CuS as a gatekeeper of mesoporous upconversion nanoparticles-based drug controlled release system for tumor-targeted multimodal imaging and synergetic chemo-thermotherapy

In this work, the core-shell mUCNPs served as drug carrier exhibiting higher UCL emission intensity, with CuS as a gatekeeper through disulfide bond cleavable under the influence of GSH. CuS could not only prevent drug from early release during the delivery but also improve the delivery system function with the ability of photothermal therapy and photoacoustic tomography. HA grafted on the surface of mUCNPs could interact with CD44 receptors overexpressed in tumor cells, facilitating the drug delivery system to accumulate in tumor tissues with high targeting ability. In cooperation with the UCL/MR/PAT imaging, the size, site and morphology of tumor were clearly observed throughout the tumor disease. As a whole, the smart drug delivery system will exert potential theranostic effect in future tumor diagnosis and treatment.302