Abstract: AimTo study the permeability of nerve growth factor (NGF) liposomes (NGF-L, NGF-SSL, NGF-SSL-T) on the blood-brain barrier (BBB) model and the distribution in vivo, and analyze the correlation between the results in vitro and in vivo. MethodsThe BBB model in vitro was established by using mouse brain microvascullar endothelial cell, and the model was applied to study the permeability of NGF liposomes. The distribution of NGF of each group was studied by ¹²⁵I labeled and SDS-PAGE method. ResultsThe highest encapsulation proportion was 34%, and the mean size of NGF liposomes was below 100 nm. The permeability of NGF liposomes on in vitro BBB model showed that the liposome could promote NGF to transport across the BBB, the permeability of NGF-SSL-T was the highest. The distribution in the brain showed in an order of NGF concentration NGF-SSL-T > NGF-SSL+RMP-7 > NGF-SSL > NGF-L. There was a close relationship between P_e (permeability coefficient on in vitro BBB model) and BUI (brain uptake constant in vivo). ConclusionLiposomes can promote NGF to transport across the BBB, and the transporting ability BBB of NGF-SSL-T which RMP-7 incorporated into the surface of NGF liposomes is the best.