Fabrication of Spindle-like ZnO@Fe3O4 Nanocarriers for Targeted Drug Delivery and Controlled Release

Developing precise tumor-targeting delivery systems while minimizing off-target toxicity continues to pose significant challenges in medicine application. The integration of two different functional materials has emerged as a promising strategy in current biomedical research. Herein, a hybrid nanocomposite consisting of Fe3O4 and ZnO was synthesized via a simple approach and employed as a nanoscale drug delivery system to explore the loading capacity and stimuli-responsive release characteristics of the anticancer agent doxorubicin (DOX). Results show that the synthesized nanoparticles (NPs) exhibit a multi-scale nanostructure consisting of the spindle-like ZnO nanorods with a mean length of 280 nm, on which the Fe3O4 NPs with a diameter of around 16 nm are uniformly dispersed. The ZnO@Fe3O4 NPs possess superparamagnetic behavior and a fast response to the external magnet and demonstrate exceptional near-infrared (NIR) photothermal conversion efficiency. In drug release studies, the ZnO@Fe3O4 NPs achieve the controlled DOX release in the simulated acidic tumor microenvironment as well as NIR laser irradiation. Further, the ZnO@Fe3O4-DOX composites significantly suppress the viability of human cervical cancer cells (HeLa) upon laser activation. These findings suggest that ZnO@Fe3O4 NPs are promising candidates for combined photothermal therapy, magnetic-targeted drug delivery, and stimuli-responsive controlled release applications.