Human acellular amniotic membrane prevents tendon adhesion after allogenic tendon transplantation to repair Achilles' tendon defects in rabbits

Abstract

Objective To investigate the effect of human acellular amniotic membrane on tendon adhesion after allogenic tendon transplantation to repair Achilles' tendon defects in rabbits.Methods Thirty New Zealand white rabbits were randomly divided into 2 groups (n =15).In the experimental group the transplanted Achilles' tendon was covered with human acellular amniotic membrane while in the control group the transplanted Achilles' tendon was covered with nothing.The transplanted tissue samples were harvested at 2 and 4 weeks for histological observation.Peripheral blood samples were harvested for flow cytometry respectively at 2,4,and 6 weeks.The transplanted Achilles' tendons were harvested for gross observation,biomechanical tests and the hydroxyproline (Hyp) content determination at 2,4,and 6 weeks after operation.Results The histological observation showed the inflammatory reaction in the experimental group was slighter than in the control group at 2 and 4 weeks and the arrangement of collagen fibers in the former was denser and more orderly than in the latter.The flow cytometry showed that at 2,4,and 6 weeks the peripheral blood in the experimental group contained significantly fewer CD4 + and CD8 + T lymphocytes than in the control group,and the ratio of CD4+/CD8+T lymphocyte in the experimental group was significantly lower than in the control group (both P ＜ 0.05).At 2,4,and 6 weeks,the maximum tensile strength in the experimental group was significantly larger than in the control group,and the tensile adhesion power consumption in the experimental group was significantly smaller than in the control group (both P ＜ 0.05).The Hyp content in the experimental group was significantly higher than in the control group (P ＜ 0.05).Conclusions Human acellular amniotic membrane can prevent tendon adhesion,promote tendon healing and intensify strength effectively,and may suppress immunological rejection to a certain extent in the allogenic tendon transplantation. Key words: Amnion; Achilles; Transplantation, homologous; Achilles' tendon adhesion; Rabbits