Carbonyl Iron Foam Surfaces Modified with Poly (L-Lysine) As Smart Surface for Bone Implant

Abstract

This article presents the surface modification of iron Fe (110) surfaces with Poly-L-Lysine (PLL) with the aim of preparing carbonyl iron bone implants which are less corrosive and more compatible with fibroblast cells. The cytocompatibility of modified surfaces with commercially available α-PLL and electrodeposited ε-PLL was compared by combination of DFT computational simulations with experimental electrochemical and cell adhesion studies to obtain “smart” surface application. Experimental study of fibroblasts adhesion showed better viability of cells on ε-PLL than on α-PLL after modification of Fe surfaces as “smart” surfaces to obtain a different hydrophobicity. The porosity of Fe (110) prevented direct measurements of contact angle and therefore surface hydrophobicity was simulated with calculation of adsorption energies for Fe with both α-/ε-PLL structures. This technique was also employed to calculate the interaction of O-H bonds at the surface. The corrosion potential of Fe (110) with superficially modified ε-PLL was shifted by 0.088V compared to the bare iron surface, thus indicating a stronger resistance to corrosion. The results suggest that modification of Fe surface with ε-PLL has a more pronounced effect on cellular growth on this implant and that the slightly hydrophobic character of ε-PLL leads to better cell adhesion ability.