Effects of ridge-modified titanium alloy surface on activity of fibroblasts / 中华创伤骨科杂志

ABSTRACT

Objective:To characterize the biological activity of fibroblasts on the surface of titanium alloy sheets with different ridge widths by investigating the effects of ridge widths on the adhesion, proliferation and differentiation of fibroblasts.Methods:Five groups of titanium sheets with ridge widths of 50 μm, 80 μm, 100 μm, 150 μm and 200 μm were prepared, with all the groove depths being 10 μm. The titanium sheets with no ridges were taken as a control group. After fibroblasts were incubated on the sheets, states of their adhesion were observed by scanning electron microscopy (SEM) at different time points. CCK-8 cell proliferation test and immunofluorescence staining were used to observe proliferation and shape of the cells. The effects of ridge widths on adhesion of fibroblasts were evaluated by Vinculin immunofluorescence staining, and the effects of ridge widths on expression of α-smooth muscle actin ( α-SMA) by immunofluorescence. Results:SEM showed that the cells adhered to the ridges on the titanium sheets 48 hours after inoculation. In the groups with smaller ridge widths (from 50 μm to 150 μm), the cells were slender in shape and grew along the ridge direction. CCK-8 indicated that different ridge widths had no significant effect on the proliferation of fibroblasts between the 6 groups ( P>0.05). Immunofluorescence staining showed that the cells arranged in an orderly direction along the ridges; the long axis of the cells in the 50 μm group showed the best consistency with the extending direction of the ridge, with significant differences among the 6 groups ( P<0.05). The Vinculin test found that the secretion of cell adhesion protein was concentrated in the ridge and semi-quantitative analysis showed that the 50 μm group had the most Vinculin secretion, with significant differences among the 6 groups ( P<0.05). The α-SMA test showed that the ridge width had a regulatory effect on the myogenic differentiation of fibroblasts, and the 50 μm group had the strongest expression of α-SMA, with significant differences among the 6 groups ( P<0.05). Conclusions:Modification of ridges on the surface of titanium sheets may affect arrangement, adhesion and myogenic differentiation of fibroblasts. The ridges of 50 μm in width may lead to stronger polarized arrangement of fibroblasts, more secretion of adhesion-related protein and more pronounced myogenic differentiation of fibroblasts.