ROS-responsive dextran-benzeneboronic acid pinacol ester micelles encapsulating edaravone for the treatment and mechanism of cerebral ischemia-reperfusion injury.

Abstract

Reperfusion, while essential for restoring blood supply, paradoxically exacerbates neuronal damage through cerebral ischemia-reperfusion injury (CIRI). This study aimed to develop a reactive oxygen species (ROS)-responsive drug delivery system (DDS) loaded with edaravone (EDA) to enhance targeted therapy for CIRI. The stimuli-responsive DDS was synthesized using dextran (DEX) as the biocompatible carrier and benzeneboronic acid pinacol ester (BAPE) as the ROS-sensitive moiety. The physicochemical characteristics of the DEX-BAPE/EDA (DB/EDA) micelles were systematically evaluated. In vitro studies assessed the anti-inflammatory, antioxidant, and anti-apoptotic effects of DB/EDA. Moreover, the neuroprotective efficacy of DB/EDA in vivo was analyzed via behavioral tests, infarct volume measurement, ELISA assays of inflammatory cytokines and OS markers, and Western blot analysis of Nrf2-related pathways. Pharmacokinetics and biosafety were analyzed through plasma profiling and H&E staining. DB/EDA exhibited high stability, efficient drug encapsulation, and ROS-responsive drug release. Cellular uptake studies confirmed enhanced internalization of DB/EDA micelles in BV2 cells. In the oxygen-glucose deprivation/reoxygenation (OGD/R) model, DB/EDA significantly suppressed TNF-α, IL-1β, IL-6, and MDA, restored SOD levels, and attenuated apoptosis. In the middle cerebral artery occlusion/reperfusion (MCAO/R) mice, DB/EDA administration effectively improves cognition and mitigates neuronal damage. Mechanistically, DB/EDA activated the Nrf2/HO-1 pathway, amplifying antioxidant and anti-inflammatory responses. Pharmacokinetic analysis revealed prolonged circulation and increased brain accumulation, and histopathological analysis demonstrated the safety profile of DB/EDA. The ROS-responsive DB/EDA nano-micelles provided targeted EDA delivery to ischemic brain regions, alleviating CIRI via Nrf2 activation, suggesting that DB/EDA is a promising strategy for CIRI treatment.