title: Novel D-penicillamine carrying nanoparticles for metal chelation therapy in Alzheimer's and other CNS diseases.
abstract: Metal ions accumulate in the brain with aging and in several neurodegenerative diseases. Aside from the copper storage disease, Wilson's disease, recent attention has focused on the accumulation of zinc, copper and iron in the Alzheimer's disease (AD) brain and the accumulation of iron in Parkinson's disease. In particular, the parenchymal deposition of beta-amyloid (Abeta) and its interaction with metal ions has been postulated to play a role in the progression of AD. Thus, the strategy of lowering brain metal ions and targeting the interaction of Abeta peptide and metal ions through the administration of chelators has merit. Our recent finding that nanoparticle delivery systems can cross the blood-brain barrier has led us to investigate whether chelators delivered conjugated to nanoparticles could act to reverse metal ion induced protein precipitation. In the present studies, the Cu (I) chelator D-penicillamine was covalently conjugated to nanoparticles via a disulfide bond or a thioether bond. Nanoparticle-chelator conjugates were stable between pH 6-8 in aqueous suspension if stored at 4 degrees C, and did not aggregate when challenged with salts and serum. Release of D-penicillamine from the nanoparticles was achieved using reducing agents such as dithiothreitol (as a model for glutathione). Nanoparticles treated only under reducing conditions that released the conjugated D-penicillamine were able to effectively resolubilize copper-Abeta (1-42) aggregates. These results indicate that nanoparticles have potential to deliver D-penicillamine to the brain for the prevention of Abeta (1-42) accumulation, as well as to reduce metal ion accumulation in other CNS diseases.
authors.affiliation: Department of Pharmaceutical Sciences, Center for Pharmaceutical Science and Technology, College of Pharmacy, University of Kentucky, Lexington, KY 40536-0082, USA.
authors.forename: Zhengrong
authors.initials: Z
authors.lastname: Cui
authors.forename: Paul R
authors.initials: PR
authors.lastname: Lockman
authors.forename: Craig S
authors.initials: CS
authors.lastname: Atwood
authors.forename: Cheng-Hsuan
authors.initials: CH
authors.lastname: Hsu
authors.forename: Anshul
authors.initials: A
authors.lastname: Gupte
authors.forename: David D
authors.initials: DD
authors.lastname: Allen
authors.forename: Russell J
authors.initials: RJ
authors.lastname: Mumper
mesh_terms: D000544:Alzheimer Disease / Q000188:drug therapy* / Q000378:metabolism; D002493:Central Nervous System Diseases / Q000188:drug therapy / Q000378:metabolism; D002614:Chelating Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000627:therapeutic use*; D003300:Copper / Q000378:metabolism; D004337:Drug Carriers / Q000008:administration & dosage / Q000493:pharmacokinetics; D004355:Drug Stability; D049329:Nanostructures; D010316:Particle Size; D010396:Penicillamine / Q000008:administration & dosage* / Q000493:pharmacokinetics
chemical_list: D002614:Chelating Agents; D004337:Drug Carriers; D003300:Copper; D010396:Penicillamine