Biologic nanoparticles and platelet reactivity

Virginia M. Miller, Larry W. Hunter, Kevin Chu, Vivasvat Kaul, Phillip D. Squillace, John C. Lieske, Muthuvel Jayachandran

Research output: Contribution to journalArticlepeer-review

29 Scopus citations


Aim: Nanosized particles (NPs) enriched in hydroxyapatite and protein isolated from calcified human tissue accelerate occlusion of endothelium-denuded arteries when injected intravenously into rabbits. Since platelet aggregation and secretory processes participate in normal hemostasis, thrombosis and vascular remodeling, experiments were designed to determine if these biologic NPs alter specific platelet functions in vitro. Methods: Platelet-rich plasma was prepared from citrate anticoagulated human blood. Platelet aggregation and ATP secretion were monitored in response to thrombin receptor agonists peptide (10 μM) or convulxin (50 μg/ml) prior to and following 15 min incubation with either control solution, humanderived NPs, bovine-derived NPs or crystals of hydroxyapatite at concentrations of 50 and 150 nephelometric turbidity units. Results: Incubation of platelets for 15 min with either human- or bovine-derived NPs reduced aggregation induced by thrombin receptor activator peptide and convulxin in a concentration-dependent manner. Hydroxyapatite caused a greater inhibition than either of the biologically derived NPs. Human-derived NPs increased ATP secretion by unstimulated platelets during the 15 min incubation period. Conclusion: Effects of bovine-derived and hydroxyapatite NPs on basal release of ATP were both time and concentration dependent. These results suggest that biologic NPs modulate both platelet aggregation and secretion. Biologically derived NPs could modify platelet responses within the vasculature, thereby reducing blood coagulability and the vascular response to injury.

Original languageEnglish (US)
Pages (from-to)725-733
Number of pages9
Issue number7
StatePublished - Oct 2009


  • ATP secretion
  • Calcium phosphate
  • Dense granules
  • Fetuin
  • Platelet aggregation
  • Protein/mineral complexes
  • Thrombin

ASJC Scopus subject areas

  • Bioengineering
  • Medicine (miscellaneous)
  • Biomedical Engineering
  • Materials Science(all)


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