Synthesis and characterization of europium-containing luminescent bioactive glasses and evaluation of in vitro bioactivity and cytotoxicity

Luminescent europium-containing bioactive glasses (EuBG) based on the 58 %SiO₂-33 %CaO-9 %P₂O₅ (in mass, %) system were synthesized using sol-gel technique by adding Eu₂O₃ in silica network. The structural, textural and optical properties, as well as in vitro bioactivity and biocompatibility of the material were characterized using various methods. The results show that all the Eu-containing bioactive glass materials exhibit an amorphous structure, large specific surface area, relatively uniform pore size distribution and high in vitro bioactivity, similar to the conventional sol-gel bioactive glass. More importantly, the addition of Eu₂O₃ endow the material with a luminescent property even after immersion in aqueous solution and the luminescent intensity increases with the increase of Eu₂O₃ content. The cytotoxicity assay indicates that pure EuBG extract significantly inhibit the growth of rat marrow mesenchymal stem cells (rMSCs), while 25 % concentration of the extract diluted by culture medium could significantly improve the proliferation of rMSCs in comparison with pure medium. According to the above results, the material presents excellent apatite-forming activity, luminescent property and biocompatibility, demonstrating their potential applications in the fields of bone regeneration and drug delivery system.