment with temperature, vacuum, and various adsorbents allowed for the observation of a possible metalinsulator transition and sorption pumping effects. The influence of adsorption on the localization phenomena in graphene would be very important if to consider the graphene-based material as possible candidates for the future spintronics that works in ambient conditions. [ABSTRACT FROM AUTHOR]

Multimodal nanomaterials have attracted much attention of scientists, in particular those working in the area of medicine. Thanks to their properties, they can be applied in therapy as well as in diagnostics permitting simultaneous treatment and imaging of various cancer diseases. Photothermal therapy (PTT) is one of the approaches in the cancer therapy based on the use of light-to-heat converting materials. The nanophotothermal agents used in PTT may represent a wide range of substances, from metals to organic compounds. Polydopamine (PDA) is a mussel-inspired polymer that can coat almost every surface, it is highly biocompatible, biodegradable and shows extraordinary photothermal properties. In this study, we used laser synthesized nanodiamonds (NDs) as fluorescent cores to obtain a combined platform for fluorescent imaging and PTT. Before PDA coating, NDs were functionalized with hyper-branched polyglycerol (hPG) to protect against their aggregation and improve their stabilization in aqueous solutions. The nanoparticles were characterized by determination of their size distribution, stability, functionalization as well as fluorescent and photothermal properties. The anticancer efficacy of the imaging-guided PTT on glioblastoma cells was also evaluated in vitro. The obtained results show that PDA coated laser synthesized NDs can be promising theranostic agents combining the fluorescent imaging modality of nanodiamonds with photothermal properties of polydopamine. [Display omitted] • Nanodiamonds for simultaneous fluorescent tracking and photothermal therapy • Surface modification enhanced colloidal stability and biocompatibility of NDs. • PDA coated NDs retained a reduced, yet stable fluorescence. • Due to the presence of PDA, NDs exhibited strong photothermal properties. [ABSTRACT FROM AUTHOR]

Core−shell nanocomposites comprising barium titanate, BaTiO3 (BTO), and poly(methyl methacrylate) (PMMA) chains grafted from its surface with varied grafting densities were prepared. BTO nanocrystals are high-k inorganic materials, and the obtained nanocomposites exhibit enhanced dielectric permittivity, as compared to neat PMMA, and a relatively low level of loss tangent in a wide range of frequencies. The impact of the molecular dynamics, structure, and interactions of the BTO surface on the polymer chains was investigated. The nanocomposites were characterized by broadband dielectric and vibrational spectroscopies (IR and Raman), transmission electron microscopy, differential scanning calorimetry, and nuclear magnetic resonance. The presence of ceramic nanoparticles in core–shell composites slowed down the segmental dynamic of PMMA chains, increased glass transition temperature, and concurrently increased the thermal stability of the organic part. It was also evidenced that, in addition to segmental dynamics, local β relaxation was affected. The grafting density influenced the self-organization and interactions within the PMMA phase, affecting the organization on a smaller size scale of polymeric chains. This was explained by the interaction of the exposed surface of nanoparticles with polymer chains. [ABSTRACT FROM AUTHOR]

This work presents the synthesis and characterization of metal-free, zinc (II), and cobalt (II) porphyrins substituted with short PEG chains. The synthesized compounds were characterized by UV-Vis, 1H and 13C NMR spectroscopy, and MALDI-TOF mass spectrometry. The origin of the absorption bands for tested compounds in the UV-Vis range was determined using a computational model based on the electron density functional theory (DFT) and its time-dependent variant (TD-DFT). The photosensitizing activity was evaluated by measuring the ability to generate singlet oxygen (ΦΔ), which reached values up to 0.54. The photodynamic activity was tested using bladder (5637), prostate (LNCaP), and melanoma (A375) cancer cell lines. In vitro experiments clearly showed the structure–activity relationship regarding types of substituents, their positions in the phenyl ring, and the variety of central metal ions on the porphyrin core. Notably, the metal-free derivative 3 and its zinc derivative 6 exerted strong cytotoxic activity toward 5637 cells, with IC50 values of 8 and 15 nM, respectively. None of the tested compounds induced a cytotoxic effect without irradiation. In conclusion, these results highlight the potential value of the tested compounds for PDT application. [ABSTRACT FROM AUTHOR]

We compared the activity enhancement effect of noble metal deposited on TiO2 in photocatalytic nitrogen oxides oxidation. Titanium dioxide was decorated with Ag, Au, Pt or Pd in the sol-gel process. Synthesized catalysts were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller measurement (BET), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDX). All catalysts together with pure TiO2 obtained by sol-gel (SG) technique were tested for their photocatalytic activity towards nitrogen oxide oxidation (high concentrations of 50, 150 and 250 ppm). FTIR spectrometry was used to determine the gas phase composition and identify TiO2 surface species. The Ag0.1 sample turned out to be deactivated within 60 min of UV/Vis irradiation. Photocatalytic oxidation rate towards NO2 turned to be the highest over SG (photocatalyst without metal deposition). NO2 formation was also observed for Au0.1, Au0.5, Pt0.1, Pt0.5 and Pd0.1. The best NOx removal, i.e., conversion to final product HNO3 was obtained with the Au0.5 photocatalyst. [ABSTRACT FROM AUTHOR]

Due to the rapidly increasing problem of antibiotic resistance in recent years, the use of phthalocyanines as photosensitizers with their superior properties in photodynamic antimicrobial therapy (PACT) applications has become important. In this study, magnesium(II) 1,4,8,11,15,18,22,25-octakis(4-[4-butoxycarbonylphenoxy]butyloxy)phthalocyanine was used in the demetalation reaction in trifluoroacetic acid, and subsequently subjected to metalation reaction in dimethylformamide with zinc(II) acetate and bis(benzonitrile)palladium(II) chloride towards zinc(II) and palladium(II) derivatives. Three phthalocyanines, including a demetalated one as well as two metalated, in the core with zinc(II) and palladium(II) were characterized using 1D and 2D NMR spectroscopy and mass spectrometry. In addition, all macrocycles were subjected to absorption and emission studies as well as photostability tests. In a photochemical study, zinc(II) and palladium(II) phthalocyanine complexes appeared to be efficient singlet oxygen generators. There were noted quantum yields of singlet oxygen generation for zinc(II) phthalocyanine derivative in DMF and DMSO at 0.55 and 0.72, whereas for palladium(II) complex at 0.73 and 0.77, respectively. Liposomal formulations of phthalocyanine derivatives were prepared, and their activity was evaluated against a broad spectrum of antibiotic-resistant microorganisms, such as methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli (ESBL+), Candida albicans resistant to fluconazole, C. auris, and against dermatophytes. Phthalocyanine palladium(II) complex showed the highest bactericidal activity against all antibiotic-resistant microorganisms, including reducing C. auris growth at 3.54 log. [ABSTRACT FROM AUTHOR]

Thin polymer films made of polystyrene-b-poly(ethylene oxide) (PS-PEO) diblock copolymer were deposited via spin-coating technique on thermally reconstructed sapphire substrates in order to obtain self-assembled polymer matrices characterized by long range domain ordering. This approach, under specific solvent vapor annealing conditions, enabled us to fabricate polymer films exhibiting quasi long-range crystalline organization of hexagonally packed PEO cylinders aligned perpendicularly with respect to the substrate surface. In order to find an optimal conditions for thin film fabrication, the influence of moisture annealing process on polymer films morphology was examined. Different drying conditions revealed semicrystalline nature of poly(ethylene oxide) block. Consequently, apart from regular amorphous layers, various crystalline forms were also observed, including dendritic crystals, densely branched structures and square shaped single crystals. Presented data show how strongly the polymer film morphology depends on annealing conditions. [ABSTRACT FROM AUTHOR]

The article presents a study on mass spectrometry of lanthanide(III) complexes and its methylation in matrix-assisted laser desorption/ionization (MALDI). It mentions electrospray ionization (ESI) and MALDI as a valuable method to study the interaction between ligands and metal ions. It informs that MALDI mass spectra show the presence of complex ions in lanthanide(III) complexes.

Raman scattering from highly/low resistive nanostructured silicon films prepared by metal-assisted chemical etching was investigated. Raman spectrum of obtained silicon nanostructures was measured. Interpretation of observed one and two-phonon Raman peaks are presented. First-order Raman peak has a redshift and broadening. This phenomenon is analyzed in the framework of the phonon confinement model taking into account mechanical stress effects. Second-order Raman peaks were found to be shifted and broadened in comparison to those in the bulk silicon. The peak shift and broadening of two-phonon Raman scattering relates to phonon confinement and disorder. A broad Raman peak between 900 and 1100 cm −1 corresponds to superposition of three transverse optical phonons ∼2TO ( X ), 2TO ( W ) and 2TO ( L ). Influence of excitation wavelength on intensity redistribution of two-phonon Raman scattering components (2TO) is demonstrated and preliminary theoretical explanation of this observation is presented. [ABSTRACT FROM AUTHOR]

19F Nuclear Magnetic Resonance spin-lattice relaxation experiments have been performed for a series of ionic liquids including the same anion, bis(trifluoromethanesulfonyl)imide, and cations with alkyl chains of different lengths: triethylhexylammonium, triethyloctylammonium, decyltriethylammonium, dodecyltriethylammonium, decyltriethylammonium, and hexadecyltriethylammonium. The experiments have been carried out in a frequency range of 10 kHz to 10 MHz versus temperature. A thorough analysis of the relaxation data has led to the determination of the cation–anion as a relative translation diffusion coefficient. The diffusion coefficients have been compared with the corresponding cation–cation and anion–anion diffusion coefficients, revealing a correlation in the relative translation movement of the anion and the triethylhexylammonium, triethyloctylammonium, decyltriethylammonium, and dodecyltriethylammonium cations, whereas the relative translation diffusion between the anion and the cations with the longer alkyl chains, decyltriethylammonium and hexadecyltriethylammonium, remains rather uncorrelated (correlated to a much lesser extent). [ABSTRACT FROM AUTHOR]

The aim of our work was the synthesis of ZnO nano- and microparticles and to study the effect of shapes and sizes on cytotoxicity towards normal and cancer cells and antibacterial activity toward two kinds of bacteria. We fabricated ZnO nano- and microparticles through facile chemical and physical routes. The crystal structure, morphology, textural properties, and photoluminescent properties were characterized by powder X-ray diffraction, electron microscopies, nitrogen adsorption/desorption measurements, and photoluminescence spectroscopy. The obtained ZnO structures were highly crystalline and monodispersed with intensive green emission. ZnO NPs and NRs showed the strongest antibacterial activity against Escherichia coli and Staphylococcus aureus compared to microparticles due to their high specific surface area. However, the ZnO HSs at higher concentrations also strongly inhibited bacterial growth. S. aureus strain was more sensitive to ZnO particles than the E. coli. ZnO NPs and NRs were more harmful to cancer cell lines than to normal ones at the same concentration. [ABSTRACT FROM AUTHOR]

Starch-based confectionery products were prepared using different types of sugar. In addition to using different sugar, starch was replaced with soy protein isolate (SPI) in some of the products. 1H NMR spin-lattice relaxation experiments were performed for the collection of products in a broad frequency range from 4 KHz to 30 MHz to get insight into the influence of different sugar types and SPI on the dynamics of water in composite gel systems. The relaxation data have been decomposed into relaxation contributions associated with two different pools of water molecules characterized by different mobility. The translation dynamics of water molecules has been quantitatively described in terms of a dedicated relaxation model. The influence of the sample composition (the type of sugar and/or the presence of SPI) on the water mobility was thoroughly discussed. The results indicate that the addition of soy protein does not affect water dynamics for samples including sucrose. In addition, as the complementary measurements, physical properties of the products, such as the moisture content, water activity and texture, were investigated in terms of X-ray diffraction and thermogravimetric analysis. [ABSTRACT FROM AUTHOR]

Highlights: [•] A cationic surfactant incorporates in structure of phospholipid (DMPC) and changes its morphology. [•] Presence of surfactants decreases of DMPC phase transition temperature. [•] A multilamellar phase of DMPC disappears and the bicellar phase is formed under the influence of BzMDDAC surfactant. [Copyright &y& Elsevier]

Abstract: The stabilizing or disturbing effect of different surfactants on the bicellar phase of phospholipids significantly depends on their type. The effect of different surfactants on the bicellar structure made of a mixture of phospholipids 1,2-dimyristoyl-sn-glycero-3-phosphocholine and 1,2-dihexanoyl-sn-glycero-3-phospho-choline (DMPC/DHPC) has been studied by the small angle scattering of synchrotron radiation. The study has been performed for three surfactants: dodecyldimethyl-(hexyloxymethyl)ammonium chloride, n-undecylammonium chloride and t-octylphenoxypolyethoxyethanol (Triton X-100) introduced into a bicellar solution of DMPC/DHPC (2.8:1). The bicellar phase has been disturbed in the shortest time in the presence of dodecyldimethyl-(hexyloxymethyl)ammonium chloride in this system a transition from the bicellar to lamellar structure has been directly visible. The changes have been less pronounced in the presence of undecylammonium chloride and practically not noted in the presence of Triton X-100. [Copyright &y& Elsevier]

Abstract: The molecular dynamics of poly(l-lactide) (PLLA) biopolymer was characterized through analyses of 1H and 2H NMR line-shapes and spin-lattice relaxation times at different temperatures. At low temperatures (e.g. 90K), the methyl group rotation is dominant leading to a significant reduction in the proton second moment. Fast methyl group reorientation occurs at ca. 130K. In additional to the fast methyl group rotation, hydroxyl groups start to reorient as the temperature increases further, eventually leading to the breakdown of the segments of the biopolymer chains above its glass transition temperature T g of 323K. The analyses of the 2H NMR line-shapes indicate that both the methyl and hydroxyl reorientations can be described by the so-called cone model, in which the former has three equilibrium positions with and while the latter one exhibits two equilibrium positions with and . [Copyright &y& Elsevier]

The Fast Field Cycling Relaxometry and the dynamical rheology were applied to study the gelation process in aqueous low methoxyl pectin solution in the presence of divalent cations from the calcium chloride. The model-free approach to the analysis of 1H NMRD data was used to separate the information on the static and dynamic behaviour of the system provided by the dispersion profiles of the systems tested. Mechanical spectroscopy was applied as a complementary method to probe the network formation. The structural changes were most pronounced for the concentration of calcium chloride between 10 and 15 mM (the static parameter β was found to vary from 0.936×107 to 1.27×107 1/s2) revealing the sol–gel transition on visual inspection. The presence of the gel network was confirmed by the rheological measurements. All mechanical spectra exhibited the gel like character, and the solid like response was more evident at higher concentrations of calcium cations. The mean correlation time 〈τc〉 increased with increasing salt concentration, but remained unchanged for the concentrations above 15 mM. The dynamical changes were most significant at the phase transition from the sol to the gel state. [Copyright &y& Elsevier]

The molecular dynamics of tert-butyl chloride (TBC) confined to Controlled Pore Glass matrices of 25 and 7.5 nm were investigated by measuring NMR linewidths, lineshapes, and 1H and 2H spin–lattice relaxation times. The behaviour of confined TBC can be explained assuming that the guest molecules form two distinct phases; the surface-affected phase, composed of molecules located at the pore surface, and the bulk-like phase located at the centre of the pores. The bulk-like component of confined TBC, at the temperatures corresponding to the phase III, is characterized by two dynamically different subphases. [Copyright &y& Elsevier]

"Western diet" containing high concentrations of sugar and fat consumed during pregnancy contributes to development of obesity and diabetes type 2 in offspring. To mimic effects of this diet in animals, a cafeteria (CAF) diet is used. We hypothesized that CAF diet given to rats before, and during pregnancy and lactation differently influences fat content, metabolic and inflammation profiles in offspring. Females were exposed to CAF or control diets before pregnancy, during pregnancy and lactation. At postnatal day 25 (PND 25), body composition, fat contents were measured, and blood was collected for assessment of metabolic and inflammation profiles. We have found that CAF diet lead to sex-specific alterations in offspring. At PND25, CAF offspring had: (1) higher percentage of fat content, and were lighter; (2) sex-specific differences in levels of glucose; (3) higher levels of interleukin 6 (IL-6), interleukin-10 (IL-10) and tumor necrosis factor (TNF-α); (4) sex-specific differences in concentration of IL-6 and TNF-α, with an increase in CAF females; (5) higher level of IL-10 in both sexes, with a more pronounced increase in females. We concluded that maternal CAF diet affects fat content, metabolic profiles, and inflammation parameters in offspring. Above effects are sex-specific, with female offspring being more susceptible to the diet. [ABSTRACT FROM AUTHOR]

Tortuosity, 1/α, and surface-to-volume ratio, S/V, were determined in aqueous solutions of decylammonium, dodecylammonium and tetradecylammonium chlorides of various concentrations by measuring the apparent diffusion coefficient of water, Dapp(Δ). This was found to be much smaller than in the bulk state. Such restricted diffusion is interpreted in terms of the Mitra model, where D(Δ) depends on diffusion time and is controlled primarily by S/V. The samples exhibit lamellar (L), hexagonal (H) and isotropic (I) liquid crystalline phases. We observed changes in S/V upon phase transition. In the lamellar and hexagonal phases, the system is ordered, resulting in relatively small S/V ratios, compared to the micellar-isotropic phase. We did not observe a dependence on the diffusion time, Δ, in the isotropic phase, because the duration of the experiment was not sufficiently short to observe the change from Dapp(Δ) to Deff. We observed the effective diffusion coefficient of water, which directly probes the tortuosity of the system. The S/V ratios were obtained by fitting the Mitra model, using known values of the bulk water diffusion coefficients, and the assumption that Dapp→D0 for Δ→0. S/V is correlated with the type of structure, increasing on transition to the isotropic phase and decreasing on transition to other phases. The change in tortuosity is small, but slightly larger for the isotropic phase. [Copyright &y& Elsevier]

The aim of the study was to establish the influence of a co-precipitation agent (i.e., NaOH–immediate precipitation; hexamethylenetetramine/urea–gradual precipitation and growth of nanostructures) on the properties and catalytic activity of as-synthesized Au-CeO2 nanocomposites. All catalysts were fully characterized with the use of XRD, nitrogen physisorption, ICP-OES, SEM, HR-TEM, UV-vis, XPS, and tested in low-temperature oxidation of benzyl alcohol as a model oxidation reaction. The results obtained in this study indicated that the type of co-precipitation agent has a significant impact on the growth of gold species. Immediate co-precipitation of Au-CeO2 nanostructures with the use of NaOH allowed obtainment of considerably smaller and more homogeneous in size gold nanoparticles than those formed by gradual co-precipitation and growth of Au-CeO2 nanostructures in the presence of hexamethylenetetramine or urea. In the catalytic tests, it was established that the key factor promoting high activity in low-temperature oxidation of benzyl alcohol was size of gold nanoparticles. The highest conversion of the alcohol was observed for the catalyst containing the smallest Au particle size (i.e., Au-CeO2 nanocomposite prepared with the use of NaOH as a co-precipitation agent). [ABSTRACT FROM AUTHOR]

Background: Lipid liquid crystalline nanoparticles (LLCNPs) emerge as a suitable system for drug and contrast agent delivery. In this regard due to their unique properties, they offer a solubility of a variety of active pharmaceutics with different polarities increasing their stability and the possibility of controlled delivery. Nevertheless, the most crucial aspect underlying the application of LLCNPs for drug or contrast agent delivery is the unequivocal assessment of their biocompatibility, including cytotoxicity, genotoxicity, and related aspects. Although studies regarding the cytotoxicity of LLCNPs prepared from various lipids and surfactants were conducted, the actual mechanism and its impact on the cells (both cancer and normal) are not entirely comprehended. Therefore, in this study, LLCNPs colloidal formulations were prepared from two most popular structure-forming lipids, i.e., glyceryl monooleate (GMO) and phytantriol (PHT) with different lipid content of 2 and 20 w/w%, and the surfactant Pluronic F-127 using the top-down approach for further comparison of their properties. Prepared formulations were subjected to physicochemical characterization and followed with in-depth biological characterization, which included cyto- and genotoxicity towards cervical cancer cells (HeLa) and human fibroblast cells (MSU 1.1), the evaluation of cytoskeleton integrity, intracellular reactive oxygen species (ROS) generation upon treatment with prepared LLCNPs and finally the identification of internalization pathways. Results: Results denote the higher cytotoxicity of PHT-based nanoparticles on both cell lines on monolayers as well as cellular spheroids, what is in accordance with evaluation of ROS activity level and cytoskeleton integrity. Detected level of ROS in cells upon the treatment with LLCNPs indicates their insignificant contribution to the cellular redox balance for most concentrations, however distinct for GMO- and PHT-based LLCNPs. The disintegration of cytoskeleton after administration of LLCNPs implies the relation between LLCNPs and F-actin filaments. Additionally, the expression of four genes involved in DNA damage and important metabolic processes was analyzed, indicating concentration–dependent differences between PHT- and GMO-based LLCNPs. Conclusions: Overall, GMO-based LLCNPs emerge as potentially more viable candidates for drug delivery systems as their impact on cells is not as deleterious as PHT-based as well as they were efficiently internalized by cell monolayers and 3D spheroids. [ABSTRACT FROM AUTHOR]

Facile electrochemical graphite oxidation and functionalization with a selected array of amine moieties are carried out. The electrochemical oxidation offers the ability to preserve graphite morphological characteristics as intact adjacent surfaces yield collective van der Waals interactions. The different amine moieties are used to tether adjacent layers within graphite oxide (GO) to produce rigid framework materials. This interconnectedness is of utmost necessity for the structures to withstand cyclability in adsorptive and electronic applications. Utilizing well-ordered electrochemically-derived graphite oxide could be advantageous for the development of large-flake-size intact graphite oxide frameworks compared to inherently defective chemically-derived graphite oxide. The produced materials are extensively characterized to understand the extent, nature, and chemistry of the amine functionalization within GO domains. A balanced aromaticity in the intercalating amine species is found favorable in order to achieve a homogeneous distribution throughout graphite flakes while enhancing the interlayer spacing. Herein, notably by applying HR-TEM methods, turbostratic domains are successfully resolved in frameworks with relatively high nitrogen abundance and obtained results corroborate with 13C MAS NMR findings plausibly. The tethering mechanism induces layers rotation/twisting, giving rise to pronounced Moiré patterns. The enhanced interlayer spacing in the frameworks makes them promising candidates for storage and electronic applications. Graphite flakes are electrochemically oxidized and functionalized with different amine moieties to develop framework materials in which original Bernal stacking is partially lost in several domains as resolved by 13C NMR and HR-TEM analyses. [Display omitted] • Electrochemical oxidation of graphite flakes preserves morphological features. • Diamine grafting within GO causes emergence of minor turbostratic domains. • Turbostratic domains exhibiting Moiré patterns are resolved using Direct 13C NMR. • Grafted amine pillars hinder adsorption of nitrogen within interlayer spaces. • GO framework material is a cheap candidate to light-localizing appliances. [ABSTRACT FROM AUTHOR]

Hydrogels of N-isopropylacrylamide and methacrylic acid (P(NIPAm- co -MAA)) display pH sensitivity and complex positively charged molecules through carboxylate groups, while having a critical solution temperature at which they reduce in volume and dehydrate. We aimed to elucidate how the responsiveness of MAA to environmental changes alters PNIPAm hydrogels at the molecular level using nuclear magnetic resonance (NMR). Time-lapse NMR allows us to follow the evolution of NMR signal under a temperature stimulus, providing unique information on conformational freedom of the hydrogel polymers. We used time-lapse NMR to follow the evolution of the NMR signal with time over a temperature change from 25 to 40 °C and to study the swelling/deswelling kinetics of P(NIPAm- co -MAA) microgels at different pH values and ionic strengths, and in the presence of positively charged molecules complexing carboxylate groups. At acid pH, hydrogel collapse is favored over neutral pH, and at basic pH the carboxylates remain steadily hydrated during temperature increase. Increasing ionic strength results in a faster, more effective collapse than decreasing pH. Complexation of medium-sized molecules with several charges (spermine, spermidine) causes a faster collapse than complexation with large molecular weight poly(allylamine) hydrochloride, but similar to the collapse effected by large poly(diallyldimethylammonium) chloride. This work opens new perspectives to using time-lapse NMR to study thermoresponsive systems that respond to multiple stimuli, with particular relevance in designing hydrogels for drug delivery. [ABSTRACT FROM AUTHOR]

This work is the first report when multiharmonic analysis (MHA) was applied for electron paramagnetic resonance imaging (EPRI) for in vivo applications. Phantom studies were performed for established methodology, and in vivo imaging was conduct as a proof-of-concept. Phantom studies showed at least six times improvement of the signal – to – noise (S/N) ratio. Application MHA for 3D EPR in vivo imaging provides images of spin probe distribution in mouse head. The EPRI, in combination with nitroxide and trityl spin probe, was performed to obtained 3D EPR in vivo images using MHA. For both used spin probes, MHA provided images with better S/N ratio, especially in the case of nitroxide, where projections obtained using conventional CW did not allow for reconstructing reliable data. Trityl radical exhibited high resolution and quality of obtained images after MHA. The MHA methodology allows the selection of a second modulation amplitude even 40 times higher than the natural EPR linewidth of the spin probe without line shape distortion, which highly improves the sensitivity of the acquired signal and allowing for imaging mice regardless of their size in a routine animal experiment. Image 1 • Multiharmonic analysis reveals more details in animal EPR imaging. • The first report of using multiharmonic for 3D in vivo EPR imaging. • Multiharmonic analysis significantly improves S/N ratio for EPR in vivo imaging. [ABSTRACT FROM AUTHOR]

• Hierarchical ZnO particles are fabricated using facile hydrothermal methods. • ZnO particles are surface decorated with gold nanoparticles and Biotin. • Decorated particles possess superior biological activity compared to pure ZnO particles. • Intensive green luminescence of ZnO particles allows their tracking in optical microscopy. ZnO (nano)structures remain of great interest in biomedical applications due to their unique properties and possible morphologies. Biocompatibility of typically fabricated ZnO structures remains questionable and they still lack desired biological functions, whence their functionalization is of high interest. In this work, we fabricated micro-sized ZnO hierarchical flower-like structures using facile template-free hydrothermal method to act as carriers for the delivery of gold nanoparticles (Au) and/or Biotin (Vitamin B) to cells. Au nanoparticles (~24 nm), as well as Biotin molecules were successfully deposited on the ZnO surface due to non-covalent physical interactions. We have then cultured two cells lines: SH-SY5Y (human malignant neural) and HEK-293 (human non-malignant) and observed that ZnO hierarchical particles exhibited cell line-dependent cytotoxicity. It appeared that further functionalization of ZnO with Au nanoparticles and subsequently with Biotin led to lower discrepancy between the two cell lines response indicating that cytotoxic pathways of pure ZnO were masked by the available surface adsorbed particles (Au/Biotin). Two-photon immunocytochemistry microscopy further confirmed that Biotin decorated particles affected neuroblastoma cells cytoskeleton. These findings contribute to the understanding of cytotoxic pathways of surface-decorated nano-micro-structures made from ZnO with two molecules typically used in anticancer and regenerative medicine therapies. [ABSTRACT FROM AUTHOR]

Many bacteria become progressively more resistant to antibiotics and it remains a challenging task to control their overall levels. Polymers combined with active biomolecules come to the forefront for the design of antibacterial materials that can address this encounter. In this work, we investigated the photo-crosslinking approach of UV-sensitive benzophenone molecule (BP) with polyvinylpyrrolidone (PVP) polymer within electrospun fibres. The BP and PVP solutions allowed fabricating polymer mats that were subsequently functionalised with antibacterial lysozyme. The physical properties of the crosslinked electrospun fibres were investigated by scanning electron microscopy and atomic force microscopy. The average diameter of the obtained fibres decreased from 290 ± 50 nm to 270 ± 70 nm upon the addition of the crosslinking molecules and then to 240 ± 80 nm and 180 ± 90 nm after subsequent crosslinking reaction at an increasing time: 3 and 5 h, respectively. The peak force quantitative nanomechanical mapping (PF-QNM) indicated the increase of DMT modulus of obtained cross-linked fibres from 4.1 ± 0.8 GPa to 7.2 ± 0.5 GPa. Furthermore, the successful crosslinking reaction of PVP and BP solution into hydrogels was investigated in terms of examining photo-crosslinking mechanism and was confirmed by rheology, Raman, Fourier transform infrared and nuclear magnetic resonance. Finally, lysozyme was successfully encapsulated within cross-linked PVP-BP hydrogels and these were successfully electrospun into mats which were found to be as effective antibacterial agents as pure lysozyme molecules. The dissolution rate of photo cross-linked PVP mats was observed to increase in comparison to pure PVP electrospun mats which opened a potential route for their use as antibacterial, on-demand, dissolvable coatings for various biomedical applications. [ABSTRACT FROM AUTHOR]

The authors would like to thank Katarzyna Staszak from Poznan University of Technology for her help in performing Zn release studies." Correction to: I Scientific Reports i https://doi.org/10.1038/s41598-022-12134-3, published online 17 May 2022 The Acknowledgements section in the original version of this Article was incomplete. [Extracted from the article]

Highlights • Recent strategies in lanthanides application in bone tissue engineering are outlined. • Insight into factors limiting the lanthanides usage in medicine is presented. • Lanthanides compounds are attractive candidates to affect the bone remodeling cycle. • Progress, potential, and challenges in lanthanides application in hydroxyapatite modifications is discussed. Abstract In this review, significant applications of lanthanides and their compounds in bone tissue engineering are described, with an emphasis on coordination compounds based on wide variety of ligands, crystalline structure and their properties, stability as well as cytotoxicity. The current challenges and several scientific discoveries related to the use of lanthanides in bone disease treatment are summarized. The influence of lanthanide compounds with different ligands on the bone remodeling cycle and their potential application in the treatment and prevention of bone diseases is presented. According to the knowledge gained so far numerous applications of lanthanides cause that these elements and their compounds especially the lanthanide-based nanomaterials were tested in bone disorders therapy: radiation therapies, drug delivery systems, biosensing, bioimaging, as well as in implants, and tissue engineering. Revealing was also the structural studies which indicated why Ln-doped Hydroxyapatite was an excellent treatment for orthopedic injuries. [ABSTRACT FROM AUTHOR]

Glioblastoma multiforme (GBM) is the most common type of malignant gliomas, characterized by genetic instability, intratumoral histopathological variability and unpredictable clinical behavior. Disappointing results in the treatment of gliomas with surgery, radiation and chemotherapy have fueled a search for new therapeutic targets and treatment modalities. Here we report new approach towards RNA interference therapy of glioblastoma multiforme based on the magnetic nanoparticles delivery of the double-stranded RNA (dsRNA) with homological sequences to mRNA of tenascin-C (TN-C), named ATN-RNA. The obtained nanocomposite consisted of polyethyleneimine (PEI) coated magnetic nanoparticles conjugated to the dsRNA show high efficiency in ATN-RNA delivery, resulting not only in significant TN-C expression level suppressesion, but also impairing the tumor cells migration. Moreover, synthesized nanomaterials show high contrast properties in magnetic resonance imaging (MRI) and low cytotoxicity combining with lack of induction of interferon response. We believe that the present work is a successful combination of effective, functional, non-immunostimulatory dsRNA delivery system based on magnetic nanoparticles with high potential for further application in GBM therapy. [ABSTRACT FROM AUTHOR]

Novel magnesium(II) porphyrazine with peripheral methyl(3,5-dibromophenylmethyl)amine groups was synthesized in a multi-step procedure starting from commercially available diaminomaleonitrile. All intermediates and the final macrocycle were characterized using UV–Vis, FT-IR, MS and various NMR techniques. The absorption and emission properties of the macrocycle were evaluated in N,N-dimethylformamide, dimethyl sulfoxide, and dichloromethane. The potential photosensitizing activity was evaluated by assessing the ability of the macrocycle to generate singlet oxygen in dimethyl sulfoxide and N,N-dimethylformamide. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • PAMAM dendrimers and PDA coated magnetic nanoparticles are assembled into one nanoplatform. • Nanocarriers with 5th generation of PAMAM dendrimers are applied in CT-PTT of liver cancer cells. • Obtained materials show additive effect in eradication of cancer cells. • Apoptosis is triggered in the cancer cells when CT and PTT are applied simultaneously. • Investigated materials possesses competitive contrast properties in MRI. Abstract Here we report the synthesis of multifunctional nanocarriers based on PAMAM dendrimers generation (G) 4.0, 5.0 and 6.0 fixed to polydopamine (PDA) coated magnetite nanoparticles (Fe 3 O 4). Synthesized nanoplatforms were characterized by transmission electron microscopy (TEM), the electrokinetic (zeta) potential, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and magnetic resonance imaging (MRI). Further, we show as a proof of concept that nanocarriers functionalized with G 5.0 could be successfully applied in combined chemo- and photothermal therapy (CT-PTT) of the liver cancer cells. The cooperative effect of the modalities mentioned above led to higher mortality of cancer cells when compared to their individual performance. Moreover, the performed in vitro studies revealed that the application of dual therapy triggered the desired cell death mechanism-apoptosis. Furthermore, performed tests using Magnetic Resonance Imaging (MRI) showed that our materials have competitive contrast properties. Overall, the functionality of dendrimers has been extended by merging them with magnetic nanoparticles resulting in multifunctional hybrid nanostructures that are promising smart drug delivery system for cancer therapy. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Organized Si nanowires (Si NWs) were produced by metal-assisted chemical etching. • The SiNWs were coated with a ZnO layer by Atomic Layer Deposition (ALD) • The structural and optical properties of the obtained nanostructures were studied. • Photoluminescence (PL) showed the domination of defect emission bands. • The PL intensity of SiNWs/ZnO decreased with the increase of Si NWs etching time. Abstract In this work, we report proof-of-concept results on the synthesis of Si core/ ZnO shell nanowires (SiNWs/ZnO) by combining nanosphere lithography (NSL), metal assisted chemical etching (MACE) and atomic layer deposition (ALD). The structural properties of the SiNWs/ZnO nanostructures prepared were investigated by X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopies. The X-ray diffraction analysis revealed that all samples have a hexagonal wurtzite structure. The grain sizes are found to be in the range of 7–14 nm. The optical properties of the samples were investigated using reflectance and photoluminescence spectroscopy. The study of photoluminescence (PL) spectra of SiNWs/ZnO samples showed the domination of defect emission bands, pointing to deviations of the stoichiometry of the prepared 3D ZnO nanostructures. Reduction of the PL intensity of the SiNWs/ZnO with the increase of SiNWs etching time was observed, depicting an advanced light scattering with the increase of the nanowire length. These results open up new prospects for the design of electronic and sensing devices. [ABSTRACT FROM AUTHOR]

A novel, (1-adamantylsulfanyl)-octasubstituted tetrapyrazinoporphyrazine has been synthesized and analyzed for its key physicochemical properties. Also, two 1-adamantylsulfanyl-substituted pyrazine derivatives were compared, and their crystallographic structures as well as chemical reactivity were assessed and discussed. Porphyrazine macrocycle showed good fluorescence and singlet oxygen generation properties as well as photostability. In addition, studied adamantylsulfanyl porphyrazine, despite its hydrophobic nature, revealed good solubility in polar solvents. Electrochemical studies revealed that the macrocycle underwent oxidation by one one-electron process and reduction with two one-electron processes. [ABSTRACT FROM AUTHOR]

This paper reports on the deposition and characterization of (TiAlSiY)N nanocomposite and (TiAlSiY)N/MoN nano-scale multilayer coatings obtained by means of arc-PVD method. The investigation of structural-phase composition and mechanical properties is carried out by means of scanning electron microscopy (SEM), equipped with energy dispersive spectrum (EDS), High resolution transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nanoindentation. The microstructure of the (TiAlSiY)N nanocomposite coating shows preferential (111) growth of fcc-(Ti, Al)N grains. Multilayers coating of (TiAlSiY)N/MoN with a bilayer period of 10 nm was synthesized, showing that the fcc-MoN layer grows coherently with the fcc-(Ti,Al)N, due to the template effect of the latter, which results in a local cube on cube fcc(Ti,Al)N||fcc(MoN) epitaxial growth with (200) preferential orientation. The hardness, reduced elastic modulus, elastic strain prior to plastic deformation and resistance to plastic deformation of the nanocomposite (TiAlSiY)N coating are determined as 24.6 GPa, 243 GPa, ~0.09 and 0.29 GPa, respectively. The enhancement of the mechanical properties of the multilayer coating up to 38.37, 392.5 GPa, ~0.09 and 0.38 GPa is also observed. [ABSTRACT FROM AUTHOR]

Combination therapy remains one of the most promising and intensively developed direction in cancer treatment. This study is aimed to combine and investigate the anticancer properties of silver nanoparticles (NPs) and Amanita muscaria mushroom in gel formulation. For this, hyaluronic acid was used as gel-forming agent, whereas Amanita muscaria extract was used as capping agent during silver and ultrasmall iron oxide (MAg) NPs synthesis. Amanita muscaria compounds formed NP's surface layer and contributed anticancer properties, whereas silver NPs contributed anticancer, fluorescence and photoactive properties to the gel. Physicochemical characterization included X-ray diffraction (XRD), microscopies (SEM, cryo-SEM, TEM, confocal fluorescence), spectrofluorometric method, thermogravimetric analysis (TGA), dynamic light scattering (DLS) techniques, energy dispersive (EDS), Fourier transform infrared (FTIR) and ultraviolet–visible (UV-Vis) spectroscopies, zeta-potential and rheological measurements. Microstructure analysis of hyaluronic acid/MAg NPs gel was performed by cryo-SEM technique. We showed that hyaluronic acid is a perfect gel-forming agent from both biomedical and technological points of view. It is well-mixed with MAg NPs forming stable gel formulation; high homogeneity of hyaluronic acid/MAg NPs gel was shown by SEM EDS elemental mapping. Microstructure of the gel was found to be highly ordered and consisted of domains from perforated parallel tubular structures. This finding expanded our understanding of gels and broke the stereotype of gel structure as chaotic network of fibers. Cytotoxicity studies performed on 2D and 3D HeLa cell cultures pointed to a high potential of hyaluronic acid/MAg NPs gel for local treatment of cancer. Cell response was found to be significantly different for 2D and 3D cell cultures that was related to their different cytoarhitecture and gene expression. Thus, the results of the cellular spheroids viability showed that they were significantly more resistant to the cytotoxic action of MAg NPs and their gel formulation than 2D cell culture. Hyaluronic acid used as gelling agent in gel formulation was found to increase an effectiveness of active components (MAg NPs, Amanita muscaria extract) probably improving their transport inside HeLa spheroids. [ABSTRACT FROM AUTHOR]

Low efficiency of anticancer drugs and their toxicity in normal tissues has motivated further study on safe and effective modern anticancer agents. In the presented study, the design and synthesis of a library of 14 fluorinated curcumin (F-CUR) derivatives and their F-CUR-BF 2 adducts are presented. Chemical modifications of curcumin derivatives included the introduction of BF 2 unit to the diketone group, as well as the substitutions of one or two fluorine atoms in different positions of the phenyl rings. The obtained compounds were broadly characterized using ESI HRM spectrometry, 1D and 2D NMR techniques (1H, 13C, 19F, HMBC, HSQC and COSY), Fourier transform infrared spectroscopy (FTIR), and melting points. Moreover, the purity of curcumin derivatives was determined using TLC and HPLC. Novel curcumin derivatives were subjected to biological studies against two bladder cancer cell lines 5637 and SCaBER using the MTT assay and then the structure-activity relationship was established. Our study demonstrated that it is the presence of the BF 2 moiety in the curcumin derivative structure, which determines the cytotoxic effect on cancer cells as the compounds with unchanged 3,5-diketone unit did not appear active in cancer cells. In addition, higher activities among the studied compounds were observed for curcumin-BF 2 adducts with methoxy than with the hydroxy or fluorine group; or for compounds containing one fluorine rather than two fluorine groups. Moreover, it has become evident that the position of substituents relative to each other plays a significant role. To sum up, all BF 2 adducts appeared more effective than curcumin, with the most cytotoxic compound belonging to F-CUR-BF 2 adducts with 3-fluoro-4-methoxyphenyl groups in its structure and IC 50 values of 6.49±0.49 μM and 3.31±0.51 μM after 24h incubation for 5637 and SCaBER cancer cell lines, respectively. The four most active F-CUR-BF 2 derivatives and their F-CUR analogs were subjected to stability tests. Based on the stress tests, the susceptibility of these compounds to various environmental factors, such as hydrolytic and oxidizing agents, light, and temperature, were assessed. [Display omitted] [ABSTRACT FROM AUTHOR]

Nanoscale multilayered TiN/SiC films are of great importance in many electronic and industrial fields. The careful control over the structure of the laminates, nanocrystalline or amorphous, is crucial for their further applicability and study. However, several limitations in their fabrication have revealed important gaps in the understanding of this system. Here, we study influence of temperature on the physico-chemical and functional properties of TiN/SiC multilayers. We will show the clear increment on hardness of the samples, while the nanocomposite structure of the layers is maintained with no increment in crystal size. We will investigate the interstitial effects and rearrangements, between the TiN/SiC phases and their role in the enhanced mechanical response. Our experiments will clearly show a change in the modulation period of the samples, pointing to interfacial reactions, diffusion of ions or crystallization of new phases. Full Investigations of the film properties were carried out using several methods of analysis: XRD, XPS, FTIR, HR-TEM and SIMS Additionally, results were combined with First Principles MD computations of TiN/SiC heterostructures. [ABSTRACT FROM AUTHOR]

5,7-Diaryl-substituted symmetrical diazepinoporphyrazine and tribenzodiazepinoporphyrazine were synthesized and characterized using UV–Vis, MS MALDI, and various NMR techniques. The expected photosensitizing potentials of these porphyrazines were evaluated by measuring their abilities to generate singlet oxygen in organic solvents and by comparing them with that of the recently obtained dendrimeric G1-type diazepinoporhyrazine. Absorbance and fluorescence measurements were performed to study the aggregation properties of the novel macrocycles. The photocytotoxicity of tribenzodiazepinoporphyrazine towards LNCaP cells in its free form and after its incorporation into liposomes was examined using MTT assay under normoxic and hypoxic conditions. It is interesting that all tested liposome formulations maintained their phototoxic activity in hypoxia. Also, tribenzodiazepinoporphyrazine incorporated into liposomes revealed better photocytotoxic effect (IC 50 values of 0.600 ± 0.357 μM and 0.378 ± 0.002 μM) than its free form (IC 50 values of 3.135 ± 0.156 μM). Following the in vitro experiments, the most promising liposomal formulation containing l -α-phosphatidyl-DL-glycerol for tribenzodiazepinoporphyrazine was found. Moreover, tribenzodiazepinoporphyrazine incorporated into liposomes containing 1,2-dioleoyl-3-trimethylammonium-propane (chloride salt) revealed moderate phototoxicity at 5 × 10 −5  μM for antibacterial photodynamic therapy. It was established that an irradiation of planktonic bacterial strains significantly reduced CFUs of Staphylococcus aureus ATCC 25923 in comparison to tribenzodiazepinoporphyrazine containing l -α-phosphatidyl-DL-glycerol liposomes. [ABSTRACT FROM AUTHOR]

Polydopamine (PDA)-coated magnetic nanoparticles functionalized with mono-6-thio-β-cyclodextrin (SH-βCD) were obtained and characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Nuclear and Magnetic Resonance Imaging (NMR and MRI), and doxorubicin (DOXO)-loading experiments. The liver cancer cellular internalization of DOXO-loaded nanoparticles was investigated by confocal imaging microscopy. Synthesized nanomaterials bearing a chemotherapeutic drug and a layer of polydopamine capable of absorbing near-infrared light show high performance in the combined chemo- and photothermal therapy (CT-PTT) of liver cancer due to the synergistic effect of both modalities as demonstrated in vitro. Moreover, our material exhibits improved T2 contrast properties, which have been verified using Carr-Purcell-Meiboom-Gill pulse sequence and MRI Spin-Echo imaging of the nanoparticles dispersed in the agarose gel phantoms. Therefore, the presented results cast new light on the preparation of polydopamine-based magnetic theranostic nanomaterials, as well as on the proper methodology for investigation of magnetic nanoparticles in high field MRI experiments. The prepared material is a robust theranostic nanoasystem with great potential in nanomedicine. [ABSTRACT FROM AUTHOR]

The present study is focused on the development of liposomes bearing gadolinium chelate (GdLip) providing two functionalities for magnetic resonance imaging (MRI) and photodynamic therapy of cancer. A lipid derivative of gadolinium(III) diethylenetriamine pentaacetic acid salt (GdDTPA1) was inserted in the liposomal membrane and served as MRI contrast agent whereas a zinc phthalocyanine (ZnPc) was used as a model photosensitizer. In addition to conventional liposomes, pegylated lipids were used for the preparation of “stealth” liposomes. The characterization of different GdLip formulations involved evaluation of the liposomes size by nanoparticle tracking analysis, thermal phase behavior by differential scanning calorimetry and ZnPc-mediated singlet oxygen production. Furthermore, relaxivity measurements were performed as well as cytotoxicity and photodynamic activity against cancerous and normal cell lines was studied. Size and thermal behavior were only slightly influenced by GdLip composition, however it distinctly affected singlet oxygen production of ZnPc-loaded GdLip. The quantum yields of singlet oxygen generation by zinc phthalocyanine incorporated in GdLip containing cationic or/and pegylated lipids were smaller than those obtained for non-pegylated carriers with l -α-phosphatidylglycerol. In general, all formulations of GdLip, irrespectively of composition, were characterized by relaxivities higher than those of commercially used contrast agents ( e.g. Magnevist®). NMR study has shown that the incorporation of ZnPc into the formulations of GdLip increases the relaxation parameters r 1 and r 2 , compared to the values for the non-loaded vesicles. GdDTPA1 did not influence the photodynamic activity of ZnPc against HeLa cells. [ABSTRACT FROM AUTHOR]

Nanostructured Si/TiO 2 core-shell nanopillar (NP) photoanodes were synthesized to overcome photodegradation stability of Si and to enhance the efficiency for photoelectrochemical water splitting. The core-shell structures were fabricated by atomic layer deposition of TiO 2 onto Si nanopillars synthesized by metal-assisted chemical etching and nanosphere lithography. Scanning electron microscopy, transmission electron microscopy, Raman and reflectance spectroscopies were utilized to characterize fabricated photoanodes. The obtained Si/TiO 2 core-shell NP arrays exhibit less than 6% of optical reflectance in UV and visible region, providing good optical absorption. Photoelectrochemical (PEC) water oxidation of fabricated photoanodes was studied. We showed that n-Si/n-TiO 2 NP exhibited a larger photocurrent than p-Si/n-TiO 2 due to a barrier at the heterojunction. Optimal morphological parameter of Si/TiO 2 NP for enhanced PEC water splitting were found. We demonstrated its enhanced PEC performance with a photocurrent density of 1.5 mA/cm 2 under simulated solar radiation with intensity of 100 mW/cm 2 . The relationship between the PEC performance and the electrolyte pH was also discussed. The design of the geometry of Si/TiO 2 core-shell NP arrays offers a new approach for preparing stable and highly efficient photoanodes for PEC water splitting. [ABSTRACT FROM AUTHOR]

[Display omitted] • The chemical character of platinum affected on Vis driven photoactivity of Au/Pt-TiO 2. • The gold in Au/Pt bimetallic system weakens the photocatalytic properties. • The greater number of Pt atoms in Au/Pt combinations has led to improve efficiency in photocatalysis. • The relatively small size of anatase crystallites responds to highest reaction rate. The TiO 2 modified by monometallic (Au-TiO 2 , Pt-TiO 2) and bimetallic (Pt/Au-TiO 2) NPs have been synthesized by a simple sol-gel method. The optimal dosage of individual components in Pt/Au composition on photocatalytic activity has been systematically investigated. The obtained photocatalysts were thoroughly characterized by BET surface area measurements, UV–vis diffuse-reflectance spectroscopy (DRS), X-ray diffraction analysis (XRD), scanning transmission microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity under visible light (λ > 420 nm and λ > 455 nm) has been estimated in phenol degradation reaction in an aqueous phase. The best photocatalytic activity has been observed for −mono (0.5)Pt_TiO 2 and bimetallic (0.5)Pt/(0.5)Au_TiO 2 samples with an optimum platinum content. The Pt/Au_TiO 2 radical formation mechanism was systematically investigated with the selected scavenger for the degradation process under vis light irradiation. The formation of O 2 − with (0.5)Pt/(0.5)Au_TiO 2 was established from the high inhibition of phenol degradation. Based on the XPS analysis it was observed that the greater photoactivity of bimetallic sample (0.5)Pt/(0.5)Au_TiO 2 could result from a relatively higher content of platinum compared to gold on the surface layer. It must be noted that only platinum takes a significant part in Pt/Au composites on the photoactivity. Furthermore, in this work we present a linear relationship between the crystal size of TiO 2 and the reaction rate of Au-TiO 2 , Pt-TiO 2 and Pt/Au-TiO 2. [ABSTRACT FROM AUTHOR]

Nanoscale multilayered TiN/ZrN films were deposited using sequential vacuum-arc deposition of Ti and Zr targets in a nitrogen atmosphere. Studies of film's properties were carried out using various modern methods of analysis, such as XRD, STEM, HRTEM, SIMS combined with results of nanoindentation and tribological tests. To interpret the mechanical properties of the deposited multilayer films first-principles calculations of TiN(111), ZrN(111) structures and TiN(111)/ZrN(111) multilayer were carried out. To study the influence of thermal annealing, several samples were annealed in air at the temperature 700 °C. All deposited samples were highly polycrystalline with quite large 20–25 nm crystals. The crystalline planes were very ordinated and demonstrated an excellent coordinated growth. The nanohardness and elastic modulus of non-annealed coatings reached 42 GPa and 348 GPa, respectively. Annealing in air at the temperature 700 °C led to partial oxidation of the multilayered coatings, however hardness of the non-oxidized part of the coatings remained as high, as for initial coatings. All deposited coatings demonstrate good wear resistance. [ABSTRACT FROM AUTHOR]

Multimodal nanoparticles (NPs) that may be used for therapies and diagnostics is the most promising trend for efficient therapy. We demonstrate that nanocomposite based on self-organizing silver and ultrasmall magnetic iron oxide NPs (MAg) produced in one-step synthesis revealed unique combination of fluorescence, bactericidal, fungicidal properties and have a potential as magnetic resonance imaging (MRI) contrast agent. Using the green chemistry approach, ginger ( Zingiber officinale ) rhizome extract was applied as capping agent for MAg synthesis, providing also additional fluorescent properties of NPs and inducing hydrocolloids structuring. The MAg were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive microanalysis (EDS), fluorescence microscopy, cryo-SEM, dynamic light scattering (DLS) techniques, Fourier transform infrared (FTIR) and ultraviolet–visible (UV–Vis) spectroscopies. MAg dispersions in water and some biological media are very stable which is important for biomedical application. The existence of microstructure in MAg hydrocolloids was proved. The hierarchical character and high ordering of this microstructure were discovered and its level-by-level building blocks were investigated. The microstructure was found to be responsible for fluorescence emittance of MAg hydrocolloids. The properties as well as potential application of the MAg hydrocolloids is yet to be discovered. [ABSTRACT FROM AUTHOR]

The chemical composition of nanoparticles (NPs) may be so designed as to provide measurability for numerous imaging techniques in order to achieve synergistic advantages. Innovative and unique structure of the core/shell ZnO@Gd 2 O 3 NPs possesses luminescent and magnetic properties, and is expected that they will become a new generation of contrast agents for Magnetic Resonance Imaging (MRI) and nanocarriers for theranostics. Thus, by surface biofunctionalization, it is possible to indicate particular nanoparticle compositions which provide efficient imaging, targeted drug delivery, and biocompatibility. Novel ZnO@Gd 2 O 3 NPs were synthesized and biofunctionalized by folic acid (FA) and doxorubicin (Doxo) to provide target and anticancer functions. Physicochemical analyses of the nanoparticles were performed. The biological study included a cytotoxicity in vitro , cellular distribution evaluation, as well as toxicity analyses, performed for the first time, on the in vivo zebrafish ( Danio rerio ) model. Nanoparticles were found to be effective double-function biomarkers (MRI T 2 contrast agents, fluorescent imaging). The biological study showed that ZnO@Gd 2 O 3 and ZnO@Gd 2 O 3 @OA-polySi@FA NPs are biocompatible in a particular concentration ranges. Conjugation with folic acid and/or doxorubicin resulted in effective drug delivery targeting. The in vivo results described the toxicology profile toward the zebrafish embryo/larvae, including new data concerning the survival, hatching ratio, and developmental malformations. [ABSTRACT FROM AUTHOR]

We report a novel room-temperature synthesis of selenium nanoparticles, which for the first time uses lignosulfonate as a stabilizer. Various lignosulfonates obtained both from hardwood and softwood were tested. Selenium oxide was used as the precursor of zero-valent selenium. Three different reducers were tested − sodium borohydride, hydrazine and ascorbic acid − and the latter proved most effective in terms of the particle size and stability of the final colloid. The lignosulfonate-stabilized selenium nanoparticles had a negative zeta potential, dependent on pH, which for some lignosulfonates reached −50 mV, indicating the excellent stability of the colloid. When spherical silica particles were introduced to the synthesis mixture, selenium nanoparticles were deposited on their surface. Additionally, star-like structures consisting of sharp selenium needles with silica cores were observed. After drying, the selenium-functionalized silica had a grey metallic hue. The method reported here is simple and cost-effective, and can be used for the preparation of large quantities of selenium colloids or the surface modification of other materials with selenium. [ABSTRACT FROM AUTHOR]

It has been long known that the physical encapsulation of oleic acid-capped iron oxide nanoparticles (OA-IONPs) with the cetyltrimethylammonium (CTA+) surfactant induces the formation of spherical iron oxide nanoparticle clusters (IONPCs). However, the behavior and functional properties of IONPCs in chemical reactions have been largely neglected and are still not well-understood. Herein, we report an unconventional ligand-exchange function of IONPCs activated when dispersed in an ethyl acetate/acetate buffer system. The ligand exchange can successfully transform hydrophobic OA-IONP building blocks of IONPCs into highly hydrophilic, acetate-capped iron oxide nanoparticles (Ac-IONPs). More importantly, we demonstrate that the addition of silica precursors (tetraethyl orthosilicate and 3-aminopropyltriethoxysilane) to the acetate/oleate ligand-exchange reaction of the IONPs induces the disassembly of the IONPCs into monodispersed iron oxide-acetate-silica core-shell-shell (IONPs@acetate@SiO2) nanoparticles. Our observations evidence that the formation of IONPs@acetate@SiO2 nanoparticles is initiated by a unique micellar fusion mechanism between the Pickering-type emulsions of IONPCs and nanoemulsions of silica precursors formed under ethyl acetate buffered conditions. A dynamic rearrangement of the CTA+-oleate bilayer on the IONPC surfaces is proposed to be responsible for the templating process of the silica shells around the individual IONPs. In comparison to previously reported methods in the literature, our work provides a much more detailed experimental evidence of the silica-coating mechanism in a nanoemulsion system. Overall, ethyl acetate is proven to be a very efficient agent for an effortless preparation of monodispersed IONPs@acetate@SiO2 and hydrophilic Ac-IONPs from IONPCs. [ABSTRACT FROM AUTHOR]

Phase transformations of Al doped NbN nanocomposite coatings are studied in detail focusing on their microstructural evolution and phase composition. Several techniques such as XRD, SEM, HR-TEM, Nanoindentation and molecular dynamics simulation are employed in order to understand the phase evolution of the Nb-Al-N system. The nanocomposite structures were formed in the coatings, the roughness of the coatings decreased with increasing the Al concentration due to decreasing grain size. First-principles investigation of Nb-Al-N solid solutions was carried out to interpret film properties. It was found, that for small Al fractions, the solid solutions will form in agreement with our experimental results. The spinodal decomposition of Nb-Al-N solid solutions is supposed to be responsible for the formation of the nanocomosite structure observed in the deposited Nb-Al-N films. [ABSTRACT FROM AUTHOR]

In this study ZnPc@TiO 2 hybrid nanostructures, both nanoparticles and nanotubes, as potential photosensitizers for the photodynamic therapy, fluorescent bioimaging agents, as well as anti-cancer drug nanocarriers, were prepared via zinc phthalocyanine (ZnPc) deposition on TiO 2 . In order to provide the selectivity of prepared hybrid nanostructures towards cancer cells they were modified with folic acid molecules (FA). The efficient attachment of both ZnPc and FA molecules was confirmed with dynamic light scattering (DLS), zeta potential measurements and X-ray photoelectron spectroscopy (XPS). It was presented that ZnPc and FA attachment has a strong effect on fluorescence emission properties of TiO 2 nanostructures, which can be further used for their simultaneous visualization upon cellular uptake. ZnPc@TiO 2 and FA/ZnPc@TiO 2 hybrid nanotubes were then employed as doxorubicin nanocarriers. It was demonstrated that doxorubicin can be easily loaded on these hybrid nanostructures via an electrostatic interaction and then released. In vitro cytotoxicity and photo-cytotoxic activity studies showed that prepared hybrid nanostructures were selectively targeting to cancer cells. Doxorubicin loaded hybrid nanostructures were significantly more cytotoxic than un-loaded ones and their cytotoxic effect was even more severe upon irradiation. The cellular uptake of prepared hybrid nanostructures and their localization in cells was monitored in vitro in 2D cell culture and tumor-like 3D multicellular culture environment with fluorescent confocal microscopy. These hybrid nanostructures preferentially penetrated into human cervical cancer cells (HeLa) than into normal fibroblasts (MSU-1.1) and were mainly localized within the cell cytoplasm. HeLa cells spheroids were also efficiently labelled by prepared hybrid nanostructures. Fluorescent imaging of Hela cells treated with doxorubicin loaded hybrid nanostructures showed that doxorubicin was effectively delivered into cells, released and evenly distributed in the cytoplasm. In conclusion, prepared hybrid nanostructures exhibit high potential as selective bioimaging agents next to their photodynamic activity and drug delivery ability. [ABSTRACT FROM AUTHOR]