In vitro bioactivity and cytocompatibility of porous scaffolds of bioactive borosilicate glasses

The bioactive borosilicate scaffolds (R₂O-RO-B₂O₃-SiO₂-P₂O₅) with four different contents of borate were fabricated by replication technique. The bioactivity, degradability and the cytotoxicity of the scaffolds were studied in this paper. The porosity of the scaffolds was found to be 73%–80%, and the pore size was in the range of 200–300 μm. The porous scaffolds immersed in 0.02 mol·L⁻¹ K₂HPO₄ solution were transformed into hydroxyapatite. And it is notable that the D-Alk-2B, D-Alk-3B-scaffolds were covered by hydroxyapatite layers after 7 h-immersion, which proved their high bioactivity. In the cell adhesion test, cells could be seen growing well on the scaffolds, showing stretched morphology and obvious pseudopodia, and only the high cumulative concentration of B ions released from the D-Alk-3B-scaffold samples had an inhibition effect on cell proliferation. But the inhibition effect could be alleviated by diluting the extract solution to a certain concentration (dilution ratio: 1:8). Therefore, after suitable pretreatment, the porous borosilicate bioactive glass scaffold can be a desirable candidate for bone tissue engineering.