Green (gemini) surfactant mediated gold nanoparticles green synthesis: Effect on triple negative breast cancer cells

Abstract

In this paper, we report the synthesis of gold nanoparticles (AuNPs) using the aqueous neem (Azadirachta indica) fruit extract as a reducing agent and capped by two different capping agents (monomeric surfactant: hexadecyltrimethylammonium chloride (CTAC) and dimeric counterion coupled gemini surfactant (COCOGS): 1, 6-Bis (N,N-hexadecyl dimethylammonium) adipate (16-6-16)). The synthesized AuNPs have been characterized by different modern techniques such as, UV–Visible spectroscopy, HR-TEM, DLS, XRD, FTIR, and XPS analyses, etc. The FTIR measurements were used to evaluate the adsorption of CTAC and COCOGS on the AuNPs surface. A significant shift in the stretching vibrations of CTAC and COCOGS head functional groups suggested their orientation towards the AuNPs surface and was further supported by the high-resolution XPS spectra of CTAC and COCOGS on the AuNPs surface. The main objective of the work is to investigate how to achieve the stability and activity of COCOGS-AuNPs for developing novel anticancer agents against triple negative breast cancer cells (TNBC). Hence, we have synthesized CTAC-AuNPs and COCOGS-AuNPs and evaluated theirs in vitro cytotoxicity against TNBC cell line (MDA-MB-231) as well as in normal NIH3T3 cells. The synthesized COCOGS-AuNPs displayed the excellent cytotoxicity against selected TNBC cell lines without affecting normal cells. In addition to the analysis of cellular apoptosis with mitochondrial membrane potential (Δψm) loss demonstrated an increased apoptotic cell death after 24 h at their dose-dependent concentrations. Thus we conclude that the synthesized AuNPs may directly inhibit the TNBC cell growth and induced the tumor cell autophagy which consequently increasing cellular apoptosis.