Wireless photonic PDT. (A) Schematic of the therapy. The therapy consists of implantation of wireless LED near the target region, administration of the PS, and wireless powering of the device. Light emitted by the device locally activates the PSs and induces tumour damage. (B) Image of the wireless photonic device emitting light. (Inset) The device illuminating an explanted tumour. (scale bar, 2 mm.) (C) Schematic of the device and individual electronic components. (D) The optical emission spectrum of the device from two LEDs. The emission wavelengths are centred at 400 nm (violet) and 660 nm (red), overlapping with the absorption peaks in the Ce6 spectrum. (E) Image panel of the penetration of light emitted by the device (radiant power, 1.3 mW) through tumours of increasing volume (scale bar, 5 mm). Reproduced from A. Bansal et al. PNAS; published by National Academy of Sciences under CC BY-NC-ND or CC BY license, 2018 [239].