SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Bovine serum albumin

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Zinc oxide nanoparticles (ZnO NPs) are widely used in medical, industrial and household application owing to excellent antimicrobial property. The biocompatibility of nanoparticles is important for specific biomedical applications. The aim of this study was to stabilize and biofunctionalize ZnO NPs using bovine serum albumin (BSA). Here we have investigated the adsorption behavior of BSA onto ZnO NPs in aqueous solutions. Influence of pH on the adsorption of BSA onto ZnO NPs was also investigated. The study suggests that the electrostatic force of attraction favors the adsorption of BSA onto ZnO NPs. The adsorption data fitted well by Freundlich isotherm compared to Langmuir isotherm. The kinetics of adsorption fitted best to pseudo-second-order.

Concepts: Ultraviolet, Adsorption, Zinc, Serum albumin, Titanium dioxide, Bovine serum albumin, Zinc oxide, Freundlich equation

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Methoxy poly (ethylene glycol) grafted carboxymethyl chitosan (mPEG-g-CMC) and alginate were chosen as the constituents of hydrogel beads for the construction of an interpenetrating polymeric network matrix. A contrast study between the mPEG-g-CMC hydrogel and mPEG physically mixed with CMC hydrogel was carried out. Bovine serum albumin (BSA) as a model for a protein drug was encapsulated in the hydrogel network, and the drug release properties were studied. The hydrogels prepared by these two methods maintained good pH sensitivity; the loading capacity of the mPEG-g-CMC/alginate hydrogel was enhanced in comparison with that of the hydrogel prepared by physically mixing mPEG. The burst release of the protein was slightly decreased at pH 1.2, while the release at pH 7.4 was improved, suggesting that the mPEG-g-CMC/alginate pH-sensitive hydrogel will be promising for site-specific protein drug delivery in the intestine.

Concepts: Blood, Polymer, Serum albumin, Polysaccharide, Bovine serum albumin, Ethylene glycol, Diol, Polyester

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Gemini surfactant displayed distinct advantages over monomeric surfactant in the liquid-liquid reverse micellar extraction process. First, less amount of gemini surfactant than monomeric surfactant was needed for transferring almost complete bovine serum albumin (BSA) into organic phase from aqueous phase. Second, the loading capacity of gemini surfactant reverse micelle phase was much higher than that of the corresponding monomeric surfactant reverse micelle. Third, efficient backward extraction (75-92%) of BSA could be effected in a wide pH range from 4 to 9 with gemini surfactant reverse micelle while a pH of ca. 4.3 is prerequisite to the recovery of BSA from monomeric surfactant reverse micelle. So far, the reports about the effect of surfactant structure on protein extraction have been limited. This study indicates the important role of the spacer of gemini surfactant in protein extraction process and may provide more knowledge on how to optimise surfactant structure.

Concepts: Blood, Effect, Serum albumin, PH, Surfactant, Micelle, Bovine serum albumin, Liquid-liquid extraction

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We design well-defined metal-semiconductor nanostructures using thiol-functionalized CdTe quantum dots (QDs)/quantum rods (QRs) with bovine serum albumin (BSA) protein-conjugated Au nanoparticles (NPs)/nanorods (NRs) in aqueous solution. The main focus of this article is to address the impacts of size and shape on the photophysical properties, including radiative and nonradiative decay processes and energy transfers, of Au-CdTe hybrid nanostructures. The red shifting of the plasmonic band and the strong photoluminescence (PL) quenching reveal a strong interaction between plasmons and excitons in these Au-CdTe hybrid nanostructures. The PL quenching of CdTe QDs varies from 40 to 86 % by changing the size and shape of the Au NPs. The radiative as well as the nonradiative decay rates of the CdTe QDs/QRs are found to be affected in the presence of both Au NPs and NRs. A significant change in the nonradiative decay rate from 4.72×10(6) to 3.92×10(10) s(-1) is obtained for Au NR-conjugated CdTe QDs. It is seen that the sizes and shapes of the Au NPs have a pronounced effect on the distance-dependent energy transfer. Such metal-semiconductor hybrid nanostructures should have great potentials for nonlinear optical properties, photovoltaic devices, and chemical sensors.

Concepts: Optics, Proton, Chemistry, Radioactive decay, Serum albumin, Solar cell, Surface plasmon resonance, Bovine serum albumin

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Azo dyes are generally resistant to biodegradation due to their complex structures. Acid orange II is one of the most widely used dyes in the textile industry. The influence of bovine serum albumin (BSA) in different concentrations, pH, and time of contact on Orange II was investigated using kinetics and adsorption-isotherm experiments. The results showed that the maximum colour removed from dye/albumin was 99.50% and that a stable dye-protein complex had been formed at pH 3.5 and in a proportion of 1:3 (v/v), respectively. The synthetic effluent did not show toxicity to the microcrustacean Artemia salina, and showed a CL(50) equal to 97 µg/mL to azo dye orange II. Additionally, the methodology was effective in removing the maximum of orange II using BSA by adsorption at pH 3.5 which mainly attracted ions to the azo dye during the adsorption process. This suggests that this form of treatment is economical and easy to use which potentially could lead to bovine serum albumin being used as a sorbent for azo dyes.

Concepts: Serum albumin, Dye, Bovine serum albumin, Azo compound, Pigments, Azo dyes

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Protein adsorption is one of the key parameters influencing the biocompatibility of medical device materials. This study investigates serum protein adsorption and bacterial attachment on polymer coatings deposited using an atmospheric pressure plasma jet system. The adsorption of bovine serum albumin and bovine fibrinogen (Fg) onto siloxane and fluorinated siloxane elastomeric coatings that exhibit water contact angles (θ) ranging from superhydrophilic (θ < 5°) to superhydrophobic (θ > 150°) were investigated. Protein interactions were evaluated in situ under dynamic flow conditions by spectroscopic ellipsometry. Superhydrophilic coatings showed lower levels of protein adsorption when compared with hydrophobic siloxane coatings, where preferential adsorption was shown to occur. Reduced levels of protein adsorption were also observed on fluorinated siloxane copolymer coatings exhibiting hydrophobic wetting behaviour. The lower levels of protein adsorption observed on these surfaces indicated that the presence of fluorocarbon groups have the effect of reducing surface affinity for protein attachment. Analysis of superhydrophobic siloxane and fluorosiloxane surfaces showed minimal indication of protein adsorption. This was confirmed by bacterial attachment studies using a Staphylococcus aureus strain known to bind specifically to Fg, which showed almost no attachment to the superhydrophobic coating after protein adsorption experiments. These results showed the superhydrophobic surfaces to exhibit antimicrobial properties and significantly reduce protein adsorption.

Concepts: Photosynthesis, Staphylococcus aureus, Staphylococcus, Polymer, Serum albumin, Bovine serum albumin, Contact angle, Fluorocarbon

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A series of compounds related to piperine and antiepilepsirine was screened in a monoamine oxidase A and B assay. Piperine is an alkaloid from the source plant of both black and white pepper grains, Piper nigrum. Piperine has been shown to have a wide range of activity, including MAO inhibitory activity. The z-factor for the screening assay was found to be greater than 0.8 for both assays. Notably, the compounds tested were selective towards MAO-B, with the most potent compound having an IC(50) of 498nM. To estimate blood-brain barrier (BBB) permeability, we used a PAMPA assay, which suggested that the compounds are likely to penetrate the BBB. A fluorescent bovine serum albumin (BSA) high-throughput screening (HTS) binding assay showed an affinity of 8μM for piperine, with more modest binding for other test compounds. Taken together, the data described here may be useful in gaining insight towards the design of selective MAO-B inhibitory compounds devoid of MAO-A activity.

Concepts: ELISA, Serum albumin, Neurotransmitter, Bovine serum albumin, Dopamine, Monoamine oxidase, Black pepper, Monoamine oxidase A

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Dithiothreitol (DTT)-based displacement is widely utilized for separating ligands from their gold nanoparticle (AuNP) conjugates, a critical step for differentiating and quantifying surface-bound functional ligands and therefore the effective surface density of these species on nanoparticle-based therapeutics and other functional constructs. The underlying assumption is that DTT is smaller and much more reactive toward gold compared with most ligands of interest, and as a result will reactively displace the ligands from surface sites thereby enabling their quantification. In this study, we use complementary dimensional and spectroscopic methods to characterize the efficiency of DTT displacement. Thiolated methoxypolyethylene glycol (SH-PEG) and bovine serum albumin (BSA) were chosen as representative ligands. Results clearly show that (1) DTT does not completely displace bound SH-PEG or BSA from AuNPs, and (2) the displacement efficiency is dependent on the binding affinity between the ligands and the AuNP surface. Additionally, the displacement efficiency for conjugated SH-PEG is moderately dependent on the molecular mass (yielding efficiencies ranging from 60 to 80 % measured by ATR-FTIR and ≈90 % by ES-DMA), indicating that the displacement efficiency for SH-PEG is predominantly determined by the S-Au bond. BSA is particularly difficult to displace with DTT (i.e., the displacement efficiency is nearly zero) when it is in the so-called normal form. The displacement efficiency for BSA improves to 80 % when it undergoes a conformational change to the expanded form through a process of pH change or treatment with a surfactant. An analysis of the three-component system (SH-PEG + BSA + AuNP) indicates that the presence of SH-PEG decreases the displacement efficiency for BSA, whereas the displacement efficiency for SH-PEG is less impacted by the presence of BSA.

Concepts: Nanoparticle, Nanotechnology, Nanomaterials, Serum albumin, Gold, Colloidal gold, Bovine serum albumin, Chloroauric acid

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The ability of grape seed extracts to bind to bovine serum albumin (BSA) and α-amylase was studied by fluorescence quenching of protein intrinsic fluorescence and nephelometry. The influence of grape seed ripeness on astringency was also evaluated. From the spectra obtained, the modified Sterm-Volmer (K(app)) and the bimolecular quenching constants were calculated. Results showed that grape seed extracts had good affinity for proteins. The association strength of tannin-protein interactions varied with changes in tannin structure associated with the degree of ripeness affecting the binding/quenching process. In all cases studied, higher values of K(app) were obtained in samples at harvest which have greater ability to bind to proteins than have samples at post-veraison time. Nephelometric assays show the same trend as do fluorescence quenching studies. A possible explanation for this is that, as seeds ripen, their tannins increase in molecular mass, which relates to an increase in hydrophobicity of the molecules, and this increases protein affinity. However, that is contrary to the reported decrease in astringency of grape seeds during maturity. This indicates that tannin-protein interactions are not the only explanation for the complex sensations of astringency of grape seeds.

Concepts: Molecular biology, Molecule, Serum albumin, Fruit, Catechin, Bovine serum albumin, Tannin, Phenolic compounds in wine

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In spray freeze drying (SFD) solutions are frozen by spraying into a very cold environment and subsequently dried by sublimation. In contrast to conventional freeze drying, spray freeze drying has the possibility to produce flowable lyophilizates which offers a variety of new pharmaceutical applications. Here, a drop jet nozzle is proposed as liquid dispenser that is able to produce droplets with a very narrow size distribution compared to standard methods. The drop jet nozzle is mounted in a spray tower designed to prevent direct contact of the product with the freezing medium. Various formulations have been tested containing lysozyme as model protein and stabilizers such as bovine serum albumin, polyvinylpyrrolidone or dextran in various concentrations and mannitol. Excellent free flowing and nearly monodispersed, porous particles are produced where particle properties can be controlled by formulation and process conditions. The particle diameter varied between 231±3μm and 310±10μm depending on the formulation composition. The lysozyme activity was >94±5% for all formulations exhibiting a full preservation of enzyme activity. This new method is very promising for the production of nearly monodisperse particulate lyophilizates in various therapeutic applications.

Concepts: Enzyme, Serum albumin, Liquid, Bovine serum albumin, Lysozyme, Food preservation, Freeze drying, Sublimation