Multifunctional Platform for Covalent Titanium Coatings: Micro-FTIR, XPS, and NEXAFS Characterizations

Abstract

This work aims at preparing and characterizing a versatile multifunctional platform enabling the immobilization of macromolecules on a titanium surface by robust covalent grafting. Functionalized titanium is widely used in the biomedical field to improve its properties. Despite its high biocompatibility and osteointegrability, titanium implants are not very stable in the long term due to the onset of inflammation and bacterial infections. The proposed method allows the superficial insertion of three different organic linkers to be used as anchors for the attachment of biopolymers or bioactive molecules. This strategy used green solvents and is a good alternative to the proposed classic methods that employ organic solvents. The uniformly modified surfaces were characterized by micro-Fourier transform infrared spectroscopy (micro-FTIR), X-ray Photoelectron spectroscopy (XPS) and Near-Edge X-ray Absorption Fine Structure (NEXAFS). The latter made it possible to assess the orientation of the linker molecules with respect to the titanium surface. To test the efficiency of the linkers, two polymers (alginate and 2-(dimethylamino)-ethyl methacrylate (PDMAEMA)), with the potential ability to increase biocompatibility, were covalently attached to the titanium surfaces. The obtained results are a good starting point for the realization of stable polymeric coatings permanently bonded to the surface that could be used to extend the life of biomedical implants.