Differential regulation of osteoblasts by microstructural features of titanium substrata

• Published in: Trends in biomaterials & artificial organs Vol. 26; no. 1; pp. 16 - 24
• Main Authors: Kokkinos, Petros A, Wright, Robert, Kirby, Paul B, Deligianni, Despina D
• Format: Journal Article
• Language: English
• Published: Society for Biomaterials and Artificial Organs 01-01-2012
• Subjects: Cell differentiation; Cellular control mechanisms; Growth; Health aspects; Osteoblasts; Properties; Substrates (Biochemistry); Titanium; United Kingdom
• ISSN: 0971-1198

The osseointegration process of bone implants crucially depends on the interaction between osteoblasts and the topography of the implant surface. Core binding factor alpha 1 (Cbfa1) is an osteoblast specific transcription factor that regulates osteoblast differentiation and expression of genes necessary for the development of a mineralized phenotype. In this study, we investigated the influence of microfabricated topographies on the activation of Cbfa1, in osteoblasts cultured on titanium substrata presenting microgroove gradients. Surface microgrooves with groove and ridge width ranging from 3 to 300 µm, and four different groove depths (4, 6, 10, 14 µm) were patterned on single crystalline silicon wafers using microlithography and deep reactive ion etching (DRIE). Titanium thin films were coated on the microgrooves by radio-frequency magnetron sputtering. All surfaces were characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM), and profilometry. Immunofluorescence staining of Cbfa1 protein was used to study the differentiation and function of osteoblasts in 3 day (72 h) culture experiments. Microtextured titanium surfaces were shown to promote contact guidance and enhanced Cbfa1 expression and activation, independently of the dimensions of the grooves of the studied microgroove gradients, compared to non micropattered surfaces. In conclusion, implant surface microgeometries may contribute to the regulation of osteoblast differentiation and function by influencing the level of bone-related transcription factors such as Cbfa1 in osteoblastic cells.