Various types of nanomaterials play currently important role in different fields of medicine. For example, silica–calcia system is a well-known basic composition of bioactive glass that is used in regenerative medicine. Glass nanostructures might show higher activity and broader range of applications in comparison to their well-known microsized counterparts. We present studies on nanoparticles (average diameter <100 nm) of bioactive glass showing photoluminescence due to a modified composition of silica–calcia system. The sol–gel route was used to fabricate the particles. To ensure photoactivity, the composition of glass was modified by addition of lanthanide ions, phthalocyanine complexes with metals, carbon structures, or zinc oxide. The optical properties (absorption and photoluminescence spectra) of the samples as well as their structural and morphological properties were examined. The results showed that glasses were active in different spectral ranges of electromagnetic spectrum – from ultraviolet to near infrared – depending on the activators. Photoactivity was presented as luminescent and photocatalytic properties as well as singlet oxygen generation. The bioactivity tests indicated that when particles were immersed in the simulated body fluid, ions release to the medium appeared and hydroxyapatite formation on the glass surface was observed. Described systems could be used, for example, for monitoring structural changes of the glass immersed in biological fluids, bioimaging, photodynamic therapy, or photocatalysis. Research was supported by the National Science Centre (Poland) grant No. 2016/22/E/ST5/00530.
|