Overview: Researchers have developed a new implantable device that can “cool” nerves and provide on-demand pain relief to people suffering from neuropathic or chronic pain.
An implantable device designed to “cool” nerves could provide targeted, on-demand pain relief, researchers report. When tested on rats with neuropathic pain, the device produced highly localized cooling.
“An implantable cooling device with on-demand local analgesia will be a game changer for long-term pain management,” write Shan Jiang and Guosong Hong in a related perspective. It offers a promising path to creating a class of analgesics for long-term, non-opioid pain relief.
Pain management is a pressing health concern for many, who often have to turn to effective but highly addictive and sometimes deadly opioid painkillers. This has made the development of localized, non-opioid and non-addictive alternatives very attractive.
One such approach is analgesic nerve cooling, which shows promise as an effective and reversible way to relieve pain, for example after amputations, nerve grafts or spinal decompression surgeries. Like placing ice on a painful joint or muscle, targeted application of cold temperature directly to nerves can block the conduction of pain signals, providing temporary relief.
However, conventional nerve cooling devices are bulky and rigid with non-specific cooling and high power requirements – properties that preclude practical clinical use.
To address this, Jonathan Reeder and colleagues developed a soft, miniaturized and implantable nerve cooling system based on state-of-the-art microfluidic and flexible electronic technologies.
Borrowing electrical nerve cuffs, Reeder et al. utilize a liquid-to-gas phase transition within microfluidic channels in an elastic band that wraps around peripheral nerves to provide targeted cooling. An integrated thermal thin film sensor in the device provides real-time temperature monitoring and control.
Because the device is made of water-soluble and biocompatible materials, it is bioresorbable (meaning it degrades), reducing the necessary surgical risk.
To demonstrate the device’s capability, the authors performed: in vivo experiments in rat models of neuropathic pain, rapid and precise cooling of peripheral nerves to provide local and on-demand pain relief.
“In addition to the proven strengths of the miniaturized flexible cooling device for pain relief,” write Jiang and Hong in the related Perspective, “the technology offers further opportunities for neuroscience research and neurological practice.”
About this news about neurotech and pain research
Original research: Closed access.
†Soft Bioresorbable Coolers for Reversible Conduction Block of Peripheral Nervesby Jonathan T. Reeder et al. Science
Soft Bioresorbable Coolers for Reversible Conduction Block of Peripheral Nerves
Implantable devices capable of targeted and reversible blockade of peripheral nerve activity may provide alternatives to opioids for the treatment of pain. Localized cooling is an attractive means of on-demand elimination of pain signals, but traditional technologies are limited by rigid, bulky form factors; inaccurate cooling; and requirements for extraction operations.
Here we introduce soft, bioresorbable, microfluidic devices that enable the delivery of targeted, minimally invasive cooling power at arbitrary depths in living tissues with real-time temperature feedback control. Construction with water-soluble, biocompatible materials leads to dissolution and bioresorption as a mechanism to eliminate unnecessary strain on the device and risk to the patient without additional surgery.
Multi-week in vivo experiments demonstrate the ability to rapidly and accurately cool peripheral nerves to provide local, on-demand analgesia in rat models of neuropathic pain.