Abstract
Cancer is still one of the main death causes worldwide. Recently the use of nanotechnology in nanobiomedicine is considered as one of the most promising research applications, nanotechnology is providing an exceptional opportunity to improve the treatment of various diseases particularly cancer. This is highly due to the unique chemical and physical properties that are observed at the nanoscale. Gold nanorods (GNRs) in specific show a surface plasmon resonance (SPR) band at the near infra-red (NIR) region for this reason they have been widely studied in biomedical research and are of great interest for the development of nanomedicine precisely phototherapy of cancer and drug delivery. The goal of the current study was to investigate the stability of GNRs in biological media and subsequently assesse their cytotoxic properties and photo killing ability on colorectal cancer (CaCo-2) cells. In this study The GNRs were firstly characterised by, Zeta potential (ζ-potential), ultraviolet–visible (UV–Vis) spectroscopy, and transmission electron microscopy (TEM). The potential cytotoxic effects of the GNRs onto CaCo-2 cell lines were assessed using inverted light microscopy for morphological changes, Trypan blue exclusion assay and (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) for viability, adenosine triphosphate luminescence and cell impedance studies for proliferation, and lactate dehydrogenase membrane integrity assay for potential cell damage. The characterisation results showed that the physicochemical properties of the GNRs in Dulbecco's Modified Eagle's medium (DMEM) were maintained when compared to GNRs suspended in DI water. The GNRs showed a slight increase in size through aggregation but retained their charge. Upon Irradiation at a wavelength of 660 nm, GNRs decreased cell viability and proliferation, increased cell damage. In conclusion, this work clearly demonstrates that GNRs activated at 660 nm significantly increase cytotoxicity induced in CaCo-2 cells.