Nanostructured niobium oxide coatings influence osteoblast adhesion

The interaction of osteoblasts was correlated to the roughness of nanosized surface structures of Nb(2)O(5) coatings on polished CP titanium grade 2. Nb(2)O(5) sol-gel coatings were selected as a model surface to study the interaction of osteoblasts with nanosized surface structures. The surface roughness was quantified by determination of the average surface finish (Ra number) by means of atomic force microscopy. Surface topographies with Ra = 7, 15, and 40 nm were adjusted by means of the annealing process parameters (time and temperature) within a sol-gel coating procedure. The observed osteoblast migration was fastest on smooth surfaces with Ra = 7 nm. The adhesion strength, spreading area, and collagen-I synthesis showed the best results on an intermediate roughness of Ra = 15 nm. The surface roughness of Ra = 40 nm was rather peaked and reduced the speed of cell reactions belonging to the adhesion process.