posted on 2024-01-17, 20:05authored byJung Park, Alexander B. Tesler, Ekaterina Gongadze, Aleš Iglič, Patrik Schmuki, Anca Mazare
Anodic
titanium dioxide (TiO2) nanostructures, i.e.,
obtained by electrochemical anodization, have excellent control over
the nanoscale morphology and have been extensively investigated in
biomedical applications owing to their sub-100 nm nanoscale topography
range and beneficial effects on biocompatibility and cell interactions.
Herein, we obtain TiO2 nanopores (NPs) and nanotubes (NTs)
with similar morphologies, namely, 15 nm diameter and 500 nm length,
and investigate their characteristics and impact on stem cell adhesion.
We show that the transition of TiO2 NPs to NTs occurs via
a pore/wall splitting mechanism and the removal of the fluoride-rich
layer. Furthermore, in contrast to the case of NPs, we observe increased
cell adhesion and proliferation on nanotubes. The enhanced mesenchymal
stem cell adhesion/proliferation seems to be related to a 3-fold increase
in activated integrin clustering, as confirmed by immunogold labeling
with β1 integrin antibody on the nanostructured layers. Moreover,
computations of the electric field and surface charge density show
increased values at the inner and outer sharp edges of the top surfaces
of the NTs, which in turn can influence cell adhesion by increasing
the bridging interactions mediated by proteins and molecules in the
environment. Collectively, our results indicate that the nanoscale
surface architecture of the lateral spacing topography can greatly
influence stem cell adhesion on substrates for biomedical applications.