Surface functionalized gold nanorods for plasmonic photothermal therapy

Abstract Gold nanorods (GNR) are considered as potential candidates for varied biological applications. They are synthesized using the cationic surfactant layers such as cetyltrimethylammonium bromide (CTAB), which create the limitation towards biocompatibility quotient. To overcome these issues, CTAB-GNR were functionalized by ligand exchange method in which first step is the pegylation followed by conjugation with RGD (arginine-glycine-aspartic acid) to the pegylated entity. RGD conjugation was done to target the overexpressed αvβ3 integrin present in cancerous cells thereby enhancing the therapeutic response of the developed system for photothermal therapy. GNR of requisite size were synthesized through two step seed mediated growth process and then functionalized with RGD through carbodiimide coupling reaction to get a biocompatible system. The RGD functionalized GNR were characterized by UV–VIS spectroscopy, Fourier transform infrared spectroscopy (FT-IR). In addition, the size and shape of GNR were confirmed using transmission electron microscopy (TEM). The photothermal studies were performed using 808 nm laser diode. Cytotoxicity studies were conducted on MDA-MB-231 cancer cells using MTT Assay.