P3.175 Friday, Jan. 6 Building Biomimetic Collagen Fibers: Viscoelastic Properties under Physiological Hydration, Temperature, and Loading SUSS, AB; PORTER, ME; BOXBERGER, J; KOOB, TJ; LONG, JH*; Vassar College; Vassar College; Doctors Research Group, Inc.; MiMedx Group, Inc.; Vassar College email@example.com
Collagen fibers undergird most load-bearing elements: tendons, ligaments, skin and bone. Using purified Type I bovine molecular collagen, we constructed collagen fibers cross-linked with carbodiimide (CD) or complexed with nordihydroguaretic acid (NDGA). Because quasi-static tension tests indicated that CD-collagen fibers were less stiff and strong than NDGA fibers, we hypothesized that their viscoelastic properties would also differ. Viscoelastic properties are extremely important to characterize, since connective tissues function under dynamic, time- and strain-dependent situations in life. Both types of fibers were mounted in either thermoplastic glue or Kryptonite ™, a calcium-based bone cement. Fibers were then placed in a heated bath of physiological saline, stress-relaxed, sinusoidally-strained at a range of strains and strain rates, and then pulled to failure. We found differences between fiber types in their breakage rates, stiffness, strength, and rate of stress relaxation. These biomimetic collagen fibers have the potential to be used in biomedical applications, biomimetic systems, and biorobotics. This work was funded, in part, by the National Science Foundation (IOS-0922605).