Investigation on the Poisson's ratio of fibroblast-compacted collagen gels

抄録

Fibroblast-compacted collagen gels are extensively used as model tissues in regenerative medicine. In this study, compacted gels with different final collagen densities were achieved by suspending 0.1 million fibroblasts in collagen solutions with different initial concentrations and following a 5-days culture after the gelation. The Poisson's ratio of these gels was measured in uniaxial tensile tests. It showed that the apparent Poisson's ratio of the gels with high collagen density (45.5 and 32.3 mg/ml) was consistently smaller than 0.5 which means that the gel volume expanded during the stretch; whereas, the apparent Poisson's ratio of the gels with low collagen density (15.3 mg/ml) showed a biphasic feature and was eventually greater than 0.5 at large deformation resulting in volumic shrinkage at large deformation. A statistical structural model for the collagen fibrils in the gels was constituted to reproduce the experimental data with good agreement.