Size-tailored nanoparticle-antibody conjugates overcome hepatic sequestration in Alzheimer's disease treatment.

Antibody-based immunotherapy targeting amyloid-β (Aβ) is a promising approach for Alzheimer's disease (AD). However, its efficacy is limited by rapid hepatic sequestration, complement activation, and liver dysfunction. In this study, we synthesized low-immunogenic 450-nm functionalized mesoporous silica nanoparticles (PEG-MSN-1F12) by conjugating the anti-Aβ42 monoclonal antibody 1F12 to polyethylene glycol-modified mesoporous silica nanoparticles to address these challenges. In APP/PS1 mice, intravenous PEG-MSN-1F12 administration markedly enhanced peripheral Aβ clearance, promoted intestinal excretion, reshaped gut microbiota, and alleviated intestinal inflammation, thus reducing AD-associated hepatic burden. Peripheral Aβ removal further led to decreased brain Aβ deposition, attenuated microglial activation, and improved cognition. These findings highlight that the use of particle size-engineered antibody-nanoparticle conjugates is a safe and effective strategy to overcome hepatic sequestration, augment Aβ clearance, and improve AD outcomes.