This new device developed by Japanese scientists from Waseda University could offer an effective and minimally invasive cancer treatment suitable for delicate organs. The principle is that of a photodynamic therapy which consists in “burning” the cancerous cells by metronomic emission of light (that is to say at low and long term). This new wirelessly powered bioadhesive electroluminescent device is featured in the journal Nature Biomedical Engineering.
Conventional photodynamic therapy induces cancer cell death using photosensitizing agents, which target tumors and trigger their exposure to a specific wavelength of light. In recent years, low-dose, long-term photodynamic therapy (metronomic photodynamic therapy or mPDT) has shown promise in the treatment of cancers of internal organs. The challenge with mPDT is tumor targeting, given the extremely low light intensity. The team of bioengineers from Waseda University, the National Defense Medical College and the Japan Science and Technology Agency therefore developed this new wireless device with the aim of exploiting improve the mPDT by optimizing its targeting.
The wireless optoelectronic device stably attaches to the inner surface of tissue like a sticker with elastic, bioadhesive nanoparticles, allowing continuous local light scattering to the tumor, says lead author Toshinori Fujie, Associate Professor of Biomedical Engineering at Waseda University. These nanosheets are composed of polydopamine polymer, a polymer inspired by mussel proteins, capable of stabilizing the device on wet tissue for more than 2 weeks without surgical sutures or medical glue. The device's LED chips are powered wirelessly.
The effectiveness of the device is demonstrated in mice , a tumor model, having received the implant, and an injection of photosensitizing agent. The animal is exposed to red and green light, approximately 1,000 times weaker than in conventional photodynamic approaches, for 10 consecutive days. Experience shows that tumor growth is reduced overall. Especially under green light and in some mice the tumor is completely eradicated.
Facilitating the treatment of microtumors that are difficult to detect and reach , without having to worry about the risk of damaging healthy tissue in the event of "overheating", this is the added value of this implant which does not require surgical suture and is suitable for the treatment of tumors located near nerves of blood vessels or fragile organs, such as the brain, liver and pancreas.
If validated in clinical practice, the implant could open up a new minimally invasive option for treating tumors affecting a fragile organ or located nearby.
