Influence of crystallite size of nanophased hydroxyapatite on fibronectin and osteonectin adsorption and on MC3T3-E1 osteoblast adhesion and morphology

► Two stable hydroxyapatite bioceramic substrates presenting nanoscale grain size sintering were successfully developed (HA1000 and HA725). ► HA1000 showed a more organized structure, with larger grain size, increased roughness, lower total surface area and lower porosity with larger pore diameters when compared to HA725. ► HA1000 surfaces allowed for a higher amount of fibronectin and osteonectin to be adsorbed. ► Regarding the MC3T3-E1 osteoblast adhesion results, higher levels of viability and cell number were found for HA1000 surfaces as compared to HA725 surfaces.