  The effects of oxidative treatment of single-walled carbon nanotubes (SWCNTs)
on the adhesion and proliferation of human osteoblasts (SAOS-2) were
investigated. The surface properties of SWCNTs after oxygen plasma treatment
were characterised by contact angle measurement, scanning electron microscopy
and Raman spectroscopy. The immunofluorescent staining of vinculin, actin
filaments and nuclei was used to probe cell adhesion and growth on SWCNT films.
Our results show that adhesion and proliferation of human osteoblasts
cultivated on SWCNT films indeed depends on the degree of an oxidative
treatment. As an optimal procedure was found the treatment with oxygen plasma
for 5 min. In the latter case the osteoblasts form a confluent layer with
pronounced focal adhesions throughout the entire cell body. The optimal
conditions compromise the effect of hydrophilic character of SWCNT films and
the level of damage of SWCNT surface.
