Effect of strontium inclusion on the bioactivity of phosphate-based glasses

Abstract

We have conducted first-principles and classical molecular dynamics simulations of various compositions of strontium-containing phosphate glasses, to understand how strontium incorporation will change the glasses' activity when implanted into the body (bioactivity). To perform the classical simulations, we have developed a new interatomic potential, which takes account of the polarizability of the oxygen ions. The Sr-O bond length is *2.44-2.49 Å , and the coordination number is 7.5-7.8. The Q n distribution and network connectivity were roughly constant for these compositions. Sr bonds to a similar number of phosphate chains as Ca does; based on our previous work (Christie et al. in J Phys Chem B 117:10652, 2013), this implies that SrO $ CaO substitution will barely change the dissolution rate of these glasses and that the bioactivity will remain essentially constant. Strontium could therefore be incorporated into phosphate glass for biomedical applications.

Structures and properties of phosphate-based bioactive glasses from computer simulation: a review

“…Strontium, like calcium, is taken up into the bone, and can occupy what are normally the calcium sites within the hydroxyapatite bone mineral structure. Recent work 39 suggests that strontium, despite having a larger coordination number than either sodium or calcium, bonds to about the same number of phosphate chains as calcium does, and hence that SrO ↔ CaO substitution should not affect the dissolution rate of the glass.…”

Guest editors’ preface

“…Another group of papers deals with fundamental studies of bioactive glasses, including compositions exhibiting mixed alkali effect [20], incorporation of radioactivatable yttrium [21] and papers dealing with the modeling (molecular dynamics simulations) of the sol-gel synthesis of bioactive glasses [22] and Srcontaining phosphate glasses [23]. Bioactive glasses are frequently combined with other materials to form composites or hybrids for a broad range of applications.…”

Structural and thermal behavior of 45S5 Bioglass®‐based compositions containing alumina and strontium

“…The idea of incorporating therapeutically active ions such as strontium and/or aluminum can contribute to a material with additional beneficial effects by providing tissue regeneration capabilities, enhanced bioactivity, and extended working range . Strontium‐containing bioactive glasses have already been recognized to affect bone growth in appropriate quantities . Strontium itself has been used for osteoporosis prevention as a ranelate form (Protelos ® ) .…”

“…9,10 Strontium-containing bioactive glasses have already been recognized to affect bone growth in appropriate quantities. [11][12][13][14] Strontium itself has been used for osteoporosis prevention as a ranelate form (Protelos ® ). 15 The strontium addition in bioactive glasses combines the known regenerative properties of bioactive glasses with anabolic and anti-catabolic effects of strontium ions.…”