87 Sr Solid-State NMR as a Structurally Sensitive Tool for the Investigation of Materials: Antiosteoporotic Pharmaceuticals and Bioactive Glasses Christian Bonhomme,* ,† Christel Gervais, † Nicolas Folliet, † Fre ́ de ́ rique Pourpoint, † Cristina Coelho Diogo, ‡ Jonathan Lao, § Edouard Jallot, § Jose ́ phine Lacroix, § Jean-Marie Nedelec, ⊥,¶ Dinu Iuga, □ John V. Hanna, □ Mark E. Smith, □,▽ Ye Xiang, # Jincheng Du, # and Danielle Laurencin $ † Laboratoire Chimie de la Matie ̀ re Condense ́ e de Paris, UMR CNRS 7574, UPMC Universite ́ Paris 06, Collè ge de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France ‡ IMPC, Institut des Mate ́ riaux de Paris Centre, FR2482, UPMC Universite ́ Paris 06, Colle ̀ ge de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France § Clermont Universite ́ , Universite ́ Blaise Pascal, CNRS/IN2P3, Laboratoire de Physique Corpusculaire, BP 10448, 63000 Clermont-Ferrand, France ⊥ Clermont Universite ́ , ENSCCF, ICCF, BP 10448, F-63000 Clermont-Ferrand, France ¶ CNRS, UMR 6296, ICCF, F-63177 Aubie ̀ re □ Department of Physics, University of Warwick, CV4 7AL Coventry, U.K. ▽ Vice-Chancellor’sOffice, University House, Lancaster University, LA1 4YW, Lancaster, U.K. # Department of Materials Science and Engineering, CASCaM, University of North Texas, Denton, Texas 76203, United States $ Institut Charles Gerhardt de Montpellier, UMR 5253, CNRS UM2 UM1 ENSCM, CC 1701 Universite ́ de Montpellier 2, Place E. Bataillon, 34095 Montpellier cedex 5, France * S Supporting Information ABSTRACT: Strontium is an element of fundamental importance in biomedical science. Indeed, it has been demonstrated that Sr 2+ ions can promote bone growth and inhibit bone resorption. Thus, the oral administration of Sr-containing medications has been used clinically to prevent osteoporosis, and Sr-containing biomaterials have been developed for implant and tissue engineering applications. The bioavailability of strontium metal cations in the body and their kinetics of release from materials will depend on their local environment. It is thus crucial to be able to characterize, in detail, strontium environments in disordered phases such as bioactive glasses, to understand their structure and rationalize their properties. In this paper, we demonstrate that 87 Sr NMR spectroscopy can serve as a valuable tool of investigation. First, the implementation of high-sensitivity 87 Sr solid-state NMR experiments is presented using 87 Sr-labeled strontium malonate (with DFS (double field sweep), QCPMG (quadrupolar Carr-Purcell-Meiboom-Gill), and WURST (wideband, uniform rate, and smooth truncation) excitation). Then, it is shown that GIPAW DFT (gauge including projector augmented wave density functional theory) calculations can accurately compute 87 Sr NMR parameters. Last and most importantly, 87 Sr NMR is used for the study of a (Ca,Sr)-silicate bioactive glass of limited Sr content (only ∼9 wt %). The spectrum is interpreted using structural models of the glass, which are generated through molecular dynamics (MD) simulations and relaxed by DFT, before performing GIPAW calculations of 87 Sr NMR parameters. Finally, changes in the 87 Sr NMR spectrum after immersion of the glass in simulated body fluid (SBF) are reported and discussed. ■ INTRODUCTION The aging of the population is one of the main causes for the growing incidence of musculoskeletal problems and diseases, which call for the development of treatments for osteoporosis and of highly compatible and reliable bone substitutes. In this context, strontium is an element which is finding increasing interest, because it is now clearly established that strontium is beneficial in bone remodeling. Strontium is a naturally occurring trace element, and as a bone seeker (like calcium), ∼99% of strontium present in the body accumulates in bone. 1,2 The absorption of pharmacological doses of strontium has been Received: April 12, 2012 Published: June 28, 2012 Article pubs.acs.org/JACS © 2012 American Chemical Society 12611 dx.doi.org/10.1021/ja303505g | J. Am. Chem. Soc. 2012, 134, 12611-12628