Supramolecular Self‐Assembly and Organization of Collagen at Solid/Liquid Interface: Effect of Spheroid‐ and Rod‐Shaped TiO₂ Nanocrystals

Abstract

The adsorption behavior of collagen on solid surfaces is a process that determines the role of this protein to mediate cell–material interaction. Herein, the mechanism of self‐assembly and organization of collagen on a model substrate is investigated in the presence of TiO2 nanoparticles. In solution, results show that nanoparticles do not alter the conformation of collagen (triple‐helix), and slightly delay the kinetics of its self‐assembly. In the adsorbed state, by exploring the dewetting patterns of collagen layers from atomic force microscopy (AFM) images, a method is developed to extract parameters describing the characteristics of collagen networks. It is shown that collagen layer is strongly impacted by the presence of nanoparticles in the medium. These results are consistent with the analysis of the protein layers in the hydrated state, showing a rigidification, as observed by quartz crystal microbalance with dissipation monitoring (QCM‐D), and the formation of shorter and/or less extended fibrillar structures with a lower surface density, as probed by AFM force spectroscopy. The approach described here provides a reconciliation between disparate views of collagen layers' characterization in the dried and the hydrated states. It also offers new perspectives to assess the impact of nanoparticles on the organization of collagen during in vitro tests, particularly at the stage of cell adhesion.

Impact of Collagen Crosslinking on Dislocated Human Shoulder Capsules—Effect on Structural and Mechanical Properties

“…However, the recorded images did not allow the structure of individual fibrils, particularly their D-periodicity, to be sufficiently resolved. This may be due to their mobility during imaging, resulting on their interaction with the AFM tip, as commonly observed on adsorbed collagen layers [21] and collagen-based tissues [22]. In the dried phase (Figure 4C,D), the organization of these fibrils showed an alignment similar to that observed in the hydrated state, even if some disrupted fibrils could be observed (see arrow in Figure 4C).…”

Embedding Collagen in Multilayers for Enzyme-Assisted Mineralization: A Promising Way to Direct Crystallization in Confinement

“…Indeed, when collagen molecules (triple-helix) adsorb onto solid surfaces, it has been shown that they adopt a conformation that favors their self-assembly into fibrillary nanostructures and, in many situations near physiological conditions, they interact with the surface through few residues while segments protrude in the solution. 54,55 Besides, the formation of fibrils has also been observed even when collagen is embedded in polyelectrolyte multilayers. 38 In the present study, AFM images recorded on (Col/HA) 3 multilayers, after cross-linking, show the presence of well-defined fibrils (Figure 7A), which becomes invisible after the subsequent deposition of (PAH/ALP) 5 multilayers (Figure 7B).…”

“…The sensors were cleaned by UV-ozone for 15 min and rinsed with ethanol before measurement. Oscillation of the quartz crystal at the resonant frequency (5 MHz) or at one of its overtones (15,25,35,45,55, and 65 MHz) was obtained by applying an ac voltage. The evolution of the resonance frequency (Δf) and of dissipation (ΔD) was monitored upon adsorption of the different components.…”

Hierarchical Collagen–Hydroxyapatite Nanostructures Designed through Layer-by-Layer Assembly of Crystal-Decorated Fibrils

“…While these studies demonstrate the promising potential of combining collagen and NPs, it is obvious that there is a lack of a comprehensive understanding regarding the mechanism by which NPs interact with collagen in aqueous solutions of biological interest. This issue remains elusive, and only a few papers have reported the impact of NPs on the self-assembly of collagen in solution or at the solid/liquid interface . By contrast, it has been the subject of a vast literature for various proteins and led, for the instance, to the emergence of the protein corona , and surface-assisted fibrillation , paradigms.…”

“…This issue remains elusive, and only a few papers have reported the impact of NPs on the self-assembly of collagen in solution 32 or at the solid/ liquid interface. 35 By contrast, it has been the subject of a vast literature for various proteins and led, for the instance, to the emergence of the protein corona 36,37 and surface-assisted fibrillation 38,39 paradigms.…”