Fibronectin and avidin-biotin as a heterogeneous ligand system for enhanced endothelial cell adhesion

Abstract

A preadsorbed layer of "heterogeneous" integrin-dependent and -independent protein was used to enhance initial integrin-mediated endothelial cell attachment and spreading. Glass substrates were treated with fibronectin (Fn) and avidin coupled through adsorbed biotinylated bovine serum albumin (b-BSA). The slides then were seeded with biotinylated BAEC. Control "homogeneous" surfaces were slides adsorbed with either Fn or avidin coupled to b-BSA. The cells were incubated for 0.5 h in serum-containing media and exposed to a range of shear stresses in a laminar flow variable-height flow chamber. The critical shear stress to detach 50% of the seeded cells on the heterogeneous ligand surface was significantly greater than for either of the control homogeneous ligand systems (p < 0.001). Cellular spreading during the initial period of 0-2 h also was higher (p < 0.05) on the heterogeneous ligand-treated surface than on the surface of either of the homogeneous controls. The close contact area of the cell membrane with the substrate 1 h after seeding in serum-containing media was measured using TIRFM. Cells attached onto the heterogeneous ligand-treated surfaces had a significantly (p < 0.01) higher area of close contact with the substrate, which is consistent with a greater degree of attachment and spreading. The results indicate that the combination of integrin-dependent and -independent adhesion systems using heterogeneous ligands further enhances initial endothelial cell attachment and spreading.

Engineering of vascular ingrowth matrices: Are protein domains an alternative to peptides?

“…While cell attachment is likely to be primarily integrin mediated, cell spreading appears to involve nonintegrin matrix-binding proteins as well (Basson et al, 1990). A heterogenous ligand-treated surface, for instance, containing both integrin-dependent adhesion systems and integrin-independent adhesion systems resulted in a significantly higher EC spreading than either of the two systems alone (Bhat et al, 1998). This has its reason in the many nonintegrin cell-extracellular matrix binding receptors on the cell surface, including proteoglykanes (syndecans) (Couchman and Woods, 1996), hyaluran receptors (CD 44, RHAMM and ICAM-1) (Entwistle et al, 1996), and receptor type protein tyrosine phosphatase (Barnea et al, 1994).…”

A biomimetic peptide fluorosurfactant polymer for endothelialization of ePTFE with limited platelet adhesion

“…Compositional data along with molecular modeling gives an estimated peptide density of 0.04-0.07 nmol/cm 2 for CRRETAWAC FSP. This is at least two orders of magnitude greater than the estimated monolayer density of FN (0.0003-0.001 nmol/cm 2 ) [24][25][26]. High attachment peptide density has been shown to enhance cell spreading, survival, focal contact formation, and proliferation [27][28][29][30].…”

In vivo performance of dual ligand augmented endothelialized expanded polytetrafluoroethylene vascular grafts

“…24 The surface Fn density, biotin receptor density, and RGD-SA density were determined by the HABA assay (Sigma) and an 125 I iodination labeling method (Pierce, IL) as previously described. 20 The cell-sodding apparatus is illustrated schematically in Figure 2. The ePTFE graft was securely clamped at one end, while the other end was connected to a 60-mL syringe via a 22-gauge needle.…”