The significance of crystallographic texture of titanium alloy substrates on pre-osteoblast responses

The aim of this study is to investigate the effects of grain orientation in polycrystalline materials on cell-substrate interactions. Samples are prepared from rods and sheets of Ti–6Al–4V substrates with predominately two distinct crystallographic orientations. X-ray diffraction analysis indicates that 36% of the surfaces of rod samples consist of plane, while the predominant orientation in the surface of the sheet samples is plane (29%). Morphological studies and cell biological experiments including cell attachment, proliferation and differentiation are conducted using MC3T3 pre-osteoblast cells cultured on these two different samples. The number of attached cells on the rod Ti- samples (70% after 1 h and 50% after 2 h) is higher than on the sheet Ti- samples. Cell proliferation after 3 days is also significantly higher on the Ti- samples. Alkaline phosphatase activity, however, shows no significant difference between the two samples. Scanning electron microscopy (SEM) analysis of MC3T3 cells grown on samples with different crystallographic texture demonstrate significant differences in morphology with respect to attachment and growth pattern. This study shows that crystal orientation of the substrate can influence cell responses and, therefore, substrate engineering can be used to improve and control cell-substrate interactions.