abstract
We investigated the structure-property relationships in a series of alkali-free phosphosilicate glass compositions co-doped with Zn2+ and Sr2+. The emphasis was laid on understanding the structural role of Se2+ and Zn2+ co-doping on the chemical dissolution behavior of glasses and its impact on their in vitro bioactivity. The structure of glasses was studied using molecular dynamics simulations in combination with solid state nuclear magnetic resonance spectroscopy. The relevant structural properties are then linked to the observed degradation behavior, in vitro bioactivity, osteoblast proliferation and oxidative stress levels. The apatite-forming ability of glasses has been investigated by X-ray diffraction, infrared spectroscopy and scanning electron microscopy-energy-dispersive spectroscopy after immersion of glass powders/bulk in simulated body fluid (SBF) for time durations varying between 1 h and 14 days, while their chemical degradation has been studied in Tris-HCl in accordance with ISO 10993-14. All the glasses exhibit hydroxyapatite formation on their surface within 1-3 h of their immersion in SBF. The cellular responses were observed in vitro on bulk glass samples using human osteosarcoma MG63 cell line. The dose-dependent cytoprotective effect of glasses with respect to the concentration of zinc and strontium released from the glasses is also discussed. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
keywords
MOLECULAR-DYNAMICS SIMULATIONS; SOLID-STATE NMR; CELL-LINE MG-63; NF-KAPPA-B; IN-VITRO; SILICATE-GLASSES; APATITE FORMATION; PHYSICOCHEMICAL DEGRADATION; OSTEOCALCIN SECRETION; MINERAL METABOLISM
subject category
Engineering; Materials Science
authors
Kapoor, S; Goel, A; Tilocca, A; Dhuna, V; Bhatia, G; Dhuna, K; Ferreira, JMF
our authors
José Maria da Fonte Ferreira
Retired Professor
Saurabh Kapoor
PhD Studentacknowledgements
The support of CICECO, University of Aveiro and Foundation for Science and Technology (FCT), Portugal in the frame of the Project Reference PTDC/CTM/99489/2008 is acknowledged. A. Tilocca thanks the U.K.'s Royal Society for financial support (University Research Fellowship).