Biodegradable Nanoparticles Targeting Circulating Immune Cells Reduce Central and Peripheral Sensitization to Alleviate Neuropathic Pain Following Spinal Cord Injury

This study investigates the use of drug-free, biodegradable nanoparticles (PLG) to treat neuropathic pain in mice after spinal cord injury (SCI). The goal was to see if these nanoparticles could reduce pain by affecting the immune system's role in the central and peripheral nervous systems. The researchers found that treating mice with PLG nanoparticles after SCI significantly reduced their sensitivity to touch and cold. This improvement was long-lasting, suggesting the nanoparticles helped reprogram pain pathways. The nanoparticles appeared to work by primarily affecting the peripheral immune responses in the early stages after injury. Later on, the nanoparticles also influenced central pain signaling, leading to an overall reduction in pain.

• 1
  Acute treatment with PLG nanoparticles following thoracic SCI significantly reduces tactile and cold hypersensitivity scores in a durable fashion.
• 2
  Nanoparticles primarily reduce peripheral immune-mediated mechanisms of neuropathic pain including neuropathic pain-associated gene transcript frequency, TRPA1 nociceptor expression, and MCP-1 (CCL2) chemokine production.
• 3
  In the chronic phase of SCI, nanoparticle treatment induces changes in both central and peripheral neuropathic pain signaling, driving reductions in cytokine production and other immune-relevant markers.