The influence of different lipid compositions on the surface charge, size, and stability of hybrid NPs was evaluated. Furthermore, the release of KLH from the hybrid NPs in phosphate-buffered saline (PBS), fetal bovine serum (FBS), and human serum was studied.

The in vitro uptake of the hybrid NPs with different surface properties by dendritic cells (DCs) was also studied. It was found that lipid shells made from cationic lipids could improve the stability of NPs, enable more controlled release of antigen, and enhance the uptake of the NPs by DCs. selleck chemicals These results should provide guidance to future design of hybrid NPs for improving drug or antigen delivery. Methods Materials Lactel® 50:50 PLGA was purchased from DURECT Corporation (DURECT Corporation, Cupertino, CA, USA). Lipids, including 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (ammonium salt) (DSPE-PEG2000), and 1,2-diphytanoyl-sn-glycero-3-phosphoethanolamine-N-(7-nitro-2-1,3-benzoxadiazol-4-yl) (ammonium salt) (NBD PE), were purchased from Avanti Polar Lipids, Inc. (Avanti Polar Lipids, Inc., Alabaster, AL, USA). KLH, poly(vinyl alcohol) (PVA; Mw 89,000 to 98,000), dichloromethane, rhodamine B, sodium deoxycholate (DOC), trichloroacetic acid (TCA), sodium dodecyl

sulfate (SDS), paraformaldehyde, and Triton™ X-100 were purchased from Sigma-Aldrich Inc. (Sigma-Aldrich Inc., Saint Louis, MO, USA). 1-Ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride PRN1371 molecular weight (EDC) was purchased from Thermo Fisher Scientific Inc. (Thermo Fisher Scientific Inc., Waltham, MA, USA). JAWSII (ATCC® CRL-11904™) immature DCs were purchased from ATCC (Manassas, VA, USA). FBS, granulocyte-macrophage colony-stimulating factor (GM-CSF)

recombinant mouse protein, minimum essential medium (MEM) α, trypsin/ethylenediaminetetraacetic acid (EDTA), and HCS CellMask™ Blue Stain were purchased from Etofibrate Life Technologies Corporation (Life Technologies Corporation, Grand Island, NY, USA). Fabrication of PLGA-KLH (PK) nanocomplex PLGA-KLH nanocomplex was prepared using double emulsion solvent evaporation method [13]. Briefly, PLGA of 200 mg was dissolved in 5 mL dichloromethane, followed by mixing with 300 μL of 10 mg/mL KLH using a vortex mixer for 2 min. The resulting mixture emulsified via sonication at 20% amplitude for 20 s using a sonic dismembrator (Model 500; Fisher Scientific, Pittsburgh, PA, USA). The primary emulsion was added dropwise into 200 mL 1% (w/v) PVA and stirred for 10 min at 500 rpm. The above suspension was emulsified through sonication at 50% amplitude for 120 s. The secondary emulsion was stirred overnight to allow organic solvent to evaporate. After settling at room temperature for 30 min, precipitant was removed.