Selective Growth Synthesis of Ternary Janus Nanoparticles for Imaging-Guided Synergistic Chemo- and Photothermal Therapy in the Second NIR Window.

Multifunctional therapeutic agents in the second near-infrared (NIR-II) window have attracted wide attention on account of their synergetic properties for effective cancer therapy. Here, we construct a selective growth strategy for the first time to fabricate ternary Janus nanoparticles (JNPs) containing hemispherical MnO2 at one side and Au core covered with CuS shell at opposite side. The obtained ternary JNPs are further modified with poly(ethylene glycol)thiol to enhance the stability and biocompatibility (designated as PEG-CuS-Au-MnO2 ternary JNPs). The MnO2 domain with mesoporous structures can serve as hydrophobic drug carriers and magnetic resonance (MR) imaging contrast agents. Meanwhile, the Au segment is used for X-ray computed tomography (CT) imaging. Moreover, the PEG-CuS-Au-MnO2 ternary JNPs can conduct hyperthermia at 1064 nm in NIR-II window to ablate tumors in deep tissue, which is ascribed to the localized surface plasmon resonance coupling effect of the Au core and CuS domain. All of the results reveal that PEG-CuS-Au-MnO2 ternary JNPs not only exhibit pre-eminent CT/MR imaging capabilities, but also provide high chemo-photothermal antitumor efficacy under the guidance of CT/MR imaging. Taking together, the PEG-CuS-Au-MnO2 ternary JNPs can be regarded as a prospective therapeutic nanoplatform for dual-modal imaging-guided synergistic chemo-photothermal cancer therapy in the NIR-II window.