Self-Assembled Responsive Bilayered Vesicles with Adjustable Oxidative Stress for Enhanced Cancer Imaging and Therapy

In the present study, we report the development of magnetic–plasmonic bilayer vesicles assembled from iron oxide–gold Janus nanoparticles (Fe3O4–Au JNPs) for reactive oxygen species (ROS) enhanced chemotherapy. The amphiphilic Fe3O4–Au JNPs were grafted with poly(ethylene glycol) (PEG) on the Au surface and ROS-generating poly(lipid hydroperoxide) (PLHP) on the Fe3O4 surface, respectively, which were then assembled into vesicles containing two closely attached Fe3O4–Au NPs layers in opposite directions. The self-assembly mechanism of the bilayered vesicles was elucidated by performing a series of numerical simulations. The enhanced optical properties of the bilayered vesicles were verified by the calculated results and experimental data. The vesicles exhibited enhanced T2 relaxivity and photoacoustic properties over single JNPs due to the interparticle magnetic dipole interaction and plasmonic coupling. In particular, the vesicles are pH responsive and disassemble into single JNPs in the acidic tumor envi...