Gold Nanorod/Reduced Graphene Oxide Composite Nanocarriers for Near-Infrared-Induced Cancer Therapy and Photoacoustic Imaging

Recently, various multifunctional nanomaterials have attracted attention as promising theranostic systems for effective diagnosis, bioimaging, and therapy of cancer. In this study, we designed multifunctional nanocarriers based on partially reduced graphene oxide (PrGO) and gold nanorods (AuNRs) for near-infrared (NIR)-induced synergistic photodynamic therapy (PDT)/photothermal therapy (PTT) and photoacoustic (PA) imaging. We synthesized AuNR/PrGO composite nanocarriers that combine photosensitizers (PSs) and tumor targeting ligands. The AuNR/PrGO composite nanocarriers (AuNR/FP-PrGO-Ce6) showed a unimodal size distribution of approximately 386.9 nm and excellent stability in aqueous solution. They also exhibited significantly improved generation kinetics of singlet oxygen and great photothermal conversion efficiency. Furthermore, the sample AuNR/FP-PrGO-Ce6 showed a PA signal intensity that was 2.4 times stronger than that of bare AuNR under the same conditions. Our measurements by confocal microscope and flow cytometry indicate that AuNR/FP-PrGO-Ce6 nanocarriers were internalized successfully in MCF7 cells (a cell line with folate receptor overexpression) due to the active targeting property of the FA ligand. Compared to free PS, the AuNR/FP-PrGO-Ce6 nanocarriers showed significant synergistic effects on PDT/PTT, destroying 95% of cancer cells by irradiating simultaneously with 670 and 880 nm lasers for 5 min. These multifunctional AuNR/PrGO composite nanocarriers are a promising approach for applications in anticancer theranostics.