title: A novel nano-structured porous polycaprolactone scaffold improves hyaline cartilage repair in a rabbit model compared to a collagen type I/III scaffold: in vitro and in vivo studies.
abstract: OBJECTIVE
  To develop a nano-structured porous polycaprolactone (NSP-PCL) scaffold and compare the articular cartilage repair potential with that of a commercially available collagen type I/III (Chondro-Gide) scaffold.
  
  
  METHODS
  By combining rapid prototyping and thermally induced phase separation, the NSP-PCL scaffold was produced for matrix-assisted autologous chondrocyte implantation. Lyophilizing a water-dioxane-PCL solution created micro and nano-pores. In vitro: The scaffolds were seeded with rabbit chondrocytes and cultured in hypoxia for 6 days. qRT-PCR was performed using primers for sox9, aggrecan, collagen type 1 and 2. In vivo: 15 New Zealand White Rabbits received bilateral osteochondral defects in the femoral intercondylar grooves. Autologous chondrocytes were harvested 4 weeks prior to surgery. There were 3 treatment groups: (1) NSP-PCL scaffold without cells. (2) The Chondro-Gide scaffold with autologous chondrocytes and (3) NSP-PCL scaffold with autologous chondrocytes. Observation period was 13 weeks. Histological evaluation was made using the O'Driscoll score.
  
  
  RESULTS
  In vitro: The expressions of sox9 and aggrecan were higher in the NSP-PCL scaffold, while expression of collagen 1 was lower compared to the Chondro-Gide scaffold. In vivo: Both NSP-PCL scaffolds with and without cells scored significantly higher than the Chondro-Gide scaffold when looking at the structural integrity and the surface regularity of the repair tissue. No differences were found between the NSP-PCL scaffold with and without cells.
  
  
  CONCLUSIONS
  The NSP-PCL scaffold demonstrated higher in vitro expression of chondrogenic markers and had higher in vivo histological scores compared to the Chondro-Gide scaffold. The improved chondrocytic differentiation can potentially produce more hyaline cartilage during clinical cartilage repair. It appears to be a suitable cell-free implant for hyaline cartilage repair and could provide a less costly and more effective treatment option than the Chondro-Gide scaffold with cells.
authors.affiliation: Orthopaedic Research Laboratory, Aarhus University Hospital, Nørrebrogade 44, Build. 1A, 1. Floor, 8000 Aarhus C, Denmark. bjornbc@gmail.com
authors.forename: Bjørn Borsøe
authors.initials: BB
authors.lastname: Christensen
authors.forename: Casper Bindzus
authors.initials: CB
authors.lastname: Foldager
authors.forename: Ole Møller
authors.initials: OM
authors.lastname: Hansen
authors.forename: Asger Albæk
authors.initials: AA
authors.lastname: Kristiansen
authors.forename: Dang Quang Svend
authors.initials: DQ
authors.lastname: Le
authors.forename: Agnete Desirée
authors.initials: AD
authors.lastname: Nielsen
authors.forename: Jens Vinge
authors.initials: JV
authors.lastname: Nygaard
authors.forename: Cody Erik
authors.initials: CE
authors.lastname: Bünger
authors.forename: Martin
authors.initials: M
authors.lastname: Lind
mesh_terms: D053674:Aggrecans / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002358:Cartilage, Articular / Q000166:cytology / Q000293:injuries / Q000502:physiology*; D019902:Chondrocytes / Q000637:transplantation; D024042:Collagen Type I / Q000378:metabolism; D024061:Collagen Type III / Q000378:metabolism; D048091:Guided Tissue Regeneration / Q000295:instrumentation*; D008297:Male; D023421:Models, Animal; D049329:Nanostructures; D011091:Polyesters; D011817:Rabbits; D060888:Real-Time Polymerase Chain Reaction; D055758:SOX9 Transcription Factor / Q000378:metabolism; D054457:Tissue Scaffolds; D014945:Wound Healing
chemical_list: D053674:Aggrecans; D015415:Biomarkers; D024042:Collagen Type I; D024061:Collagen Type III; D011091:Polyesters; D055758:SOX9 Transcription Factor; C016240:polycaprolactone