title: Lipid-based nanoparticles with high binding affinity for amyloid-beta1-42 peptide.
abstract: The neurotoxic beta-amyloid peptide (Abeta), formed in anomalous amounts in Alzheimer's disease (AD), is released as monomer and then undergoes aggregation forming oligomers, fibrils and plaques in diseased brains. Abeta aggregates are considered as possible targets for therapy and/or diagnosis of AD. Since nanoparticles (NPs) are promising vehicles for imaging probes and therapeutic agents, we realized and characterized two types of NPs (liposomes and solid lipid nanoparticles, 145 and 76 nm average size, respectively) functionalized to target Abeta(1-42) with high affinity. Preliminary immunostaining studies identified anionic phospholipids [phosphatidic acid (PA) and cardiolipin (CL)] as suitable Abeta(1-42) ligands. PA/CL-functionalized, but not plain, NPs interacted with Abeta(1-42) aggregates as indicated by ultracentrifugation experiments, in which binding reaction occurred in solution, and by Surface Plasmon Resonance (SPR) experiments, in which NPs flowed onto immobilized Abeta(1-42). All these experiments were carried out in buffered saline. SPR studies indicated that, when exposed on NPs surface, PA/CL display very high affinity for Abeta(1-42) fibrils (22-60 nm), likely because of the occurrence of multivalent interactions which markedly decrease the dissociation of PA/CL NPs from Abeta. Noteworthy, PA/CL NPs did not bind to bovine serum albumin. The PA/CL NPs described in this work are endowed with the highest affinity for Abeta so far reported. These characteristics make our NPs a very promising vector for the targeted delivery of potential new diagnostic and therapeutic molecules to be tested in appropriate animal models.
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, Mario Negri Institute for Pharmacological Research, Milano, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Gobbi
authors.forename: Francesca
authors.initials: F
authors.lastname: Re
authors.forename: Mara
authors.initials: M
authors.lastname: Canovi
authors.forename: Marten
authors.initials: M
authors.lastname: Beeg
authors.forename: Maria
authors.initials: M
authors.lastname: Gregori
authors.forename: Silvia
authors.initials: S
authors.lastname: Sesana
authors.forename: Sandro
authors.initials: S
authors.lastname: Sonnino
authors.forename: Doriano
authors.initials: D
authors.lastname: Brogioli
authors.forename: Claudia
authors.initials: C
authors.lastname: Musicanti
authors.forename: Paolo
authors.initials: P
authors.lastname: Gasco
authors.forename: Mario
authors.initials: M
authors.lastname: Salmona
authors.forename: Massimo E
authors.initials: ME
authors.lastname: Masserini
mesh_terms: D000544:Alzheimer Disease / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D006801:Humans; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry* / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D010446:Peptide Fragments / Q000378:metabolism*; D011485:Protein Binding; D020349:Surface Plasmon Resonance; D014461:Ultracentrifugation
chemical_list: D016229:Amyloid beta-Peptides; D008055:Lipids; D008081:Liposomes; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42)