Abstract
Antioxidant enzyme therapy shows promise for treating Alzheimer's disease (AD), but significant challenges remain in achieving effective blood-brain barrier (BBB) penetration and sustained therapeutic effects. We developed a novel neutrophil membrane (NM)-coated cerium-doped Prussian blue biomimetic nanozyme (NM@PB-Ce) that demonstrates outstanding enzymatic properties and targeted therapeutic efficacy. Extensive physicochemical characterization using transmission electron microscopy, X-ray photoelectron spectroscopy, and dynamic light scattering confirmed the successful synthesis of uniform nanoparticles (~ 142 nm) with preserved membrane protein functionality. In vitro studies utilizing SH-SY5Y neuroblastoma cells revealed that NM@PB-Ce effectively scavenged reactive oxygen species through multiple enzyme-mimetic activities (catalase, superoxide dismutase, and peroxidase). The nanozyme significantly suppressed NLRP3 inflammasome activation and subsequent pyroptosis, reducing inflammatory markers (IL-1β, IL-18) while attenuating Aβ aggregation. Using a sophisticated co-culture BBB model and real-time in vivo fluorescence imaging, we demonstrated NM@PB-Ce's ability to traverse the BBB and accumulate specifically in AD-affected regions. In an Aβ1-42 oligomer-induced AD mouse model, systematic administration of NM@PB-Ce (320 μg/mL, 0.01 mL/g/day for 14 days) significantly improved cognitive performance across multiple behavioral paradigms, including the Morris water maze, Y-maze, and open field tests. Molecular and histological analyses revealed decreased neuroinflammation markers (GFAP, Iba-1) in the hippocampus, reduced levels of NLRP3, caspase-1, and phosphorylated tau (demonstrated by Western blot and ELISA), and enhanced dendritic spine density (visualized through Golgi staining). This comprehensive study establishes NM@PB-Ce as a promising therapeutic platform for AD treatment, providing both mechanistic insights into its mode of action and robust evidence of its therapeutic efficacy in targeting neuroinflammation and cognitive decline.