title: Effect of nanoparticles binding β-amyloid peptide on nitric oxide production by cultured endothelial cells and macrophages.
abstract: BACKGROUND
  As part of a project designing nanoparticles for the treatment of Alzheimer's disease, we have synthesized and characterized a small library of nanoparticles binding with high affinity to the β-amyloid peptide and showing features of biocompatibility in vitro, which are important properties for administration in vivo. In this study, we focused on biocompatibility issues, evaluating production of nitric oxide by cultured human umbilical vein endothelial cells and macrophages, used as models of cells which would be exposed to nanoparticles after systemic administration.
  
  
  METHODS
  The nanoparticles tested were liposomes and solid lipid nanoparticles carrying phosphatidic acid or cardiolipin, and PEGylated poly(alkyl cyanoacrylate) nanoparticles (PEG-PACA). We measured nitric oxide production using the Griess method as well as phosphorylation of endothelial nitric oxide synthase and intracellular free calcium, which are biochemically related to nitric oxide production. MTT viability tests and caspase-3 detection were also undertaken.
  
  
  RESULTS
  Exposure to liposomes did not affect the viability of endothelial cells at any concentration tested. Increased production of nitric oxide was detected only with liposomes carrying phosphatidic acid or cardiolipin at the highest concentration (120 μg/mL), together with increased synthase phosphorylation and intracellular calcium levels. Macrophages exposed to liposomes showed a slightly dose-dependent decrease in viability, with no increase in production of nitric oxide. Exposure to solid lipid nanoparticles carrying phosphatidic acid decreased viability in both cell lines, starting at the lowest dose (10 μg/mL), with increased production of nitric oxide detected only at the highest dose (1500 μg/mL). Exposure to PEG-PACA affected cell viability and production of nitric oxide in both cell lines, but only at the highest concentration (640 μg/mL).
  
  
  CONCLUSIONS
  Liposomal and PEG-PACA nanoparticles have a limited effect on vascular homeostasis and inflammatory response, rendering them potentially suitable for treatment of Alzheimer's disease. Moreover, they highlight the importance of testing such nanoparticles for production of nitric oxide in vitro in order to identify a therapeutic dose range suitable for use in vivo.
authors.affiliation: Department of Health Sciences, University of Milano-Bicocca, Monza, Italy.
authors.forename: Antonina
authors.initials: A
authors.lastname: Orlando
authors.forename: Francesca
authors.initials: F
authors.lastname: Re
authors.forename: Silvia
authors.initials: S
authors.lastname: Sesana
authors.forename: Ilaria
authors.initials: I
authors.lastname: Rivolta
authors.forename: Alice
authors.initials: A
authors.lastname: Panariti
authors.forename: Davide
authors.initials: D
authors.lastname: Brambilla
authors.forename: Julien
authors.initials: J
authors.lastname: Nicolas
authors.forename: Patrick
authors.initials: P
authors.lastname: Couvreur
authors.forename: Karine
authors.initials: K
authors.lastname: Andrieux
authors.forename: Massimo
authors.initials: M
authors.lastname: Masserini
authors.forename: Emanuela
authors.initials: E
authors.lastname: Cazzaniga
mesh_terms: D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000032:analysis; D053148:Caspase 3 / Q000737:chemistry / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D042541:Intracellular Space / Q000737:chemistry; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008422:Materials Testing; D051379:Mice; D053758:Nanoparticles; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000737:chemistry / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects
chemical_list: D016229:Amyloid beta-Peptides; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D053148:Caspase 3; D002118:Calcium
keywords: Alzheimer’s disease; endothelial cells; macrophages; nanoparticles; nitric oxide