Nanocomposite plasters for the treatment of superficial tumors by chemo-photothermal combination therapy

INTRODUCTION: Novel nanomedical systems are being developed as multiple therapeutic modalities because the combinational therapies for cancer on a single platform can have larger chance to address tumor heterogeneity and drug resistance than any mono-therapeutic modality. METHODS: In this study, photothermal therapy (PTT) and chemotherapy (CT) were combined to treat squamous cell carcinoma by using a novel type of noninvasive plaster composed of carboxylated-reduced graphene oxide (rGO–COOH), gold nanorods (Au NRs), and doxorubicin (DOX). Firstly, DOX was loaded onto rGO–COOH to form DOX_rGO–COOH. Then, the obtained DOX_rGO–COOH and Au NRs were co-assembled to obtain nanocomposite multilayer. rGO–COOH and Au NRs were combined together to obtain high light-to-heat conversion efficiency. Using them as photothermal agents for PTT and using DOX in rGO–COOH as an anticancer drug for CT, their synergistic combination therapy could be applicable practically. RESULTS: As a result, DOX_rGO–COOH/Au NRs showed higher photothermal effects than that showed by rGO–COOH or Au NRs alone. It also showed higher therapeutic effects than DOX_rGO–COOH (for CT) or Au nr (for PTT) alone. Moreover, the system can repeatedly produce heat and simultaneously stimulate the release of the encapsulated anticancer drug into the tumor upon being irradiated by near-infrared laser. In vivo experiments demonstrated that the squamous cell carcinoma-bearing mice treated with DOX_rGO–COOH/Au NRs were healthy for more than 60 days without tumor recurrence. CONCLUSION: The as-developed DOX_rGO–COOH/Au NRs plaster could be an effective, convenient, and noninvasive treatment option for treating superficial tumors.