Bioactive compounds immobilized on Ti and TiNbHf: AFM-based investigations of biofunctionalization efficiency and cell adhesion

• Published in: Colloids and surfaces, B, Biointerfaces Vol. 136; pp. 704 - 711
• Main Authors: Herranz-Diez, C., Li, Q., Lamprecht, C., Mas-Moruno, C., Neubauer, S., Kessler, H., Manero, J.M., Guillem-Martí, J., Selhuber-Unkel, C.
• Format: Journal Article Publication
• Language: English
• Published: Netherlands Elsevier B.V 01.12.2015
• Subjects: Aliatges; Alloys; Atomic force microscopy; Atomic forcemicroscopy; Biocompatibility; Biomedical materials; Cell Adhesion; Enginyeria dels materials; Fibronectin; Fragmentation; Implants artificials; Implants, Artificial; Materials; Materials biomèdics; Mesenchymal stem cell; Microscopy, Atomic Force; Recombinant; Recombinant protein; RGD peptide; Titani; Titanium; Titanium - chemistry; Titanium alloy; Titanium alloys; Àrees temàtiques de la UPC; Titanium alloy; Mesenchymal stem cell; Atomic forcemicroscopy; Recombinant protein; RGD peptide; Cell adhesion
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2015.10.008

[Display omitted] •Immobilization of bioactive molecules on Ti and a Ti25Nb21Hf alloy.•AFM topography and lithography reveal silanization as superior to physisorption.•Cell adhesion is enhanced on fibronectin fragments compared to RGD.•Ti25Nb21Hf supports biomolecule immobilization on its surface. 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.