Temperature/pH dual-responsive and luminescent drug carrier based on PNIPAM-MAA/lanthanide-polyoxometalates for controlled drug delivery and imaging in HeLa cells

In this paper, the luminescent temperature/pH dual-responsive nanoparticles based on lanthanide-polyoxometalates were fabricated as a controllable drug delivery system. In the drug delivery carrier, the mesoporous silica acted as the core, and the poly (N-isopropylacrylamide-co-methacrylic acid) and lanthanide-polyoxometalates served as the dual-responsive shell and luminescent labeling, respectively. Composite hydrogels exhibited red luminescence under UV irradiation, which was visible to the naked eye. The releases of doxorubicin hydrochloride (DOX) from the composites were temperature/pH-dependent. DOX can be quickly released in an acidic environment and at high temperatures. Moreover, the drug delivery carrier showed minimal toxicity to HeLa cells and exhibited good biocompatibility. However, DOX loaded drug-delivery system showed the significant toxicity to HeLa cancer cells in vitro. Cell imaging has shown that lanthanide polyoxometalates composites can be used as bioimaging materials for cell monitoring. As a result, the drug delivery systems based on lanthanide-polyoxometalates have potential applications in the field of biomedical science.