Effects of alloy elements on adsorption of fibrinogen on biodegradable magnesium alloys surfaces: The MD simulations and experimental studies

The interactions between fibrinogen (Fg) and biodegradable Mg alloy are of great significance in the fields of vascular stents and bone implants. In this work, the effects of eight alloy elements (Ca, Li, Ce, Y, Zr, Mn, Zn and Cu) on the adsorption behavior of C-terminal fragment of Fg on Mg alloy surfaces are systematically investigated using molecular dynamic (MD) simulations and experimental methods. It was revealed by MD simulations that the adsorption energy of Fg on Mg alloys surfaces could be greatly enhanced and more residues were anchored to the surfaces when the alloy elements with lower electronegativity than that of Mg were added. Addition of alloy elements with higher electronegativity than that of Mg slightly reduced the adsorption capacity of proteins and fewer residues were anchored to the surfaces. Furthermore, the MD simulation results of Fg adsorption on Mg alloy samples were further confirmed by the corresponding experiments. Our studies contribute a deep understanding on the adsorption behavior of Fg on various Mg alloy surfaces, which would provide a significant guidance on the design of Mg-based biomaterials.