Nanoparticles of varying composition, size, shape, and architecture have been explored for use as photothermal agents in the field of
cancer nanomedicine. Among them,
gold nanoparticles provide a simple platform for thermal ablation owing to its biocompatibility in vivo. However, the synthesis of such
gold nanoparticles exhibiting suitable properties for photothermal activity involves cumbersome routes using toxic chemicals as capping agents, which can cause concerns in vivo. Herein,
gold nanoparticles, synthesized using green chemistry routes possessing near-infrared (NIR) absorbance facilitating
photothermal therapy, would be a viable alternative. In this study, anisotropic
gold nanoparticles were synthesized using an aqueous route with cocoa extract which served both as a reducing and
stabilizing agent. The as-prepared
gold nanoparticles were subjected to density gradient centrifugation to maximize its NIR absorption in the wavelength range of 800-1000 nm. The particles also showed good biocompatibility when tested in vitro using A431, MDA-MB231, L929, and NIH-3T3 cell lines up to concentrations of 200 μg/mL. Cell death induced in
epidermoid carcinoma A431 cells upon irradiation with a femtosecond
laser at 800 nm at a low power density of 6 W/cm(2) proved the suitability of green synthesized NIR absorbing anisotropic
gold nanoparticles for photothermal ablation of
cancer cells. These
gold nanoparticles also showed good X-ray contrast when tested using computed tomography (CT), proving their feasibility for use as a
contrast agent as well. This is the first report on green synthesized anisotropic and cytocompatible
gold nanoparticles without any capping agents and their suitability for
photothermal therapy.