Cell Adhesion Strength Increases Linearly with Adsorbed Fibronectin Surface Density (original) (raw)
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A Review of Cell Adhesion Studies for Biomedical and Biological Applications
International journal of molecular sciences, 2015
Cell adhesion is essential in cell communication and regulation, and is of fundamental importance in the development and maintenance of tissues. The mechanical interactions between a cell and its extracellular matrix (ECM) can influence and control cell behavior and function. The essential function of cell adhesion has created tremendous interests in developing methods for measuring and studying cell adhesion properties. The study of cell adhesion could be categorized into cell adhesion attachment and detachment events. The study of cell adhesion has been widely explored via both events for many important purposes in cellular biology, biomedical, and engineering fields. Cell adhesion attachment and detachment events could be further grouped into the cell population and single cell approach. Various techniques to measure cell adhesion have been applied to many fields of study in order to gain understanding of cell signaling pathways, biomaterial studies for implantable sensors, artif...
2006
The ability of fibronectin (Fn) to mediate cell adhesion through binding to a 5 b 1 integrins is dependent on the conditions of its adsorption to the surface. Using a model system of alkylsilane SAMs with different functional groups (X ¼ OH, COOH, NH 2 and CH 3 ) and an erythroleukemia cell line expressing a single integrin (a 5 b 1 ), the effect of surface properties on the cellular adhesion with adsorbed Fn layers was investigated. 125 I-labeled Fn, a modified biochemical cross-linking/extraction technique and a spinning disc apparatus were combined to quantify the Fn adsorption, integrin binding and adhesion strength, respectively. This methodology allows for a binding equilibrium analysis that more closely reflects cellular adhesion found in stable tissue constructs in vivo. Differences in detachment strength and integrin binding were explained in terms of changes in the adhesion constant (c, related to affinity) and binding efficiency of the adsorbed Fn for the a 5 b 1 integrins (CH 3 ENH 2 oCOOHEOH) and the resulting average bond strength. Fn interacted more strongly with a 5 b 1 integrins when adsorbed on COOH vs. OH surfaces suggesting that negative charge may be a critical component of inducing efficient cellular adhesion. As evident by the low c values, Fn adsorbed on NH 2 and CH 3 surfaces interacted inefficiently with a 5 b 1 integrins and also possessed significant non-specific components to adhesion. Lastly, comparison of cellular adhesion to Fn adsorbed onto smooth and rough surfaces showed that nano-scale roughness altered cellular adhesion by increasing the surface density of adsorbed Fn. r
Biomaterials, 2006
The ability of fibronectin (Fn) to mediate cell adhesion through binding to a 5 b 1 integrins is dependent on the conditions of its adsorption to the surface. Using a model system of alkylsilane SAMs with different functional groups (X ¼ OH, COOH, NH 2 and CH 3 ) and an erythroleukemia cell line expressing a single integrin (a 5 b 1 ), the effect of surface properties on the cellular adhesion with adsorbed Fn layers was investigated. 125 I-labeled Fn, a modified biochemical cross-linking/extraction technique and a spinning disc apparatus were combined to quantify the Fn adsorption, integrin binding and adhesion strength, respectively. This methodology allows for a binding equilibrium analysis that more closely reflects cellular adhesion found in stable tissue constructs in vivo. Differences in detachment strength and integrin binding were explained in terms of changes in the adhesion constant (c, related to affinity) and binding efficiency of the adsorbed Fn for the a 5 b 1 integrins (CH 3 ENH 2 oCOOHEOH) and the resulting average bond strength. Fn interacted more strongly with a 5 b 1 integrins when adsorbed on COOH vs. OH surfaces suggesting that negative charge may be a critical component of inducing efficient cellular adhesion. As evident by the low c values, Fn adsorbed on NH 2 and CH 3 surfaces interacted inefficiently with a 5 b 1 integrins and also possessed significant non-specific components to adhesion. Lastly, comparison of cellular adhesion to Fn adsorbed onto smooth and rough surfaces showed that nano-scale roughness altered cellular adhesion by increasing the surface density of adsorbed Fn. r
The quantification of single cell adhesion on functionalized surfaces for cell sheet engineering
Biomaterials, 2010
The use of force spectroscopy to measure and quantify the forces involved in the adhesion of 3T3 fibroblasts to different chemically functionalized surfaces has been investigated. Cells were grown on glass surfaces as well as on surfaces used for cell sheet engineering: surfaces coated with polyelectrolyte multilayers (poly-L-lysine and hyaluronic acid) and thermally-responsive poly(N-isopropylacrylamide) (PNIPAM) brushes. Individual adherent cells were detached from their culture substrate using an AFM cantilever coated with fibronectin. The maximum forces of detachment of each cell were measured and taken as characteristic of the cellular adhesion. Large differences in cellular adhesion were observed on polyelectrolyte coatings depending on the number of polyelectrolyte layers. On PNIPAM-grafted surfaces, changes of more than an order of magnitude were observed in cell adhesion above and below the lower critical solution temperature. Glass surfaces patterned with periodic PNIPAM microdomains were also investigated, and it was shown that cellular adhesion could be reduced while keeping cellular morphology unchanged.
2008
Cell-implant adhesive strength is important for prostheses. In this paper, an investigation is described into the adhesion of bovine chondrocytes to Ti-6Al-4V-based substrates with different surface roughnesses and compositions. Cells were cultured for 2 or 5 days, to promote adhesion. The ease of cell removal was characterised, using both biochemical (trypsin) and mechanical (accelerated buoyancy and liquid flow) methods. Computational fluid dynamics (CFD) modelling has been used to estimate the shear forces applied to the cells by the liquid flow. A comparison is presented between the ease of cell detachment indicated using these methods, for the three surfaces investigated.
Colloids and Surfaces B: Biointerfaces, 2012
Using single-cell force spectroscopy, we compared the initial adhesion of L929 fibroblasts to planar and nanostructured silicon substrates as a function of fibronectin concentration. The nanostructures were periodically grooved with a symmetric groove-summit period of 180 nm and a groove depth of 120 nm. Cell adhesion strength to the bare nanostructure was lower (79% ± 13%) than to the planar substrate, which we attribute to reduced contact area. After pre-incubation with a low fibronectin concentration (5 g/ml) the adhesion strengths to both surfaces increased, with adhesion strength on the nanostructure outweighing that of the planar substrate by 133% ± 14%. At a high fibronectin concentration (25 g/ml) the adhesion strengths on both surfaces further increased and showed wide variations. In parallel, the nanostructure lost its clear advantage over the planar substrate. Our results demonstrate that cell adhesion is influenced by substrate topography and fibronectin, which mediate the interplay between specific interactions, non-specific interactions, and cell mechanics. Two parallel processes govern the initial adhesion strength: the detachment of the cell body from the substrate and the extraction of tethers from the cell membrane. The duration of the latter process is determined by tether lifetimes, and is a major contributor to the overall work required for cell-substrate detachment. Cell body detachment and tether lifetimes are affected by surface topography and may be strongly modulated by the presence of adsorbed proteins, whereas the tether extraction forces remained unchanged by these factors.
Journal of Biomaterials Science, Polymer Edition, 1995
The adhesion of human peripheral lymphocytes (HPL) was studied after preadsorption of fibronectin (FN) and vitronectin (VN) on hydrophilic glass and hydrophobic octadecyl glass. The adhesion of HPL was shown to be dependent not only on the wettability but also on the protein preadsorbed. Vitronectin expressed not only a higher extent of adhesion under static conditions but also a stronger interaction with HPL, indicated by the low detachment under shear stress. The flow experiments also demonstrated that FN adsorbed on octadecyl glass may undergo conformational changes because HPL could be easily removed. Scanning electron microscopy revealed that HPL on both FN-and VN-coated glass spread well whereas particularly on FN-coated octadecyl glass less cell spreading was observed; moreover, some round cells were detected. The typing of adherent HPL by immunofluorescence microscopy showed that on FN-and VN-coated glass about 70% of all HPL were T-cells (CD 3+). However, on octadecyl glass, particularly on VN, a smaller percentage of CD 3+ cell was observed. The testing for the beta 1 integrin-the receptor for FN and the alpha v integrin-the receptor for VN demonstrated that about 70% of all cells on FN-coated glass were positive for the beta 1 integrin. On VN-coated glass, however, only 5% of HPL were positive for the beta 1 integrin. Although on VN a high adhesion and strong binding of HPL was observed, no presence of the alpha v integrin was detected.
Journal of Biomedical Materials Research, 2003
Integrin-mediated cell adhesion to proteins adsorbed onto synthetic surfaces anchors cells and triggers signals that direct cell function. In the case of fibronectin (Fn), adsorption onto substrates of varying properties alters its conformation/structure and its ability to support cell adhesion. In the present study, self-assembled monolayers (SAMs) of alkanethiols on gold were used as model surfaces to investigate the effects of surface chemistry on Fn adsorption, integrin binding, and cell adhesion. SAMs presenting terminal CH 3 , OH, COOH, and NH 2 functionalities modulated adsorbed Fn conformation as determined through differences in the binding affinities of monoclonal antibodies raised against the central cell-binding domain (OH Ͼ COOH ϭ NH 2 Ͼ CH 3 ). Binding of ␣ 5  1 integrin to adsorbed Fn was controlled by SAM surface chemistry in a manner consistent with antibody binding (OH Ͼ COOH ϭ NH 2 Ͼ CH 3 ), whereas ␣ V integrin binding followed the trend:
Targeted cellular adhesion at biomaterial interfaces
Current Opinion in Solid State & Materials Science, 1998
The interface of biomaterials must be carefully designed to elicit and eliminate specific responses when placed in contact with the body. The interaction of cells with the surfaces of biomaterials is a complex phenomenon that depends on a large number of variables. To design novel biomaterials that possess the desired characteristics, materials scientists and engineers rely heavily upon information provided by molecular biologists. Information regarding cell receptor-ligand interactions is used to understand the role of cellular adhesion in the natural environment so that synthetic biomaterials may be developed successfully. The production of new synthetic materials, understanding how native proteins mediate cellular adhesion with these materials, molecularly engineering surfaces with controlled spatial patterns for optimal responses, evaluation of mechanical properties, and analyzing bioadhesion and surface properties of these materials are topics that must be addressed when discussing targeted cellular adhesion at biomaterial surfaces.