ABSTRACT Increasing interest in the role of ions such as calcium and strontium in bone formation has called for the investigation of multifunctional ion-doped implant coatings. Mesoporous titania coatings incorporating calcium or strontium enabled a unique pore morphology and potential for drug delivery. Coatings were produced on titanium by an evaporation induced self-assembly method with the addition of calcium or strontium to the sol causing a shift in morphology from a hexagonally-packed to a worm-like porous network. Pore sizes ranged from 3.8 - 5 nm and coatings exhibited high surface areas between 181 - 215.5 m2/g, as measured by N2 adsorption-desorption. Coatings were loaded with 1 mg/ml Cephalothin, and showed sustained release of the antibiotic over one week in vitro. Cell studies confirmed that the ion addition had no toxic effect on human-like osteoblastic SaOS-2 cells. The results of this study suggest the potential for mesoporous coatings with calcium or strontium incorporation for direct bone-interfacing and combined drug delivery implant applications.
Cite this paper
K. Grandfield, S. Pujari, M. Ott, H. Engqvist and W. Xia, "Effect of Calcium and Strontium on Mesoporous Titania Coatings for Implant Applications," Journal of Biomaterials and Nanobiotechnology, Vol. 4 No. 2, 2013, pp. 107-113. doi: 10.4236/jbnb.2013.42014.
 M. Vallet-Regì, F. Balas and D. Arcos, “Mesoporous Materials for Drug Delivery,” Angewandte Chemie International Edition, Vol. 46, No. 40, 2007, pp. 7548-7558.
 X. Yan, C. Yu, X. Zhou, J. Tang and D. Zhao, “Highly Ordered Mesoporous Bioactive Glasses with Superior in Vitro Bone-Forming Bioactivities,” Angewandte Chemie International Edition, Vol. 43, No. 44, 2004, pp. 5980- 5984. doi:10.1002/anie.200460598
 W. Xia and J. Chang, “Well-Ordered Mesoporous Bioactive Glasses (MBG): A Promising Bioactive Drug Delivery System,” Journal of Control Release, Vol. 110, No. 3, 2006, pp. 522-530. doi:10.1016/j.jconrel.2005.11.002
 H. A. Santos, J. Salonen, L. M. Bimbo, V. P. Lehto, L. Peltonen and J. Hirvonen, “Mesoporous Materials as Controlled Drug Delivery Formulations,” Journal of Drug Delivery Science and Technology, Vol. 21, No. 2, 2011, pp. 139-155.
 J. D. Bass, D. Grosso, C. Boissiere, E. Belamie, T. Coradin and C. Sanchez, “Stability of Mesoporous Oxide and Mixed Metal Oxide Materials under Biologically Relevant Conditions,” Chemistry of Materials, Vol. 19, No. 17, 2007, pp. 4349-4356.
 W. Xia, K. Grandfield, A. Hoess, A. Ballo, Y. Cai and H. Engqvist, “Mesoporous Titanium Dioxide Coating for Metallic Implants,” Journal of Biomedical Materials Research Part B: Applied Biomaterials, Vol. 100, No. 1, 2012, pp. 82-93. doi:10.1002/jbm.b.31925
 R. LeGeros, “Apatites in Biological-Systems,” Progress in Crystal Growth and Characterization of Materials, Vol. 4, 1981, pp. 1-45. doi:10.1016/0146-3535(81)90046-0
 F. Yao, J. P. LeGeros and R. Z. LeGeros, “Simultaneous Incorporation of Carbonate and Fluoride in Synthetic Apatites: Effect on Crystallographic and Physico-Chemical Properties,” Acta Biomaterialia, Vol. 5, No. 6, 2009, pp. 2169-2177. doi:10.1016/j.actbio.2009.02.007
 P. Marie, “Strontium Ranelate: A Physiological Approach for Optimizing Bone Formation and Resorption,” Bone, Vol. 38, No. 2, 2006, pp. 10-14.
 M. Looney, H. O. Shea and D. Boyd, “Preliminary Evaluation of Therapeutic Ion Release from Sr-Doped Zinc- Silicate Glass Ceramics,” Journal of Biomaterials Applications, Vol. 27, No. 5, 2011, pp. 5111-524.
 E. Boanini, P. Torricelli, M. Fini and A. Bigi, “Osteopenic Bone Cell Response to Strontium-Substituted Hydroxyapatite,” Journal of Materials Science: Materials in Medicine, Vol. 22, No. 9, 2011, pp. 2079-2088.
 G.-X. Ni, Z.-P. Yao, G.-T. Huang, W.-G. Liu and W. W. Lu, “The Effect of Strontium Incorporation in Hydroxyapatite on Osteoblasts in Vitro,” Journal of Materials Science: Materials in Medicine, Vol. 22, No. 4, 2011, pp. 961-967. doi:10.1007/s10856-011-4264-0
 B. Feng, J. Weng, B. Yang, S. Qu and X. Zhang, “Characterization of Titanium Surfaces with Calcium and Phosphate and Osteoblast Adhesion,” Biomaterials, Vol. 25, No. 17, 2004, pp. 3421-3428.
 T. Hanawa, M. Kon, H. Doi, H. Ukai, K. Murakami, H. Hamanaka and K. Asaoka, “Amount of Hydroxyl Radical on Calcium-Ion-Implanted Titanium and Point of Zero Charge of Constituent Oxide of the Surface-Modified Layer,” Journal of Materials Science: Materials in Medicine, Vol. 9, No. 2, 1998, pp. 89-92.
 X. Liu, P. Chu and C. Ding, “Surface Modification of Titanium, Titanium Alloys, and Related Materials for Biomedical Applications,” Materials Science and Engineering: R, Vol. 47, 2004, pp. 49-121.
 C.-W. Wu, T. Ohsuna, M. Kuwabara and K. Kuroda, “Formation of Highly Ordered Mesoporous Titania Films Consisting of Crystalline Nanopillars with Inverse Meso-space by Structural Transformation,” Journal of the American Chemical Society, Vol. 128, No. 14, 2006, pp. 4544- 4545. doi:10.1021/ja060453p
 I. I. Slowing, B. G. Trewyn, S. Giri and V. S. Y. Lin, “Mesoporous Silica Nanoparticles for Drug Delivery and Biosensing Applications,” Advanced Functional Materials, Vol. 17, No. 8, 2007, pp. 1225-1236.
 A. Peterson, T. Lopez, E. Islas and R. Gonzalez, “Pore Structures in an Implantable Sol-Gel Titania Ceramic Device Used in Controlled Drug Release Applications: A Modeling Study,” Applied Surface Science, Vol. 253, No. 13, 2007, pp. 5767-5771.
 K. Cai, J. Bossert and K. D. Jandt, “Does the Nanometre Scale Topography of Titanium Influence Protein Adsorption and Cell Proliferation?” Colloids and Surfaces B: Biointerfaces, Vol. 49, No. 2, 2006, pp. 136-144.
 J. D. Bass, E. Belamie, D. Grosso, C. Boissiere, T. Coradin and C. Sanchez, “Nanostructuration of Titania Films Prepared by Self-Assembly to Affect Cell Adhesion,” Journal of Biomedical Materials Research, Vol. 93, No. 1, 2010, pp. 96-106.
 R. Rohanizadeh, M. Al-Sadeq and R. Z. LeGeros, “Titanium Oxide Layers Obtained by Different Methods: Effect on Apatite Deposition,” Key Engineering Materials, Vol. 240, 2003, pp. 449-452.