Force spectroscopy of collagen fibers to investigate their mechanical properties and structural organization.
Tendons are composed of collagen and other molecules in a highly organized hierarchical assembly, leading to extraordinary mechanical properties. To probe the cross-links on the lower level of organization, we used a cantilever to pull substructures out of the assembly. Advanced force probe technology, using small cantilevers (length <20 microm), improved the force resolution into the sub-10 pN range. In the force versus extension curves, we found an exponential increase in force and two different periodic rupture events, one with strong bonds (jumps in force of several hundred pN) with a periodicity of 78 nm and one with weak bonds (jumps in force of <7 pN) with a periodicity of 22 nm. We demonstrate a good correlation between the measured mechanical behavior of collagen fibers and their appearance in the micrographs taken with the atomic force microscope.
Gutsmann
Thomas
T
Department of Physics, University of California, Santa Barbara, California 93101, USA. tguts@fz-borstel.de
Fantner
Georg E
GE
Kindt
Johannes H
JH
Venturoni
Manuela
M
Danielsen
Signe
S
Hansma
Paul K
PK
D000818:Animals; D001696:Biomechanical Phenomena; D001703:Biophysics / Q000379:methods*; D003094:Collagen / Q000737:chemistry* / Q000648:ultrastructure; D004548:Elasticity; D018625:Microscopy, Atomic Force / Q000295:instrumentation / Q000379:methods*; D051381:Rats; D013057:Spectrum Analysis / Q000379:methods; D013623:Tail / Q000378:metabolism; D013710:Tendons / Q000648:ultrastructure
D003094:Collagen