Toward a painkilling nanomedicine

Pain Medications America's opioid epidemic has resulted in large-scale initiatives to identify opioid substitutes. However, for many cases of chronic pain, no viable alternatives to opioids exist. In an effort to expand the arsenal of antipain treatments, Feng et al. bonded Leu-enkephalin with the lipid squalene. Enkephalins, like endorphins, are naturally occurring peptides in the human brain. They act on the opioid receptors to manage pain but have proved difficult to exploit therapeutically. When incorporated into nanoparticles with squalene, Leu-enkephalin exhibited a more controlled release that localized in inflamed tissue, which is promising news for nonopioid pain treatment. Sci. Adv. 10.1126/sciadv.aau5148 (2019).