Combinatorial Plasma Polymerisation Approach to Produce thin films for Testing Cell Proliferation

tPlasma enhanced physical vapor depositions are extensively used to fabricate substrates for cell cultureapplications. One peculiarity of the plasma processes is the possibility to deposit thin films with repro-ducible chemical and physical properties. In the present work, a combinatorial plasma polymerizationprocess was used to deposit thin carbon based films to promote cell adhesion, in the interest of test-ing cell proliferation as a function of the substrate chemical properties. Peculiarity of the combinatorialapproach is the possibility to produce in just one deposition experiment, a set of surfaces of varying chem-ical moieties by changing the precursor composition. A full characterization of the chemical, physical andthermodynamic properties was performed for each set of the synthesized surfaces. X-ray photoelectronspectroscopy was used to measure the concentration of carboxyl, hydroxyl and amine functional groupson the substrate surfaces. A perfect linear trend between polar groups' density and precursors' concentra-tion was found. Further analyses reveled that also contact angles and the correspondent surface energiesof all deposited thin films are linearly dependent on the precursor concentration.To test the influence of the surface composition on the cell adhesion and proliferation, two cancercell lines were utilized. The cell viability was assessed after 24 h and 48 h of cell culture. Experimentsshow that we are able to control the cell adhesion and proliferation by properly changing the thin filmdeposition conditions i.e. the concentration and the kind of chemical moiety on the substrate surface.The results also highlight that physical and chemical factors of biomaterial surface, including surfacehydrophobicity and free energy, chemical composition, and topography, can altered cell attachment.