The initial stages of bioglass dissolution: a Car-Parrinello molecular-dynamics study of the glass-water interface

The initial dissolution stages following implantation of a biomaterial in a physiological environment are critical for its bioactive properties. Car-Parrinello molecular-dynamics (CPMD) simulations of the interface between the 45S5 bioglass surface and liquid water have been carried out to investigate these processes. The analysis of a 40 ps CPMD trajectory has highlighted the potential mechanism of Na(+)/H(+) exchange, leading to formation of surface silanols through water dissociation. Moreover, by comparing the properties of water layers arranged at different distances from the glass surface, we discuss the way in which the particular structure and composition of the bioglass surface affects the hydrogen-bond network and orientation of water in its close proximity.