Molecular modelling of protein adsorption on the surface of titanium dioxide polymorphs

Abstract

This paper reports a molecular modelling study of the adsorption of protein subdomains with unlike secondary structures on different surfaces of ceramic titanium dioxide (TiO 2 ), forming a passivating film on titanium biomaterials that provides the interface between the bulk metal and the physiological environment, affecting its biocompatibility and performance. Using molecular dynamics methods, we study the effect of the nanoscale structure of the common TiO 2 polymorphs (rutile, anatase and brookite) on the adsorption of an albumin subdomain and on two connected fibronectin modules, respectively containing a-helices and b-sheets. We find that the larger protein subdomain shows a stronger adsorption, as expected because of its size, but also that the three surfaces behave differently. In particular, brookite shows the weakest adsorption, whereas anatase leads to the strongest intrinsic adsorption, in particular for the fibronectin modules. Moreover, the simulations indicate a significant conformational change of the adsorbed protein subdomains with extensive surface nanopatterning. These results show that classical molecular dynamics methods can provide useful information about the influence of nanostructure and topology on protein physisorption at a fixed surface chemistry.

Utilization of Molecular Dynamics Simulation Coupled with Experimental Assays to Optimize Biocompatibility of an Electrospun PCL/PVA Scaffold

“…This structure is composed of 93 amino acids as shown in Fig 1B, where the anti-parallel β-sheets represent unlike hydrophobicity. The structure has been previously employed in other studies connected with protein adsorption mechanism, leading to reliable results in good accordance with experimental observations [14,15,17]…”

“…MD simulation has been widely employed in the literature for a variety of surfaces including structured surfaces and carbon nanostructures [9–15], but there are only a few studies for polymeric amorphous surfaces [16, 17]. In all of these researches, interaction energies between protein and surface have been studied as the main criterion for assessment of protein adsorption strength.…”

Modeling and simulation of protein–surface interactions: achievements and challenges

“…Ideally, reconstruction of surfaces has to be taken into account in the simulation of adsorption (Ghiringhelli et al 2008): an enormous task in most cases. On the other hand, it has been reported in several studies that the reconstruction of some surfaces in certain conditions is negligible (Feng et al 2011;Raffaini & Ganazzoli, 2012;Wright et al 2013a). However, other experimental and computational studies show that large scale surface reconstruction may take place after adsorption of small molecules (Eralp et al 2011;Gibbs et al 1990;Lal et al 2004Lal et al , 2006.…”

Bacterial adhesion on amorphous and crystalline metal oxide coatings

“…TiO 2 and ZrO 2 were chosen since it has already been demonstrated that both materials are biocompatible; TiO 2 as the passive coating on Ti-based implants [26] and ZrO 2 as a ceramic-based dental implant [27]. In the particular case of the interaction TiO 2 surfaces-biological media, experimental and theoretical works have shown that the surface atomic arrangement, which depends on both the crystalline structure and the exposed crystalline plane or facet, plays an important role for protein adsorption [28][29][30]. Sul et al [31] studied the effect of the TiO 2 surface properties on the in vivo bone tissue response concluding that surface crystallinity and surface porosity were the surface properties with larger impact on the bone response; however, no further details have been given.…”