Cell‐Type‐Specific adhesion mechanisms mediated by fibronectin adsorbed to chemically derivatized substrata

Abstract

Plasma fibronectin (pFN) adhesion mechanisms on inert substrata were evaluated for murine fibroblasts (3T3) and human neuroblastoma (Platt) cells using glass coverslips chemically derivatized with a self-assembled monolayer of aliphatic chains terminated with a specific endgroup to interact with adsorbed pFN: [CH3], [SH], [SCOCH3], [NH2], [SO3H], or underivatized glass [SiOH]. All surfaces bound similar amounts of pFN and facilitated attachment of both cell types within narrow ranges. However, spreading/differentiation responses of cells differed considerably among the surfaces. While 3T3 cells spread and developed microfilament stress fibers comparably on all surfaces, inclusion of an RGDS-containing synthetic peptide in the medium revealed variation in resistance to stress fiber formation mediated by an RGDS-recognizing integrin: [NH2] greater than [CH3] much greater than [SiOH],[SH],[SCOCH3]. Different patterns of neurite formation were observed for neuroblastoma cells: [SiOH], [SO3H] greater than [SCOCH3],[SH] much greater than [CH3] greater than [NH2]. Similarity in cell responses to both [CH3] and [NH2] surfaces argues against a pattern dependent upon the hydrophobicity of substrata. When pFN was diluted to a subsaturable concentration with albumin for adsorption, neuroblastoma responses changed significantly from those observed on pFN-saturated surfaces, for both spreading and neurite generation: [NH2],[SO3H] much greater than [SH], [SCOCH3] greater than [SiOH],[CH3]. Responses to the pFN: albumin mixture were markedly improved from responses after sequential adsorptions, demonstrating "optimization" of pFN conformation (not merely binding) by coadsorption of albumin molecules. In most cases, the [NH2] surface yielded responses distinctively different from the other surfaces. Overall, these data suggest many variations in the conformation of pFN molecules adsorbed to specific inert surfaces, as well as variations in the responses of cell surface receptors to conformationally specific pFNs. They also reveal cell-type-specific changes in differentiated cell responses on derivatized substrata, mediated by different classes of cell surface receptors for the two cell types, and provide optimism for regulating FN-dependent adhesion mechanisms in either positive or negative contexts on biomaterial surfaces derivatized with one or more of these chemical end-groups.

Proteins at Interfaces

“…Modulation of the biologic activity of adsorbed fibronectin is indicated by several studies showing that fibronectin adsorbed to various surfaces is not equivalent in its interactions with cells, despite the presence of similar amounts of adsorbed fibronectin (77)(78)(79)(80)(81)(82). For example, fibronectin adsorbed to tissue culture grade polystyrene supports BHK cell attachment and spreading, whereas fibronectin adsorbed to ordinary polystyrene does not support spreading unless some albumin is added to the fibronectin solution (77).…”

“…For example, fibronectin adsorbed to tissue culture grade polystyrene supports BHK cell attachment and spreading, whereas fibronectin adsorbed to ordinary polystyrene does not support spreading unless some albumin is added to the fibronectin solution (77). Similarly, substrata of varying chemical composition to which fibronectin was pre-adsorbed varied considerably in their ability to induce cell spreading and intracellular stress fiber formation in fibroblasts and neural cells, in their ability to induce neurite formation in neuroblastoma cells, and in their degree of inhibition of stress fiber formation by an RGDS peptide (78). Finally, the ability of fibronectin adsorbed to various surfaces to promote the outgrowth of corneal cells was found to vary considerably, even when compared at similar amounts of adsorbed fibronectin.…”

Hybrid Organic-Inorganic Scaffolding Biomaterials for Regenerative Therapies

“…Currently, the grafting of biomolecules (peptides or proteins) is in fact an approach extensively used in tissue engineering to guide cellular adhesion and activity [71,72]. In this case, ligand identity, conformation and density are key parameters when developing materials [12,73] because they regulate the efficiency of integrin-mediated cell adhesion [74], modulate the matrix deposition by osteogenic cells [75] and control the cell-type specificity of these responses [76].…”

Interaction of an ionic complementary peptide with a hydrophobic graphite surface

“…It is also suggested that adsorption is related to functional groups, not simply the degree of hydrophobicity or hydrophilicity. 1,23 Our group has systemically studied the self-assembly and adsorption behavior of an ioniccomplementary peptide, EAK16-II, a 16-mer peptide. [24][25][26][27][28] Although the experimental findings are very promising, it is still necessary for us to verify these findings theoretically and to obtain the knowledge about the roles of different interaction compositions played in the adsorption.…”