Janus nanostructures formed by mesoporous silica coating Au nanorods for near-infrared chemo–photothermal therapy

It is challenging to develop a chemo–photothermal combination therapy using Au-based nanostructures. Au nanorods (AuNRs) provide an attractive method for treating solid tumors in a minimally invasive manner because of their capability of converting the absorbed radiation into heat energy. Although anisotropic AuNRs possess an excellent photothermal effect, the addition of other therapeutic agents is still needed for enhanced antitumor efficiency. With the aim of finding a combination therapy, in the present study, mesoporous silica (mSiO2) was employed to partly coat AuNRs to build a Janus AuNRs@mSiO2 as a chemo–photothermal platform. The experimental results indicate that the mSiO2 shell apparently reduces the cytotoxicity of AuNRs. In addition, the coated mSiO2 can load doxorubicin (DOX) for chemotherapy, resulting in the improved chemo–photothermal therapy of Janus AuNRs@mSiO2–DOX compared with the single photothermal therapy of AuNRs. This work provides an alternative approach for establishing a multifunctional platform based on Au nanostructures for biomedical applications.