Carrier-free nanoassembly with dual antioxidant and anti-inflammatory activities camouflaged by melanoma cell membrane for tau-targeted therapy of Alzheimer's disease.

Targeting phosphorylated tau (p-tau) across the blood-brain barrier (BBB) represents a critical prerequisite for attenuating tau pathology and disease progression in Alzheimer's disease (AD) by alleviating oxidative stress and neuroinflammation. To address this challenge, we developed a novel carrier-free selenium-based nanoassembly stabilized by hydroxyl-rich fingolimod (FTY720), a sphingosine analogue. Following camouflaging with melanoma cell membranes and further functionalizing with T807, the resulting nanocomposite (FSMT) demonstrated robust capacity for BBB crossing and target p-tau both in vitro and in vivo. Additionally, FTY720 and nano-selenium exert remarkable antioxidant and anti-inflammatory effects by modulating the GSK-3β and NF-κB signaling pathways, respectively, thereby attenuating tau hyperphosphorylation and preventing neuronal cell death. In an okadaic acid-induced AD mouse model, the FSMT treatment not only significantly ameliorated oxidative stress and neuroinflammation, but also improved spatial learning and memory impairments. The reduction in abnormal tau aggregation following treatment was confirmed by PET-CT imaging. Overall, this p-tau-targeted biomimetic nanocomposite demonstrated excellent biocompatibility and therapeutic efficacy, presenting a translatable strategy for treating AD and other neurological disorders through analogous mechanisms.