title: Size-controlled synthesis of granular polyphosphate nanoparticles at physiologic salt concentrations for blood clotting.
abstract: Size-controlled granular polyphosphate (PolyP) nanoparticles were synthesized by precipitation in aqueous solutions containing physiological concentrations of calcium and magnesium. We demonstrate using dynamic light scattering (DLS) that the solubility is correlated inversely with PolyP chain length, with very long chain PolyP (PolyP1000+, more than 1000 repeating units) normally found in prokaryotes precipitating much more robustly than shorter chains like those found in human platelet dense granules (PolyP80, range 76-84 repeating units). It is believed that the precipitation of PolyP is a reversible process involving calcium coordination to phosphate monomers in the polymer chain. The particles are stable in aqueous buffer and albumin suspensions on time scales roughly equivalent to catastrophic bleeding events. Transmission electron microscopy images demonstrate that the PolyP nanoparticles are spherical and uniformly electron dense, with a particle diameter of 200-250 nm, closely resembling the content of acidocalcisomes. X-ray elemental analysis further reveals that the P/Ca ratio is 67:32. The granular nanoparticles also manifest promising procoagulant effects, as measured by in vitro clotting tests assaying contact pathway activity.
authors.affiliation: Department of Chemical Engineering, University of Illinois at Chicago , Chicago, Illinois 60607, United States.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Donovan
authors.forename: Joseph
authors.initials: J
authors.lastname: Kalkowski
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Smith
authors.forename: James H
authors.initials: JH
authors.lastname: Morrissey
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
mesh_terms: D001777:Blood Coagulation / Q000187:drug effects* / Q000502:physiology; D002122:Calcium Chloride / Q000737:chemistry*; D006801:Humans; D015636:Magnesium Chloride / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011122:Polyphosphates / Q000138:chemical synthesis* / Q000494:pharmacology
chemical_list: D011122:Polyphosphates; D015636:Magnesium Chloride; D002122:Calcium Chloride