Preparation of a cationic nanoemulsome for intratumoral drug delivery and its enhancing effect on cellular uptake in vitro

Abstract

To develop an appropriate carrier for intratumoral drug delivery, cetyltrimethylammonium bromide (CTAB) modified nanoemulsome (CTAB-NES) was designed and prepared by solvent evaporation method. Coumarin-6 was chosen as the fluorescent probe and the conventional nanoemulsome (NES) without CTAB modification served as a control. The results demonstrated that CTAB-NES had a smaller particle size of 71.9 +/- 4.32 nm, considerate positive zeta potential of +48.7 +/- 0.2 mV, preferably entrapment efficiency of 97.483 +/- 0.693% and the release of coumarin-6 in 24 h was little. The in vitro cytotoxicity of CTAB-NES to the CHO cells and MCF-7 cells increased consistently with concentrations and was higher than that of NES, especially to the cancer cells. Both the fluorescence microscopy images and HPLC assay verified that the cellular uptake of CTAB-NES in MCF-7 cells was much higher than that of NES, and the uptake was time-, concentration- and temperature- dependent. The uptake mechanism results demonstrated that the internalization of CTAB-NES and NES involved clathrin- and caveolae-mediated endocytosis while macropinocytosis only influenced the uptake of CTAB-NES in MCF-7 cells for CTAB could mediate adsorptive pinocytosis. Thus, CTAB-NES with high positive charge and good intracellular uptake ability could be a promising drug carrier for intratumoral drug delivery.