ROS-responsive quercetin-based polydopamine nanoparticles for targeting ischemic stroke by attenuating oxidative stress and neuroinflammation.

Ischemic stroke (IS), a prevalent cerebrovascular disorder, is characterized by high morbidity rates and significant disability. However, relevant drug therapy for IS still suffers from limitations such as limited blood-brain barrier (BBB) penetration efficiency, single therapeutic target, short half-life, and strong side effects. The development of multi-target neuroprotective agents using natural drug molecules with low toxicity and combining them with nanotechnology to improve BBB permeability and drug utilization is an important direction in the development of IS therapeutic strategies. Based on the anti-inflammatory and antioxidant properties of quercetin (Que), as well as the ROS-responsive degradation properties of polydopamine (PDA), an IS therapeutic strategy (Que@DAR NPs) was developed in this study. Que@DAR NPs were formed by dopamine wrapping Que by oxidative self-assembly and wrapping the rabies virus glycoprotein (RVG29) on the surface. The results showed that Que@DAR NPs greatly improved the dispersion stability of Que and exhibited ROS-responsive degradation properties. Cellular internalization assay in human neuroblastoma cells (SH-SY5Y) showed that RVG29 peptide substantially augmented the cellular uptake of Que@DAR NPs. Moreover, Que@DAR NPs can effectively reduce the oxidative damage of SH-SY5Y cells and induce the polarization of microglia to anti-inflammatory (M2) phenotype. In vivo studies further demonstrated that Que@DAR NPs inhibited neuroinflammation, reduced neuronal apoptosis, and significantly ameliorated neurological dysfunction in a rat model of middle cerebral artery occlusion (MCAO). In conclusion, Que@DAR NPs provide a safe and effective new strategy for the precision treatment of IS.