The influence of quadrupole effects on Cu(II) ESR spectra in glasses

Evaluation of borate bioactive glass scaffolds as a controlled delivery system for copper ions in stimulating osteogenesis and angiogenesis in bone healing

“…CuO has an agglutination effect and Cu 2+ ions in oxide glasses are surrounded by two non-bridging oxygen (NBO) atoms to preserve electroneutrality. 36 In silicate 45S5 glass, it was suggested that when CuO was replaced with CaO, the Cu-O bond showed more covalent character, compared to the Ca-O bond, which led to the re-polymerization of Si-NBOs and higher network connectivity. 37 Due to this reason, CuO could reduce the degradation of glass and the release of ions into the medium.…”

In vitro reactivity of Cu doped 45S5 Bioglass® derived scaffolds for bone tissue engineering

“…47 Cu 2+ (as well as Cu + ) predominantly work as network modi-ers and are incorporated in the glass work matrix in octahedral coordination. 48 According to Abdrakhmanov et al, 49 Cu 2+ is surrounded by two non-bridging oxygens (NBO) in order to achieve electroneutrality. Since no major differences were observed in FT-IR and Raman spectroscopy, the SiO 2 network of the 45S5 glass seems to be dominant and is not signicantly affected by the Cu-doping.…”

A review on borate bioactive glasses (BBG): effect of doping elements, degradation, and applications

“…Consequently, as the proportion of Cu doping in the glass system increased, more BO 4 groups were formed, creating a more stable structure, which led to a reduced boron ion release rate in the dissolution medium. 44 Abdrakhmanov et al 116 have made similar assumptions, asserting that the NBO coordinates Cu ions in BGs and that their influence is visible through the agglutination effect, which is the process by which alkali ions achieve electroneutrality. 112,116 However, a different study by Schuhladen et al 117 revealed that the copper added to the borate glass resulted in a lesser release of Ca and B and a marginally reduced release of the other elements.…”

“…44 Abdrakhmanov et al 116 have made similar assumptions, asserting that the NBO coordinates Cu ions in BGs and that their influence is visible through the agglutination effect, which is the process by which alkali ions achieve electroneutrality. 112,116 However, a different study by Schuhladen et al 117 revealed that the copper added to the borate glass resulted in a lesser release of Ca and B and a marginally reduced release of the other elements. Furthermore, the results discussed above showed that the influence of Cu doping in borosilicate glass led to a more stable glass network connectivity and a lower ions release rate during the degradation process.…”