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 (SrF 2 ), strontium chloride (SrCl 2 Á6H 2 O), strontium bromide (SrBr 2 ), or strontium iodide (SrI 2 ). Brushite cements containing 10 wt % SrCl 2 Á6H 2 O, SrBr 2 , or SrI 2 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 SrF 2 , 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 SrCl 2 Á6H 2 O, SrBr 2 , and SrI 2 showed no significant differences in Saos-2 cell viability and proliferation with respect to the control. Strontium halides: SrCl 2 Á6H 2 O, SrBr 2 , and SrI 2 may be potential candidates as radiopacifiers in resorbable biomaterials although their in vivo biocompatibility, when incorporated into injectable implants, is yet to be assessed.

Strontium modified calcium phosphate cements – approaches towards targeted stimulation of bone turnover

“…This is of interest since high radiopacity is required to monitor the positioning of injectable cements during surgery and follow-up imaging. Various species such as SrCl 2 , SrCO 3 , SrBr 2 , and SrF 2 have been evaluated to modify CPC [86][87][88]90,113,114 or calcium-aluminiumphosphate cements 115 for that purpose. In most cases an increase of radiopacity with Sr content was shown.…”

Bone cements for percutaneous vertebroplasty and balloon kyphoplasty: Current status and future developments

“…Furthermore, Sr-CPCs are radiopaque cements. The radiopacity of brushite cements containing 10 wt% strontium halides was similar to or higher than that of commercial radiopaque cements, which usually contain 20 wt% or more radiopacifiers [55] . With moderate mechanical strength yet without the need for the addition of another radiopacifier, Sr-CPCs may be good candidates for repairing nonloading sites or reinforcing osteoporotic vertebrae through MISs [51] .…”

Enhanced Drug Delivery of Antibiotic-Loaded Acrylic Bone Cements Using Calcium Phosphate Spheres

“…The effect of the content of strontium on radiopacity of cements has been investigated previously. Strontium halides have been evaluated as radiopacifiers in injectable calcium phosphate cements (24), and the radiopacity of glass ionomer cements has been found to increase as strontium content increases (25). An increased radiopacity could be especially useful in minimally invasive procedures.…”