In Vitro Transformation of Sol-gel Derived Bioactive Glass from Sand

¹ Department of Chemistry, University of Lagos, Nigeria

² Department of Chemical Sciences, Bells University of Technology, Nigeria

^*Corresponding Author

Luqman A. Adams

Department of Chemistry

University of Lagos

Nigeria

Email: ladams@unilag.edu.ng.

Abstract

A Bioactive glass in the quaternary system SiO₂-Na₂O-CaO-P₂O₅ was prepared from sand as precursor in place of alkoxysilanes such as tetraethyl orthosilicate (TEOS) and tetramethyl orthosilicate (TMOS). Sodium metasilicate extracted from the sand was processed to a gel via the sol-gel technique. The gel, after aging was dried at lower temperatures before sintering at 950 ^oC for 3 h to form Na₂Ca₂Si₃O₉ crystals for enhanced mechanical property. The glass monolith was then subjected to standard in vitro bioactivity study in simulated body fluid (SBF) over 0-21 days. Characterization of the samples before and after immersion in SBF were performed using mechanical tester, scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction and Fourier transform infrared (FTIR) to evaluate compression strength, morphology, composition, diffraction patterns and chemical bonding respectively. The compression strength of the glass was 1.77 Mpa. The major crystalline phase was Na₂Ca₂Si₃O₉ which, however, transformed to an amorphous phase in SBF while forming hydroxyapatite (HA) and hydroxycarbonate apatite (HCA). The material may be a useful candidate in the regeneration of trabecular bones.

Keywords: Silica source; Na₂Ca₂Si₃O₉; Compression strength; Trabecular bone; Hydroxycarbonate apatite.

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