Adsorption Behavior Of Fibronectin Research Articles

Oxygen Ion Implantation Improving Cell Adhesion on Titanium Surfaces through Increased Attraction of Fibronectin PHSRN Domain.

Mechanistic understanding of fibronectin (FN) adsorption which determines cell adhesion on cell-implant interfaces is significant for improving the osteoconduction and soft-tissue healing of implants. Here, it is shown that the adsorption behavior of FN on the titanium oxide surface (TiO2 ) is highly relative to its Pro-His-Ser-Arg-Asn (PHSRN) peptide. FN lacking PHSRN fails to bind to surfaces, resulting in inhibited cell adhesion and spreading. Molecular dynamics simulation shows higher affinity and greater adsorption energy of PHSRN peptide with TiO2 surface due to the stronger hydrogen bonds formed by the serine and arginine residues with O ion of the substrate. Finally, by increasing O content in TiO2 surfaces through O ion-beam implantation, improving the cell adhesion, cell differentiation, and the subsequent biomineralization on titanium implant is realized. This study reveals the vital role of PHSRN in FN-mediated cell adhesion on implant surfaces, providing a promising new target for further tissue integration and implant success.

Fibronectin Adsorption on Hydroxyapatite Nanosensors and the Effect of Fibronectin Preadsorption on Biological Apatite Growth.

In this study, hydroxyapatite (HA) nanoparticles were prepared at 30 °C by the chemical precipitation method. The adsorption behavior of fibronectin (Fn) on Au and HA surfaces at different Fn concentrations (50, 100, and 200 μg mL-1 and the effect of fibronectin preadsorption on the apatite growth process were investigated by the quartz crystal microbalance technique. The surface properties of Au and HA were characterized by atomic force microscopy and field emission scanning electron microscopy. Fn adsorption experiments show that the adsorption capacity of Fn on Au and HA surfaces is in the order Au-Fn200> Au-Fn100≈ HA-Fn100≈ HA-Fn200> HA-Fn50> Au-Fn50, where the number after Fn corresponds to the concentration of the Fn solution. The order of the viscoelasticity of the adsorbed layer is HA-Fn200> HA-Fn100> Au-Fn200> HA-Fn50> Au-Fn50> Au-Fn100. These results suggest that the Fn concentration and the chemical composition and topography of the substrate surface affect Fn adsorption and the viscoelasticity of the adsorbed Fn layer. A high Fn concentration is not conducive to Fn adsorption on the HA surface and formation of a viscoelastic Fn layer. Based on the experimental results, the states and orientations of Fn adsorbed on Au and HA are rationally discussed. Mineralization experiments show that the order of the mass of the apatite layer is HA > HA-Fn50 > Au-Fn50» Au. The apatite growth rate on the Au surface is essentially zero, whereas the apatite growth rate on the Au-Fn50 surface linearly increases. For the HA and HA-Fn50 surfaces, the apatite growth rate can be divided into several stages. An adsorbed Fn layer affects apatite nucleation on both the Au and HA surfaces and decreases the apatite growth rate on the HA surface.

Simple surface treatment of cell-culture scaffolds with ultrafine bubble water.

We propose a novel method to treat polymeric scaffold surfaces for cell culture with water containing nanobubbles, called ultrafine bubbles (UFBs), with typical diameters less than 1 μm. A thin film of polystyrene (PS) prepared on a solid substrate was exposed to UFB water for 2 days at room temperature. The PS surface was characterized by X-ray photoelectron spectroscopy (XPS), static contact angle measurements in water, and atomic force microscopy (AFM). The surface chemical composition and wettability of PS films remained unchanged after treatment, so that aggregation states of PS at film surfaces remained unaltered by UFB water. On the other hand, after treatment, many UFBs were adsorbed on hydrophobic PS surfaces. To study the effect of UFBs on scaffold properties, the adsorption behavior of fibronectin, which is a typical extracellular matrix protein involved in cell adhesion and proliferation, was examined. While the effect on the adsorption was unclear, the structural denaturation of fibronectin was enhanced after UFB treatment, so that the proliferation of fibroblast cells on PS surfaces was promoted.

Influence of surface wettability on competitive protein adsorption and initial attachment of osteoblasts

This study investigated the influence of surface wettability on competitive protein adsorption and the initial attachment of osteoblasts. A thin-film coating of hexamethyldisiloxane (HMDSO) and subsequent O2-plasma treatment was carried out on substrates with a mirror surface in order to create a wide range of wettabilities. The adsorption behavior of fibronectin (Fn) and albumin (Alb) in both individual and competitive mode, and the initial attachment of mouse osteoblastic cells (MC3T3-E1) over a wide range of wettabilities were investigated. The contact angle of HMDSO coatings without O2-plasma treatment against double-distilled water was more than 100°, whereas it dramatically decreased after the O2-plasma treatment to almost 0°, resulting in super-hydrophilicity. Individually, Fn adsorption showed a biphasic inclination, whereas Alb showed greater adsorption to hydrophobic surfaces. In the competitive mode, in a solution containing both Fn and Alb, Fn showed greater adsorption on hydrophilic surfaces, whereas Alb predominantly adsorbed on hydrophobic surfaces. The initial attachment of osteoblastic cells increased with an increase in surface wettability, in particular, on a super-hydrophilic surface, which correlated well with Fn adsorption in the competitive mode. These results suggest that Fn adsorption may be responsible for increasing cell adhesion on hydrophilic surfaces in a body fluid or culture media under physiological conditions.

Adsorption behavior of fibronectin on well-characterized silica surfaces

The adsorption behavior of human plasma fibronectin at physiological pH and ionic strength was investigated by in situ ellipsometry on silica substrates of two different surface energies. The silica substrate was characterized by ellipsometry, galvanic potential, and critical surface tension measurements. Adsorption isotherms in the low concentration range for fibronectin were compared with human fibrinogen and found to be qualitatively similar with increased amounts of protein adsorbed at the plateau on a hydrophobic surface as compared to a hydrophilic one. Reversibility for fibronectin upon dilution was found to be small on a hydrophobic surface while a partial desorption was found on a hydrophilic one. Interaction of antibodies with preadsorbed fibronectin suggests that fibronectin adsorbs in different conformations and/or arrangements on the two types of surfaces. The lectin Concanavalin A and its interaction with preadsorbed fibronectin was also investigated.