Zinc-doped calcium magnesium silicate ceramics: A comprehensive study on bioactivity, mechanical strength, and microbial resistance

The demand for bone tissue engineering materials has increased significantly due to the rising prevalence of bone-related diseases and injuries. This study focuses on the development of a bioceramic material offering enhanced mechanical strength, antibacterial properties, biomineralization potential, and biocompatibility, aiming to overcome the limitations associated with conventional calcium silicate-based ceramics. Zinc doped-diopside (Ca (1-X) Zn X MgSi 2 O 6 ) was prepared through the sol-gel combustion method, utilizing tartaric acid as a fuel. Zinc (Zn 2+ ) ion was incorporated as a dopant to enhance the in-vitro biological performance of the material. Zinc incorporation into the diopside matrix was analysed using FT-IR spectroscopy and X-ray diffraction, confirming successful incorporation of zinc ion, while SEM imaging highlighted the morphological effects of zinc doping. Zinc doping significantly enhanced the apatite-forming ability of diopside, improved compressive strength up to 109 MPa, and facilitated controlled degradation factors that are critical for effective bone regeneration. Furthermore, the release of Zn 2+ ions imparted strong antimicrobial activity, with Pseudomonas aeruginosa showing up to 69% inhibition, representing a 1.08-fold increase compared to pure diopside. Antifungal efficacy was also evident, with inhibition rates of approximately 60% against Aspergillus niger and Fusarium oxysporum , corresponding to a 1.28-fold improvement over the pure diopside. Notably, the material exhibited a microbial static effect, inhibiting the growth and proliferation of the tested clinical pathogens. These results underscore the potential of zinc-doped diopside as a multifunctional biomaterial with significant promise for hard tissue engineering applications. • Zinc-doped diopside was synthesized via the sol-gel combustion method with phase purity confirmed by XRD and FT-IR, without secondary phases. • The zinc-doped diopside exhibited significant apatite formation after 9 days in simulated body fluid (SBF), indicating bioactivity and potential for bone regeneration. • Zinc doping increased the mechanical strength, with 3%ZNDP showing compressive strength comparable to human cortical bone. • The 3%ZNDP exhibited potent antibacterial and antifungal activity, inhibiting S. aureus , E. coli , Aspergillus sp. , and Fusarium sp. , while also showing strong anti-inflammatory effects with 99% at 2 mg/mL concentration. • The findings highlight the importance of optimizing zinc ion concentration to balance antimicrobial efficacy and cellular compatibility in biomaterial applications.