ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

Table 2. Stresses on a portion of the fixed cell boundary. The x-component of
the stress tensor on the portion of the fixed 2 nd cell, as shown in Fig. 6.
Model Minimum x-component Maximum x-component
Homogeneous -0.91 Pa 0.16 Pa
25 entangled fibers -20.54 Pa 34.98 Pa
F1 untangled -20.70 Pa 33.78 Pa
F6 untangled -28.75 Pa 37.12 Pa
F10 untangled - 11.49 Pa 8.37 Pa
F6_F10 untangled -5.81 Pa 4.51 Pa
F1_F6_F10 untangled -5.28 Pa 6.89 Pa
5. DISCUSSION
These simple models have quantitatively demonstrated that fiber connections are
critically important for long distance stress propagation between cells embedded in a
fibrous matrix. Tangled fibers are needed for stress transmission, and for these simple
models, just one untangled fiber (Fiber 10) decreases the maximum x-component of the
stress tensor by a factor of 4. Careful attention to fiber interactions, including contact
and friction, will likely be needed to fully understand the mechanics of stress
transmission in collagen gels and other ECM.
6. REFERENCES
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7. ACKNOWLEDGMENTS
This work was supported by NSF CMMI-0928739; the authors thank Mark Stevenson
and Maureen Weber for the collagen cell experiments and images used to inspire the
simulations.