title: Synthesis, characterization, and bioavailability in rats of ferric phosphate nanoparticles.
abstract: Particle size is a determinant of iron (Fe) absorption from poorly soluble Fe compounds. Decreasing the particle size of metallic Fe and ferric pyrophosphate added to foods increases Fe absorption. The aim of this study was to develop and characterize nanoparticles of FePO(4) and determine their bioavailability and potential toxicity in rats. Amorphous FePO(4) nanopowders with spherical structure were synthesized by flame spray pyrolysis (FSP). The nanopowders were characterized and compared with commercially available FePO(4) and FeSO(4), including measurements of specific surface area (SSA), structure by transmission electron microscopy, in vitro solubility at pH 1 and 2, and relative bioavailability value (RBV) to FeSO(4) in rats using the hemoglobin repletion method. In the latter, the potential toxicity after Fe repletion was assessed by histological examination and measurement of thiobarbituric acid reactive substances (TBARS). The commercial FePO(4) and the 2 FePO(4) produced by FSP (mean particle sizes, 30.5 and 10.7 nm) had the following characteristics: SSA: 32.6, 68.6, 194.7 m(2)/g; in vitro solubility after 30 min at pH 1: 73, 79, and 85% of FeSO(4); and RBV: 61, 70, and 96%, respectively. In the histological examinations and TBARS analysis, there were no indications of toxicity. In conclusion, nanoparticles of FePO(4) have a solubility and RBV not significantly different from FeSO(4). Reducing poorly soluble Fe compounds to nanoscale may increase their value for human nutrition.
authors.affiliation: Institute of Food Science and Nutrition, ETH Zürich, Switzerland.
authors.forename: Fabian
authors.initials: F
authors.lastname: Rohner
authors.forename: Frank O
authors.initials: FO
authors.lastname: Ernst
authors.forename: Myrtha
authors.initials: M
authors.lastname: Arnold
authors.forename: Monika
authors.initials: M
authors.lastname: Hilbe
authors.forename: Ralf
authors.initials: R
authors.lastname: Biebinger
authors.forename: Frank
authors.initials: F
authors.lastname: Ehrensperger
authors.forename: Sotiris E
authors.initials: SE
authors.lastname: Pratsinis
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Langhans
authors.forename: Richard F
authors.initials: RF
authors.lastname: Hurrell
authors.forename: Michael B
authors.initials: MB
authors.lastname: Zimmermann
mesh_terms: D018798:Anemia, Iron-Deficiency / Q000178:diet therapy; D000818:Animals; D001682:Biological Availability; D005290:Ferric Compounds / Q000737:chemistry* / Q000493:pharmacokinetics* / Q000633:toxicity; D006801:Humans; D019266:Iron, Dietary / Q000008:administration & dosage; D008297:Male; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D008854:Microscopy, Electron; D051381:Rats; D017207:Rats, Sprague-Dawley; D012449:Safety
chemical_list: D005290:Ferric Compounds; D019266:Iron, Dietary; C035885:ferric phosphate