ABSTRACT
The changes in the atomic structure and in the network of bonds between oxide tetrahedra in 60S bioactive glass upon modification of its structure by yttrium and lanthanum atoms were investigated via XPS, FTIR, and NMR spectroscopy methods. The presence of nanostructure in the samples of 60S bioactive glass modified with yttrium and lanthanum was demonstrated. The formation of a bioinert core of 60S bioactive glass nanoparticles with the subsequent formation of a biocompatible layer is facilitated by the redistribution of electron density when oxygen bridge bonds are broken, PO4 and SiO4 tetrahedra are fragmented in the polymer matrix, and isolated nanoclusters are formed. Given the fact that during the interaction with the extracellular matrix, the breakdown of covalent bonds -O-Si-O-P- is more energetically costly than the rapid ionic exchange of network modifiers Ca2+ (Y3+, La3+) and the leaching of isolated nanoclusters into the surrounding physiological environment, it is argued that modification of 60S bioactive glass with yttrium or lanthanum can accelerate bioactive ionic processes in the extracellular matrix.
