Targeting and reprogramming microglial phagocytosis of neutrophils by ginsenoside Rg1 nanovesicles promotes stroke recovery

Abstract

Stroke remains one of the leading causes of adult disability worldwide, with neovascularization is crucial for brain repair after stroke. However, neutrophil infiltration hinders effective neovascularization, necessitating timely clearance by microglia through phagocytosis. Unfortunately, microglial phagocytic function is often impaired by metabolic defects, hindering post-stroke recovery. Ginsenoside Rg1, derived from Panax ginseng, exhibits neuroprotective properties and regulates cellular metabolism in vitro but its therapeutic application is limited by poor brain penetration. Here, we present a targeted delivery system utilizing neutrophil-like cell membrane vesicles (NCM), prepared via nitrogen cavitation, to enhance Rg1 delivery to the brain. These biomimetic vesicles exploit the inherent targeting ability of neutrophil membranes to reach brain injury sites and are subsequently taken up by microglia. Our findings demonstrate that Rg1-loaded vesicles enhance microglial clearance of neutrophils, reduce neutrophil extracellular traps release, and mitigate tissue damage. These effects improve the post-stroke microenvironment, promote vascular remodeling, and ultimately contribute to functional recovery. This strategy highlights the potential of targeted reprogramming microglial cells to enhance their endogenous repair capabilities, offering a promising therapeutic avenue for ischemic stroke management. Illustration of neutrophil-like cell-membrane-derived vesicles loaded with ginsenoside Rg1 for targeted ischemic stroke therapy. Rg1@NCM targets the infarct border zone, where it interacts with inflamed vascular endothelial cells and crosses the BBB. Microglia partially uptake Rg1@NCM, leading to the activation of AMP-activated protein kinase (AMPK) signaling. This activation enhances microglial phagocytosis of neutrophils, attenuates the formation of NETs, and downregulates the cGAS-STING pathway. Consequently, the production of pro-inflammatory cytokines IL-6 and IFN-β is reduced. Furthermore, Rg1@NCM upregulates the expression of tight junction proteins ZO-1 and occludin, promoting vascular repair in the peri-infarct area. These effects collectively contribute to enhanced functional recovery after ischemic stroke, highlighting the potential of Rg1@NCM as a therapeutic strategy for targeted reprogramming microglia toward a neuroprotective phenotype and promoting endogenous brain repair. • Rgl@NCM targets the injured brain after ischemic stroke. • Rgl@NCM promotes functional recovery after stroke by clearing neutrophils. • Rgl@NCM selectively enhances microglial phagocytosis of neutrophils. • Rgl@NCM reprograms microglial energy metabolism in an AMPK-dependent manner.