Structural Characterization of a Biogenic Secretion Extracted from the Tendon or Ligament in Rabbits for Artificial Ligament Formation

Abstract

Thus far, our research group has conducted a basic investigation for the development of an artificial ligament, which was performed by utilizing a biogenic secretion that was derived from the Achilles tendon in mice; this was achieved using the film model method. In this study, an attempt has been made to derive a biogenic secretion from the Achilles tendon (tendon gel) and the medial collateral ligament (ligament gel) in rabbits. Subsequently, a discussion was carried out on the possibility of forming a ligament-like structure that was based on the structural, mechanical, and spectroscopic investigations. The tendon gel was successfully formed from a parent tendon that was preserved in vivo for 3, 5, 10, and 15 d. Further, an aligned collagen fiber emerged in the tendon gel, which was subjected to tension on every preservation date. Further, the mechanical behavior of the tendon gel specimens was classified in two groups. The values of the Young's modulus of the specimens preserved for 10 and 15 d were higher than those of the specimens preserved for 3 and 5 d. Within the range of this experimental condition, the aligned collagen fiber structure was formed by applying a tension of approximately greater than 0.05 N. Conversely, only a 10-d preservation period yielded a sufficient amount of ligament gel for the experiment. Notably, the volume of ligament gel was less than that of the tendon gel. In the ligament gel specimen without the synovial membrane, the collagen fiber structure was formed by applying a tension, which was similar to that experienced by the tendon gel specimen. However, the cross-linking and growth of collagen fibers in the ligament gel samples were insignificant as compared with those of the tendon gel samples.