[Biodegradation of synthetic bioglasses with different crystallinity in vitro]

SG600, SG900 and SG1100 were synthesized by the sol-gel method. Further treatments with increasing temperatures influenced and determined the crystallization degree of the material. Primary cultured osteoclasts were incubated for 4h and 48h on samples. Osteoclast actin labeling was examined by cytochemical staining. The concentrations of Ca and P in culture medium were quantified by colorimetric methods. SEM examined osteoclast morphology and resorption lacuna. Actin staining revealed on all three materials the typical adhesion contact ring. The Ca concentration in the culture medium of SG600 was significantly higher than that in control medium, SG900 and SG1100. Ca and P concentrations were always higher in culture media with the presence of osteoclasts. Morphological studies by scanning electron microsopy(SEM) showed a good adhesion behavior of osteoclasts on all three samples. Well-developed and deep resorption lacunae appearing after the osteoclastic resorption action were detected on all three samples. The synthetic bioglasses with different crystallizations caused different solubility, which seemed to have little effect on the osteoclast resorption behavior. The results of morphological studies on osteoclasts and resorption lacunae clearly demonstrate that the synthetic bioglasses are easily resorbed in vitro by osteoclasts.