A narrow-bandgap RuI₃ nanoplatform to synergize radiotherapy, photothermal therapy, and thermoelectric dynamic therapy for tumor eradication.

Abstract

Therapeutic resistance is an essential challenge for nanotherapeutics. Herein, a narrow bandgap RuI₃ nanoplatform has been constructed firstly to synergize radiotherapy (RT), photothermal therapy (PTT), and thermoelectric dynamic therapy (TEDT) for tumor eradication. Specifically, the photothermal performance of RuI₃ can ablate tumor cells while inducing TEDT. Noteworthy, the thermoelectric effect is found firstly in RuI₃, which can spontaneously generate an electric field under the temperature gradient, prompting carrier separation and triggering massive ROS generation, thus aggravating oxidative stress level and effectively inhibiting HSP-90 expression. Moreover, RuI₃ greatly enhances X-ray deposition owing to its high X-ray attenuation capacity, resulting in a pronounced computed tomography imaging contrast and DNA damage. In addition, RuI₃ possesses both catalase-like and glutathione peroxidase-like properties, which alleviate tumor hypoxia and reduce antioxidant resistance, further exacerbating ¹O₂ production during RT and TEDT. This integrated therapy platform combining PTT, TEDT, and RT significantly inhibits tumor growth. STATEMENT OF SIGNIFICANCE: RuI₃ nanoparticles were synthesized for the first time. RuI₃ exhibited the highest photothermal properties among iodides, and the photothermal conversion efficiency was 53.38 %. RuI₃ was found to have a thermoelectric effect, and the power factor could be comparable to that of most conventional thermoelectric materials. RuI₃ possessed both catalase-like and glutathione peroxidase-like properties, which contributed to enhancing the effect of radiotherapy.