Nanoporous anodic oxidation titanium enhances cell proliferation and differentiation of immortalized mouse embryonic cells

Abstract

Biological integration of dental implants into the surrounding tissue determines clinical success and the attraction of bone cells. Titanium and its alloys are widely used biomaterials with high mechanical strength and excellent biocompatibility; nanotopographies are currently under investigation for efficiency in promoting cell functions. The purpose of this study was to carry out nanoporous anodic oxidation (NAO) surface treatment on titanium and to observe the responses of immortalized mouse embryonic (ME) cells. The titanium surface was modified in two ways; by NAO via hydrofluoric acid and by microporous anodic oxidation (MAO). The ME cells were solely obtained from mesenchymal mouse (embryonic day 14.5) molar tissue (tooth germ). Field emission scanning electron microscopy was used to visualize the titanium surface morphology as well as the attachment and morphological features of the ME cells. Cytotoxicity, cell proliferation, and alkaline phosphatase activity were assayed as well. The nano- and microporous structures of the modified titanium surfaces were well formed, with diameters of 100nm and 1–3μm, respectively. ME cells were well attached to the NAO and MAO treated surfaces, resulting in no cytotoxicity to ME cells. Cell proliferation was significantly higher for the cells at the NAO treated surface than cells at the MAO treated surface. Alkaline phosphatase activity on the NAO treated surface increased from 1 to 3weeks. Hence it was concluded that NAO treated surfaces provide an attractive substrate for ME cell adhesion, proliferation, and differentiation, and may serve as useful materials for the construction of dental implants.