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

Abstract

This article reports results of endothelial cell interaction with atom beam source N-doped a-C:H (diamond-like carbon, DLC) as it compares with that of Si-doped DLC thin films. The RF plasma source exhibits up to 40% N-dissociation and N-atomic fluxes of approximately 0.85 x 10(18) atoms/s, which ensures better atomic nitrogen incorporation. Two different types of nitrogen species (with and without the use of sweep plates to remove charged ions) were employed for nitrogen doping. The number of attached endothelial cells is highest on Si-DLC, followed by the N-DLC (where the sweep plates were used to remove ions), the N-DLC (without the use of sweep plates), undoped DLC, and finally the uncoated sample. The contact angle values for these films suggest that water contact angle is higher in the atomic nitrogen neutral films and Si-DLC films compared to the ionized-nitrogen specie doped films and undoped DLC thin films, suggesting that the more hydrophobic films, semiconducting films, and film with relieved stress have better interaction with human microvascular endothelial cells. It seems evident that N-doping increases the Raman I(D)/I(G) ratios, whereas N-neutral doping decreases it slightly and Si-doping decreases it even further. In this study, lower Raman I(D)/I(G) ratios are associated with increased sp(3)/sp(2) ratio, an increased H concentration, photoluminescence intensity, and a higher endothelial cellular adhesion. These investigations could be relevant to biocompatibility assessment of nanostructured biomaterials and tissue engineering.

Bioactivity and hemocompatibility study of amorphous hydrogenated carbon coatings produced by pulsed magnetron discharge

“…A previous work established such a relationship for N-doped DLC and Si-doped DLC coatings. 21 In that case, a high hydrogen concentration together with a low I D /I G value (0.2-0.5) had a good influence on endothelial cell adhesion. At the present case, the I D /I G ratio should be in the range of 0.77-0.92 to get a good cell proliferation on a-C:H coatings without any additional chemical element, as Figure 11(C) indicates.…”

“…This work links the cell spreading on a‐C:H coatings deposited by reactive pulsed magnetron sputtering to the structure of the coating ( I D / I G ratio) at the same level of importance than those of the wettability, the chemical composition or the topography. A previous work established such a relationship for N‐doped DLC and Si‐doped DLC coatings 21. In that case, a high hydrogen concentration together with a low I D / I G value (0.2–0.5) had a good influence on endothelial cell adhesion.…”

“…For example, while fibroblast cells do not require special tuning to proliferate on a‐C:H material deposited by laser or plasma techniques,15, 16 osteoblast cell growth is improved by the incorporation of elements like titanium,3, 17 boron,18 or silicon 19. Moreover, good bioactivity response of endothelial cells has been observed after doping with nitrogen or silicon of such material grown by plasma systems 3, 20–23. Biocompatibility is not only dependent on the chemical composition since other physico‐chemical properties such as the wettability, polarity, or roughness are also of importance 3, 6.…”

“…19 Moreover, good bioactivity response of endothelial cells has been observed after doping with nitrogen or silicon of such material grown by plasma systems. 3,[20][21][22][23] Biocompatibility is not only dependent on the chemical composition since other physico-chemical properties such as the wettability, polarity, or roughness are also of importance. 3,6 For example, an hydrophilic surface seems to enhance the adsorption of several cell-adhesion mediating proteins, hence cell adhesion itself 3 and the surface polarity can improve cell proliferation.…”

Human Umbilical Vein Endothelial Cell Interaction with Fluorine-Incorporated Amorphous Carbon Films

“…In their literature, they also reported that surface wetting increased with silicone incorporation. 19) In order to reveal more detailed information on HUVEC adhesion, proliferation, and migration on a-C:H:F surfaces, it is necessary to evaluate the behavior of ECM proteins on surfaces. More extensive investigations are required in the future studies.…”