Blood-brain barrier in neurodegenerative diseases: perspectives for Nanomedicine

The blood-brain barrier (BBB) is the most restrictive barrier in the body, presenting a formidable obstacle to drug delivery into the brain. In neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS) therapeutic trials have frequently failed. One of the reasons involved may be that the therapeutic agents are not able to reach their target in effective concentrations due to the restricted anatomical access to the brain. Selective delivery of diagnostic and therapeutic agents across the BBB using nanotechnological carrier devices such as liposomes or nanoparticles is a potentially safe and minimal invasive strategy to overcome the BBB. In addition, there is evidence for a dysfunction of the BBB itself in various neurodegenerative disorders that also offers perspectives for a restorative therapy with nanomedicinal devices. We review the literature on the potential role of the BBB in neurodegenerative diseases and discuss recent developments in Nanomedicine and their potential for targeted drug delivery across the BBB in neurodegenerative diseases.