Theranostic Approach for Cancer Treatment: Multifunctional Gold Nanorods for Optical Imaging and Photothermal Therapy

A critical problem in the treatment of cancer is the inability to identify microsized tumors and treat them without normal tissue destruction. While surgical excision of tumors is highly effective, residual micrometastases and remaining positive margins are the main cause of recurrence. In this study, we propose a theranostic approach for the detection and therapy of head and neck cancer (HNC). We developed a plasmonic-based nanoplatform for combined, ultrasensitive in vivo spectroscopic detection and targeted therapy of HNC. This detectionmethod involves near-infrared (NIR) spectroscopy of gold nanorods (GNRs) that selectively target and attach to squamous cell carcinoma HNC cells, through an immune complex. Diagnosis is based on a spectral shift analysis, which is generated by interparticle-plasmon-resonance patterns of the specifically targeted GNRs. Additionally, the ability to design the GNRs to strongly absorb light in the NIR region enables efficient irradiation of these GNRs, for selective photothermal therapy (PTT) of the cancer cells. We expect this targeted, noninvasive, and nonionizing spectroscopic detection method to provide a highly sensitive and simple diagnostic tool for micrometastasis. In addition, the concomitant development of targeted PTT, based on specific cancer markers, may pave the way for tailoring effective therapy for patients, toward an era of personalized medicine.