Effect of grooves on adsorption of RGD tripeptide onto rutile TiO(2) (110) surface.

Molecular dynamics (MD) simulations have been performed to investigate the adsorption mechanism of Arg-Gly-Asp (RGD) tripeptide onto perfect and grooved rutile TiO(2) (110) surfaces, respectively. The simulation results suggest that RGD tripeptide can strongly adsorb onto TiO(2) surface through specified Ti coordination sites. Analysis of adsorption energy, mean-squared displacements and radial distribution functions indicates that the adsorption of RGD onto grooved surface is more stable and rapid than that onto the perfect surface, with the adsorption energy around -331.59 kcal/mol. And among the chosen groove surfaces, adsorption energies, adsorption speeds and adsorption depths of RGD onto the surfaces increase evidently with the extension of groove dimensions. For both perfect and grooved surfaces, once bonded to the surfaces by interactions of carboxyl groups or carbonyl groups with nearby surface Ti atoms, RGD tripeptides show a reasonable propensity to remain there and undergo relatively limited hinge-bending motions.