title: Bioactive compounds immobilized on Ti and TiNbHf: AFM-based investigations of biofunctionalization efficiency and cell adhesion.
abstract: Implant materials require optimal biointegration, including strong and stable cell-material interactions from the early stages of implantation. Ti-based alloys with low elastic modulus are attracting a lot of interest for avoiding stress shielding, but their osseointegration potential is still very low. In this study, we report on how cell adhesion is influenced by linear RGD, cyclic RGD, and recombinant fibronectin fragment III8-10 coated on titanium versus a novel low-modulus TiNbHf alloy. The bioactive molecules were either physisorbed or covalently coupled to the substrates and their conformation on the surfaces was investigated with atomic force microscopy (AFM). The influence of the different bioactive coatings on the adhesion of rat mesenchymal stem cells was evaluated using cell culture assays and quantitatively analyzed at the single cell level by AFM-based single-cell force spectroscopy. Our results show that bioactive moieties, particularly fibronectin fragment III8-10, improve cell adhesion on titanium and TiNbHf and that the covalent tethering of such molecules provides the most promising strategy to biofunctionalize these materials. Therefore, the use of recombinant protein fragments is of high importance for improving the osseointegration potential of implant materials.
authors.affiliation: Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC), Spain.
authors.forename: C
authors.initials: C
authors.lastname: Herranz-Diez
authors.affiliation: Dept. Biocompatible Nanomaterials, Institute for Materials Science, University of Kiel, Kaiserstr. 2, D-24143 Kiel, Germany.
authors.forename: Q
authors.initials: Q
authors.lastname: Li
authors.affiliation: Dept. Biocompatible Nanomaterials, Institute for Materials Science, University of Kiel, Kaiserstr. 2, D-24143 Kiel, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Lamprecht
authors.affiliation: Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC), Spain; Centre for Research in NanoEngineering (CRnE)-UPC, c/Pacual i Vila 15, 08028 Barcelona, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Mas-Moruno
authors.affiliation: Institute for Advanced Study and Center for Integrated Protein Science, Department Chemie, Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany; Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Neubauer
authors.affiliation: Institute for Advanced Study and Center for Integrated Protein Science, Department Chemie, Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Kessler
authors.affiliation: Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC), Spain; Centre for Research in NanoEngineering (CRnE)-UPC, c/Pacual i Vila 15, 08028 Barcelona, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Manero
authors.affiliation: Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC), Spain; Centre for Research in NanoEngineering (CRnE)-UPC, c/Pacual i Vila 15, 08028 Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Guillem-Martí
authors.affiliation: Dept. Biocompatible Nanomaterials, Institute for Materials Science, University of Kiel, Kaiserstr. 2, D-24143 Kiel, Germany. Electronic address: cse@tf.uni-kiel.de.
authors.forename: C
authors.initials: C
authors.lastname: Selhuber-Unkel
mesh_terms: D000497:Alloys; D002448:Cell Adhesion; D018625:Microscopy, Atomic Force; D014025:Titanium / Q000737:chemistry*
chemical_list: D000497:Alloys; D014025:Titanium
keywords: Atomic forcemicroscopy; Cell adhesion; Mesenchymal stem cell; RGD peptide; Recombinant protein; Titanium alloy