Molecular dynamics simulation of the adhesive behavior of collagen on smooth and randomly rough TiO2 and Al2O3 surfaces

Molecular dynamics (MD) simulations are performed to investigate the adhesion energy of type I collagen on smooth and rough ceramic rutile TiO2 (1 0 0) and α-Al2O3 (0 0 0 1) surfaces. To generate almost real-like rough surfaces, the self affine fractal method is employed and the effect of degree of roughness on adhesion is investigated. By adopting an overlayer-substrate model, the variation of adhesion force with distance is computed. We show that when the surface roughness is increased, the adhesion energy and the adhesion force correspondingly increase. It is found that the adhesion to rutile TiO2 (1 0 0) surface is far stronger than that to the α-Al2O3 (0 0 0 1) surface. Furthermore, we show that the deformation of collagen layer is dependent on the degree of surface roughness.