Effects of injecting massive amounts of bioactive ceramics in mice

The effects of massive administration of bioactive ceramic powder (Bioglass (45S5), Ceravital (KGS), apatite-wollastnite containing glass ceramics (A-W GC), and hydroxyapatite (HA], by intraperitoneal (IP), intramuscular (IM), or subcutaneous (SC) injection in Balb/c mice were examined in this investigation. Alumina, Silica Glass (SG), and A-W-Al (containing the same amount of crystal as A-W GC and 6.3% Alumina) were used as nonbioactive controls. The particle size of each material injected was smaller than 44 microns. In addition to the above, two more sizes (smaller than 105 microns and smaller than 255 microns) of A-W GC powder, and a 1 x 1 x 0.2 cm plate of the A-W GC were also evaluated. When the particle size was smaller than 44 microns, intraperitoneal injections of 5 mg per g of body weight of BG, KGS, A-W GC, and A-W-Al were lethal to the mice. Ceramics in fine powder form, which are generally believed to have higher bioactivity, are associated with higher mortality except A-W-Al. On the other hand, when the particle size of the ceramic was increased, the fatal effects of ceramic powders in mice decreased. Plate form of ceramics implanted I.P. had no systemic effects. Intramuscular or SC injections of bioactive ceramic powder with a particle size smaller than 44 microns had almost no systemic effects. Both the particle size of the ceramic powder and the route of administration influenced the reactivity of the bioactive ceramics in the mice. In conclusion, regardless of particle size, neither SC nor IM injection of large doses of highly bioactive ceramics had an adverse effect on the host (mouse).