Engineered microglial membrane-coated polydopamine-based nanomedicine for precise treatment of Alzheimer's disease.

Multimodal treatment for Alzheimer's disease (AD) is a pivotal option because of its complex pathogenesis. The major challenge of pharmacotherapies is effective drug delivery to the diseased brain and reduction of associated toxicity. Here, we propose a dual-target nanomedicine (PDA@R@M/K) for the management of AD by coating engineered microglial cell membrane (M/K) onto polydopamine (PDA) cores encapsulated with rivastigmine. M/K conferred nanoparticles (NPs) with reduced circulation clearance, pathological blood-brain barrier recognition, and enhanced brain inflammation chemotaxis. PDA cores not only acted as potent ROS scavengers to alleviate neuroinflammation but also piggybacked rivastigmine and implemented responsive release. After applying PDA@R@M/K in preclinical transgenic mouse models, amyloid plaque deposition, neurologic changes, and cognitive decline were largely rescued. These results provide the possibility of directly using NPs as therapeutics rather than merely as nanocarriers, and demonstrate the feasibility of engineered microglia membrane-coated NPs to improve the pharmacokinetics and efficacy of anti-AD drugs.