Molecular dynamics simulations of a Bioglass spherical nanoparticle (∼6 nm diameter) have been carried out to investigate the main structural features induced by the reduced size, which could play a specific role in the observed enhanced bioreactivity of these systems, in addition to the higher surface area. Compared to the bulk glass or to the extended flat surface, the simulations reveal that the most relevant effects of the reduced size are a further slight reduction in the already low silicate connectivity on the nanoparticle surface, together with a ring size distribution shifted towards three-membered rings, and a higher Na+/Ca2+ ratio in close proximity of the surface. The possible ways in which these effects can translate into higher bioreactivity are discussed.
