# Characterization, in-vitro biological and antimicrobial testing of replacing Sr/Ca in wollastonite (Ca1 − x Srx SiO3) glass-ceramics

## TL;DR

This study explores how adding strontium to wollastonite glass-ceramics improves their structure and biological performance for medical uses.

## Contribution

The paper introduces a new Sr-doped wollastonite system with enhanced bioactivity and antifungal properties for orthopedic and dental applications.

## Key findings

- Strontium doping promotes hydroxyapatite formation and alters crystal structure in the glass-ceramics.
- The W3Sr sample (0.5 wt% Sr) showed optimal mechanical and biological performance.
- The material exhibited antifungal activity against Aspergillus niger and Fusarium solani but no antibacterial activity.

## Abstract

Strontium-doped wollastonite glass-ceramics with varying Sr concentrations (0.125, 0.25, and 0.50 wt%) were successfully synthesized via a melt-quenching technique and comprehensively evaluated for structural, physical, and biological performance, including in vitro biocompatibility, antimicrobial activity, and cytotoxicity. Characterization using DTA, XRD, and FE-SEM/EDX confirmed progressive hydroxyapatite (HA) formation following 28 days of immersion in simulated body fluid (SBF), with XRD revealing a reduction in wollastonite peaks and distinct HA signals, particularly in Sr-containing samples. FTIR spectra showed intensified phosphate absorption bands, while FE-SEM/EDX analyses highlighted a morphological shift from plate-like structures to needle-like HA crystals. Strontium doping was found to play a key role in guiding HA crystallization pathways while supporting wollastonite’s intrinsic isovalent cation exchange capacity. Among all compositions, the W3Sr sample (0.5 wt% Sr) exhibited the best balance of mechanical properties and biological efficacy. Biologically, the material demonstrated dose-dependent antifungal activity against Aspergillus niger (11–18 mm IZD) and Fusarium solani (10–16 mm IZD), no antibacterial activity, and excellent cytocompatibility with BJ1 human fibroblasts. Overall, this Sr-doped wollastonite system shows strong potential for next-generation orthopedic and dental applications, combining Sr-mediated bioactivity, mechanical strength, antifungal efficacy, and cell compatibility.

The online version contains supplementary material available at 10.1038/s41598-026-36649-1.