Drug targeting to the CNS is challenging due to the presence of blood-brain barrier. We investigated chitosan (Cs) nanoparticles (NPs) as drug transporter system across the blood-brain barrier, based on mAb OX26 modified Cs.Cs NPs functionalized with PEG, modified and unmodified with OX26 (Cs-PEG-OX26) were prepared and chemico-physically characterized. These NPs were administered (intraperitoneal) in mice to define their ability to reach the brain.Brain uptake of OX26-conjugated NPs is much higher than of unmodified NPs, because: long-circulating abilities (conferred by PEG), interaction between cationic Cs and brain endothelium negative charges and OX26 TfR receptor affinity.Cs-PEG-OX26 NPs are promising drug delivery system to the CNS.