Processing and characterization of Ca3ZrSi2O9 ceramics doped with Ag+ ions for bone tissue engineering applications

This study presents the sol-gel synthesis, structural characterization and biological evaluation of silver-doped baghdadite (Ca 3 ZrSi 2 O 9 ) ceramics intended for bone tissue engineering applications. The proposed combination was selected to integrate the excellent bioactivity and mechanical stability of baghdadite with the well-known antimicrobial properties of silver ions, aiming to develop a multifunctional bioceramic suitable for osteointegration and infection prevention. Baghdadite powders were synthesized with varying Ag + contents (0, 2, 4 and 6 mol%) and thermally treated at 1350°C to obtain dense ceramic bodies. Structural analyses confirmed the successful incorporation of Ag + into the monoclinic baghdadite lattice without formation of secondary phases. SEM investigations revealed that silver doping enhanced microstructural densification, leading to increased crystallinity and reduced porosity. These structural improvements were reflected in the mechanical performance, with Ag6 achieving the highest compressive strength (∼52 MPa) and lowest porosity (∼34 %). In vitro assays using osteoblast-like cells demonstrated excellent cytocompatibility for all compositions, with Ag4 showing the highest cell viability (120 %) and no signs of morphological alteration. Although Ag⁺ doping did not accelerate mineralization, all Ag-containing samples exhibited significant antibacterial activity against S. aureus , E. coli , and C. Albicans. Overall, silver doping improved both the structural integrity and biological performance of baghdadite, confirming its potential as a multifunctional material for bone regeneration. • The sol-gel synthesis and characterization of Ag + -doped baghdadite ceramics (concentrations of Ag + - 2, 4 and 6 mol%). • The baghdadite ceramics have adequate strength and porosity and good biological properties (e.g. antibacterial properties). • The Ag + -doped baghdadite emerges as a promising candidate for bone tissue engineering applications.