title: Pretreatment of periosteum with TGF-beta1 in situ enhances the quality of osteochondral tissue regenerated from transplanted periosteal grafts in adult rabbits.
abstract: OBJECTIVE
  To compare the efficacy of in situ transforming growth factor-beta1 (TGF-beta1)-pretreated periosteum to untreated periosteum for regeneration of osteochondral tissue in rabbits.
  
  
  METHODS
  In the pretreatment group, 12 month-old New Zealand white rabbits received subperiosteal injections of 200 ng of TGF-beta1 percutaneously in the medial side of the proximal tibia, 7 days prior to surgery. Control rabbits received no treatment prior surgery. Osteochondral transverse defects measuring 5mm proximal to distal and spanning the entire width of the patellar groove were created and repaired with untreated or TGF-beta1-pretreated periosteal grafts. Post-operatively the rabbits resumed normal cage activity for 6 weeks.
  
  
  RESULTS
  Complete filling of the defects with regenerated tissue was observed in both the TGF-beta1-pretreated and control groups with reformation of the original contours of the patellar groove. The total histological score (modified O'Driscoll) in the TGF-beta1-pretreated group, 20 (95% Confidence Interval (CI), 19-21), was significantly higher (P=0.0001) than the control group, 18 (16-19). The most notable improvements were in structural integrity and subchondral bone regeneration. No significant differences in glycosaminoglycan or type II collagen content, or equilibrium modulus were found between the surgical groups. The cambium of the periosteum regenerated at the graft harvest site was significantly thicker (P=0.0065) in the TGF-beta1-pretreated rabbits, 121 microm (94-149), compared to controls, 74 microm (52-96), after 6 weeks.
  
  
  CONCLUSIONS
  This study demonstrates that in situ pretreatment of periosteum with TGF-beta1 improves osteochondral tissue regeneration at 6-weeks post-op compared to untreated periosteum in 12 month-old rabbits.
authors.affiliation: Department of Orthopedic Surgery, Cartilage and Connective Tissue Research Laboratory, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: A
authors.initials: A
authors.lastname: Olivos-Meza
authors.forename: J S
authors.initials: JS
authors.lastname: Fitzsimmons
authors.forename: M E
authors.initials: ME
authors.lastname: Casper
authors.forename: Q
authors.initials: Q
authors.lastname: Chen
authors.forename: K-N
authors.initials: KN
authors.lastname: An
authors.forename: T J
authors.initials: TJ
authors.lastname: Ruesink
authors.forename: S W
authors.initials: SW
authors.lastname: O'Driscoll
authors.forename: G G
authors.initials: GG
authors.lastname: Reinholz
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000187:drug effects* / Q000293:injuries* / Q000503:physiopathology; D020219:Chondrogenesis / Q000187:drug effects* / Q000502:physiology; D004195:Disease Models, Animal; D010521:Periosteum / Q000187:drug effects* / Q000473:pathology*; D011817:Rabbits; D023822:Tissue Engineering / Q000379:methods*; D016378:Tissue Transplantation; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*; D014182:Transplantation, Autologous; D014945:Wound Healing / Q000187:drug effects / Q000502:physiology
chemical_list: D053773:Transforming Growth Factor beta1