Liposomes as Brain Targeted Delivery Systems

Liposomes and lipid vesicles are leading strategies in allowing brain targeted drug release with prominent success. Liposome rational design and functionalization have improved the brain bioavailability of several blood-brain barrier (BBB)-impermeable molecules, demonstrating the thrilling therapeutic potential of these nanocarriers. PEGylation continues to be a strategy for enhanced circulation times, and its associated EPR effect could be exploited to target vascularized brain tumors. Surface modifications with antibodies, transferrin, insulin and targeting glucose transporters, among others, are strategies used in research of new potential therapies for cerebral ischemia, brain tumors, and Alzheimer’s and Parkinson’s diseases. More recent advancements include technologies based on cationic liposomes (untargeted and targeted to the brain microvasculature) as well as surface modifications with cell-penetrating peptides. These strategies to modify liposomes to improve drug bioavailability in the brain are thoroughly presented and discussed in this chapter.