Porous microneedle patch with sustained delivery of extracellular vesicles mitigates severe spinal cord injury

The study introduces a novel microneedle (MN) patch for delivering mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) to treat spinal cord injuries (SCI). The patch allows sustained release of MSC-EVs, reducing neuroinflammation and promoting tissue repair. The MN patch is designed to bypass the limitations of direct MSC or MSC-EV transplantation, which can damage healthy tissue. The porous structure of the MNs facilitates the release of MSC-EVs without requiring direct invasion of MSCs into the spinal cord. In a rat SCI model, the MN-MSC patch reduced cavity and scar tissue formation, promoted angiogenesis, and improved the survival of nearby tissues and axons, leading to significant functional recovery.

• 1
  The porous MN-MSC patch can effectively maintain the survival of MSCs and sustainably release MSC secretome for at least one week.
• 2
  The MN-MSC patch reduces the expression of pro-inflammatory markers and increases the expression of anti-inflammatory markers in the injured spinal cord.
• 3
  MN-MSC patch treatment promotes hindlimb locomotor functional recovery in rats after SCI, as evidenced by improved BBB scores and muscle control.