Role of Surface Hydrophobicity of Dicationic Amphiphile-Stabilized Gold Nanoparticles on A549 Lung Cancer Cells.

Herein, we report the surface functionality of dicationic cysteamine conjugated cholic acid (DCaC), dicationic cysteamine conjugated deoxycholic acid (DCaDC), and dicationic cysteamine conjugated lithocholic acid (DCaLC) templated gold nanoparticles (AuNPs) on mammalian cells. The haemocompatibility of the synthesized NPs was evaluated by in vitro hemolysis and erythrocyte sedimentation rate using human red blood cells (RBCs). In all of the systems, no toxicity was observed on human erythrocytes (RBCs) up to the concentration of 120 µg/mL. The anticancer activity of these dicationic amphiphile-stabilized AuNPs on A549 lung cancer cells was demonstrated by in vitro cell viability assay, intracellular reactive oxygen species estimation by DCFH-DA, apoptosis analysis using AO-EtBr fluorescence staining, DNA fragmentation analysis by agarose gel electrophoresis, and western blot analysis of caspase-3 expression. These results suggest that the cytotoxicity of AuNPs to A549 cells increase with the dose and hydrophobicity of amphiphiles and were found to be in the order: DCaLC-AuNPs > DCaDC-AuNPs > DCaC-AuNPs.

Auric Chloride Induced Micellization on Fractal Patterned Dicationic Amphiphiles and Stabilization of Gold Nanoparticles.

The present article reports the development of sunlight-mediated rapid synthesis of bile acid derived dicationic amphiphiles, namely, dicationic cysteamine-conjugated cholic acid (DCaC), dicationic cysteamine-conjugated deoxycholic acid (DCaDC), and dicationic cysteamine-conjugated lithocholic acid (DCaLC) by adopting thiol-yne click chemistry approach. The auric chloride (AuHCl4) induced micellization of amphiphiles from fractal pattern to chainlike aggregates was examined by critical micelle concentration measurements, quenching studies, field emission scanning electron microscopy, and optical microscopy techniques. The micelles thus formed act as ideal templates for the stabilization of gold nanoparticles (AuNPs) and exhibit good stability for more than 6 months. The synthesized AuNPs were characterized using UV-visible spectroscopy, high-resolution transmission electron microscopy, DLS, zeta potential, and contact angle measurements. These NPs showed high salt tolerance, and the levels were found to be 420, 460, and 580 mM for DCaC-, DCaDC-, and DCaLC-capped AuNPs, respectively.