Gold nanorod-assembled PEGylated graphene-oxide nanocomposites for photothermal cancer therapy.

Gold nanorod-attached PEGylated graphene-oxide (AuNR-PEG-GO) nanocomposites were tested for a photothermal platform both in vitro and in vivo. Cytotoxicity of AuNR was reduced after encapsulation with PEG-GO along with the removal of cetyltrimethylammonium bromide (CTAB) from AuNR by HCl treatment. Cellular internalization of the CTAB-eliminated AuNR-PEG-GO nanocomposites was examined using dark-field microscopy (DFM), confocal Raman microscopy and transmission electron microscopy (TEM). To determine the photothermal effect of the AuNR-PEG-GO nanocomposites, A431 epidermoid carcinoma cells were irradiated with Xe-lamp light (60 W cm(-2)) for 5 min after treatment with the AuNR-PEG-GO nanocomposites for 24 h. Cell viability significantly decreased by ~40% when the AuNR-PEG-GO-encapsulated nanocomposites were irradiated with light as compared with the cells treated with only the AuNR-PEG-GO nanocomposites without any illumination. In vivo tumor experiments also indicated that HCl-treated AuNR-PEG-GO nanocomposites might efficiently reduce tumor volumes via photothermal processes. Our graphene and AuNR nanocomposites will be useful for an effective photothermal therapy.