Effect Of SrO Doping On Network Structure And Degradation Behaviour Of Alkali-free Borate Bioactive Glass

Abstract

Borate-based glasses are attractive for bone regeneration due to their rapid dissolution and their ability to promote the formation of an apatite-like layer in physiological environments. However, a challenge associated with borate glasses is controlling boron ion (B) release, which is critical for maintaining biocompatibility and structural stability. In this study, a borate glass series based on 47B2O3-XSrO-17ZnO-11Ag2O-(25-X)CaO (wt%, X = 0, 1, 3, and 5) glasses were synthesized to investigate the influence of strontium oxide (SrO) on glass structure, thermal behaviour, and B release. X-ray diffraction (XRD) confirmed that all compositions were fully amorphous, and 11B magic angle spinning nuclear magnetic resonance (MAS-NMR) revealed no significant changes in B speciation with SrO incorporation. Differential scanning calorimetry (DSC) showed a progressive decrease in melting temperature with increasing SrO content, suggesting that SrO modifies the melt behavior of the borate glass system. However, the relatively constant Tg and Tc values across compositions indicate that overall thermal stability and network rigidity were not substantially altered. Immersion in phosphate-buffered saline for up to 60 days demonstrated that B release increased with immersion time, while only the highest SrO substitution (5 wt%) showed a statistically significant difference compared with the Sr-free control. These findings suggest that, within alkali-free borate glass systems, SrO acts as a secondary network modifier that modestly influences long-term B dissolution without substantially altering early-stage degradation behavior.

Department(s)

Chemical and Biochemical Engineering

Keywords and Phrases

Bioactive glass; Borate glass; Calcium; Glass degradation; Strontium

International Standard Serial Number (ISSN)

1873-4812; 0022-3093

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2026 Elsevier, All rights reserved.

Publication Date

15 Oct 2026

Link to Full Text

Share

 
COinS