Novel Multi-Doped Apatite-Related Calcium Phosphates and Composites With SiO2 for Medical Application.
This study presents the synthesis and comprehensive characterization of the structural, mechanical, and biological properties of multi-doped with cations (Na+, Mg2+, Zn2+) and anions (SiO4 4-, CO3 2-, BO3 3-, BO2 -) hydroxyapatites, as well as their composites containing 25 wt% SiO2. XRD analysis confirmed the formation of a hexagonal apatite structure (space group P63/m) with crystallite sizes range from 17 nm to 23 nm. FTIR spectroscopy verified the successful incorporation of anionic groups into the calcium phosphate lattice via A-type and B-type substitution mechanisms. It was established that the introduction of silicate anions in structure or silica in composite allows for the precise tailoring of material surface reactivity in a model solution (pH elevation to 8.2-9.4) without significant degradation of mechanical performance (microhardness ∼0.32-0.33 GPa). The composite of (Na+, Mg2+, Zn2+, CO3 2-)-doped HAP with 25 wt% SiO2 exhibited the highest antimicrobial activity against Staphylococcus aureus and Pseudomonas aeruginosa, alongside superior nucleic acid sorption efficiency, outperforming borate-containing analogues by 1.36-1.89 times. These findings highlight the potential of the developed composites as multifunctional bioactive materials for bone tissue regeneration and nucleic acid extraction systems.