Whole proteome analysis of osteoprogenitor differentiation induced by disordered nanotopography and mediated by ERK signalling.

Topographic features can modulate cell behaviours such as proliferation, migration, differentiation and apoptosis. Biochemical mechanotransduction implies the conversion of mechanical forces (e.g. changes in cell spreading and morphology from changing surface topography) into biochemical signal via biomolecules. Still, little is known concerning which pathways may be directly involved in cell response to changes in the material surface. A number of pathways have been implicated using focused studies of 'selected' biomolecules rather than a global analysis of signal pathways. This study used a controlled disorder nanopit topography (NSQ50, fabricated by electron beam lithography) to direct osteoblast differentiation of progenitor cells. This topography is unique as it represents a middle route (from absolute order or random roughness) that allows osteoconversion with similar efficiency as dexamethasone and ascorbate treatment. Two direct-comparison proteomics techniques, firstly gel-based and then chromatography-based, were used to analyse progenitor proteome changes in response to the nanotopography. Many of the changed proteins form part of the Extracellular Signal-regulated Kinase (ERK1/2) pathway.