title: Timing of administration of transforming growth factor-beta and epidermal growth factor influences the effect on material properties of the in situ frozen-thawed anterior cruciate ligament.
abstract: One of the future goals in ligament reconstruction is to prevent graft deterioration after transplantation. The aim of this study is to clarify whether an administration of TGF-beta1 and EGF significantly affect biomechanical properties of the in situ frozen-thawed anterior cruciate ligament (ACL), an ACL autograft model, and to elucidate whether the timing of this administration may influence its effect. Rabbits were randomly divided into 4 groups after the freeze-thaw treatment with liquid nitrogen was applied to the right knee. In 2 groups, 4-ng TGF-beta1 and 100-ng EGF mixed with 0.2-ml fibrin sealant were applied around the ACL at 3 and 6 weeks after the treatment, respectively. In the remaining two groups, only 0.2-ml fibrin sealant was applied around the ACL at 3 and 6 weeks, respectively. In each group, all animals were sacrificed at 12 weeks after the freeze-thaw treatment. These growth factors applied at 3 weeks significantly inhibited not only the increase of water content and the cross-sectional area of the ACL but also reduction of the tensile strength and the tangent modulus of the ACL (p<0.0001), which were induced by the freeze-thaw treatment. However, the application at 6 weeks did not significantly affect the changes of these parameters after the treatment. This study demonstrated that the timing of administration of TGF-beta and EGF after the freeze-thaw treatment significantly influences its effect on the biomechanical properties of the frozen-thawed ACL.
authors.affiliation: Department of Medical Bioengineering and Sports Medicine, Hokkaido University School of Medicine, Kita-15 Nishi-7, Kita-ku, 060-8638, Sapporo, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Azuma
authors.forename: Kazunori
authors.initials: K
authors.lastname: Yasuda
authors.forename: Harukazu
authors.initials: H
authors.lastname: Tohyama
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Sakai
authors.forename: Tokifumi
authors.initials: T
authors.lastname: Majima
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Aoki
authors.forename: Akio
authors.initials: A
authors.lastname: Minami
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology* / Q000637:transplantation; D015925:Cryopreservation / Q000379:methods*; D004334:Drug Administration Schedule; D004548:Elasticity; D004815:Epidermal Growth Factor / Q000008:administration & dosage*; D006085:Graft Survival / Q000187:drug effects; D011817:Rabbits; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D016212:Transforming Growth Factor beta / Q000008:administration & dosage*; D014867:Water / Q000032:analysis
chemical_list: D016212:Transforming Growth Factor beta; D014867:Water; D004815:Epidermal Growth Factor