According to the findings of a recent study, a new water-soluble, soft, biocompatible device softly wraps around nerves and delivers precise, targeted cooling to numb neurons and stop pain signals from reaching the brain. For pain treatment, opioids may be replaced with implantable devices capable of inhibiting peripheral nerve activity in a targeted, reversible manner.

The on-demand removal of pain signals by local cooling is appealing.  However, traditional technologies are constrained by their extraction surgery needs, inaccurate cooling, and rigid, bulky form factors. Several forms of pain mitigation might be needed after an injury caused by an accident or medical procedure. These may involve administering something cold to the area producing the pain, such as ice packs for bruised or sore joints or muscles, or they may involve local injections of analgesic drugs to block pain receptors.

By adopting a liquid-to-gas phase transition as the chilling mechanism, Reeder et al. created a tiny, soft, implantable cooler to temporarily inhibit nerve transmission. The design of an electrical nerve cuff was used and the electrical wires were substituted with a microfluidic channel carrying a microliter volume of bioinert coolant. Real-time temperature monitoring was made possible using a thermal thin-film sensor incorporated within the cuff. This enabled closed-loop control.

These bioresorbable microfluidic devices provide real-time temperature feedback management while delivering focussed, minimally intrusive cooling power at any depth in living tissues. To minimize redundant device load and patient risk without additional operations, construction with biocompatible, water-soluble materials is beneficial for bioresorption and dissolution.

Multiweek in vivo studies show that this device has the potential to expeditiously and accurately cool peripheral nerves, thus offering local, on-demand analgesia in rat models for neuropathic pain.

Hence, the novel bioresorbable coolers appear to be beneficial for reversible conduction block of the peripheral nerves.