In the present study we demonstrated that composite PPHMDS/DND coatings with elastic moduli close to those of mature bone tissue (– GPa) stimulated growth and osteogenic differentiation of human adipose-derived mesenchymal stem cells (hADMSCs). | Turkish Journal of Biology Turk J Biol (2018) 42: 195-203 © TÜBİTAK doi: Research Article Increased elastic modulus of plasma polymer coatings reinforced with detonation nanodiamond particles improves osteogenic differentiation of mesenchymal stem cells 1 2 2 1 Milena KEREMIDARSKA-MARKOVA , Ekaterina RADEVA , Dimitar MITEV , Kamelia HRISTOVA-PANUSHEVA , 3 3 4 5 6 1, Brett PAULL , Pavel NESTERENKO , Joseph ŠEPITKA , Ita JUNKAR , Aleš IGLIČ , Natalia KRASTEVA * 1 Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria 2 Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, Sofia, Bulgaria 3 University of Tasmania, Hobart, Australia 4 Faculty of Mechanical Engineering, Czech Technical University in Prague, Prague, Czech Republic 5 Jozef Stefan Institute, Ljubljana, Slovenia 6 Laboratory of Biophysics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia Received: Accepted/Published Online: Final Version: Abstract: In the present study we demonstrated that composite PPHMDS/DND coatings with elastic moduli close to those of mature bone tissue (– GPa) stimulated growth and osteogenic differentiation of human adipose-derived mesenchymal stem cells (hADMSCs). Composite coatings were prepared by a method of plasma polymerization (PP) where detonation nanodiamond (DND) particles in different amounts (, , and 1 mg/mL) were added to hexamethyldisiloxane (HMDS) before plasma deposition. This method allows variation only in the reduced elastic modulus (Er´) with increase in the particle concentration, while the other surface properties, including surface wettability and topography, did not change. The response of hAD-MSCs to the increasing stiffness showed an effect on adhesion and osteogenic differentiation but not on cell proliferation. Matrix mineralization and cell .