Modulating cell adhesion and spreading by control of FnIII_7–10 orientation on charged self‐assembled monolayers (SAMs) of alkanethiolates

Abstract

In this work, we demonstrate that surface charge can be used to modulate cell adhesion/spreading through the control of the orientation of adsorbed FnIII(7-10), which is a cell-adhesive protein containing RGD residues. Carboxylic acid (COOH) and amine (NH(2))-terminated self-assembled monolayers (SAMs) of alkanethiolates were used as model negatively and positively charged surfaces, respectively. The adsorbed amount of FnIII(7-10) is controlled to be equivalent on both SAMs as confirmed by the adsorption isotherms determined using I(125)-radiolabeled FnIII(7-10.) The binding of a monoclonal antibody specific for the cell-binding domain of FnIII(7-10) was measured by surface plasmon resonance (SPR) to evaluate FnIII(7-10) orientations on different SAMs. Results indicate that adsorbed FnIII(7-10) on NH(2)-SAM has an orientation with more cell-binding domains accessible than on COOH-SAM, confirming our predictions from Monte Carlo simulations. Both phase contrast images and Vybrant MTT cell proliferation assays show that the adhesion/spreading of bovine aortic endothelial cells (BAECs) on the NH(2)-SAM is significantly better than that on the COOH-SAM coated with an equivalent amount of FnIII(7-10). These results indicate that surface charge can be used to specifically orient cell adhesive proteins such as FnIII(7-10), thus providing a promising strategy to increase the activity of materials incorporating biological moieties.

MC3T3-E1 cell adhesion to hydroxyapatite with adsorbed bone sialoprotein, bone osteopontin, and bovine serum albumin

“…30,33,34,36 In previous studies with MC3T3-E1 cells, it was shown that heat denatured BSA effectively prevents cell binding to TCPS and this was confirmed in this study. Additionally, in both cell binding assays, the lowest amount of cell binding was seen on -COOH terminated SAMs (0 days of HAP growth) with adsorbed BSA.…”

“…30,31 The ability to control protein orientation with charged SAMs is mediated by the conformational stability and size of the adsorbed protein. 32,33 Other efforts have focused on utilizing specific protein-protein interactions to impart a natural biological orientation or conformation to one of the proteins. 34-36 Our previous efforts examined the MC3T3-E1 osteoblast-like cell binding onto both OPN and BSP covered surfaces when the proteins were randomly adsorbed to tissue culture polystyrene (TCPS) or specifically bound to collagen I.…”

Surface Coating as a Key Parameter in Engineering Neuronal Network Structures In Vitro

“…Surface chemistry [37][38][39] allowed elegantly patterned neuronal networks with potentially useful functions, but long term maintenance of the networks is a problem. SAMs [40,41] represent a convenient way for engineering cell adhesion [42], as SAMs do not involve complicated instruments during the experiment. Coating is widely used for tailoring the biocompatibility of the neuron-materials interfaces [43][44][45].…”

Dynamic culture substrate that captures a specific extracellular matrix protein in response to light

“…Although this small peptide sequence is sufficient for cell adhesion, its biological activity is lower than that of the native protein owing to the absence of complementary domains such as the PHSRN (phenylalanine-histidine-serine-arginine-asparagine) sequence [15,16]. On the other hand, larger protein fragments containing such complementary sequences exhibit stronger cell adhesion and higher biological activities [17,18]. Therefore, dynamic substrates will become more physiologically relevant when used in combination with such larger protein fragments instead of the RGD peptides.…”