Multilayered Silica-Core/Chitosan-Coated Nanostructures Co-Delivering Tamoxifen and Quercetin Mitigate LPS-Associated...

Cholinergic dysfunction, oxidative stress, neuroinflammation, and proteinopathies are among the major hallmarks of Alzheimer's disease (AD). This study aimed to develop and evaluate the therapeutic potential of multilayered silica-based/chitosan-coated nanoparticles (Si@CsNPs) co-loaded with quercetin (QUR) and tamoxifen (TAM) in an LPS-induced neuroinflammatory murine model exhibiting AD-like neuropathological alterations associated with bacterial endotoxin exposure. Molecular docking and target prediction analyses suggested that TAM may exert partial cholinesterase inhibitory activity and potentially interact with muscarinic receptor- and epidermal growth factor receptor (EGFR)-associated pathways, which are implicated in neuroinflammation and oxidative stress regulation. The resulting silica-based/chitosan-coated nanoparticles (Si@CsNPs) co-loaded with QUR and TAM (QUR/TAM-Si@CsNPs) were spherical in shape, exhibited a core-shell architecture, and demonstrated high loading efficiencies for QUR (93.1% ± 2.56) and TAM (84.27 ± 3.66), with a mean particle diameter of approximately 135 nm as determined by TEM. Behavioral assessment using Morris Water Maze revealed that lipopolysaccharide (LPS) administration impaired spatial learning and memory in rats; these effects were significantly ameliorated by QUR/TAM-Si@CsNPs treatment, to a greater extent than Si@CsNPs loaded individually with QUR or TAM. Biochemical, apoptotic, and histopathological analyses further demonstrated that treatment with QUR/TAM-Si@CsNPs normalized acetylcholinesterase activity, Tau protein level, β-amyloid accumulation, pro-inflammatory mediators, and apoptotic indices while preserving hippocampal architecture. Collectively, these findings demonstrate that QUR/TAM-Si@CsNPs exert combined anti-inflammatory and neuroprotective effects, highlighting their promise as a multifunctional nanotherapeutic strategy against LPS-associated neurodegenerative and AD-like neuropathological alterations.