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PURPOSE. To determine the effect of fibronectin (FN)-conjugated, microgrooved titanium (Ti) on osteoblast differentiation and gene expression in human bone marrow--derived mesenchymal stem cells (MSCs). MATERIALS AND METHODS. Photolithography was used to fabricate the microgrooved Ti, and amine functionalization (silanization) was used to immobilize fibronectin on the titanium surfaces. Osteoblast differentiation and osteoblast marker gene expression were analyzed by means of alkaline phosphatase activity assay, extracellular calcium deposition assay, and quantitative real-time PCR. RESULTS. The conjugation of fibronectin on Ti significantly increased osteoblast differentiation in MSCs compared with non-conjugated Ti substrates. On the extracellular calcium deposition assays of MSCs at 21 days, an approximately two-fold increase in calcium concentration was observed on the etched 60-µm-wide/10-µm-deep microgrooved surface with fibronectin (E60/10FN) compared with the same surface without fibronectin (E60/10), and a more than four-fold increase in calcium concentration was observed on E60/10FN compared with the non-etched control (NE0) and etched control (E0) surfaces. Through a series of analyses to determine the expression of osteoblast marker genes, a significant increase in all the marker genes except type I collagen α1 mRNA was seen with E60/10FN more than with any of the other groups, as compared with NE0. CONCLUSION. The FN-conjugated, microgrooved Ti substrate can provide an effective surface to promote osteoblast differentiation and osteoblast marker gene expression in MSCs. [ABSTRACT FROM AUTHOR]

Surface microgrooves and acid etching on titanium (Ti) have been proposed to enhance various cell behaviors. In this study, surface hydrophilicity, protein adsorption, and alkaline phosphatase activity of osteoblasts were analyzed and compared between microgrooved Ti, Ti with microgrooves and further acid etching, smooth Ti, and acid-etched smooth Ti. Correlations between the results of each experiment were analyzed using Pearson's correlation analysis, and the influential factor on alkaline phosphatase activity was determined using multiple stepwise regression analysis. Among groups, the Ti substrata with microgrooves and subsequent acid etching showed significantly greater surface hydrophilicity and alkaline phosphatase activity compared with smooth Ti, whereas the Ti substrata with only microgrooves showed the greatest protein adsorption. Multiple stepwise regression analysis determined the surface hydrophilicity of Ti as the influential factor on alkaline phosphatase activity. This study indicates that surface microgrooves and acid etching on Ti substrata enhance surface hydrophilicity, leading to increased alkaline phosphatase activity. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to investigate the influence of titanium (Ti) substrata with etched surface microgrooves on in vitro responses of human gingival fibroblasts. Material and methods: Commercially pure Ti discs with surface microgrooves 15, 30, and 60 μm in width were fabricated using photolithography. Microgrooves 15 μm in widths were designed to be 3.5 μm in depth, whereas microgrooves 30 and 60 μm in width varied between 5 and 10 μm in depth. The entire surface of the microgrooved Ti substrata was further acid etched and used as the five experimental groups in this study (E15/3.5, E30/5, E30/10, E60/5, and E60/10), whereas the smooth and acid-etched Ti discs were both used as the control (NE0 and E0). Human gingival fibroblasts were cultured on all groups of substrata on successive timelines. Fibroblast adhesion and morphology was analyzed using confocal laser scanning microscopy (CLSM). Cell adhesion and proliferation were analyzed and compared using crystal violet staining and sulforhodamine B protein staining assays, respectively. Results: In CLSM, the cells in E30/10 and E60/10 were observed to be able to readily descend into and form focal adhesions inside the microgrooves, whereas the cells in E15/3.5 were mostly found on the ridge tops. Cell adhesion was significantly increased in E60/10 compared with that in NE0 or E0 at 4-h incubation. Cell proliferation was significantly increased in E60/10 and E15/3.5 compared with NE0 or E0 after 72 and 96 h of culture. Conclusion: This study indicates that Ti substrata with etched microgrooves 60 μm in width and 10 μm in depth significantly enhance human gingival fibroblast adhesion and proliferation. [ABSTRACT FROM AUTHOR]

Abstract: Objective: This study aimed to identify the optimal micro- and submicroscale topographies of titanium (Ti) substrata that would most significantly influence adhesion, proliferation, and other activities of these cells. Design: Truncated V-shaped microgrooves in 60μm-wide and 10μm-deep cross-sections with 0°, 30°, 60°, or 90° angles between the microgrooves and ridge-top submicroscale texture were created on the Ti substrata (designated NE60/10-0°, NE60/10-30°, NE60/10-60° and NE60/10-90°, respectively). Ground titanium with submicroscale texture but with no microgrooves was used as the control substratum, NE0. Scanning electron microscopic observation and the assays determining the cell adhesion, cell proliferation and osteoblast differentiation were performed. Results: Cells more actively migrated into the microgrooves on NE60/10-30° than into the microgrooves on any other substrata tested, suggesting that the cells utilise the increased surface area of the substrata at the microscale level. NE60/10-0° and NE60/10-30° substrata generally enhanced adhesion, proliferation, alkaline phosphatase activity, and osteoblast differentiation of human primary cells when compared to other Ti substrata, and significant correlations were observed between these cellular activities. Conclusions: Here, we show that the contact guidance of human primary cells grown on Ti substrata can be controlled more by specific submicroscale textures on ridge tops than by the dimensions of surface microgrooves only. Also, the degree of angles created between the submicroscale textures and microgrooves on Ti substrata significantly affect cell adhesion, proliferation and differentiation in human primary cells. [Copyright &y& Elsevier]