Adhesion of Human U937 Monocytes to Nitrogen‐Rich Organic Thin Films: Novel Insights into the Mechanism of Cellular Adhesion

Abstract

We present a two-fold study designed to elucidate the adhesion mechanism of human U937 monocytes on novel N-rich thin films deposited by plasma- and VUV photo-polymerisation, so-called "PVP:N" materials. It is shown that there exist sharply-defined ("critical") surface-chemical conditions that are necessary to induce cell adhesion. By comparing the film chemistries at the "critical" conditions, we demonstrate the dominant role of primary amines in the cell adhesion mechanism. Quantitative real-time RT-PCR experiments using U937 cells that had adhered to PVP:N materials for up to 24 h are presented. The adhesion induces a transient expression of cytokines, markers of macrophage activation, as well as a more sustained expression of PPAR gamma and ICAM-I.

Nitrogen‐Rich Plasma‐Polymerized Coatings on PET and PTFE Surfaces Improve Endothelial Cell Attachment and Resistance to Shear Flow

“…[31] Yet, the PPE:N coatings studied here performed quite similarly. Therefore, the choice between PPE:N coatings was made according to their uniformity, their stability and their facility of transfer to real prostheses.…”

Adhesion of U937 monocytes on polymer surfaces: Chemistry or electrostatics?

“…However, in a recent article [8] we have shown that they can be made to adhere to our plasma-or photo-chemically synthesized organic thin ("PE-N") films, provided that the outer surfaces of these coatings contain a minimum ("critical") concentration of 4.2 atomic % of primary amine groups, R-NH2. This is illustrated in Figure 1, where we note that the different surfaces have Now, numerous investigations [10][11][12][13] have been able to unambiguously demonstrate the ability of charged polymer surfaces to bind proteins [12] or living cells [10,11,13] in vitro.…”

Ultra-Shallow Chemical Characterization of Organic Thin Films Deposited by Plasma and Vacuum-Ultraviolet, Using Angle- and Excitation Energy-Resolved XPS

“…As already mentioned, we selected two well-characterised PVP:N coating-types. Samples were necessarily exposed to ambient air for limited periods of time after deposition; the reader is referred to our earlier reports regarding these materials [24,25,[39][40][41]. The films were chosen for their high amine content and the resulting technological relevance, particularly their good performance in biomedical applications.…”