ABSTRACT
BACKGROUND: With excellent biocompatibility and bioactivity, bioglass and bioceramics have attracted more attention. However, the poor degradability limits their application in bone tissue engineering.OBJECTIVE: To observe the bioactivity and controllable degradation of a novel borosilicate glass.DESIGN: Single sample observation.SETTING: School of Materials Science and Engineering, Tongji University.MATERIALS: The experiment was performed at School of Materials Science and Engineering, Tongji University from October 2005 to September 2007. Thee reagent grade chemicals such as carbonate, phosphate, boric acid and silicon dioxide were self-made; D/max2550VB3+/PC X-ray diffractometer and S-2360 scanning electron microscope (SEM) were products of Olympus, Japan.METHODS: Three-dimensional, highly porous scaffolds with interconnected pores similar to trabecular bone were fabricated using melt-derived borosilicate glass powder by polymeric sponge method. The composition of glass material was 25Na2O·30CaO·5P2O5·(40-x)SiO2·xB2O3 (x=0, 20, 26, 30, 40).MAIN OUTCOME MEASURES: ①Hydroxyapatite formation on the surfaces of the samples and morphologies of the scaffolds were observed by X-ray diffractometer and SEM. ②Ion concentrations of the Na+, Ca2+, P5+ and B3+ in the solution of K2HPO4 were determined using atomic emission spectrum.RESULTS: ①The borosilicate glass made of 25Na2O·30CaO·5P2O5·(40-26)SiO2·26B2O3 showed better pore connectivity, and cells proliferated on the porous structure. ②In the borosilicate glass made of 25Na2O·30CaO·5P2O5·40SiO2, Na+ and B3+ release was less and their degradability was lower than other compositions.CONCLUSION: Hydroxyapatite formation on the surface and the degradation rate of scaffold materials could be controlled by changing the composition of the bioglass samples.