Commentary on “Influence of glass composition on the network structure and mineralization of europium containing mesoporous bioactive glass nanoparticles”

This letter addresses critical issues in a recent study on europium-containing mesoporous bioactive glass nanoparticles. First, the term “mineralization” is repeatedly applied in the manuscript in a manner inconsistent with mineralogical standards. The calcium phosphate layers formed during simulated body fluid (SBF) immersion are synthetic, amorphous, and laboratory-derived, and should instead be described as “calcium phosphate deposition”, “bioactive layer formation”, or “apatite-like phase development”. Second, the attribution of enhanced surface reactivity to Eu^³⁺ incorporation lacks proper validation. Since all glass compositions contain identical Eu_₂O_₃ concentrations, while SiO_₂ and CaO contents vary, the observed differences in apatite-like deposition likely arise from network connectivity and dissolution behavior, not europium alone. The absence of a Eu-free control limits any definitive conclusion about Eu^³⁺ effects. Finally, although the multifunctionality of Eu^³⁺ is emphasized, no experimental evidence of luminescence or osteogenic activity is provided, leaving claims of optical and biological benefits unsubstantiated. Addressing these issues would improve the accuracy, rigor, and practical relevance of the work, ensuring alignment with established terminology and enhancing its contribution to biomaterials research.