Effects of surface modification on delivery efficiency of biodegradable nanoparticles across the blood-brain barrier

Aim: The aim of this work was to investigate the effect of surface modification of biodegradable nanoparticles on their cellular uptake, cytotoxicity and biodistribution for the delivery of imaging and therapeutic agents across the blood brain barrier. Materials & methods: Coumarin-6- and docetaxel-encapsulated poly(D,L-lactide-co-glycolide) nanoparticles were prepared by a modified single emulsion method using polyvinyl alcohol or D-alpha-tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS or TPGS) as emulsifier. The nanoparticles' surface was further modified with surfactants such as polysorbate-80 (Tween (R) 80), poloxamer 188 (F68) and poloxamer 407 (F127) to enhance cellular uptake of the NPs. Results: The F68-coated poly(D,L-lactide-co-glycolide) nanoparticles demonstrated the greatest cellular uptake and achieved highest fluorescence concentration in the brain tissues over those with 180 and F127 surface modification. Conclusion: Surface modification is a feasible and efficient strategy for nanoparticles made of biodegradable polymers to deliver diagnostic and therapeutic agents across the blood-brain barrier.