Effect of nanoparticles binding β-amyloid peptide on nitric oxide production by cultured endothelial cells and macrophages

Int J Nanomedicine. 2013:8:1335-47. doi: 10.2147/IJN.S40297. Epub 2013 Apr 15.

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).

Conclusion: 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.

Keywords: Alzheimer’s disease; endothelial cells; macrophages; nanoparticles; nitric oxide.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid beta-Peptides / chemistry
  • Amyloid beta-Peptides / metabolism*
  • Animals
  • Calcium / analysis
  • Caspase 3 / chemistry
  • Caspase 3 / metabolism
  • Cell Line
  • Cell Survival / drug effects
  • Endothelial Cells / cytology
  • Endothelial Cells / drug effects*
  • Endothelial Cells / metabolism
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Intracellular Space / chemistry
  • Macrophages / cytology
  • Macrophages / drug effects*
  • Macrophages / metabolism
  • Materials Testing
  • Mice
  • Nanoparticles*
  • Nitric Oxide / analysis
  • Nitric Oxide / metabolism*
  • Nitric Oxide Synthase Type III / chemistry
  • Nitric Oxide Synthase Type III / metabolism
  • Phosphorylation / drug effects

Substances

  • Amyloid beta-Peptides
  • Nitric Oxide
  • Nitric Oxide Synthase Type III
  • Caspase 3
  • Calcium