Neutrophil membrane-coated multifunctional biomimetic nanoparticles for spinal cord injuries.

Spinal cord injury (SCI) is one of the most complex diseases. After SCI, severe secondary injuries can cause intense inflammatory storms and oxidative stress responses, leading to extensive neuronal apoptosis. Effective regulation of inflammation and oxidative stress after SCI remains an unresolved challenge. In this study, resveratrol-loaded nanoparticles coated with neutrophil membranes (NMR) were prepared using the emulsion-solvent evaporation method and membrane encapsulation technology. Multifunctional biomimetic nanoparticles retain neutrophil membrane-related receptors and possess a strong adsorption capacity for inflammatory factors. As a drug carrier, NMR can sustainably release resveratrol for >72 h. Moreover, co-culture studies show that the NMR help regulate macrophage polarization to relieve inflammatory response, reduce intracellular reactive oxygen species by approximately 50%, and improve mitochondrial membrane potential to alleviate oxidative stress. After injecting NMR into the injury site, it reduces early apoptosis, inhibit scar formation, and promote neural network recovery to improve motor function. This study demonstrates the anti-inflammatory, antioxidant, and neuroprotective effects of NMR, thus providing a novel therapeutic strategy for SCI.