Interfibrillar stiffening of echinoderm mutable collagenous tissue demonstrated at the nanoscale

DOI: 10.1073/pnas.1609341113

Authors: Jingyi Mo (School of Engineering and Material Science, Queen Mary University of London) , Sylvain F. Prévost (Beamline ID02, European Synchrotron Radiation Facility) , Liisa M. Blowes (Queen Mary, University of London) , Michaela Egertová (School of Biological and Chemical Sciences, Queen Mary University of London) , Nicholas J. Terrill (Diamond Light Source) , Wen Wang (Queen Mary University of London) , Maurice R. Elphick (cSchool of Biological and Chemical Sciences, Queen Mary University of London) , Himadri S. Gupta (Queen Mary, University of London)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Proceedings Of The National Academy Of Sciences

State: Published (Approved)
Published: October 2016
Diamond Proposal Number(s): 10311 , 11806

Abstract: The mutable collagenous tissue (MCT) of echinoderms (e.g., sea cucumbers and starfish) is a remarkable example of a biological material that has the unique attribute, among collagenous tissues, of being able to rapidly change its stiffness and extensibility under neural control. However, the mechanisms of MCT have not been characterized at the nanoscale. Using synchrotron small-angle X-ray diffraction to probe time-dependent changes in fibrillar structure during in situ tensile testing of sea cucumber dermis, we investigate the ultrastructural mechanics of MCT by measuring fibril strain at different chemically induced mechanical states. By measuring a variable interfibrillar stiffness (EIF), the mechanism of mutability at the nanoscale can be demonstrated directly. A model of stiffness modulation via enhanced fibrillar recruitment is developed to explain the biophysical mechanisms of MCT. Understanding the mechanisms of MCT quantitatively may have applications in development of new types of mechanically tunable biomaterials.

Journal Keywords: mutable collagenous tissue | synchrotron small-angle X-ray diffraction | nanoscale mechanics | fibrillar deformation | sea cucumbers

Subject Areas: Biology and Bio-materials, Physics, Materials


Instruments: I22-Small angle scattering & Diffraction

Other Facilities: ESRF ID02

Documents:
E6362.full.pdf