@article{938509a1ec174d71afa6aa936b963899,
title = "Investigation of strontium transport and strontium quantification in cortical rat bone by time-of-flight secondary ion mass spectrometry",
abstract = "Next-generation bone implants will be functionalized with drugs for stimulating bone growth. Modelling of drug release by such functionalized biomaterials and drug dispersion into bone can be used as predicting tool for biomaterials testing in future. Therefore, the determination of experimental parameters to describe and simulate drug release in bone is essential. Here, we focus on Sr2+ transport and quantification in cortical rat bone. Sr2+ dose-dependently stimulates bone-building osteoblasts and inhibits bone-resorbing osteoclasts. It should be preferentially applied in the case of bone fracture in the context of osteoporotic bone status. Transport properties of cortical rat bone were investigated by dipping experiments of bone sections in aqueous Sr2+ solution followed by time-of-flight secondary ion mass spectrometry (ToF-SIMS) depth profiling. Data evaluation was carried out by fitting a suitable mathematical diffusion equation to the experimental data. An average diffusion coefficient of D = (1.68 +/- 0.57). 10(-13) cm(2) s(-1) for healthy cortical bone was obtained. This value differed only slightly from the value of D = (4.30 +/- 1.43). 10(-13) cm(2) s(-1) for osteoporotic cortical bone. Transmission electron microscopy investigations revealed a comparable nano- and ultrastructure for both types of bone status. Additionally, Sr2+-enriched mineralized collagen standards were prepared for ToF-SIMS quantification of Sr2+ content. The obtained calibration curve was used for Sr2+ quantification in cortical and trabecular bone in real bone sections. The results allow important insights regarding the Sr2+ transport properties in healthy and osteoporotic bone and can ultimately be used to perform a simulation of drug release and mobility in bone.",
keywords = "strontium, osteoporosis, diffusion, time-of-flight secondary ion mass spectrometry, bone nanostructure, quantification, CALCIUM-PHOSPHATE CEMENTS, OSTEOGENIC DIFFERENTIATION, LOCAL-DELIVERY, DRUG-RELEASE, MARROW, OSTEOPOROSIS, MECHANISMS, RANELATE, COLLAGEN, IMPLANT",
author = "Christine Kern and Mandy Quade and Seemun Ray and J{\~A}¼rgen Thomas and Matthias Schumacher and Thomas Gemming and Michael Gelinsky and Volker Alt and Marcus Rohnke",
note = "Funding Information: Ethics. All interventions were performed in full compliance with the institutional and German protection laws and approved by the local animal welfare committee (reference number: V 54-19 c 20-15 (1) GI 20/28 no. 108/2011). Data accessibility. The authors confirm that the data support the findings of this study. Data are exemplarily shown within the article and its electronic supplementary material. Additional data that support the findings of this study are available from the corresponding author upon request. Authors{\textquoteright} contributions. C.K. performed ToF-SIMS analysis, data evaluation and interpretation, and drafted the manuscript. M.Q. synthesized and analysed the collagen standards and edited the manuscript. S.R. performed animal experiment including sample preparation. J.T. and T.G. performed TEM analysis including data interpretation and edited the manuscript. M.S. and M.G. developed, synthesized and characterized the bone cement pS100. V.A. performed the animal experiments. M.R. designed the study, assisted in the experiments{\textquoteright} design, data evaluation and revised the manuscript. All authors proofread the manuscript and approved the final version. Competing interests. We declare we have no competing interests. Funding. This work was funded by the German Research Foundation (DFG, Collaborative Research Centre Transregio 79—subprojects M5, M4, T2 and Z2). We gratefully acknowledge the financial support within this project. Acknowledgements. The authors thank Nils D{\"o}hner and Yannick Mory-son for their support with ToF-SIMS measurements and Stefanie Kern for her support with statistical evaluation. We are grateful to Andrea Vo{\ss} (Leibniz-Institute for Solid State and Materials Research IFW Dresden, Germany) for ICP-OES analysis. Publisher Copyright: {\textcopyright} 2019 The Author(s) Published by the Royal Society. All rights reserved.",
year = "2019",
month = feb,
day = "1",
doi = "10.1098/rsif.2018.0638",
language = "English",
volume = "16",
journal = "Journal of the Royal Society Interface",
issn = "1742-5689",
publisher = "The Royal Society of New Zealand",
number = "151",
}