title: Covalent functionalization of TiO2 nanotube arrays with EGF and BMP-2 for modified behavior towards mesenchymal stem cells.
abstract: In the present work we show the covalent immobilization of two bioactive molecules, epidermal growth factor (EGF) and bone morphogenetic protein-2 (BMP-2), on TiO(2) nanotube surfaces and the resulting influence on the behavior of mesenchymal stem cells. Covalent immobilization of these growth factors onto the oxide surfaces was achieved by N,N-carbonyldiimidazole (CDI) coupling via binding to amine groups of the proteins either directly or via a spacer, namely 11-hydroxy-undecylphosphonic acid (PhoA). The behavior of mesenchymal stem cells can be significantly altered by such an activation procedure. The effect is depending on the diameters of the nanotubes. Most importantly, on 100 nm diameter tubes the cell activity and cell number were drastically increased by grafting such nanotube surfaces with EGF. This demonstrates that the strong diameter dependence on cell activity in the range between 15 and 100 nm observed in prior work can be compensated by coating of the nanotube surfaces with EGF.
authors.affiliation: Department of Materials Science, WW4-LKO, Friedrich-Alexander-University of Erlangen-Nuremberg, Martensstrasse 7, D-91058 Erlangen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Bauer
authors.forename: Jung
authors.initials: J
authors.lastname: Park
authors.forename: Andreas
authors.initials: A
authors.lastname: Pittrof
authors.forename: Yan-Yan
authors.initials: YY
authors.lastname: Song
authors.forename: Klaus
authors.initials: K
authors.lastname: von der Mark
authors.forename: Patrik
authors.initials: P
authors.lastname: Schmuki
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D002448:Cell Adhesion; D049109:Cell Proliferation; D020099:Coated Materials, Biocompatible; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D055767:Immobilized Proteins / Q000494:pharmacology; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects* / Q000502:physiology; D053768:Metal Nanoparticles / Q000737:chemistry; D043942:Nanotubes / Q000737:chemistry*; D019736:Prostheses and Implants; D051381:Rats; D014025:Titanium / Q000737:chemistry*
chemical_list: C525720:Bmp2 protein, rat; D055396:Bone Morphogenetic Protein 2; D020099:Coated Materials, Biocompatible; D055767:Immobilized Proteins; C009495:titanium dioxide; D004815:Epidermal Growth Factor; D014025:Titanium