title: Biomechanical response of collagen fascicles to restressing after stress deprivation during culture.
abstract: In vitro tissue culture experiments were performed to study the biomechanical response of collagen fascicles to restressing after exposure to non-loaded condition. Collagen fascicles of approximately 300 microm in diameter were aseptically dissected from rabbit patellar tendons. They were cultured under no-load condition for 1 week, and then under a static stress of approximately 1.2 MPa for the subsequent 1 or 2 weeks. After culture, their mechanical properties were determined with a micro-tensile tester, and were compared to those of fascicles cultured under no-load condition and non-cultured, control fascicles. Tangent modulus and tensile strength of the non-loaded fascicles were significantly lower than those of the control fascicles at 1 week and gradually decreased thereafter. However, the modulus and strength were increased by restressing. After 2-week restressing, both parameters were significantly greater than those of the time-matched, non-loaded fascicles, although these values were still significantly lower than those of the control fascicles. That is, the application of stress after exposure to non-loaded condition suppressed the deterioration of the biomechanical properties of fascicles, although it did not improve. These results indicate that a short period of stressing is not sufficient for cultured collagen fascicles to completely recover their mechanical properties, if they are once exposed to no-stress condition even for a short period of time. These are similar to previous results observed in tendons and ligaments inside the body.
authors.affiliation: Biomechanics Laboratory, Department of Mechanical Engineering and Biomimetics, School of Biology-Oriented Science and Technology, Kinki University, Kinokawa, Wakayama 649-6493, Japan. ei@waka.kindai.ac.jp
authors.forename: Ei
authors.initials: E
authors.lastname: Yamamoto
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kogawa
authors.forename: Susumu
authors.initials: S
authors.lastname: Tokura
authors.forename: Kozaburo
authors.initials: K
authors.lastname: Hayashi
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D003094:Collagen / Q000502:physiology*; D005260:Female; D011817:Rabbits; D013314:Stress, Mechanical
chemical_list: D003094:Collagen