Nanoparticles Ease Spinal Inflammation

In spinal cord wounds, immune cells often aggravate the injury by stirring up inflammation, which hinders healing and can lead to chronic pain. Researchers now demonstrate that, in mice, they can quiet the inflammation-causing cells by targeting them directly with drug-laden nanoparticles (ACS Nano 2013, DOI: 10.1021/nn4036014). Davide Moscatelli of Polytechnic University of Milan and colleagues used polymer nanoparticles that degrade inside cells. They predicted that these particles would easily get inside microglia—the immune cells that launch inflammation around the spinal cord—because microglia readily engulf foreign invaders. Once ingested by microglia, the particles would disperse their payload. To test the particles, the researchers loaded them with minocycline, an anti-inflammation drug. Three days after they injected the drug-loaded particles into mice with injured spinal cords, the levels of molecules indicating inflammation were 50% lower in microglia from treated animals compared with cells from untreated mice.