A Novel Microwave Stimulus Remote Controlled Anticancer Drug Release System Based on FeO@ZnO@mGdO:Eu@P(NIPAm-co-MAA) Multifunctional Nanocarriers

The design of stimuli-responsive controlled drug delivery systems is a promising approach in cancer therapy, but it is still a major challenge to be capable of optimum therapeutic efficacy. Herein, we have elaborately fabricated FeO@ZnO@mGdO:Eu (mGdO:Eu was short for mesoporous GdO:Eu) multifunction composite nanoparticles by a simple process, with mesoporous GdO:Eu shells as supports to increase the anticancer drug loading and thermally responsive polymer poly[(N-isopropylacrylamide)-co-(methacrylic acid)] (P(NIPAm-co-MAA)) gated mesoporous shells as microwave stimulus gatekeepers. The as-synthesized hybrid nanoparticles show a large accessible pore volume (0.19 cm g) and a high magnetization saturation value (27.8 emu g) for drug loading and targeting. The ZnO shells can effectively absorb and convert microwave to heat upon irradiation with microwaves, as a result of the microwave irradiation P(NIPAm-co-MAA) shrinks to a smaller volume and exposes the pores of the mesoporous luminescent shell, realizing the triggered release of the entrapped etoposide (VP16) drug (under microwave irradiation the VP16 release was about 81.7% within 10 h). In vitro studies show the multifunctional nanocarrier feasibility and advantage for remote-controlled drug release systems.