Osteoblasts preferentially adhere to peaks on micro-structured titanium

The aim of the study was to investigate cell adhesion to micro-structured titanium. Osteoblastic MC3T3 cells were cultured on smooth (P) or sand-blasted/acid-etched (SLA) titanium discs and were observed at scanning electron microscope/focused ion beam (SEM/FIB). Myosin II and actin microfilaments were labelled for epifluorescence microscopy. FIB revealed that cell adhesion initiated centrally and expanded to the cell periphery and that cells attached on the substrate by bridging over the titanium irregularities and adhering mostly on surface peaks. Gaps were visible between concave areas and cytoplasm and areas around ridges represented preferred attachment points for cells. A different myosin distribution was observed between samples and myosin inhibition affected cell responses. Taken together our data indicate that cells attach on micro-rough titanium by bridging over its irregularities. This is likely mediated by myosin II, whose distribution is altered in cells on SLA discs.