Bioactive borosilicate glass scaffolds: improvement on the strength of glass-based scaffolds for tissue engineering

Three-dimensional macroporous scaffolds with the pore size of 200-500 mu m were fabricated by replication method using bioactive borosilicate glass from Na2O-K2O-MgO-CaO-SiO2-P2O5-B2O3 system. The effects of the strength of the strut in reticulated scaffold, as well as the geometrical parameter of the scaffold on the strength of reticulated scaffold were investigated. Scanning electron microscope (SEM) and X-ray diffraction (XRD) results show that the solidified glass struts in the reticulated scaffold could be obtained through a sufficient vicious flow of glass, during the fabrication. By increasing the solid content in slurries, from which the scaffold was made, the load-bearing units of the reticulated scaffold switch from struts to the walls between the pores, and the compressive strength dramatically climbs higher than the theoretical strength calculated by Gibson model. In particular, the compressive strength of the reticulated scaffold, as high as 10 MPa with the porosity of 70%, is close to the reported compressive values of human cancellous bone. This indicates the bioactive borosilicate glass-based scaffold is a promising candidate for bone tissue engineering.