Structural, chemical and biological properties of SiO2-CaO-Er2O3 flexible ceramic nanofibers for biomedical applications

Rare earth-doped bioactive ceramics are promising biomaterials due to their unique optical properties, biocompatibility, antioxidants, and antibacterial activity. In this study, a series of SiO₂-CaO-Er₂O₃ nanofiber mats were fabricated by sol-gel electrospinning. The morphology, flexibility, physicochemical and biological properties of the nanofibers were investigated. The flexibility of the nanofiber mats containing 5 and 10 wt% of Er₂O₃ was better than that of samples without or with >10 wt% Er₂O₃. The chemical property assay indicated that addition of Er can lead to changes in the degree of crystallinity and the degree of silica network polymerization, which further affect the flexibility. Photoluminescent spectra showed that the Er-doped nanofibers exist green and near infrared emissions. The in vitro bio experiments demonstrated that Er-doped nanofibers present excellent biocompatibility, and the mineralization experiment demonstrated that Er-doped nanofibers present favorable mineralization activity. Therefore, these SiO₂-CaO-Er₂O₃ flexible nanofibers may be promising candidates for biomedical applications.