Gold Nanorod−Photosensitizer Complex for Near-Infrared Fluorescence Imaging and Photodynamic/Photothermal Therapy <i>In Vivo</i>

Abstract

A gold nanorod (GNR)-photosensitizer complex was developed for noninvasive near-infrared fluorescence imaging and cancer therapy. We showed that (a) fluorescence emission and singlet oxygen generation by AlPcS(4) were quenched after complex formation with GNRs; (b) 4-fold greater intracellular uptake and better in vitro phototoxicity were observed in GNR-AlPcS(4)-treated cells than in free AlPcS(4)-treated cells; and (c) after intravenous injection of the GNR-AlPcS(4) complex, tumor sites were clearly identified on near-infrared fluorescence images as early as 1 h after injection. The tumor-to-background ratio increased over time and was 3.7 at 24 h; tumor growth reduced by 79% with photodynamic therapy (PDT) alone and by 95% with dual photothermal therapy (PTT) and PDT. This novel multifunctional nanomedicine may be useful for near-infrared fluorescence imaging and PTT/PDT in various cancers.