title: Calcium phosphate cements with strontium halides as radiopacifiers.
abstract: High radiopacity is required to monitor the delivery and positioning of injectable implants. Inorganic nonsoluble radiopacifiers are typically used in nondegradable bone cements; however, their usefulness in resorbable cements is limited due to their low solubility. Strontium halides, except strontium fluoride, are ionic water-soluble compounds that possess potential as radiopacifiers. In this study, we compare the radiopacity, mechanical properties, composition, and cytotoxicity of radiopaque brushite cements prepared with strontium fluoride (SrF2 ), strontium chloride (SrCl2 ·6H2 O), strontium bromide (SrBr2 ), or strontium iodide (SrI2 ). Brushite cements containing 10 wt % SrCl2 ·6H2 O, SrBr2 , or SrI2 exhibited equal to or higher radiopacity than commercial radiopaque cements. Furthermore, the brushite crystal lattice in cements that contained the ionic radiopacifiers was larger than in unmodified cements and in cements that contained SrF2 , indicating strontium substitution. Despite the fact that the strontium halides increased the solubility of the cements and affected their mechanical properties, calcium phosphate cements containing SrCl2 ·6H2 O, SrBr2 , and SrI2 showed no significant differences in Saos-2 cell viability and proliferation with respect to the control. Strontium halides: SrCl2 ·6H2 O, SrBr2 , and SrI2 may be potential candidates as radiopacifiers in resorbable biomaterials although their in vivo biocompatibility, when incorporated into injectable implants, is yet to be assessed.
authors.affiliation: Department of Engineering Sciences, Division of Applied Materials Science, The Ångström Laboratory, Uppsala University, 751 21, Uppsala, Sweden.
authors.forename: Alejandro
authors.initials: A
authors.lastname: López
authors.forename: Maryam
authors.initials: M
authors.lastname: Montazerolghaem
authors.forename: Håkan
authors.initials: H
authors.lastname: Engqvist
authors.forename: Marjam Karlsson
authors.initials: MK
authors.lastname: Ott
authors.forename: Cecilia
authors.initials: C
authors.lastname: Persson
mesh_terms: D001843:Bone Cements / Q000737:chemistry / Q000494:pharmacology*; D002130:Calcium Phosphates / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D008422:Materials Testing; D013324:Strontium / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D001843:Bone Cements; D002130:Calcium Phosphates; C020243:calcium phosphate; C025700:strontium chloride; D013324:Strontium
keywords: brushite; calcium phosphate; radiopaque bone cement; strontium halide; water-soluble radiopacifier