Today’s neurostimulators, such as those used to control chronic pain, bladder incontinence, and depression, use electricity to activate nerves. While very effective in many patients, electrical stimulation can lead to inflammation, produce unwanted sensations and pain, and injure fragile tissues. Optogenetics is an approach that offers an alternative, potentially safer option, that relies on light and light sensitive proteins to activate individual neural cells.
To help make it a practical reality, researchers at Washington University in St. Louis, the University of Illinois at Urbana-Champaign, and Northwestern University worked together to create a soft and flexible wireless implant that senses the movements of an overactive bladder and delivers light to bring it under control.
Electrical sacral nerve stimulation for overactive bladder has been around for decades, but instead of having electrodes, the new device sports LEDs that can shine light on the nerve. A virus is used to deliver opsin proteins, which are sensitive to light, into the nerve cells in the bladder. The implant is in the shape of a belt, which is wrapped around the bladder, and which can sense the bladder as it expands and contracts. The device uses Bluetooth wireless connectivity to relay its readings to an external computer, which can identify when the bladder needs to be stimulated and tell the implant to turn on its LEDs.
While the implant is impressive, and has already shown to be effective in lab rats, the overall technology still requires the delivery of proteins using viruses, the safety of which will require years of pre-clinical and clinical trials. Nevertheless, having a working, proof-of-concept model of the entire therapeutic system will go a long way to helping bring all this to reality.