Structural and Mechanical Differences Between Pure Collagen and Fibrin Gels and Partially Digested Co-Gels

Abstract

Natural and bio-engineered tissues are often composed of multiple fiber networks (fibrin, collagen, elastin, etc.). The microstructure and interactions between components determine the macroscopic mechanical properties of the tissues. Examples of multi-fiber networks include skin (collagen and elastin) and thrombus during the wound healing process (collagen and fibrin). In addition, tissue engineers (eg. [1]) use fibrin as a scaffold to seed cells for tissue growth; over time, networks of collagen and fibrin coexist as the fibrin is degraded and replaced with cell-synthesized collagen. Our group has previously investigated the mechanical properties of single fiber networks of fibrin and collagen, but has shown that these do not obey the law of mixtures in a collagen-fibrin co-gel [2]. The goal of this project was to understand the interactions between the collagen and fibrin networks in a collagen-fibrin co-gel.