Pt(IV)-BODIPY Nanoparticles for Photoinduced Tumor Ablation and NIR Light-Activated Chemotherapy

Phototheranostics, which combine light-induced therapeutic and diagnostic modalities in a single platform, is a novel approach in tumor treatment and diagnostics. The development of dual-action nanomaterials with photothermal activity and the ability to act as photoactivated chemotherapy, capable of the light-induced release of chemotherapeutic agents, is a challenging task. However, different nanosystems reported to date represent either photoactivated chemotherapy (PACT), agents of photothermal therapy (PTT), or the loading of a drug and photoabsorber in a single polymer carrier. Herein, we report a near-infrared-light-activatable theranostic nanoplatform CF3-Pt-NPs with dual antitumor action, PTT/PACT, which is also capable of fluorescent and photothermal imaging of tumor tissues, based on the photoactivated Pt(IV) prodrug CF3-Pt with BODIPY in the axial position. A barrier-free CF3 rotor moiety in the BODIPY core provides excellent photothermal efficacy for the nanoplatform, while both the Pt(IV) prodrug CF3-Pt and nanoparticles CF3-Pt-NPs based on it act as PACT agents by releasing cisplatin under 740 nm light irradiation. Metabolomic profiles of CF3-Pt-NP-treated MCF-7 cells confirmed strong thermal- and cisplatin-induced responses of cells. CF3-Pt-NPs demonstrated the ability to accumulate in vivo in tumors, with the degree of fluorescence in the tumor correlating well with platinum accumulation, thereby confirming the ability of CF3-Pt-NPs to reach the tumor intact. A strong photothermal effect in vivo was confirmed after both intratumoral and intravenous administration of CF3-Pt-NPs with 808 nm laser irradiation. This is the first theranostic nanoplatform with dual PTT/PACT antitumor action, which is also capable of fluorescent and photothermal imaging of tumor tissues.