SELF-ASSEMBLY OF COLLAGEN-FIBERS - INFLUENCE OF FIBRILLAR ALIGNMENT AND DECORIN ON MECHANICAL-PROPERTIES

Collagen is the primary structural element in extracellular matrices. In the form of fibers it acts to transmit forces, dissipate energy, an d prevent premature mechanical failure in normal tissues. Deformation of collagen fibers involves molecular stretching and slippage, fibrill ar slippage, and, ultimately, defibrillation. Our laboratory has devel oped a process for self-assembly of macroscopic collagen fibers that h ave structures and mechanical properties similar to rat tail tendon fi bers. The purpose of this study is to determine the effects of subfibr illar orientation and decorin incorporation on the mechanical properti es of collagen fibers. Self-assembled collagen fibers were stretched 0 -50% before cross-linking and then characterized by microscopy and mec hanical testing. Results of these studies indicate that fibrillar orie ntation, packing, and ultimate tensile strength can be increased by st retching. In addition, it is shown that decorin incorporation increase s ultimate tensile strength of uncross-linked fibers. Based on the obs erved results it is hypothesized that decorin facilitates fibrillar sl ippage during deformation and thereby improves the tensile properties of collagen fibers.