NanoTune

Influence of nanopatterend titanium surfaces on the osteogenic differentiation of human mesenchymal stem cells in combination with chemical and biological surface modifications

The influence of anisotropic, ordered surface topographies at the low nanometer level on the behavior of human mesenchymal stem cells (hMSC) is thus far insufficiently investigated and poorly understood. Yet topographies with vertical dimensions in the sub-10 nm range and lat­eral dimensions in the order of few 10 nm exhibit potential to influence cellular attachment and osteogenic commitment, especially in combination with tailored chemical and biochemical sur­face modifications.

Within the project NanoTune, financed by the German Research Foundation (DFG), the inves­tigative focus will be placed on whether and how nanostructures on titanium substrates can significantly influence protein adsorption as well as hMSC adhesion, migration, and osteogenic differentiation, both by themselves and amplified with chemical and biological surface modifi­cations. As such, ion bombardment is used to generate ordered wave-like ripple patterns with lateral periodicities of few ten nanometers and corresponding heights. Silanization provides tailored surface chemistry, where crosslinking will be used to specifically couple different pro­teins to promote hMSC adhesion, migration, and differentiation. The topographical, chemical, and biochemical parameters are systematically investigated to reveal influences of the individ­ual surfaces on the hMSC. The response of stem cells on structures on the small nanometer scale learned from this project will help understand the mechanisms of osseointegration of metal implants.

Figure 1: Nanostructures influence the orientation of pseudopodia. SEM images of pseudopo-dia of MG-63 cells seeded on (a) polished alumina and (b,c) ripple patterns with (b) 24 nm and (c) 179 nm periodicity, respectively. A higher magnification of (c) is shown in (d). The images were taken after 3 days of incubation. Scale bars are 2 µm.1

1 Wittenbrink I, Hausmann A, Schickle K, Lauria I, Davtalab R, Foss M, Keller A, Fischer H (2015). Low-aspect ratio nanopatterns on bioinert alumina influence the response and morphology of osteoblast-like cells. Biomaterials 62: 58-65.