LTF and Alzheimer disease: Meng et al. developed Huperzine A (HupA)-loaded mucoadhesive polylactide-co-glycoside (PLGA) nanoparticles with surface modification by lactoferrin (Lf)-conjugated N-trimethylated chitosan (TMC) (HupA Lf-TMC NPs) for efficient intranasal delivery to the brain for AD treatment.