Polymeric nanoparticles for the drug delivery to the central nervous system

Background: Nanoparticulate polymeric systems (nanoparticles [Np]) have been widely studied for the delivery of drugs to a specific target site. This approach has been recently considered for the therapy of brain diseases. The major problem in accessing the CNS is linked to the presence of the blood-brain barrier. Objective: The present review deals with the different strategies that have been developed in order to allow Np drug carriers entry into the CNS parenchyma. Among these, the use of magnetic Np, Np conjugation with ligands for blood-brain barrier receptors, with antibodies, and the use of surfactants have been considered. Methods: All the literature available is reviewed in order to highlight the potential of this drug delivery system to be used as a drug carrier for the treatment of CNS pathologies. Conclusions: Polymeric Np have been shown to be promising carriers for CNS drug delivery due to their potential both in encapsulating drugs, hence protecting them from excretion and metabolism, and in delivering active agents across the blood-brain barrier without inflicting any damage to the barrier. Different polymers have been used and different strategies have been applied; among these, the use of specific ligands to enhance the specificity of drugs delivered to the CNS has recently been considered. At present, clinical trials are being conducted appeared for the use of these drug carriers but none related to the treatment of CNS diseases.