Adsorption of RGD tripeptide on anatase (001) surface - A first principle study

An appropriate cell response to implant surface is essential for tissue integration and regeneration. The implant material is precoated with proteins such as elastin, fibronectin, vitronectin, laminin or Arg-Gly-Asp (RGD) to improve the cell adhesive properties and tissue integration and accelerated bone healing. In the present work, the first principle calculations are performed to investigate the adsorption of arginine, aspartic acid, glycine and RGD tripeptide on anatase TiO2 (001) surface. The adsorption energies are calculated using PBE, PBEsol and DFT-D2 methods. For arginine, the adsorption with anatase TiO2 is occurring through hydrogen bonds between amino groups of arginine and oxygen atom of TiO2 surface. The zwitterionic form of aspartic acid has strong interaction with anatase TiO2 (001) surface. The adsorption strength of glycine in dissociative adsorption configuration is higher than that of molecular and zwitterionic adsorption configurations. For RGD tripeptide, RGD-4 configuration is having maximum adsorption energy of - 1.19, - 1.46 and - 1.62 eV at PBE, PBEsol and DFT-D2 methods. Analysis of the electron density difference plot and Bader charge analysis shows that the carboxyl groups of aspartic acid furnish the maximum contribution for the adsorption of RGD tripeptide on TiO2. (C) 2015 Elsevier B.V. All rights reserved.