Surfactant-assisted sonochemical synthesis of hollow calcium silicate hydrate (CSH) microspheres for drug delivery

Hollow calcium silicate hydrate (CSH) microspheres with diameters around 1 μm were synthesized by a surfactant-assisted sonochemical route, and the products were characterized by XRD, SEM, FETEM and BET techniques. The results suggested that the ultrasound radiation, surfactant and Ca source were important factors which affected the formation of hollow microspheres. Based on the observation of products in different reaction systems, the possible mechanism for the formation of hollow CSH spheres was discussed. Furthermore, gentamicin, a typical anti-inflammatory drug, was used to investigate the drug loading and release behavior of the hollow spheres. The results indicated that CSH hollow spheres had high drug loading capacity and favorable drug release behavior, and might be used for preparation of bone grafts with drug delivery properties.