Vitronectin as a Micromanager of Cell Response in Material‐Driven Fibronectin Nanonetworks

Abstract

Surface functionalization strategies of synthetic materials for regenerative medicine applications comprise the development of microenvironments that recapitulate the physical and biochemical cues of physiological extracellular matrices. In this context, material‐driven fibronectin (FN) nanonetworks obtained from the adsorption of the protein on poly(ethyl acrylate) provide a robust system to control cell behavior, particularly to enhance differentiation. This study aims at augmenting the complexity of these fibrillar matrices by introducing vitronectin, a lower‐molecular‐weight multifunctional glycoprotein and main adhesive component of serum. A cooperative effect during co‐adsorption of the proteins is observed, as the addition of vitronectin leads to increased fibronectin adsorption, improved fibril formation, and enhanced vitronectin exposure. The mobility of the protein at the material interface increases, and this, in turn, facilitates the reorganization of the adsorbed FN by cells. Furthermore, the interplay between interface mobility and engagement of vitronectin receptors controls the level of cell fusion and the degree of cell differentiation. Ultimately, this work reveals that substrate‐induced protein interfaces resulting from the cooperative adsorption of fibronectin and vitronectin fine‐tune cell behavior, as vitronectin micromanages the local properties of the microenvironment and consequently short‐term cell response to the protein interface and higher order cellular functions such as differentiation.

Functionalization of PLLA with Polymer Brushes to Trigger the Assembly of Fibronectin into Nanonetworks

“…We previously showed the importance of these nanonetworks in driving myogenic differentiation, highlighting that the conformational changes in the molecule are able to enhance the differentiation degree. [16b,41] This study confirms that C2C12 differentiation on the nanonetworks is a contractility‐dependent process, as the introduction to the media of blebbistatin, a myosin II inhibitor, inhibited differentiation . The dependence of cellular differentiation on contractility has been previously reported,[17b] indicating that actin–myosin contractility is activated by these physiological‐like FN nanofibrils .…”

“…Murine myoblast cells (C2C12) were utilized as a cell model due to their general utility and capacity to form myotubes in vitro. [17b,41] Cell density can impact the degree of differentiation, with increased density inducing higher differentiation in C2C12 cell populations . Here, density was maintained between the different conditions, while myotube formation was increased (Figure B,C) in the presence of FN nanonetworks.…”

“…The FN fibrils seemed thicker and slightly less interconnected on PLLA‐ b PEA compared to those found on control PEA. Fractal analysis confirmed the slight decrease of interconnection, while the fractal properties of the protein network were maintained (Figure A,B) . The observed differences in the FN nanofibrils assembled on PEA and PLLA‐ b PEA are likely due to the increased roughness and to the brush organization of the surface after ATRP polymerization.…”

Multifunctional Biomaterials: Combining Material Modification Strategies for Engineering of Cell-Contacting Surfaces

“…Immunostaining of proteins such as FN or VN with nanoparticle-tagged antibodies allowed specific and quantitative detection of the protein with AFM characterization. 199 Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a promising method for characterization of multicomponent surfaces and gradients. 200 Its high sensitivity and specificity for different chemical groups allows for distinguishing footprints of individual amino acids and gives information about the orientation of the immobilized molecules.…”

Evaluation of immunoresponses and cytotoxicity from skin exposure to metallic nanoparticles

“…Substances like vitronectin enhanced cell differentiation by improving fibronectin absorption and fibril formation in the ECM. 108 Adhered cells have also been subjected to a variety of stimuli, such as the stiffness of the ECM, polarity of charged substrates, and stresses from the motion of neighboring cells or surrounding fluid. 109 Therefore, the cellular uptake of metallic NPs could also be regulated by the cell microenvironment, which would influence the efficiency and toxicity of NPs.…”