Near-infrared light-triggered NO release for spinal cord injury repair

Traumatic spinal cord injury (SCI) is caused by external physical impacts and can induce complex cascade events, sometimes converging to paralysis. Existing clinical drugs to traumatic SCI have limited therapeutic efficacy because of either the poor blood–spinal cord barrier (BSCB) permeability or a single function. Here, we suggest a “pleiotropic messenger” strategy based on near-infrared (NIR)–triggered on-demand NO release at the lesion area for traumatic SCI recovery via the concurrent neuroregeneration and neuroprotection processing. This NO delivery system was constructed as upconversion nanoparticle (UCNP) core coated by zeolitic imidazolate framework–8 (ZIF-8) with NO donor (CysNO). This combined strategy substantial promotes the repair of SCI in vertebrates, ascribable to the pleiotropic effects of NO including the suppression of gliosis and inflammation, the promotion of neuroregeneration, and the protection of neurons from apoptosis, which opens intriguing perspectives not only in nerve repair but also in neurological research and tissue engineering.