Effects of elastin-derived peptide on Achilles' tendon healing: an experimental study

Different matrix macromolecules modulate the tendon healing process. Elastin contains sequences which exhibit chemotactic activity both in vitro and in vivo. We analyzed the effects of synthetic elastin-derived peptide Val-Gly-Val-Ala-Pro-Gly suspended in a gel solution on the healing process of Achilles' tendon in a rat model. A total tenotomy at the middle 3rd was performed in 32 rats. During the suture repair the gel with (Group A) or without (Group B) the elastin-derived peptide was applied to the tendon stumps. Four animals for each period and group were killed at 10, 30, 60 and 90 days after surgery. The scar tissue was processed for histochemical, immuno-histochemical and morphometric analysis. An improved healing process with increase in cellularity and vascularity, especially at the early stage of the Achilles' tendon healing process was observed in Group A compared to Group B. The fiber alignment was also positively influenced by the factor. Immunolabeling with HAM 56 and lisozyme revealed a stronger reaction for the presence of monocyte/macrophage in Group A vs Group B especially in early stages. Chondral metaplasia and endochondral ossification occurred in the healed tissue of both group at 60 and 90 days.