In particular, Ag-adsorbed NP enhanced T-cell proliferation responses in human PBMC (TT) and mouse splenocytes (HIV gp140). Also, gp140-adsorbed NP greatly enhanced serum IgG and IgA after systemic immunization and, more importantly, induced high levels of vaginal IgG and IgA after intranasal immunization. Solid lipid NP were prepared using a low pressure melt-emulsify-chill (MEC) process. A molten yellow carnauba (YC) wax (Koster Keunen, Watertown, CT) was dispersed into a hot

aqueous emulsifier solution under control shear and then cooled to yield a stable dispersion of solid lipid NP. For the preparation of fluorescence NP, the oil-soluble fluorescent dye Pyrromethene-567A (emission wavelength 546 nm, Exciton, Dayton, OH) was encapsulated in the NP. Cationic, anionic and non-ionic emulsifiers comprised MLN8237 ic50 of long carbon chains were used to stabilize and also modify the surface charge of the NP. Particle size was determined by photon correlation spectroscopy using a Brookhaven BI90

Plus (Brookhaven Instruments, Holtsville, NY). The zeta (Z) potential (a measure of the surface electrical charge) of the NP and Ags was measured in 1 mM KCl by phase analysis light scattering using a Malvern Zetasizer NanoZS90 (Malvern Instruments, Malvern, UK). Particle morphology was analyzed by electron microscopy. Serial dilutions of the NP in nanopure water were dispensed in 400 nl and drops onto a silicon chip, and left to dry. Samples Forskolin were kept in the sputtering chamber at 5 × 102 mbar for about 4 h, and then sputter-coated with 15 nM gold. All images were taken at 20 kV, and at various magnifications using a Hitachi S3500N scanning electron microscope. NP colloidal stability was determined by storing 10% solid NP dispersions in glass vials at 5 °C and 25 °C. Particle size and

zeta potential were measured over a 12 month period as described above. For viscosity assessment, NP suspensions were stored in 125 ml plastic bottles for the length of the stability studies and the viscosity measured at different time points using a Brookfield viscometer LVT (Brookfield Engineering Labs, Middleboro, MA). Spindle #4 (low viscosity sample spindle) was placed directly in the sample, and speed setting 6 was used for all measurements. A clade C HIV-1 envelope clone p97CN54 was originally isolated from a Chinese patient [23] and was made available by H. Wolf and R. Wagner, University of Regensburg, Germany. Trimeric gp140 (gp120 plus the external domain (ED) of gp41), designated CN54 gp140, was produced as a recombinant product in CHO cells and manufactured to GMP specification by Polymun Scientific, Vienna, Austria. Bovine serum albumin (BSA) and TT were obtained from Sigma–Aldrich, Ayrshire, UK and Statens Serum Institute, Denmark, Copenhagen, respectively.