Format

Send to

Choose Destination
Biomaterials. 2016 Nov;107:15-22. doi: 10.1016/j.biomaterials.2016.08.038. Epub 2016 Aug 24.

Studies of chain substitution caused sub-fibril level differences in stiffness and ultrastructure of wildtype and oim/oim collagen fibers using multifrequency-AFM and molecular modeling.

Author information

1
Department of Mechanical Engineering, National University of Singapore, Singapore.
2
Department of Civil Engineering, National Taiwan University, Taipei 10617, Taiwan; Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
3
Department of Bioengineering, Imperial College London, London SW7 2AZ, UK.
4
Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
5
Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA, USA. Electronic address: s.shefelbine@neu.edu.
6
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA. Electronic address: mingdao@mit.edu.
7
Department of Mechanical Engineering, National University of Singapore, Singapore. Electronic address: mpezk@nus.edu.sg.

Abstract

Molecular alteration in type I collagen, i.e., substituting the α2 chain with α1 chain in tropocollagen molecule, can cause osteogenesis imperfecta (OI), a brittle bone disease, which can be represented by a mouse model (oim/oim). In this work, we use dual-frequency Atomic Force Microscopy (AFM) and incorporated with molecular modeling to quantify the ultrastructure and stiffness of the individual native collagen fibers from wildtype (+/+) and oim/oim diseased mice humeri. Our work presents direct experimental evidences that the +/+ fibers have highly organized and compact ultrastructure and corresponding ordered stiffness distribution. In contrast, oim/oim fibers have ordered but loosely packed ultrastructure with uncorrelated stiffness distribution, as well as local defects. The molecular model also demonstrates the structural and molecular packing differences between +/+ and oim/oim collagens. The molecular mutation significantly altered sub-fibril structure and mechanical property of collagen fibers. This study can give the new insight for the mechanisms and treatment of the brittle bone disease.

KEYWORDS:

Bone; Collagen; Dual-frequency AFM; Oim; Stiffness

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center