Preparation of stimulus-sensitive gel particles with a DNA-dye complex and their pH sensitivity

Appropriate pretreatment of proteins and addition of xanthan gum (XG) has the potential to improve the stability of oil-in-water (O/W) emulsions. However, the factors that regulate the enhancement and the mechanism are still not clear, which restricts the realization of improving the emulsion stability by directional design of its structure. Therefore, the effects of whey protein micro-gel particles (WPMPs) and WPMPs-XG complexes on the stability of O/W emulsion were investigated in this article to provide theoretical support. WPMPs with different structures were prepared by pretreatment (controlled high-speed shear treatment of heat-set WPC gels) at pH 3.5–8.5. The impact of initial WPC structure and XG addition on Turbiscan Indexes, mean droplet size and the peroxide values of O/W emulsions was investigated. The results indicate that WPMPs and XG can respectively inhibit droplet coalescence and gravitational separation to improve the physical stability of WPC-stabilized O/W emulsions. The pretreatment significantly enhanced the oxidative stability of WPC-stabilized O/W emulsions. The addition of XG did not necessarily enhance the oxidative stability of O/W emulsions. Whether the oxidative stability of the O/W emulsion with XG is increased or decreased depends on the interface structure of the protein-XG complex. This study has significant implications for the development of novel structures containing lipid phases that are susceptible to oxidation.

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Nanocarriers based on block copolymers of l-proline and lactide: the effect of core crosslinking versus its pH-sensitivity on their cellular uptake

European Polymer Journal ◽

10.1016/j.eurpolymj.2021.110572 ◽

2021 ◽

pp. 110572

Author(s):

Marek Brzeziński ◽

Bartłomiej Kost Investigatio ◽

Weronika Gonciarz ◽

Agnieszka Krupa ◽

Marta Socka ◽

...

Keyword(s):

Block Copolymers ◽

Cellular Uptake ◽

Ph Sensitivity

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Potentiometric Carboxylate Sensors Based on Carbazole-Derived Acyclic and Macrocyclic Ionophores

Chemosensors ◽

10.3390/chemosensors9010004 ◽

2020 ◽

Vol 9 (1) ◽

pp. 4

Author(s):

Ville Yrjänä ◽

Indrek Saar ◽

Mihkel Ilisson ◽

Sandip A. Kadam ◽

Ivo Leito ◽

...

Keyword(s):

Detection Limit ◽

Vinyl Chloride ◽

Anion Exchanger ◽

Linear Range ◽

Ph Sensitivity ◽

Ion Selective Electrodes ◽

Solid Contact ◽

Response Characteristics ◽

Potentiometric Response ◽

Poly Vinyl Chloride

Solid-contact ion-selective electrodes with carbazole-derived ionophores were prepared. They were characterized as acetate sensors, but can be used to determine a number of carboxylates. The potentiometric response characteristics (slope, detection limit, selectivity, and pH sensitivity) of sensors prepared with different membrane compositions (ionophore, ionophore concentration, anion exchanger concentration, and plasticizer) were evaluated. The results show that for the macrocyclic ionophores, a larger cavity provided better selectivity. The sensors exhibited modest selectivity for acetate but good selectivity for benzoate. The carbazole-derived ionophores effectively decreased the interference from lipophilic anions, such as bromide, nitrate, iodide, and thiocyanate. The selectivity, detection limit, and linear range were improved by choosing a suitable plasticizer and by reducing the ionophore and anion exchanger concentrations. The influence of the electrode body’s material upon the composition of the plasticized poly(vinyl chloride) membrane, and thus also upon the sensor characteristics, was also studied. The choice of materials for the electrode body significantly affected the characteristics of the sensors.

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