Structural origin of the mechanical properties of biological networks


Danilo C. Pozzo and Lionel Porcar



            Cells and tissues have mechanical properties that are of critical importance to biological processes but which cannot be easily reproduced in synthetic materials. In this work, small angle neutron scattering (SANS) experiments with simultaneous rheological measurements are used to characterize the structural origin of strain-hardening in biological networks. Fibrin gels (blood clots) are used as a model to correlate the strain-hardening mechanical response to nanometer scale changes in the structure of the network. Preliminary results show that, during strain-hardening, there is a reversible anisotropic deformation of the gel network. The implications of these new results are discussed in relation to two conflicting models that have recently described the structural origin of strain-hardening. The outcome of this work is expected to clarify important bio-physical questions while also providing important insight to guide the design of novel tissue engineering materials.