Human microvascular endothelial cellular interaction with atomic N-doped DLC compared with Si-doped DLC thin films

Area of Science:

• Materials Science
• Biotechnology
• Surface Science

Background:

• Diamond-like carbon (DLC) thin films are investigated for biomedical applications.
• Understanding endothelial cell interaction with DLC surfaces is crucial for biocompatibility.
• Nitrogen (N) and Silicon (Si) doping are explored to modify DLC properties.

Purpose of the Study:

• To compare the interaction of endothelial cells with N-doped and Si-doped DLC thin films.
• To investigate the influence of nitrogen species (ionized vs. neutral) on cell adhesion.
• To correlate film properties (hydrophobicity, stress, sp3/sp2 ratio) with cellular response.

Main Methods:

• Fabrication of N-doped and Si-doped DLC thin films using an RF plasma source.
• Nitrogen doping using both ionized and neutral atomic nitrogen species.
• Assessment of endothelial cell attachment and cell density on different film surfaces.
• Measurement of water contact angles and Raman spectroscopy to characterize film properties.

Main Results:

• Si-doped DLC films exhibited the highest endothelial cell attachment.
• Neutral N-doped DLC films showed better cell adhesion than ionized N-doped DLC films.
• Hydrophobic, semiconducting DLC films with lower Raman I(D)/I(G) ratios (higher sp3/sp2 ratio) demonstrated enhanced endothelial cell adhesion.

Conclusions:

• Si-doping and neutral N-doping of DLC films can improve their biocompatibility for endothelial cell interactions.
• Surface hydrophobicity, semiconducting properties, and reduced internal stress are key factors for enhanced cellular adhesion.
• These findings are relevant for the biocompatibility assessment of nanostructured biomaterials in tissue engineering.