title: Time evolution of in vivo articular cartilage repair induced by bone marrow stimulation and scaffold implantation in rabbits.
abstract: OBJECTIVE
  Tissue engineering techniques were used to study cartilage repair over a 12-month period in a rabbit model.
  
  
  METHODS
  A full-depth chondral defect along with subchondral bone injury were originated in the knee joint, where a biostable porous scaffold was implanted, synthesized of poly(ethyl acrylate-co-hydroxyethyl acrylate) copolymer. Morphological evolution of cartilage repair was studied 1 and 2 weeks, and 1, 3, and 12 months after implantation by histological techniques. The 3-month group was chosen to compare cartilage repair to an additional group where scaffolds were preseeded with allogeneic chondrocytes before implantation, and also to controls, who underwent the same surgery procedure, with no scaffold implantation.
  
  
  RESULTS
  Neotissue growth was first observed in the deepest scaffold pores 1 week after implantation, which spread thereafter; 3 months later scaffold pores were filled mostly with cartilaginous tissue in superficial and middle zones, and with bone tissue adjacent to subchondral bone. Simultaneously, native chondrocytes at the edges of the defect started to proliferate 1 week after implantation; within a month those edges had grown centripetally and seemed to embed the scaffold, and after 3 months, hyaline-like cartilage was observed on the condylar surface. Preseeded scaffolds slightly improved tissue growth, although the quality of repair tissue was similar to non-preseeded scaffolds. Controls showed that fibrous cartilage was mainly filling the repair area 3 months after surgery. In the 12-month group, articular cartilage resembled the untreated surface.
  
  
  CONCLUSIONS
  Scaffolds guided cartilaginous tissue growth in vivo, suggesting their importance in stress transmission to the cells for cartilage repair.
authors.affiliation: 3 CIBER-BBN in Bioengineering, Biomaterials and Nanomedicine, Valencia - Spain.
authors.forename: María
authors.initials: M
authors.lastname: Sancho-Tello
authors.forename: Francisco
authors.initials: F
authors.lastname: Forriol
authors.forename: Pablo
authors.initials: P
authors.lastname: Gastaldi
authors.forename: Amparo
authors.initials: A
authors.lastname: Ruiz-Saurí
authors.forename: José J
authors.initials: JJ
authors.lastname: Martín de Llano
authors.forename: Edurne
authors.initials: E
authors.lastname: Novella-Maestre
authors.forename: Carmen M
authors.initials: CM
authors.lastname: Antolinos-Turpín
authors.forename: José A
authors.initials: JA
authors.lastname: Gómez-Tejedor
authors.forename: José L
authors.initials: JL
authors.lastname: Gómez Ribelles
authors.forename: Carmen
authors.initials: C
authors.lastname: Carda
mesh_terms: D000179:Acrylates / Q000627:therapeutic use*; D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use; D002358:Cartilage, Articular / Q000293:injuries / Q000502:physiology / Q000601:surgery; D019902:Chondrocytes / Q000502:physiology; D004195:Disease Models, Animal; D048091:Guided Tissue Regeneration / Q000379:methods; D008264:Macrophages / Q000378:metabolism; D008422:Materials Testing / Q000379:methods; D011817:Rabbits; D012038:Regeneration / Q000187:drug effects / Q000502:physiology; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds
chemical_list: D000179:Acrylates; D001672:Biocompatible Materials; C523542:poly(ethyl acrylate-co-hydroxyethyl acrylate)