Metal chelators coupled with nanoparticles as potential therapeutic agents for Alzheimer's disease

Alzheimer's disease (AD) is a devastating neuro-degenerative disorder characterized by the progressive and irreversible loss of memory followed by complete dementia. Despite the disease's high prevalence and great economic and social burden, an explicative etiology or viable cure is not available. Great effort has been made to better understand the disease's pathogenesis, and to develop more effective therapeutic agents. However, success is greatly hampered by the presence of the blood-brain barrier that limits a large number of potential therapeutics from entering the brain. Nanoparticle-mediated drug delivery is one of the few valuable tools for overcoming this impediment and its application as a potential AD treatment shows promise. In this review, the current studies on nanoparticle delivery of chelation agents as possible therapeutics for AD are discussed because several metals are found excessive in the AD brain and may play a role in the disease development. Specifically, a novel approach involving transport of iron chelation agents into and out of the brain by nanoparticles is highlighted. This approach may provide a safer and more effective means of simultaneously reducing several toxic metals in the AD brain. It may also provide insights into the mechanisms of AD pathophysiology, and prove useful in treating other iron-associated neurodegenerative diseases such as Friedreich's ataxia, Parkinson's disease, Huntington's disease and Hallervorden-Spatz Syndrome. It is important to note that the use of nanoparticle-mediated transport to facilitate toxicant excretion from diseased sites in the body may advance nanoparticle technology, which is currently focused on targeted drug delivery for disease prevention and treatment. The application of nanoparticle-mediated drug transport in the treatment of AD is at its very early stages of development and, therefore, more studies are warranted.