[Applying Chitosan-Modified Nanoemulsion in Nasal Vaccine Delivery].

OBJECTIVE: To prepare a chitosan-modified cationic nanoemulsion that could be used to prolong the residence time of nasal vaccines in the nasal cavity and improve the cellular uptake efficiency so as to enhance the immune efficacy of nasal vaccines. METHODS: A nanoemulsion-based vaccine coated with chitosan was prepared, and the particle size, potential, antigen encapsulation efficiency, stability as well as cytotoxicity were examined. The uptake efficiency of vaccine on different cells and the residence time of vaccine in the nasal cavity were measured. Finally, nasal vaccine was administered on mice and the antibody levels in the serum and in the nasal lavage fluids of the immunized mice were examined. RESULTS: The nanoemulsion-based vaccine had an average particle size of (167.2±0.75) nm, a polydispersity index (PDI) of 0.21±0.01, and an average potential of (13.7±0.85) mV. The encapsulation efficiency of antigen was 92.7%. The nanoemulsion-based vaccine had good stability and did not show obvious cytotoxicity in Madin-Darby canine kidney (MDCK) epithelial cells. The vaccine demonstrated relatively high cellular uptake of antigens on DC2.4 and MDCK cells at (49.7±3.45)% and (59.7±2.19)%, respectively. Besides, the cationic nanoemulsion also significantly increased the residence time of the antigen, and a considerable amount of nanoemulsion-based vaccine was found remaining in the nasal cavity 60 minutes after administration. Compared with free antigen and the nanoemulsion without chitosan modification, the chitosan-modified nanoemulsion vaccine induced higher systemic and mucosal antibody levels in mice after nasal immunization ( P<0.01). CONCLUSION: The chitosan-modified nanoemulsion vaccine prepared in the study can enhance the immune efficacy of nasal vaccines, showing great potential to be used as a delivery carrier for nasal vaccines.

Extraction of ferulic acid and vanilla acid by hydrophobic ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate.

The study was carried out to evaluate the extraction efficiency of ferulic acid (FA) and vanilla acid (VA) from aqueous phase into IL phase. To achieve the highest extraction efficiency, the influence of varying key parameters was evaluated and optimized by response surface methodology based on Box-Behnken design, including phase volume ratio, extraction temperature and extraction time. FA (or VA) extraction under the optimal conditions were: phase volume ratio of 1.38 (1.28), extraction temperature of 66.34 °C (49.28 °C) and extraction time of 33.83 min (36.64 min) under optimum conditions an average extraction efficiency of 97.11 ± 1.05% for FA was achieved, while VA was 85.43 ± 1.62%. This was very close to the predicted value from the model, 98.05% (86.16%). Additionally, recycling and utilization of ILs were performed well with the recovery ratio for 81.0%. Based on thermodynamic analysis, FTIR and 1H NMR analysis, the combination of hydrophobic interaction and hydrogen-bond interaction resulted in the real extraction result above. It is desirable to provide a useful reference for the separation and purification of FA, VA, and extend the potential application of ionic liquid in the separation of natural active compounds with great prospects.

[Relationship Between Landscape Pattern and Spatial Variation of Heavy Metals in Aquatic Sediments in Headwaters Area of Yuqiao Reservoir].

Yuqiao Reservoir, an important adjusting reservoir in the project of diverting water from the Luanhe River to Tianjin City, is an important water resource for Tianjin City. Concentrations and spatial variation characteristics of Cd, As, Pb, Cu, Cr, and Zn from 33 sub watershed sampling sites of Yuqiao reservoir and the relationship to landscape pattern were discussed. The result showed that average concentrations of Cd, As, Cu, Cr in suspended particulate matter were higher than Chinese environmental quality standard Grade one for soils, and there were ecological risks for them because they could arrive at Yuqiao reservoir. The average concentrations of Cd, As, Pb, Cu, Cr, and Zn in surface sediments were 0.32 mg·kg-1, 30.39 mg·kg-1, 33.49 mg·kg-1, 58.20 mg·kg-1, 90.16 mg·kg-1 and 94.80 mg·kg-1 respectively. The average concentrations of Cd, As, Cu and the concentrations of Pb, Cr, Zn in partial samples exceeded Chinese environmental quality standard Grade one for soils. The average concentrations of Cd, Cr, Zn in surface sediments of three tributaries increased in the order of Linhe River >Shahe River >Lihe Rier, Cu decreased in the order of Linhe River < Shahe River < Lihe River, and As, Pb increased in the order of Shahe River >Linhe River >Lihe Ricer. Land use types in Yuqiao reservoir basin had some impact on the distribution of heavy metal concentrations in river surface sediments. Woodland and shrub grass land determined the natural distribution trend of heavy metals in surface sediments. Gardenland and industrial & mining land usage had impact on Cd, As, Pb, Cr distributions. Farmland and village & town land usage did not produce negative influence on heavy metal distribution.

[Expression of serum Clara cell secretory protein 10 in wheezing children under 5 years old].

OBJECTIVE: To study the expression of serum Clara cell secretory protein 10 (CC10) and total IgE concentration in wheezing children under 5 years old. METHODS: Fifty-nine children with recurrent wheezing under 5 years old were classified into two groups: wheezing group 1 with atopic high risks (n=33) and wheezing group 2 without atopic high risks (n=26). Twenty-three children without infectious diseases served as a control group. Serum levels of CC10 and IgE were measured using a solid-phase sandwich ELISA. RESULTS: The serum levels of CC10 in wheezing group 1 (3.95 ± 1.26 ng/mL) and wheezing group 2 (5.41 ± 1.64 ng/mL) were significantly lower than those in the control group (8.72 ± 2.23 ng/mL; P<0.01). The wheezing group 1 showed more decreased serum levels of CC10 compared with wheezing group 2 (P<0.05). The serum IgE levels in wheezing group 1 were significantly higher than those in wheezing group 2 and the control group (P<0.05). There were no significant differences in serum IgE levels between the wheezing group 2 and control group. There was a negative correlation between serum levels of CC10 and IgE in wheezing group 1 (r=-0.912, P < 0.01). CONCLUSIONS: Serum CC10 levels decrease remarkably in wheezing children, and more significant decrease is noted in patients with atopic high risks. Serum CC10 levels are negatively correlated to serum IgE levels in patients with atopic high risks.