Chi Zhang

Solanum tuberosum lectin (STL) conjugated poly (DL-lactic-co- glycolic acid) (PLGA) nanoparticle (STL-NP) was constructed in this paper as a novel biodegradable nose-to-brain drug delivery system. The in vitro uptake study showed markedly enhanced endocytosis of STL-NP compared to unmodified PLGA nanoparticles (NP) in Calu-3 cells and significant inhibition of uptake in the presence of inhibitor sugar (chitin hydrolysate). Following intranasal administration, coumarin-6 carried by STL-NP was rapidly absorbed into blood and brain. The AUC((0→12 h)) of coumarin-6 in blood, olfactory bulb, cerebrum and cerebellum were about 0.77-, 1.48-, 1.89- and 1.45-fold of those of NP, respectively (p < 0.05). STL-NP demonstrated 1.89-2.45 times (p < 0.01) higher brain targeting efficiency in different brain tissues than unmodified NP. Enhanced accumulation of STL-NP in the brain was also observed by near infrared fluorescence probe image following intranasal administration. The fluorescence signal of STL-NP appeared in olfactory bulb, cerebrum and brainstem early at 0.25 h. The signal in olfactory bulb decreased gradually after 2 h, while the obvious signal in brainstem, cerebrum and cerebellum lasted for more than 8 h. The STL-NP safety experiments showed mild cytotoxicity and negligible cilia irritation. These intriguing in vitro and in vivo results suggest that STL-NP might serve as a promising brain drug delivery system.