Supervisors info:
Αθανασία Σιαφάκα- Καπάδαη Καθηγήτρια Ε.Κ.Π.Α. (επιβλέπουσα), Σωτήριος Κακαμπάκος Ερευνητής Α' Ε.Κ.Ε.Φ.Ε. "Δημόκριτος", Μαργαρίτα Χατζηχρηστίδη Λέκτορας Ε.Κ.Π.Α.
Summary:
Surface nanotopography influences cell attachment and proliferation, as well as
other basic cell functions. The aim of this work was to study the effect of
surface nanotexturing on the adhesion, viability and proliferation of normal
fibroblasts and cancer cells. Thin poly(methyl methacrylate) (PMMA) films on Si
substrate were treated with O2 plasma under different etching conditions (bias
voltage: 0-100 Volts; electrode temperature: 15 oC and 65 oC; etching time: 3
s, 1 min and 3 min) in order to achieve varying roughness and surface
nanotexturing. The O2 plasma nanotextured surfaces along with untreated ones
were used as substrates to culture normal fibroblasts and cancer cells
(fibrosarcoma cell line HT1080). It was found that normal fibroblasts adhered
and proliferated on the untreated PMMA surfaces while HT1080 adhered negligibly
on these surfaces. On the other hand, employing O2 plasma nanotextured
surfaces prepared using bias voltage of -100 V for 3 min as culture substrates,
three times more HT1080 cells adhered after one day culture compared to normal
cells. Furthermore, at three days, the number of HT1080 cells was increased 6
times compared to the one day culture, whereas the number of normal cells was
reduced by half providing a ratio of cancer to normal cells of approximately
33. The same results were obtained during coculture after one and three days.
Although the initial number of HT1080 was 10 times less than the number of
normal fibroblasts, the population of the cancer cells was enhanced 1,6 times
after one day and 2,1 times after 3 days of coculture. Moreover, it was shown
that nanotextured surfaces influenced the shape of the cytoplasm and the area
of the nucleus of normal fibroblasts, thus they had no effect on HT1080 cancer
cells. Furthermore, normal fibroblasts formed mature focal adhesion complexes
on the untreated surfaces, but not on the treated ones. This fact was observed
through the expression of vinculin and explains the reduction of their
population on the very rough surfaces. HT1080 cancer cells expressed vinculin
very vaguely. It was also found that the surfaces did not cause apoptosis to
either the normal or the cancer cells, as apoptotic bodies were not present at
their nucleuses. In conclusion, O2 plasma nanotextured PMMA surfaces could be
a useful tool for the enrichment and isolation of cancer cells derived from
tissues suspected for neoplasias and thus, could help to improve cancer
diagnosis and facilitate personalized therapy approaches.
Keywords:
Cell attachment , Nanostructured surfaces, Oxygen plasma, Enrichment of cancer cells
