title: Nanoparticles induce platelet activation in vitro through stimulation of canonical signalling pathways.
abstract: Nanomaterials are attracting growing interest for their potential use in several applications as nanomedicine; therefore, the analysis of their potential toxic effects on various cellular models, including circulating blood cells, is mandatory. This study aimed to investigate the effect of three unrelated nanomaterials, namely nanoscale silica, multiwalled carbon nanotubes, and carbon black, on platelet activation and aggregation. We found that these nanomaterials stimulate some of the typical biochemical pathways involved in canonical platelet activation, such as the stimulation of phospholipase C and Rap1b, resulting in the integrin α(IIb)β3-mediated platelet aggregation, through a mechanism largely dependent on the release of the extracellular second messengers ADP and thromboxane A2. Importantly, we found that doses of nanoparticles unable to trigger appreciable responses can synergize with subthreshold amounts of physiological agonists to mediate platelet aggregation, indicating that even small amounts of nanomaterials in the bloodstream might contribute to the development of thrombosis.
  
  
  BACKGROUND
  In this study, nanosized particles of three virtually unrelated materials (silica, multi-walled carbon nanotubes and carbon black) were investigated regarding their effects on platelet activation and aggregation. All were found to stimulate some of the typical biochemical pathways involved in canonical platelet activation, and were found to have synergistic effects with physiologic platelet activator agonists.
authors.affiliation: Department of Biology and Biotechnology, Division of Biochemistry, University of Pavia, Pavia, Italy. gianni.guidetti@unipv.it
authors.forename: Gianni F
authors.initials: GF
authors.lastname: Guidetti
authors.forename: Alessandra
authors.initials: A
authors.lastname: Consonni
authors.forename: Lina
authors.initials: L
authors.lastname: Cipolla
authors.forename: Piercarlo
authors.initials: P
authors.lastname: Mustarelli
authors.forename: Cesare
authors.initials: C
authors.lastname: Balduini
authors.forename: Mauro
authors.initials: M
authors.lastname: Torti
mesh_terms: D001798:Blood Proteins / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D039421:Integrin alpha2 / Q000097:blood; D053758:Nanoparticles / Q000633:toxicity; D037742:Nanotubes, Carbon / Q000009:adverse effects; D010750:Phosphoproteins / Q000378:metabolism; D015539:Platelet Activation / Q000187:drug effects*; D010974:Platelet Aggregation / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D012822:Silicon Dioxide / Q000494:pharmacology; D053260:Soot / Q000009:adverse effects / Q000494:pharmacology; D010738:Type C Phospholipases / Q000097:blood; D020668:rap GTP-Binding Proteins / Q000097:blood
chemical_list: D001798:Blood Proteins; C056564:ITGA2B protein, human; D039421:Integrin alpha2; D037742:Nanotubes, Carbon; D010750:Phosphoproteins; D053260:Soot; C039077:platelet protein P47; D012822:Silicon Dioxide; D010738:Type C Phospholipases; C116753:RAP1B protein, human; D020668:rap GTP-Binding Proteins