Nanostructured apatite-mullite glass-ceramics for enhanced primary human osteoblast cell response

This work investigates the difference in viability of primary human foetal osteoblast cells on a glass-ceramic surface with nanoscale topography relative to viability on a smooth glass-ceramic surface containing a bioactive phase. Apatite-mullite glass-ceramics containing bioactive fluorapatite (Ca10(PO4)6F2) and bioinert mullite (Si2Al6O13) were synthesised and subsequent heat-treatment was optimised to form nano-sized fluorapatite crystals. Etching was used to selectively remove the bioactive phase, producing a surface with disordered nanoscale topography. Cells were seeded onto a smooth polished glass-ceramic substrate with the bioactive phase intact, an etched nanostructured glass-ceramic with the bioactive phase removed, and a borosilicate glass control. Cell viability after 24 h and 48 h was significantly greater on the nanostructured surface compared to the smooth bioactive surface, while cell viability at both time points was significantly greater on both nanostructured and smooth bioactive surfaces compared to the control.