In Vivo Multimodality Imaging and Cancer Therapy by Near-Infrared Light-Triggered <i>trans</i>-Platinum Pro-Drug-Conjugated Upconverison Nanoparticles

TLDR

Controlling anticancer drug activity on demand is crucial, and photoactivated platinum(IV) pro‑drugs are stable in the dark but require UV activation, whereas NIR offers deeper tissue penetration and lower harm. The study develops a multifunctional drug delivery system that integrates trimodal imaging with NIR‑activated platinum pro‑drug delivery. Core‑shell upconversion nanoparticles convert absorbed NIR light into UV to activate the trans‑platinum(IV) pro‑drug and deliver it into cells via endocytosis. In mice, NIR‑irradiated pro‑drug‑conjugated nanoparticles more effectively inhibited tumor growth than direct UV, and the nanocomposite serves as a multimodal imaging contrast agent and NIR‑to‑UV drug activator for practical cancer therapy.

Abstract

Controlling anticancer drug activity and release on demand is very significant in cancer therapy. The photoactivated platinum(IV) pro-drug is stable in the dark and can be activated by UV light. In this study, we develop a multifunctional drug delivery system combining upconversion luminescence/magnetic resonance/computer tomography trimodality imaging and NIR-activated platinum pro-drug delivery. We use the core-shell structured upconversion nanoparticles to convert the absorbed NIR light into UV to activate the trans-platinum(IV) pro-drug, trans,trans,trans-[Pt(N3)2(NH3)(py)(O2CCH2CH2COOH)2]. Compared with using the UV directly, the NIR has a higher tissue penetration depth and is less harmful to health. Meanwhile, the upconversion nanoparticles can effectively deliver the platinum(IV) pro-drugs into the cells by endocytosis. The mice treated with pro-drug-conjugated nanoparticles under near-infrared (NIR) irradiation demonstrated better inhibition of tumor growth than that under direct UV irradiation. This multifunctional nanocomposite could be used as multimodality bioimaging contrast agents and transducers by converting NIR light into UV for control of drug activity in practical cancer therapy.