Functional TiO nanocoral architecture for light-activated cancer chemotherapy.

To achieve light-triggered drug release in cancer chemotherapy, we developed multimodal titanium dioxide (TiO) nanocorals modified with methoxy polyethylene glycol (mPEG). TiO nanocoral-like structures were synthesized by optimizing a solvothermal method. The developed nanocoral structures were efficiently conjugated with chemotherapeutic drugs on the surfaces of the TiO nanoparticles. The mPEG on the surfaces of the multifunctional nanocorals effectively conjugated the drug and improved the biocompatibility of the nanocorals. Following UV light irradiation, the TiO nanocorals produce free radicals (˙OH and ˙O ) and are effective for drug release in cancer cells. Importantly, the amount of drug released from the multimodal TiO nanocorals can be regulated by UV-light irradiation time, which allows for further control of the anti-cancer effect. The multimodal TiO nanocorals exhibit a combination of light-activated, stimuli-triggered drug release for killing of cancer cell. The cytotoxicity, cellular uptake, and intracellular location of the formulations were evaluated in MCF7 cells. Our results showed that nanocoral-DOX complexes exhibited a greater cytotoxicity toward MCF7 cells than free DOX. Our work demonstrates that the therapeutic efficacy of DOX-loaded TiO nanocorals is strongly dependent on their loading mode and the chemotherapeutic effect is improved under UV light illumination, which provides a significant breakthrough for future applications of TiO as a light activated drug carrier in cancer chemotherapy.