No abstract

The design of topographically patterned surfaces is considered to be a preferable approach to influence cellular behavior in a controllable manner, in particular to improve the osteogenic ability in bone regeneration. In the present study, we fabricated nanolamellar tantalum (Ta) surfaces with lamella wall thicknesses of 40 nm and 70 nm. The cells attached onto nanolamellar Ta surfaces exhibited higher protein adsorption and expression of β1 integrin, as compared to the non-structured bulk Ta, which would facilitate the initial cell attachment and spreading. We thus as expected, observed a significantly enhanced osteoblast adhesion, growth, and alkaline phosphatase activity on nanolamellar Ta surfaces. However, the enhancement effects 2 of nanolamellar structures on the osteogenesis were weakened as the lamella wall thickness increases. The interaction between cells and Ta surfaces is examined through adhesion forces using atomic force microscopy. Our findings indicate that Ta surface with a lamella wall thickness of 40 nm possessed the highest stimulatory effect. The observed strongest adhesion force between cellattached tip and the Ta surface with 40 nm-thick lamella wall, encourages the much stronger binding of cells with the surface, and thus well-attached, stretched, and grown cells. We attributed this to the increase in available contact area of cells with the thinner-nanolamellar Ta surface. The increased contact area allows the enhancement of the cell-surface interaction strength, and thus the improved osteoblast adhesion. This study suggests that the thin-nanolamellar topography shows immense potential in improving the clinical performance of dental and orthopedic implants.