A novel zein-selenium complex nanoparticle with controllable size: Quantitative design, physical properties and cytotoxicity in vitro.

In this study, after proposing a method for the preparation of selenium nanoparticles (Se NPs) with stable properties using zein, the physico-chemical properties of zein-Se NPs were tested. The complex structure of zein-Se NPs was deduced by SEM, and the binding mechanism was determined by FT-IR and XPS. The particle size of zein-Se NPs could be regulated from 11.4 ± 0.1 nm to 138.7 ± 0.9 nm under different preparation parameters, the reason for the change in particle size had been speculated. The pH responsiveness and 30-day storage stability of the zein-Se NPs were discussed. The zein-Se NPs still had strong DPPH radical scavenging activity after heat treatment. The zein-Se NPs were cell-friendly and was able to effectively protect cells from H2O2-induced cell-death. This study performed an extensive determination of the underlying physico-chemical properties of zein-Se NPs, we anticipate this approach will open up new possibilities in using natural material to stabilize Se NPs.

Fabrication of food grade zein-dispersed selenium dual-nanoparticles with controllable size, cell friendliness and oral bioavailability.

In this study, novel bioavailable selenium nanoparticles with controllable particle size and low toxicity were developed. With selenium modified zein nanoparticles (zein NPs) in-situ, dispersed nano-selenium particles with different structure were formed simultaneously. The particle size, zeta potential, morphology and binding mechanism of synthesized zein-selenium nanoparticles (zein-Se NPs) were systematically discussed. Selenium was considered to be combined with OH and -CO-NH- groups of zein. The selenium in the complex particles presented an amorphous structure with zero valence. The cytotoxicity of zein-Se NPs was significantly lower than that of sodium selenite, even exhibited a growth-promoting effect on normal liver cells (L-02), and were proven to be orally absorbed by organisms in vivo experiments. The difference in particle structure had certain effects on cytotoxicity and oral targeting. The complex particles obtained by this method were anticipated be further used as food fortifiers or medicines.

Development, characterization and in vitro bile salts binding capacity of selenium nanoparticles stabilized by soybean polypeptides.

The paper presents the positive effect of soybean polypeptides (SP) on the stability and the potential hypolipidemic effect of selenium nanoparticles (SeNPs). After preparing SeNPs, SP with different molecular weight were introduced to stabilize SeNPs. We found that the SP with molecular weight >10 kDa (SP5) had the best stabilizing effect on SeNPs. We inferred that the steric resistance resulting from the long chains of SP5 protected SeNPs from collision-mediated aggregation, and the electrostatic repulsions between SP5 and SeNPs also played a positive role in stabilizing SeNPs. The as-prepared SP5-SeNPs were spherical, amorphous and zero valent. It was proved that SeNPs were bound with SP5 through O- and N- groups in SP5, and the main forces were hydrogen bonds and van der Waals forces. The bile salts binding assay showed that the SP5-SeNPs exhibited a high binding capacity to bile salts, which indicated their potential in hypolipidemic application.

Microgel-Stabilized Hydroxypropyl Methylcellulose and Dextran Water-in-Water Emulsion: Influence of pH, Ionic Strength, and Temperature.

A stable water-in-water (W/W) emulsion was formed by mixing dextran and hydroxypropyl methylcellulose (HPMC) with addition of ß-lactoglobulin (Blg) microgels. The microstructure and stability of the W/W emulsion were investigated under different conditions. The microgels accumulating at the liquid-liquid interface led to a stable emulsion at pH 3-5, where the microgels carried positive charges. When the pH was increased above the pI of microgels (∼pH 5), the emulsion was destabilized because the microgels tended to stay in the continuous phase (i.e., dextran) rather than at the interface. The HPMC-in-dextran emulsions were stable under ionic strength levels up to 300 mM. The HPMC-in-dextran emulsion stabilized by Blg microgels was thermally stable, and the heat treatment promoted partial Blg microgel particle-particle fusion on the surface of HPMC droplets at 90 °C. Electrostatic and hydrophobic interactions between dextran and HPMC phase were further investigated to understand the microgels' accumulation at the liquid-liquid interface.

The formation of zein-chitosan complex coacervated particles: Relationship to encapsulation and controlled release properties.

The complex coacervation between zein and chitosan (CS) as well as the relationship with the controlled release properties of their complex nanoparticles were studied. The factors influencing the nanoparticle formation between zein and CS, including solid to liquid ratio, zein to CS ratio and pH, were systematically investigated. The isothermal titration calorimetry (ITC) showed that zein-CS interaction was spontaneous exothermic process. The pH the higher was, the stronger the interaction between zein and CS. The mean particle sizes of ZCNPs were increased by enhanced turbidity between zein and CS (from 90.89 nm to 1368.77 nm). The morphology study showed that spherical particles and coacervate were obtained with the increased interaction between zein and CS. The release profiles of curcumin in vitro indicated that slight burst effect followed by slow release was observed after interacting CS. The ZCNPs at pH 4.0 exhibited smaller particle size (162.07 nm), more stable ζ-potential (49.7 mV), higher encapsulation efficiency (94.67%) and slower release rate. In conclusion, the stronger the interaction was, the lower the curcumin released from the nanoparticles in vitro, and the ZCNPs at pH 4.0 had better potential in oral delivery application.

Development, physicochemical characterization and cytotoxicity of selenium nanoparticles stabilized by beta-lactoglobulin.

Novel Selenium nanoparticles (SeNPs) were developed using beta-lactoglobulin (Blg) as a stabilizer in redox systems of selenite and ascorbic acid in this study. Particle size, morphology, stability, and in vitro biological activity of synthesized Blg stabilized selenium nanoparticles (Blg-SeNPs) were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), ultraviolet-visible spectrophotometry (UV/Vis), and cell toxicity assays, respectively. Stabilizing mechanisms of Blg-SeNPs were investigated by Fourier-transform infrared spectroscopy (FTIR) and protein fluorescence probe. The results revealed that the Blg-SeNPs were spherical with mean particle size of 36.8±4.1nm. They were stable in acidic or neutral to basic solutions (pH 2.5-3.5 or 6.5-8.5) at 4°C for 30days as a result of electrostatic repulsions. FTIR results showed that functional groups of NH2 and OH on Blg molecules were responsible for binding with SeNPs. Furthermore, decreases in protein surface hydrophobicity indicated that possible binding happened between Se and the hydrophobic domains of Blg. The cell toxicity of Blg-SeNPs was significantly lower than that of sodium selenite on both cancerous and non-cancerous cells. This study provides a facile and green method for chemically synthesizing stable SeNPs which are suitable for further evaluation in medicinal applications.

Structural characterization and dissolution profile of mycophenolic acid cocrystals.

Three novel cocrystals of mycophenolic acid (MPA) with isonicotinamide (MPA-ISO), minoxidil (MPA-MIN) and 2,2'-dipyridylamine (MPA-DPA) as coformers have been prepared successfully by both slow evaporation and liquid-assisted grinding. The structures of these cocrystals show that all the three coformers form hydrogen bonds with the carboxylic acid group of MPA. The cocrystal MPA-ISO possesses remarkably improved solubility and dissolution rate, while two other cocrystals exhibit the opposite characteristics. The solids in the slurry with pH6.8 phosphate buffer and cocrystals remain as the incipient cocrystal after 24h. However, evidence of slight polymerization was shown in the slurry of pH6.8 phosphate buffer with MPA and MPA-ISO cocrystal.