Realistic Models of Bioactive Glass Radioisotope Vectors in Practical Conditions: Structural Effects of Ion Exchange

Yttrium-doped silicate glasses with bioactive properties (YBGs) have potential applications in radiotherapy. The effect of gradual release of sodium and calcium from a YBG composition, modeling the ion-exchange processes occurring upon contact with an aqueous biological medium, was investigated through molecular dynamics simulations. The ion-exchanged hydroxylated structures exhibit some important differences with respect to the pristine dry composition, such as increased cross-linking and yttrium clustering, whose potential effects on their performances as radioisotope vectors are discussed. These findings also highlight the importance of taking into account the structural effects of ion exchange with an aqueous environment in order to develop more realistic predictive models of the behavior of bioactive glasses and related materials in practical conditions.