Effect of Gas-foaming Porogen-NaHCO$lt;inf$gt;3$lt;/inf$gt; and Citric Acid on the Properties of Injectable Macroporous Borate Bioactive Glass Cement

Borate bioactive glass (BBG) is a promising candidate material for bone tissue engineering. Mostly, it was applied in the form of scaffolds and granules. Till now, little work has been done to investigate the fabrication of porous borate bioactive glass cement (BBGC). In this work, we prepared an injectable macroporous BBGC via gas-foaming method, where NaHCO 3 and citric acid were used as porogen. Porous structure was analyzed by using SEM. The properties of soaking products were characterized by XRD, FTIR and ATR. The injection test showed that the injection rate of BBGC was over 80%. SEM images presented that there were apparent pores in BBGC. The diameter of the macropores varied from 10 m to 800 m. Furthermore, the degradability of BBGC was greatly improved. After one month in vitro soaking, the weight loss of non-foamed BBGC was only 50wt%, while for the foamed samples, their weight loss reached 70wt%. Meanwhile, the XRD, FTIR and ATR results exhibited that there were hydroxyapatite (HA) formation and confirmed that the introduction of macropores into the BBGC did facilitate the mineralization reaction.