High-Speed Nanomechanical Mapping of the Early Stages of Collagen Growth by Bimodal Force Microscopy
2021; American Chemical Society; Volume: 15; Issue: 1 Linguagem: Inglês
10.1021/acsnano.0c10159
ISSN1936-086X
AutoresVictor G. Gisbert, Simone Benaglia, M. Uhlig, Roger Proksch, Ricardo Garcı́a,
Tópico(s)Cell Adhesion Molecules Research
ResumoHigh-speed atomic force microscopy (AFM) enabled the imaging of protein interactions with millisecond time resolutions (10 fps). However, the acquisition of nanomechanical maps of proteins is about 100 times slower. Here, we developed a high-speed bimodal AFM that provided high-spatial resolution maps of the elastic modulus, the loss tangent, and the topography at imaging rates of 5 fps. The microscope was applied to identify the initial stages of the self-assembly of the collagen structures. By following the changes in the physical properties, we identified four stages, nucleation and growth of collagen precursors, formation of tropocollagen molecules, assembly of tropocollagens into microfibrils, and alignment of microfibrils to generate microribbons. Some emerging collagen structures never matured, and after an existence of several seconds, they disappeared into the solution. The elastic modulus of a microfibril (∼4 MPa) implied very small stiffness (∼3 × 10
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