Optimizing controlled degradation, bioactivity, and mechanical behavior in sol-gel synthesized aluminum titanate biomaterials.

Abstract

Orthopaedic applications require materials that balance mechanical strength, biocompatibility, and controlled degradation, particularly for bone regeneration and load-bearing purposes. This study investigates the effects of varying weight percentages of Al₂O₃and TiO₂(25:75, 50:50, and 75:25) on the characteristics of Al₂TiO₅biomaterials synthesized via the sol-gel method. Structural and chemical characterizations, including XRD and FTIR, confirmed the successful synthesis of phase-pure Al₂TiO₅, highlighting functional groups such as Al-O and Ti-O. Among the tested compositions, the 50:50 ratio exhibited the strongest antibacterial efficacy againstS. aureusandE. coli, comparable to a commercial antibiotic, while also promoting hydroxyapatite (HAp) deposition in simulated body fluid (SBF). Additionally, cytotoxicity assessments using the L929 murine fibroblast cell line revealed that the 50:50 composition had the lowest toxicity. All formulations demonstrated controlled degradation, minimizing pH fluctuations and enhancing bioactivation and biocompatibility. Zeta potential analysis indicated that the 50:50 composition exhibited the most negative values over time, suggesting strong surface interactions with SBF and a favorable environment for HAp nucleation. Furthermore, the compressive strength of all formulations (71-74 MPa) was sufficient for load-bearing applications. These findings suggest that optimizing the 50:50 weight ratio enhances bioactivity, mechanical stability, and biocompatibility, making it a promising candidate for orthopedic and bone tissue engineering applications.