Novel bioactive amorphous glass–glass composite
scaffolds (ICIE16/BSG)
with interconnected
porosity have been developed.
Hierarchically interconnected porous glass
scaffolds were prepared from a mixture of two melt-derived glasses: a ICIE16 bioactive glass that was previously developed by Wu et al. (2011) to prevent crystallization, and a borosilicate glass of composition 73.48 SiO
2–11.35 B
2O
3–15.15 Na
2O (wt%). The resulting melt derived glass–glass composite
scaffolds (ICIE16/BSG) were subject to surface functionalization to further improve its interaction
with biological systems. Surface functionalization was performed by a nitridation process
with hot gas N
2/ammonia at 550 °C for 2 h, obtaining the ICIE16/BSG-NITRI. Evaluation of the degradation rate and the conversion to hydroxyapatite after immersion in simulated body fluid predicted a good biological activity of all the
scaffolds, but particularly of the nitrided ones. In vitro evaluation of osteoblastic cells cultured onto the nitrided and non-nitrided
scaffolds showed cell attachment, proliferation and differentiation on all
scaffolds, but both proliferation and differentiation were improved in the nitrided ICIE16/BSG-NITRI.
Statement of significance
Biomaterials are often required in the clinic to stimulate bone repair. We have developed a novel bioglass (ICIE16/SBG-NITRI) that can be sintered into highly porous 3D scaffolds, and we have further improved its bioactivity by nitridation. ICIE16/SBG-NITRI was synthesized from a mixture of two melt-derived glasses through combined gel casting and foam replication techniques, followed by nitridation. To mimic bone, it presents high-interconnected porosity while being mechanically stable. Nitridation improved its reactivity and bioactivity facilitating its resorption and the deposition of apatite (bone-like mineral) on its surface and increasing its degradation rate. The nitrided surface also improved the bioglass’ interaction with bone cells, which were found to attach better to ICIE16/SBG-NITRI and to differentiate earlier on its surface.
