In this paper, nanocrystalline silicate-substituted
hydroxyapatites
(nSi-HAps) codoped with Eu3+ were functionalized with Bi3+ ions. Biomaterials were synthesized using a microwave-assisted
hydrothermal method and heat-treated at 700 °C. The concentration
of Eu3+ ions was established at 1 mol %, and the concentration
of Bi3+ was in the range of 0.5–2 mol %. The physicochemical
properties of the obtained biomaterials were determined using previously
established methods, including X-ray powder diffraction, scanning
electron microscopy techniques, and IR spectroscopy. Particle sizes
obtained in this study were in the range of 22–65 nm, which
was established by the Rietveld method. The luminescence properties
of the Eu3+ ion-doped silicate-substituted apatite were
recorded depending on the bismuth(III) concentration. The cytocompatibility
of obtained biomaterials was tested using the model of mouse pre-osteoblasts
cell line, that is, MC3T3-E1. We showed that the obtained biomaterials
exerted anti-apoptotic effect, reducing the number of early and late
apoptotic cells and decreasing caspase activity and reactive oxygen
species accumulation. The transcripts levels of genes associated with
apoptosis confirmed the anti-apoptotic effect of the biomaterials.
Increased metabolic activity of MC3T3-E1 in cultures with biomaterials
functionalized with Bi3+ ions has been observed. Moreover,
the determined profile of osteogenic markers indicates that the obtained
matrices, that is, Eu3+:nSi-HAp functionalized with Bi3+ ions, exert pro-osteogenic properties. The biological features
of Eu3+:nSi-HAp modified with Bi3+ ions are
highly desired in terms of functional tissue restoration and further
efficient osteointegration.