Dendritic mesoporous silica nanoparticle-based nasal delivery carriers for passive immunotherapy of Alzheimer’s disease

Hyperphosphorylation of tau is a key pathological hallmark of Alzheimer's disease and is closely associated with cognitive impairment. Passive immunotherapy targeting hyperphosphorylated tau is a promising approach to inhibit tau pathology. However, the blood-brain barrier restricts antibodies from reaching the central nervous system and exerting their therapeutic effects. Here, we developed an intranasal biomacromolecule delivery strategy for the treatment of Alzheimer's disease using dendritic mesoporous silica nanoparticles modified with hyaluronic acid as a drug carrier. Ten-month-old C57BL/6J mice, htau mice, and 5×FAD mice were intranasally administered 100 μg of hyaluronic acid-dendritic mesoporous silica nanoparticles@4B1 (antibody dose), and brain tissues were collected to evaluate antibody delivery efficiency. Using this delivery system, the anti-p-tau396,404 antibody 4B1 was efficiently delivered to the brains of 5×FAD mice, with an enrichment of 7.31% ± 0.18% ID/g. Entry of the 4B1 antibody into the brain ameliorated tauopathy in Alzheimer's disease model mice, reduced neuronal loss and neuroinflammation caused by tau pathology, and reversed cognitive dysfunction. These findings suggest that the nasal delivery strategy based on hyaluronic acid-responsive release is an effective method for delivering antibody biomacromolecules to the central nervous system, showing high efficiency of antibody entry into brain tissue and intracellular delivery. Our findings also demonstrate the role of p-tau396,404 in passive immunotherapy for Alzheimer's disease, suggesting that immunotherapy targeting p-tau396,404 is a promising strategy for ameliorating Alzheimer's disease pathology, inhibiting the aggregation of hyperphosphorylated tau, and alleviating neurological damage and cognitive dysfunction.