Indentation micromechanics of three-dimensional fibrin/collagen biomaterial scaffolds

摘要

The underlying relationships between the microstructure and time-dependent mechanical properties of hydrated fibrin, collagen, and fibrin/collagen composite materials have been explored using an adaptation of the classical rigid, cylindrical, flat punch loaded normally to a planar specimen surface. A suite of quasi-static elastic and viscoelastic indentation experiments have been conducted with uniformly mixed fibrin, collagen, and fibrin/collagen composites, in addition to macrolayered collagen materials. Coupled with insights obtained from optical and confocal fluorescence microscopy, a simple micromechanics model has been developed for the effect of local microstructural variables on the macroscopic mechanical stiffness. These results demonstrate the efficacy of this technique to efficiently and reproducibly probe hydrated engineered tissue replacement materials for local variations in viscoelastic material behavior without the need for extensive specimen preparation or grips, as well as being suitable for performing directly comparable measurements with explants of human skin.