title: Procoagulant properties of bare and highly PEGylated vinyl-modified silica nanoparticles.
abstract: OBJECTIVE
  Undesired alterations of the blood clotting balance may follow the intravascular injection of nanotherapeutics/diagnostics. Here, we tested the procoagulant activity of synthetic amorphous silica (SAS) and organically modified silica (ORMOSIL) nanoparticles (NPs) and whether a high-density polyethylene glycol coating minimizes these effects.
  
  
  METHODS
  Hageman factor- and tissue factor-dependent activation of human blood/plasma coagulation, and binding to human monocytes, endothelial cells and platelets were quantified in vitro using naked and PEGylated ORMOSIL-NPs. Their effects were compared with those of SAS-NPs, present in many industrial products, and of poly(lactic-co-glycolic acid)- and small unilamellar vesicles-NPs, already approved for use in humans.
  
  
  RESULTS
  Both SAS-NPs and ORMOSIL-NPS presented a significant procoagulant activity. However, highly PEGylated ORMOSIL-NPs were particularly averse to the interaction with the soluble factors and cellular elements that may lead to intravascular blood coagulation.
  
  
  CONCLUSIONS
  Stealth, highly PEGylated ORMOSIL-NPs with a poor procoagulant activity can be used as starting blocks to design hemocompatible nanomedical-devices.
authors.affiliation: Dipartimento di Scienze Biomediche Sperimentali, Università di Padova, Padova, Italy.
authors.forename: Regina
authors.initials: R
authors.lastname: Tavano
authors.forename: Daniela
authors.initials: D
authors.lastname: Segat
authors.forename: Elena
authors.initials: E
authors.lastname: Reddi
authors.forename: Janko
authors.initials: J
authors.lastname: Kos
authors.forename: Matija
authors.initials: M
authors.lastname: Rojnik
authors.forename: Petra
authors.initials: P
authors.lastname: Kocbek
authors.forename: Selma
authors.initials: S
authors.lastname: Iratni
authors.forename: Dietrich
authors.initials: D
authors.lastname: Scheglmann
authors.forename: Mario
authors.initials: M
authors.lastname: Colucci
authors.forename: Iria Maria Rio
authors.initials: IM
authors.lastname: Echevarria
authors.forename: Francesco
authors.initials: F
authors.lastname: Selvestrel
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Mancin
authors.forename: Emanuele
authors.initials: E
authors.lastname: Papini
mesh_terms: D003029:Coagulants; D006801:Humans; D053758:Nanoparticles; D011092:Polyethylene Glycols; D012822:Silicon Dioxide
chemical_list: D003029:Coagulants; D011092:Polyethylene Glycols; D012822:Silicon Dioxide