Photodynamic Therapy for Deep Organ Cancer by Implantable Wireless OLEDs

Metronomic photodynamic therapy (mPDT) is a method of continuously delivering low-intensity light to a cancer lesion. Since high light intensity is not required, the light device can be miniaturized and implanted in the body. Nevertheless, for clinical implementation, it is essential to develop a light source apparatus that can effectively illuminate the entire tumor and operate stably without damaging internal organs. To address this issue, an organic light-emitting diode (OLED) optical device that has an area large enough to cover the entire lesion and is powered by a wireless power supply has been developed. The device is thin and lightweight and it functioned stably in the abdominal cavity of rats for more than two weeks without causing foreign body reactions. By covering the tumor site of rat liver cancer with this device and continuously illuminating the tumor with appropriate administration of a photosensitizer, the entire tumor under the emitting surface was eliminated through apoptosis without leaving any residual tumor margins. This is the first report of a robust antitumor effect on parenchymal organ cancers by mPDT using a biocompatible, wirelessly powered OLED device, which represents a potential new deep organ cancer therapy.