Enhancement of dynamic wettability, cell adhesion, and alkaline phosphatase activity of primary cells on titanium substrata with combined surface topographies of microgrooves and acid-etched roughness

The purpose of this study was to investigate the dynamic wettability, cell adhesion and alkaline phosphatase activity of primary cells on titanium substrata with combined surface topographies of microgrooves and acid-etched roughness. Two distinct combinations of titanium surface topographies were fabricated: microgrooves with submicron-textured ridges or microgrooves with subsequent acid etching. Using photolithography, microgrooves were designed and fabricated to have 15- and 60-μm width and 3.5- and 10-μm depth, respectively. Subsequent acid etching was applied to generate additional experiment substrata with both microgrooves and acid-etched roughness. Both ground and acid-etched titanium were used as controls. Dynamic wettability was analyzed by determining static, advancing, and receding water contact angles. Cell adhesions and alkaline phosphatase (ALP) activities of human periodontal ligament cells (hPDLCs) and human bone marrow stromal cells (hBMSCs) were analyzed using the bromodeoxyuridine assay and ALP activity test, respectively. Surface microgrooves and/or acid etching enhanced the dynamic wettability of titanium. 60-μm-wide microgrooves with subsequent acid etching promoted cell adhesions and ALP activities of both hPDLCs and hBMSCs. Significant correlations were found among the results of dynamic contact angle analysis, bromodeoxyuridine cell adhesion assay, and ALP activity test. This study indicates that combined microgrooves and submicron acid-etched roughness on Ti substrata enhance dynamic wettability of, cell adhesion to, and ALP activity on these surfaces.