A Multifuntional Nanoplatform Based on Responsive Fluorescent Plasmonic ZnO-Au@PEG Hybrid Nanogels

Under a rational design, combining multiple constituents into a single nano-object will not only bridge the unique properties of individual materials to leverage research both fundamentally and practically, but will also improve conventional sensing, imaging, and therapeutic efficacies. Such a nano-object (<100 nm) can be constructed by covalently bonding ZnO quantum dots (QDs) to nonlinear poly(ethylene glycol)-based nanogel network chains, followed by appropriate growth of metallic Au. With the polymer gel network serving as a three-dimensional scaffold, the fluorescence of ZnO QDs can be well protected, while metal Au still retains its surface plasmon resonance property. The ZnO QDs covalently bonded to the thermo-responsive gel network chains can sensitively respond to temperature change of the surrounding fluids over the physiologically important range of 37-42 degrees C, converting the disruptions in homeostasis of local temperature into stable, robust and high-resolution fluorescent signals. The thermoresponsive hybrid nanogels can not only enter into and light up B16F10 cells, but also regulate the release of a model anticancer drug, temozolomide, in response to either local environmental temperature change or external near-infrared light-induced localized hyperthermia from metal Au. The combined chemo-photothermal therapy can significantly improve the therapeutic efficacy due to a synergistic effect.