Correlating fibronectin adsorption with endothelial cell adhesion and signaling on polymer substrates

Abstract

Fibronectin (Fn) adsorption was studied on different commercial polymer surface chemistries, including tissue culture polystyrene (TCPS), bacteriologic polystyrene (BPS), fluoropolymer Teflon AF, and poly-L-lactide (PLLA). Antibody probes detected the availability of Fn's cell binding domain on adsorbed Fn in the competitive presence and absence of bovine serum albumin (BSA). Domain availability was highest for Fn adsorbed on TCPS, especially in the presence of either serum albumin or dilute serum. Attachment and growth efficiencies for human umbilical venous endothelial cells (HUVECs) cultured on surfaces preadsorbed with Fn in serum and serum-free media correlated with antibody cell-binding domain availability: TCPS > BPS, Teflon AF > PLLA. Intracellular signaling from the GTPase, RhoA, was highest (RhoA:RhoGDI inhibitor ratio) in cells cultured on the Teflon AF surfaces, indicating that despite lower attached cell numbers on Teflon AF compared to TCPS, cell signaling remained activated after 24 h of growth. Up-regulated cellular Fn mRNA messages, assessed using RT-PCR techniques, supported HUVECs' producing the endogenous extracellular matrix (ECM) protein Fn in order to attach and survive on the suboptimal Teflon AF culture surfaces.

Rho GTPase protein expression and activation in murine monocytes/macrophages are not modulated by model biomaterial surfaces in serum-containing in vitro cultures

“…Culture surfaces represent a wide wettability range, as determined by static aqueous contact angle measurement: hydrophilic TCPS (54 ± 2°) [26], moderately hydrophobic PS (92 ± 1°) [26] and PLA (82 ± 1°) [26,27] and very hydrophobic Teflon ® AF (116 ± 2°) [27], consistent with values previously reported. Cell adhesive and proliferative behavior was expected to vary on these different substrates related to surface chemistry effects on protein selection from complex biological milieu (serum).…”

“…Our previous work characterized these surface chemistries using X-ray photoelectron spectroscopy and correlated surface characteristics to endothelial cell culture support. For this attachment-ependent cell type, adhesion from serum and contact angle were proportional to surface oxygen content [26].…”

“…Interestingly, these cells have the unique ability to proliferate efficiently on fluorocarbon surfaces (Figs 1 and 2) that are non-or poorly supportive of most mammalian cell adhesion (e.g., endothelial cells, fibroblasts) [26,43]. Furthermore, cell morphologies were markedly different on control versus Teflon ® AF surfaces [15], suggesting that expression of specific Rho proteins related to the most commonly observed morphological features could be differentially regulated by the surface.…”

Hepatic stellate cells require a stiff environment for myofibroblastic differentiation

“…Teflon is stiff, with an elastic modulus four to five orders of magnitude stiffer than normal or cirrhotic liver (33). Although matrix, in particular fibronectin, is deposited by cells onto Teflon (23), cells are unable to generate mechanical tension due to the nature of the polymer. Cells cultured on Teflon for 7 days remained viable, with UV autofluorescence indicating the persistence of vitamin A droplets (Fig.…”

Quantifying fibronectin adhesion with nanoscale spatial resolution on glycosaminoglycan doped polypyrrole using Atomic Force Microscopy

“…Their initial adsorption, adherence and subsequent conformation are critical to the cell interactions and as such the effect of different surface chemistries and materials on ECM protein interactions has significantly featured in many studies 2,3,4 . While the importance of ECM protein interactions is well recognized, this has been emphasized in recent times by the role they play in regulating stem cell niches 5 .…”