Search results for "nanostructure"

Semiconductor mixed oxides as innovative materials for the photocatalytic removal of organic pollutants

2020

Abstract This work aims to provide a critical survey of the extensive literature concerning the potential applications of nanostructured mixed oxides for environmental remediation. In particular, our attention was focused on the feasibility to employ these materials as photocatalysts for the elimination of toxic organic pollutants contained in water and wastewater. The advantages and perspectives of the various nanocomposites are briefly discussed.

Cationic polyaspartamide-based nanocomplexes mediate siRNA entry and down-regulation of the pro-inflammatory mediator high mobility group box 1 in ai…

2015

Abstract High-mobility group box 1 (HMGB1) is a nonhistone protein secreted by airway epithelial cells in hyperinflammatory diseases such as asthma. In order to down-regulate HMGB1 expression in airway epithelial cells, siRNA directed against HMGB1 was delivered through nanocomplexes based on a cationic copolymer of poly(N-2-hydroxyethyl)- d,l -aspartamide (PHEA) by using H441 cells. Two copolymers were used in these experiments bearing respectively spermine side chains (PHEA-Spm) and both spermine and PEG2000 chains (PHEA-PEG-Spm). PHEA-Spm and PHEA-PEG-Spm derivatives complexed dsDNA oligonucleotides with a w/w ratio of 1 and higher as shown by a gel retardation assay. PHEA-Spm and PHEA-P…

2019

Lamella-forming ABC triblock terpolymers are convenient building blocks for the synthesis of soft Janus nanoparticles (JNPs) by crosslinking the B domain that is “sandwiched” between A and C lamellae. Despite thorough synthetic variation of the B fraction to control the geometry of the sandwiched microphase, so far only Janus spheres, cylinders, and sheets have been obtained. In this combined theoretical and experimental work, we show that the blending of polybutadiene homopolymer (hPB) into lamella morphologies of polystyrene-block-polybutadiene-block-polymethylmethacrylate (SBM) triblock terpolymers allows the continuous tuning of the polybutadiene (PB) microphase. We systematically vary …

Effect of Core-Crosslinking on Protein Corona Formation on Polymeric Micelles.

2021

Most nanomaterials acquire a protein corona upon contact with biological fluids. The magnitude of this effect is strongly dependent both on surface and structure of the nanoparticle. To define the contribution of the internal nanoparticle structure, protein corona formation of block copolymer micelles with poly(N-2-hydroxypropylmethacrylamide) (pHPMA) as hydrophilic shell, which are crosslinked-or not-in the hydrophobic core is comparatively analyzed. Both types of micelles are incubated with human blood plasma and separated by asymmetrical flow field-flow fractionation (AF4). Their size is determined by dynamic light scattering and proteins within the micellar fraction are characterized by…

Prospective Cancer Therapies Using Stimuli‐Responsive DNA Nanostructures

2021

Financial support by the Emil Aaltonen Foundation, the Sigrid Jusélius Foundation, the Magnus Ehrnrooth Foundation, Academy of Finland (grants no. 317042 and 331151), the Jane and Aatos Erkko Foundation and the Vilho, Yrjö and Kalle Väisälä Foundation of the Finnish Academy of Science and Letters is gratefully acknowledged Nanostructures based on DNA self-assembly present an innovative way to address the increasing need for target-specific delivery of therapeutic molecules. Currently, most of the chemotherapeutics being used in clinical practice have undesired and exceedingly high off-target toxicity. This is a challenge in particular for small molecules, and hence, developing robust and ef…

Hydrophilic/Hydrophobic Nanostripes in Lipopolymer Monolayers

2000

Illustrating the processability of magnetic layered double hydroxides: layer-by-layer assembly of magnetic ultrathin films.

2013

We report the preparation of single-layer layered double hydroxide (LDH) two-dimensional (2D) nanosheets by exfoliation of highly crystalline NiAl-NO3 LDH. Next, these unilamellar moieties have been incorporated layer-by-layer (LbL) into a poly(sodium 4-styrenesulfonate)/LDH nanosheet multilayer ultrathin film (UTF). Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible light (UV-vis), and X-ray diffraction (XRD) profiles have been used to follow the uniform growth of the UTF. The use of a magnetic LDH as the cationic component of the multilayered architecture enables study of the resulting magnetic properties of the UTFs. Our magnetic data show the appearance of spontaneous …

Supramolecular silver polyoxometalate architectures direct the growth of composite semiconducting nanostructures.

2009

Nanosilver on a string: Crystalline silver polyoxovanadate supramolecular architectures are employed as precursors for the synthesis of composite nanowires (see scheme). The nanostructures are composed of semiconducting vanadium oxide which forms wires with high aspect ratios, and are embedded with metallic silver nanoparticles. © 2009 Wiley-VCH Verlag GmbH & Co. KCaA.

Porous Anodic Alumina as template for the cathodic electrodeposition of oxide and hydroxide nanostructures

2009

Polystyrene Sulfonate–Porphyrin Assemblies: Influence of Polyelectrolyte and Porphyrin Structure

2011

In this study, electrostatic self-assembly of different polystyrene sulfonates and a set of tetravalent cationic porphyrins is investigated. It is shown that association of linear polystyrene sulfonates of different molar masses yields finite size nanoscale assemblies that are stable in aqueous solution. Aggregates are compared to the ones of cylindrical brushes, revealing that both form assemblies in the 100 nm range with the charge ratio (molar ratio of porphyrin charges to polyelectrolyte charges) being determining, while the morphology of the resulting network-like assemblies is different for both polyelectrolyte architectures. For the smallest 8k polystyrene sulfonate, in addition, sto…