Potential use of polymeric nanoparticles for drug delivery across the blood-brain barrier

Nanomedicine is certainly one of the scientific and technological challenges of the coming years. In particular, biodegradable nanoparticles formulated from poly (D,L-lactide-co-glycolide) (PLGA) have been extensively investigated for sustained and targeted delivery of different agents, including recombinant proteins, plasmid DNA, and low molecular weight compounds. PLGA NPs present some very attractive properties such as biodegradability and biocompatibility, protection of drug from degradation, possibility of sustained release, and the possibility to modify surface properties to target nanoparticles to specific organs or cells. Moreover, PLGA NPs have received the FDA and European Medicine Agency approval in drug delivery systems for parenteral administration, thus reducing the time for human clinical applications. This review in particular deals on surface modification of PLGA NPs and their possibility of clinical applications, including treatment for brain pathologies such as brain tumors and Lysosomal Storage Disorders with neurological involvement. Since a great number of pharmacologically active molecules are not able to cross the Blood-Brain Barrier (BBB) and reach the Central Nervous System (CNS), new brain targeted polymeric PLGA NPs modified with glycopeptides (g7- NPs) have been recently produced. In this review several in vivo biodistribution studies and pharmacological proof-of evidence of brain delivery of model drugs are reported, demonstrating the ability of g7-NPs to create BBB interaction and trigger an efficacious BBB crossing. Moreover, another relevant development of NPs surface engineering was achieved by conjugating to the surface of g7-NPs, some specific and selective antibodies to drive NPs directly to a specific cell type once inside the CNS parenchyma.