Janus nanoparticles in cancer diagnosis, therapy and theranostics.

Anisotropic Janus nanoparticles (JNPs), due to their several distinct merits, have been widely investigated for cancer theranostics. Firstly, the asymmetric modification of JNPs allows the independent release of multiple drugs. Secondly, the spatial separation of imaging materials effectively diminishes the signal interference and attenuation that usually take place in core-shell or alloy nanoparticles. Thirdly, their asymmetric composition contributes to the photothermal or potential gradient that could drive the motion of JNPs for dynamic drug delivery. This review focuses on the state-of-the-art progress of JNPs for cancer theranostics, including their categorization, fabrication strategies, and biomedical applications in cancer theranostics. The performances of JNPs and conventional core-shell nanoparticles are compared. Last but not least, the challenges and opportunities of JNPs in cancer theranostics are also discussed.