NIR-labeled nanoparticles engineered for brain targeting: in vivo optical imaging application and fluorescent microscopy evidences.

The presence of the blood–brain barrier (BBB)makes extremely difficult to develop efficacious strategiesfor targeting contrast agents and delivering drugs inside theCentral Nervous System (CNS). To overcome this drawback,several kinds of CNS-targeted nanoparticles (NPs)have been developed. In particular, we proposed polylactide-co-glycolide (PLGA) NPs engineered with a similopioidglycopeptide (g7), which have already proved to bea promising tool for achieving a successful brain targetingafter i.v. administration in rats. In order to obtain CNStargetedNPs to use for in vivo imaging, we synthesizedand administrated in mice PLGA NPs with double coverage:near-infrared (NIR) probe (DY-675) and g7. Theoptical imaging clearly showed a brain localization of thesenovel NPs. Thus, a novel kind of NIR-labeled NPs wereobtained, providing a new, in vivo detectable nanotechnologytool. Besides, the confocal and fluorescencemicroscopy evidences allowed to further confirm the abilityof g7 to promote not only the rat, but also the mouseBBB crossing.