title: Autologous tenocyte therapy for experimental Achilles tendinopathy in a rabbit model.
abstract: BACKGROUND
  Tendinopathy of the Achilles tendon is a chronic degenerative condition that frequently does not respond to treatment. In the current study, we propose that autologous tenocytes therapy (ATT) is effective in treating tendon degeneration in a collagenase-induced rabbit Achilles tendinopathy model.
  
  
  METHODS
  Chronic tendinopathy was created in the left Achilles tendon of 44 rabbits by an intratendonous injection of type I collagenase. Forty-two rabbits were randomly allocated into three groups of 14 and received control treatment; autologous tenocytes digested from tendon tissue; and autologous tenocytes digested from epitendineum tissue. For cell tracking in vivo, the remaining two animals were injected with autologous tenocytes labeled with a nano-scale super-paramagnetic iron oxide (Feridex). Rabbits were sacrificed at 4 and 8 weeks after the therapeutic injection, and tendon tissue was analyzed by histology, immunostaining, and biomechanical testing to evaluate tissue repair.
  
  
  RESULTS
  Autologous tenocyte treatment improved tendon remodeling, histological outcomes, collagen content, and tensile strength of tendinopathic Achilles tendons. Injected tenocytes were integrated into tendon matrix and could be tracked up to 8 weeks in vivo. Immunohistochemistry showed that ATT improved type I collagen expression in repaired tendon but did not affect type III collagen and secreted protein, acidic and rich in cysteine expression.
  
  
  CONCLUSIONS
  ATT may be a useful treatment of chronic Achilles tendinopathy.
authors.affiliation: Centre for Orthopaedic Research, School of Surgery, University of Western Australia, Nedlands, Western Australia, Australia.
authors.forename: Jimin
authors.initials: J
authors.lastname: Chen
authors.forename: Qian
authors.initials: Q
authors.lastname: Yu
authors.forename: Bing
authors.initials: B
authors.lastname: Wu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Lin
authors.forename: Nathan J
authors.initials: NJ
authors.lastname: Pavlos
authors.forename: Jiake
authors.initials: J
authors.lastname: Xu
authors.forename: Hongwei
authors.initials: H
authors.lastname: Ouyang
authors.forename: Allan
authors.initials: A
authors.lastname: Wang
authors.forename: Ming H
authors.initials: MH
authors.lastname: Zheng
mesh_terms: D000125:Achilles Tendon / Q000473:pathology* / Q000637:transplantation*; D000818:Animals; D001696:Biomechanical Phenomena; D002470:Cell Survival; D024042:Collagen Type I / Q000378:metabolism; D003911:Dextrans / Q000378:metabolism; D004195:Disease Models, Animal; D005109:Extracellular Matrix / Q000378:metabolism; D058185:Magnetite Nanoparticles; D015676:Osteonectin / Q000378:metabolism; D010865:Pilot Projects; D011817:Rabbits; D052256:Tendinopathy / Q000473:pathology / Q000628:therapy*; D014182:Transplantation, Autologous; D014945:Wound Healing
chemical_list: D024042:Collagen Type I; D003911:Dextrans; D058185:Magnetite Nanoparticles; D015676:Osteonectin; C065507:ferumoxides