Recent Advances in Preclinical Studies and Potential Applications of Dendrimers as Drug Carriers in the Central Nervous System

Background: The brain is a well-protected organ, with a complex system of cells, proteins and transporters, that acts as a sentinel to prevent potentially harmful substances from entering the brain, stopping also active molecules administered with a therapeutic goal. Although their limited exploitation, dendrimers are currently under evaluation as drug vectors to improve pharmacological treatments, targeting active molecules across the blood-brain barrier and penetrating brain tissues. Methods: Up to date, only three different families of dendrimers, poly(amidoamine)-, poly(propyleneimine)- and poly(L-lysine)-based, have found application as drug transporters in the Central Nervous System. Their development, functionalization and characterization are reported in the literature, with interesting preliminary outcomes in the treatment of brain disorders. Surface functionalization also affects the interaction between dendrimers and cells or tissues, with effects not only on penetration and retention, but also on the safety profile of this drug carrier. Conclusion: This review focuses on the application of dendrimers in the field of targeted drug delivery toward the Central Nervous System, highlighting their interesting properties. Discussion will be promising and represent an important starting point for a further diffusion of dendrimers in pharmacological treatment of the Central Nervous System.