Biomimetic Bacterium-like Particles Loaded with Aggregation-Induced Emission Photosensitizers as Plasma Coatings for Implant-Associated Infections.

Developing novel antibacterial strategies has become an urgent requisite to overcome the increasing pervasiveness of antimicrobial-resistant bacteria and the advent of biofilms. Aggregation-induced emission-based photosensitizers (AIE PSs) are promising candidates due to their unique photodynamic and photothermal properties. Bioengineering structure-inherent AIE PSs for developing thin film coatings is still an unexplored area in the field of nanoscience.

Towards the rapid detection of haze-forming proteins.

Protein haze in white wine can be a serious quality defect because consumers perceive hazy wines as "spoiled". Unfortunately, a specific method for the detection, or selective treatment, of such proteins in affected wines does not exist. Herein we investigate on the development of an easy-to-use sensor device that allows detection of haze-forming proteins (HFPs).

A novel solution to tartrate instability in white wines.

Tartrate stabilization remains a necessary step in commercial wine production to avoid the precipitation of crystals in bottled wine. The conventional refrigeration method to prevent crystallization of potassium bitartrate is time-consuming, energy-intensive, and involves a filtration step to remove the sediment. Nevertheless, it is still the most used stabilization method by winemakers.

Surface nanoengineering technology for the removal of sulfur compounds associated with negative attributes in wines.

Volatile sulfur compounds (VSCs), such as hydrogen sulfide, methanethiol, and ethanethiol, are associated with 'reductive' aromas in wine and contribute to approximately 30% of all wine faults. These compounds can have a significant impact on wine aroma and perceived quality, and subsequently, consumer preference. In this communication, we report a method for the removal of VSC compounds based on nanoengineered surfaces that incorporate immobilized gold nanoparticles.

Quantification of protein by acid hydrolysis reveals higher than expected concentrations in red wines: Implications for wine tannin concentration and colloidal stability.

Protein is reportedly negligible in most red wines, due to its loss following co-precipitation with phenolic substances. A method for protein quantification in red wine was developed which overcame analytical interference from phenolic substances, based on ethanol precipitation, followed by acid-hydrolysis and amino acid quantification. Protein concentration was surveyed in a range of red wines produced from V.

Nanoparticles Surface Chemistry Influence on Protein Corona Composition and Inflammatory Responses.

Nanoparticles are widely used for biomedical applications such as vaccine, drug delivery, diagnostics, and therapeutics. This study aims to reveal the influence of nanoparticle surface functionalization on protein corona formation from blood serum and plasma and the subsequent effects on the innate immune cellular responses. To achieve this goal, the surface chemistry of silica nanoparticles of 20 nm diameter was tailored via plasma polymerization with amine, carboxylic acid, oxazolines, and alkane functionalities.

Fluorescence sensing technology for the rapid detection of haze-forming proteins in white wine.

The methods currently available for determining haze proteins in wine are time-consuming, expensive, and often not sufficiently accurate. The latter may lead to bentonite over-fining of a wine, which might strip wine phenolics and aroma compounds, or wine under-fining, which increases the risk of protein instability. In this work, an efficient and rapid fluorescence-based technology to detect haze-forming proteins in white wines was developed.

Fluorescence correlation spectroscopy to unravel the interactions between macromolecules in wine.

In this work, the interaction of wine macromolecules with a bovine serum albumin (BSA) was investigated using fluorescence correlation spectroscopy (FCS). FCS offers the opportunity to study molecular and macromolecular aggregation without disturbing the wine by introducing only very small amounts of fluorescently labelled molecules to the system. It was observed that the diffusion coefficient of fluorescently labelled BSA varies with the addition of wine macromolecules, indicating changes in the protein conformation and the formation of complexes and aggregates.

The Influence of Nanoparticle Shape on Protein Corona Formation.

Nanoparticles have become an important utility in many areas of medical treatment such as targeted drug and treatment delivery as well as imaging and diagnostics. These advances require a complete understanding of nanoparticles' fate once placed in the body. Upon exposure to blood, proteins adsorb onto the nanoparticles surface and form a protein corona, which determines the particles' biological fate.

Regeneration of Magnetic Nanoparticles Used in the Removal of Pathogenesis-Related Proteins from White Wines.

Protein haze remains a serious problem for the wine industry and requires costly bentonite treatment, leading to significant wine volume loss. Recently developed magnetic separation technology that allows a fast and efficient separation of haze proteins from wine shows promise for the development of an alternative method for white wine fining. The key purpose of this study was to understand the potential of the nanoparticles to be reused in multiple fining and regeneration cycles.

Differentiation of Rat Mesenchymal Stem Cells toward Osteogenic Lineage on Extracellular Matrix Protein Gradients.

This report addresses the issue of optimizing extracellular matrix protein density required to support osteogenic lineage differentiation of mesenchymal stem cells (MSCs) by culturing MSCs on surface-bound density gradients of immobilized collagen type I (COL1) and osteopontin (OPN). A chemical surface gradient is prepared by tailoring the surface chemical composition from high hydroxyl groups to aldehyde groups using a diffusion-controlled plasma polymerization technique. Osteogenesis on the gradient surface is determined by immunofluorescence staining against Runx2 as an early marker and by staining of calcium phosphate deposits as a late stage differentiation marker.

Biomaterial Surface Hydrophobicity-Mediated Serum Protein Adsorption and Immune Responses.

The nature of the protein corona forming on biomaterial surfaces can affect the performance of implanted devices. This study investigated the role of surface chemistry and wettability on human serum-derived protein corona formation on biomaterial surfaces and the subsequent effects on the cellular innate immune response. Plasma polymerization, a substrate-independent technique, was employed to create nanothin coatings with four specific chemical functionalities and a spectrum of surface charges and wettability.

Applying Nanoparticle Tracking Analysis to Characterize the Polydispersity of Aggregates Resulting from Tannin-Polysaccharide Interactions in Wine-Like Media.

Interactions between grape seed tannin and either a mannoprotein or an arabinogalactan in model wine solutions of different ethanol concentrations were characterized with nanoparticle tracking analysis (NTA), UV-visible spectroscopy and dynamic light scattering (DLS). NTA results reflected a shift in particle size distribution due to aggregation. Furthermore, the light scattering intensity of each tracked particle measured by NTA demonstrated the presence of aggregates, even when a shift in particle size was not apparent.

Magnetic separation technology: Functional group efficiency in the removal of haze-forming proteins from wines.

Magnetic nanoparticles were modified by plasma polymerization, using allylamine, acrylic acid and 2-methyl-2-oxazoline as precursor to produce amine, carboxyl and oxazoline functional group rich surfaces. The nanoparticles were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and zeta potential measurements. The capacity of nanoparticles carrying different surface properties to remove haze-forming proteins from Sémillon and Sauvignon Blanc unfined wines was examined by high-performance liquid chromatography (HPLC).

A novel technology for the rapid, selective, magnetic removal of pathogenesis-related proteins from wines.

Haze formation is a significant problem for the wine industry. A novel technology for the rapid, selective, magnetic removal of pathogenesis-related proteins from wine was developed. The pathogenesis-related proteins in nine different white wines were selectively captured and removed by acrylic acid plasma-coated magnetic nanoparticles.

Adsorption of Wine Constituents on Functionalized Surfaces.

The adsorption of macromolecules on solid surfaces is of great importance in the field of nanotechnology, biomaterials, biotechnological, and food processes. In the field of oenology adsorption of wine macromolecules such as polyphenols, polysaccharides, and proteins is much less desirable on membrane materials because of fouling and reduced filtering performance. On the other hand, adsorption of these molecules on processing aids is very beneficial for achieving wine clarity and stability.

The effects of pH and copper on the formation of volatile sulfur compounds in Chardonnay and Shiraz wines post-bottling.

The effects of pH and Cu(2+) treatment on the formation of volatile sulfur compounds (VSCs) were investigated in Chardonnay and Shiraz wine samples. Four VSCs were significantly affected by pH, with lower wine pH associated with decreased hydrogen sulfide (H2S), methanethiol, dimethyl sulfide, and carbon disulfide concentrations. The effects of pH and Cu(2+) on H2S formation from known precursor compounds were subsequently studied in a model wine system.

Characterization of macromolecular complexes in red wine: Composition, molecular mass distribution and particle size.

Precipitates were prepared from two compositionally different Pinot noir wines with addition of excess ethanol, and contained primarily polysaccharide, tannin and protein. The ethanol-soluble material was further fractionated into polymeric (tannin) and monomeric phenolics. Tannin associated with precipitates was of a higher molecular mass than that remaining in ethanolic solution.

In situ ATR FTIR study of dextrin adsorption on anatase TiO2.

The adsorption of two dextrin-based polymers, a regular wheat dextrin (TY) and a carboxymethyl-substituted (CM) dextrin, onto an anatase TiO(2) particle film has been studied using in situ attenuated total reflection (ATR) FTIR spectroscopy. Infrared spectra of the polymer solutions and the polymer adsorbed at the anatase surface were acquired for two solution conditions: pH 3 and pH 9; below and above the isoelectric point (IEP) of anatase, respectively. Comparison of the polymer solution spectra and the adsorbed layer spectra highlighted a number of spectral differences that were attributed to involvement of the carboxyl group of CM Dextrin interacting with the anatase surface directly and the adsorption of oxidized dextrin chains in the case of regular dextrin (TY) at high pH.

Synchrotron FTIR microscopy of Langmuir-Blodgett monolayers and polyelectrolyte multilayers at the solid-solid interface.

Synchrotron FTIR microscopy has been used to probe the structure of model boundary lubricant layers confined at the solid-solid interface. The combination of high brightness of the IR source and a novel contact geometry that uses a hemispherical internal reflection element as the means for light delivery has enabled the detection of <2.5 nm thin monolayer lubricant layers in the solid-solid contact, in addition to allowing for spectral acquisition from specific regions of the contact.

Adsorption of modified dextrins on molybdenite: AFM imaging, contact angle, and flotation studies.

The adsorption of three dextrins (a regular wheat dextrin, Dextrin TY, carboxymethyl (CM) Dextrin, and hydroxypropyl (HP) Dextrin) on molybdenite has been investigated using adsorption isotherms, tapping mode atomic force microscopy (TMAFM), contact angle measurements, and dynamic bubble-surface collisions. In addition, the effect of the polymers on the flotation recovery of molybdenite has been determined. The isotherms revealed the importance of molecular weight in determining the adsorbed amounts of the polymers on molybdenite at plateau coverage.

The role of mineral surface chemistry in modified dextrin adsorption.

The adsorption of two modified dextrins (phenyl succinate dextrin--PS Dextrin; styrene oxide dextrin--SO Dextrin) on four different mineral surfaces has been studied using X-ray photoelectron spectroscopy (XPS), in situ atomic force microscopy (AFM) imaging, and captive bubble contact angle measurements. The four surfaces include highly orientated pyrolytic graphite (HOPG), freshly cleaved synthetic sphalerite (ZnS), and two surfaces produced through surface reactions of sphalerite: one oxidized in alkaline solution (pH 9, 1 h immersion); and one subjected to metal ion exchange between copper and zinc (i.e.

Chemical defects in the highly fluorescent conjugated polymer dots.

We present strong evidence for the oxidation of conjugated polymers in the formation of conjugated polymer dots (CPdots) using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Although recent studies show that folding of the polymer chain into a compact 3D structure is involved in the formation of these nanoparticles, the process by which these intrinsically hydrophobic nanoscale particles circumvent aggregation in water is still not well understood. Zeta potential results show that these dots have a negatively charged surface at neutral pH, with a zeta potential and surface charge density of approximately -40 mV and (1.

Evolution of carboxymethyl cellulose layer morphology on hydrophobic mineral surfaces: variation of polymer concentration and ionic strength.

The adsorption of carboxymethyl cellulose (CMC) on the basal planes of talc and molybdenite has been studied using in situ atomic force microscope (AFM) imaging. These experiments were partnered with quantitative adsorption isotherm determinations on particulate samples. The isotherms revealed a clear increase of the CMC adsorbed amount upon increasing the solution ionic strength for adsorption on both minerals.

In situ atomic force microscopy of modified dextrin adsorption on hydrophobic and hydrophilic layered silicate minerals.

We have used in situ atomic force microscopy (AFM), captive bubble contact angle measurements, and colloid-probe AFM to investigate the adsorption of two modified dextrins (a phenyl succinate substituted dextrin, PS Dextrin, and a styrene oxide substituted dextrin, SO Dextrin) on the basal plane surfaces of talc and clinochlore. The experiments have probed the effect that the polymers have on the mineral hydrophobicity and on the expected particle-particle interactions in single mineral aggregation. Distinct correlations were seen between the adsorbed polymer layer morphology (coverage, thickness) and the ability of the polymers to reduce the contact angle of the talc basal plane surfaces (SO Dextrin>PS Dextrin).