Effective cancer treatment by targeted pH sensitive–gold nanoparticles without using laser irradiation

In this article, gold nanoparticles <5 nm, coated with two different natural ligand; Bovine Serum Albumin (BSA) and Glutathione (GSH) was applied in cancer treatment, by exploiting the physiochemical properties of them (size, surface charge and the chemistry of the coating ligand). Gold nanoparticles were prepared and characterized using Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), Zeta potential, and UV–Vis spectrophotometer. The nano-complex (BSA-AuNPs and GSH-AuNPs) was applied against Rhabdomyosarcoma (RD) cancer and Lymphocytosis normal cell lines, in vitro. The cytotoxicity effect of the complex was evaluated by MTT assay, after cells incubation with different concentrations (0.125, 0.25, 0.5, 1 mg/ml), for 24 and 48 h. The results demonstrated that the smaller sized GSH-AuNPs (~3 nm) exhibit more selective targeting and toxicity effect in cancer cells than BSA-AuNPs (≥3 nm) at all nanoparticles concentrations, by the impact of the isoelectric point (IP) impact of GSH (~ 6) that is a near value of the pH of the cancer cell, in comparison with that of BSA (~5). Whereas no toxic effect have been investigated for normal cells. These results make the GSH-AuNPs more pH-sensitive to the acidic cancer environment. This study promises that small-sized AuNPs will act as a simple therapeutic agent for cancer diseases, targeting the deep, irregular, and complicated cancer regions of the human body, subsequently dispense the usage of laser light irradiation in photothermal therapy.