Bone cell–materials interaction on alumina ceramics with different grain sizes

The objective of this work was to study adhesion, proliferation and differentiation of osteoblast cells (OPC1) on alumina ceramic, a bio-inert material. Alumina ceramic with different average grain sizes, 1 μm and 12 μm, respectively, were used in as-prepared condition without any grinding and polishing to understand the influence of grain size on cell–material interactions. Scanning electron microscopy and confocal imaging were used to study attachment, adhesion and differentiation of OPC1 cells. Cells attached, proliferated and differentiated well on both the substrates. Adhesion of cells, as assessed by observing the production of vinculin, was found to be a consistent phenomenon on both the substrates. On day 5 of cell culture, significant cell-attachment was observed and vinculin was detected throughout cytoplasm. MTT assay showed that proliferation of OPC1 cells was consistently higher in the case of 12 μm-alumina. Cells of different morphology, nodular, plate-like as well as elongated, were found to get anchored at grains, grain boundaries as well as pores. On day 16, there were clear signs of mineralization as well. Over all, alumina with average grain size of 12 μm showed better cell-attachment, growth and differentiation compared to 1 μm grain size samples.