Extended interaction of β1 integrin subunit-deficient cells (GD25) with surfaces modified with fibronectin-derived peptides: Culture optimization, adhesion and cytokine panel studies

Abstract

The modification of biomaterials with extracellular matrix-mimicking factors to influence the cellular response through mainly integrin-mediated signaling is a common technique. The inherent limitations of antibody-inhibition studies necessitate the use of complementary methods to block integrin function to confirm cell-surface interaction. In this study, we employed a β1 integrindeficient cell line, GD25, to investigate the role of β1 subunit in cell adhesion and subsequent cytokine (granulocyte macrophage colony stimulating factor, interleukin (IL)-1α, IL-1β, IL-6, granulocyte macrophage colony stimulating factor -1, regulated upon activation, normal T-cell expressed, and secreted, tumor necrosis factor-α) release kinetics in the presence of tissue culture polystyrene (TCPS) and semi-interpenetrating polymer networks (sIPN) modified with fibronectin (FN)-mimic peptides (RGD, PHSRN). Culture conditions (i.e. seeding density, medium, serum supplementation) were optimized for long-term observation. Differences in cell adhesion, cell viability and cytokine release behavior were dependent on the presence of the β1 integrin subunit, FN, sIPN cast method and peptide identity. By comparing two complementary techniques for assaying integrin function, we observed both similarities (i.e. decreased adhesion to FN-absorbed TCPS and increased IL-1β release at 96 h) and differences (i.e. no difference in adhesion or IL-1β release in the presence of sIPN surfaces) when the function of the β1 subunit was blocked in cell adhesion and signaling in the presence of biomaterials.

Fibroblasts regulate monocyte response to ECM‐derived matrix: The effects on monocyte adhesion and the production of inflammatory, matrix remodeling, and growth factor proteins

“…N‐hydroxysuccinimide activated esters were prepared from PEGdiol (2k) as previously described 22. All starting materials were purchased from Aldrich unless otherwise specified.…”

“…Ligand-PEG-grafted gelatin synthesis: PEG-diol modification to Bis-N-hydroxysuccinimide-PEG and Ligand-PEG grafting to gelatin N-hydroxysuccinimide activated esters were prepared from PEGdiol (2k) as previously described. 22 All starting materials were purchased from Aldrich unless otherwise specified. First, bis-t-butylacetate-PEG (Bis-tBuOAc-PEG) was prepared by activating PEG with sodium hydride and then by reacting it with t-butyl bromoacetate for 24 h. T-butyl bromoacetate was filtered and extracted to remove impurities and analyzed by 1 H NMR.…”

Mechanochemical mechanism of integrin clustering modulated by nanoscale ligand spacing and rigidity of extracellular substrates

“…A large number of experiments have already demonstrated that many physical factors such as mechanical property of extracellular matrices/substrates and spatial arrangement of integrin ligands (i.e, RGD peptides), can remarkably regulate initial cell adhesion and subsequent formation of mature focal adhesions (FAs) on extracellular matrices/substrates [2][3][4][5][6][7][8][9][10][11][12][13][14]. For instance, it has been recognized that substrate rigidities are able to upregulate the dynamics of cell adhesion nucleation to some extent owing to that it can promote chemical affinity of integrin receptors by mechanically changing the molecules from bent to extended conformations [8,9,15].…”

ZnO nanorod–templated well-aligned ZrO2 nanotube arrays for fibroblast adhesion and proliferation

“…Among cell responses to different nanopatterns, a porous surface involving nanotubes has recently received attention. Nanotubes improve osteoblast attachment, function, and proliferation [27] and exhibit very low immunogenicity, eliciting low levels of monocyte activation and cytokine secretion [31]. They may be used in vascular applications to enhance endothelial cell extracellular matrix (ECM) production and motility [15].…”