Microglia-Derived Cell Membranes Encapsulated Schisandra chinensis Polysaccharide-Zinc Complex for the Treatment of Spinal Cord Injury.

Spinal cord injury (SCI) is a devastating condition from which there is limited recovery of motor function. Inhibiting oxidative stress and inflammation is an effective strategy for treating SCI. The polysaccharide component of Schisandra chinensis is receiving increasing attention due to its potential in neuroprotection. Based on our previous research, we synthesized an Schisandra chinensis polysaccharide-zinc complex (SPZn) for synergistic treatment of SCI. However, poor blood-spinal cord barrier permeability limited the efficacy of SPZn. Microglia are immune cells that are inherent to the spinal cord and possess intrinsic targeting ability combined with immune evasion capacity, making them an ideal drug delivery system for SCI. Therefore, in this study, we selected microglia membranes to encapsulate SPZn (M-SPZn) for the treatment of SCI. The nanovesicle (M-SPZn) designed by us can target the site of spinal cord trauma and has good biosafety. The results, both in vivo and in vitro, showed that M-SPZn is more effective at alleviating oxidative stress and inhibiting inflammation. Moreover, M-SPZn reduced cell death and promoted motor function recovery in mice after SCI. In summary, M-SPZn has multiple roles in treating SCI and has a good usage potential.