Wireless Powered Microwave-Light Conversion Platform with Dual-Stimulus Nanoresponder Coating for Deep-Seated Photodynamic Therapy

Traditional external field-assisted therapies, e.g., microwave (MW) therapy and phototherapy, cannot effectively and minimally damage eliminate deep-seated infection, owing to the poor penetrability of light and low reactive oxygen species (ROS) stimulation capability of MW. Herein, an implantable and wireless-powered therapeutic platform (CNT-FeTHQ-TS), in which external MW can be converted into internal light via MW wireless-powered light-emitting chips, is designed to eradicate deep-seated tissue infections by MW-induced deep-seated photodynamic therapy. In application, CNT-FeTHQ-TS is implanted at internal lesions, and the chip emits light under external MW irradiation. Subsequently, CNT-FeTHQ coating in the platform can respond to both MW and light simultaneously to generate ROS and MW-hyperthermia for rapid and precise sterilization at focus. Importantly, MW also improves the photodynamic performance of CNT-FeTHQ by introducing vacancies in FeTHQ to facilitate the photoexcitation process and changing the spin state of electrons to inhibit the complexation of photogenerated electron–hole pairs, which were confirmed by simulation calculations and in situ MW-irradiated photoluminescence experiments. In vivo, CNT-FeTHQ-TS can effectively cure mice with Staphylococcus aureus infection in dorsal subcutaneous tissue. This work overcomes the key clinical limitations of safe energy transmission and conversion for treating deep-seated infections.