A microglia membrane biomimetic platinum-based MOF-loaded quercetin nanodrug delivery system for the treatment of Alzheimer's disease.

The aberrant deposition of β-amyloid (Aβ) is a central pathological hallmark of Alzheimer's disease (AD), triggering oxidative stress, metal ion dyshomeostasis, and excessive microglial activation in a self-perpetuating pathological cascade. To address these interconnected processes, a platinum-based metal-organic framework (Pt-MOF) with intrinsic antioxidant enzyme-mimetic activity was constructed and loaded with quercetin (Qu) to regulate microglial dysfunction. To enhance blood-brain barrier (BBB) penetration and inflammation-targeting capability, Pt-MOF/Qu was further camouflaged with microglial cell membranes (BV2), yielding Pt-MOF/Qu/BV2 nanoparticles. In vitro studies demonstrated that Pt-MOF/Qu/BV2 efficiently scavenged reactive oxygen species and effectively chelated Cu2+ ions via surface functional groups, thereby inhibiting Aβ aggregation and promoting the disassembly of preformed Aβ aggregates. In addition, the Pt-MOF enabled efficient loading and controlled release of Qu, which significantly restored mitochondrial membrane potential and alleviated microglial over-activation. The BV2 membrane coating markedly improved the biocompatibility and BBB translocation efficiency of the nanoplatform. Furthermore, Pt-MOF/Qu/BV2 significantly reduced reactive oxygen species (ROS) in vivo and Aβ brain plaque accumulation in the head region, alleviated neurotoxicity and improved the behavioral phenotype in the C. elegans AD model. Overall, this biomimetic multifunctional MOF-based nanoplatform represents a promising multi-target therapeutic strategy for AD.