Hydrophobically Associating Polyacrylamide "Water-in-Water" Emulsion Prepared by Aqueous Dispersion Polymerization: Synthesis, Characterization and Rheological Behavior.

The hydrophobically associating polyacrylamide (HAPAM) is an important kind of water-soluble polymer, which is widely used as a rheology modifier in many fields. However, HAPAM products prepared in a traditional method show disadvantages including poor water solubility and the need for hydrocarbon solvents and appropriate surfactants, which lead to environmental pollution and increased costs. To solve these problems, we reported a novel kind of HAPAM "water-in-water" (w/w) emulsion and its solution properties. In this work, a series of cationic hydrophobic monomers with different alkyl chain lengths were synthesized and characterized. Then, HAPAM w/w emulsions were prepared by the aqueous dispersion polymerization of acrylamide, 2-methylacryloylxyethyl trimethyl ammonium chloride and a hydrophobic monomer. All these emulsions can be stored more than 6 months, showing excellent stability. An optical microscopy observation showed that the particle morphology and the particle size of the HAPAM emulsion were more regular and bigger than the emulsion without the hydrophobic monomer. The solubility tests showed that such HAPAM w/w emulsions have excellent solubility, which took no more than 180 s to dilute and achieve a homogeneous and clear solution. The rheology measurements showed that the HAPAM association increases with a hydrophobe concentration or the length of hydrophobic alkyl chains, resulting in better shear and temperature resistances. The total reduced viscosity was 124.42 mPa·s for cw101, 69.81 mPa·s for cw6-1, 55.38 mPa·s for cw8-0.25, 48.95 mPa·s for cw12-0.25 and 28 mPa·s for cw16-0.25 when the temperature increased from 30 °C to 90 °C. The cw8-2.0 that contains a 2 mol% hydrophobe monomer has the lowest value at 19.12 mPa·s due to the best association. Based on the excellent stability, solubility and rheological properties, we believe that these HAPAM w/w emulsions could find widespread applications.

A Gemini-Type Superwettable Separator for Consecutive Purification of Water and Oil Phases from Oil-Water Mixtures and Emulsions.

Oil pollution results from daily activities and a variety of industries have caused not only severe environmental problems but also wastage of valuable petrochemical resources. Separation based on superwettable materials holds promise; however, practical applications of a single type of superwettable materials were often limited due to their ability in treatment of complicated oil-water systems. Herein, a Gemini-type separator was created through the cooperation of two kinds of superwettable sand particles with opposite wettability, i. e., one is superhydrophobic whereas the other is superhydrophilic. Cooperatively by the two types of superwettable sand, consecutive separation and purification of both water and oil phases from complicated oil-water systems (e. g., water mixed with a lighter or denser oil, water emulsified in oil, oil emulsified in water, and/or a combination of them in one batch) could be achieved with high flux and superior efficiency just in one single operation unit.

Self-assembled chitosan nanoparticles for intranasal delivery of recombinant protein interleukin-17 receptor C (IL-17RC): preparation and evaluation in asthma mice.

Asthma is mentioned as a chronic airway inflammatory disease, whose pathogenesis is complicated. The promotion of inflammation in asthma by IL-17A and IL-17F has been confirmed. In addition to covalent homodimers, both cytokines are also able to form heterodimers, further inducing downstream pathways via binding to the IL-17RA and IL-17RC receptor complex. In recent years, IL-17RA and its signal transduction pathway have been extensively researched. IL-17RC, however, remains relatively unexplored. In the present study, we self-assembled chitosan (CS) nanoparticles for intranasal delivery of recombinant protein IL-17RC (rIL-17RC) and preliminarily investigated its effect on a murine model of allergic asthma induced by ovalbumin (OVA). rIL-17RC was produced by the prokaryotic expression system and encapsulated into the CS nanoparticles via ionic cross-linking technique. The results showed that CS-RC nanoparticles via intranasal intervention significantly caused inhibition of mucus secretion and airway inflammatory cell infiltration, and reduced IL-4, IL-17, IL-17F levels in BALF. Hence, delivering receptor proteins such as IL-17RC, through CS nanoparticles as a carrier, could be an attractive therapeutic intervention for asthma.

The effect of cadmium on Aß levels in APP/PS1 transgenic mice.

Cadmium (Cd), which is a poisonous trace element, has been reported extensively to lead to morphological and biochemical abnormalities of the central nervous system, memory loss and mental retardation. We studied the Alzheimer's disease-related toxicity of Cd in a mouse model [amyloid precursor protein (APP)/ presenilin 1 (PS1) transgenic mice, dual transfection of APP695swe and mutated PS1 genes]. Behavioral changes were detected using the Morris water maze test. The ß-amyloid protein (Aß) levels were determined using immunohistochemistry and ELISA. The free zinc ion concentration in mouse brain was determined using autometallography. The protein expression of α-secretase, soluble APPα (sAPPα) and neutral endopeptidase (NEP) in the mouse cerebral cortex and hippocampus was detected using western blotting. We found that Cd treatment increased the latency and distance of the platform search and reduced the number of platform crossings. The number and size of senile plaques in the brains of Cd-treated mice were significantly increased. The levels of Aß(1-42) and free zinc ions were increased. The expression of ADAM10, sAPPα and NEP protein was reduced. We speculated that Cd reduced the expression of ADAM10, sAPPα and NEP protein, which caused an increase in the levels of Aß(1-42) and free zinc ions and led to the accelerated Aß deposition found in the experimental animals and their abnormal behavior.