Electrospinning preparation and drug delivery properties of Eu/Tb doped mesoporous bioactive glass nanofibers

Luminescent Eu³⁺/Tb³⁺ doped mesoporous bioactive glass nanofibers (MBGNFs) with average diameter of 100-120 nm were fabricated by electrospinning method. Pluronic P123 and N-cetyltrimethylammonium bromide (CTAB) were used as co-surfactants to generate porous structure of the nanofibers. N₂ adsorption-desorption measurement reveals that the MBGNF:Eu³⁺ have a surface area of 188 m² g⁻¹, a pore volume of 0.246 cm³ g⁻¹ and average pore size of 4.17 nm, and the MBGNF:Tb³⁺ have a surface area of 171 m² g⁻¹, a pore volume of 0.186 cm³ g⁻¹ and average pore size of 3.65 nm. Photoluminescence measurements reveal that the MBGNF:Eu³⁺ show strong red emission dominated by the ⁵D₀ → ⁷F₂ transition of Eu³⁺ at 614 nm with a lifetime of 1.356 ms, and MBGNF:Tb³⁺ show strong green emission dominated by the ⁵D₄ → ⁷F₅ transition of Tb³⁺ at 544 nm with a lifetime of 1.982 ms. The biocompatibility tests on L929 fibroblast cells using MTT assay reveal low cytotoxicity of MBGNF. These luminescent nanofibers show sustained release properties for ibuprofen (IBU) in vitro. The emission intensities of Eu³⁺ in the drug delivery system vary with the released amount of IBU, thus making the drug release be easily tracked and monitored by the change of the luminescence intensity.