Physiological removal of silicon from bioactive glass

Bioactive glass granules were implanted in the paraspinal muscle and tibiae of rabbits in order to determine the pathway of the silicon released from bioactive glass it? vivo. We traced and quantified the silicon released by obtaining 24-hour urine samples, as well as blood samples for up to 7 months after implantation. Furthermore, local muscle and bone tissue as well as the following organs were resected for chemical and histopathological analyses: brain, heart, kidney, liver, lung, lymph nodes, spleen, and thymus. The concentrations of silicon found in the urine were well below saturation and no accumulation of silicon was found in the major organs after silicon excretion had halted. The removal of silicon from the bony matrix was slower overall compared to an intramuscular site, taking a total of 24 weeks versus 19 weeks to complete silicon removal, respectively.