title: A preliminary study of osteochondral regeneration using a scaffold-free three-dimensional construct of porcine adipose tissue-derived mesenchymal stem cells.
abstract: BACKGROUND
  Osteoarthritis (OA) is a major joint disease in humans and many other animals. Consequently, medical countermeasures for OA have been investigated diligently. This study was designed to examine the regeneration of articular cartilage and subchondral bone using three-dimensional (3D) constructs of adipose tissue-derived mesenchymal stem cells (AT-MSCs).
  
  
  METHODS
  AT-MSCs were isolated and expanded until required for genetical and immunological analysis and construct creation. A construct consisting of about 760 spheroids that each contained 5.0 × 10(4) autologous AT-MSCs was implanted into an osteochondral defect (diameter: 4 mm; depth: 6 mm) created in the femoral trochlear groove of two adult microminipigs. After implantation, the defects were monitored by computed tomography every month for 6 months in animal no. 1 and 12 months in animal no. 2.
  
  
  RESULTS
  AT-MSCs were confirmed to express the premature genes and to be positive for CD90 and CD105 and negative for CD34 and CD45. Under specific nutrient conditions, the AT-MSCs differentiated into osteogenic, chondrogenic, and adipogenic lineages, as evidenced by the expressions of related marker genes and the production of appropriate matrix molecules. A radiopaque area emerged from the boundary between the bone and the implant and increased more steadily upward and inward for the implants in both animal no. 1 and animal no. 2. The histopathology of the implants after 6 months revealed active endochondral ossification underneath the plump fibrocartilage in animal no. 1. The histopathology after 12 months in animal no. 2 showed not only that the diminishing fibrocartilage was as thick as the surrounding normal cartilage but also that massive subchondral bone was present.
  
  
  CONCLUSIONS
  The present results suggest that implantation of a scaffold-free 3D construct of AT-MSCs into an osteochondral defect may induce regeneration of the original structure of the cartilage and subchondral bone over the course of 1 year, although more experimental cases are needed.
authors.affiliation: Veterinary Surgery, Department of Veterinary Clinical Science, Joint Faculty of Veterinary Medicine, Kagoshima University, 21-24 Korimoto 1-chome, Kagoshima, 890-0065, Japan. daiki_net_offficial@yahoo.co.jp.
authors.forename: Daiki
authors.initials: D
authors.lastname: Murata
authors.affiliation: Veterinary Teaching Hospital, Joint Faculty of Veterinary Medicine, Kagoshima University, 21-24 Korimoto 1-chome, Kagoshima, 890-0065, Japan. s_toku@vet.kagoshima-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tokunaga
authors.affiliation: Cyfuse Biomedical K.K., 1-1 Maidashi 3-chome, Higashi-ku, Fukuoka, 812-8582, Japan. tadashi.tamura@cyfusebm.com.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Tamura
authors.affiliation: Veterinary Pathology, Department of Pathological and Preventive Sciences, Joint Faculty of Veterinary Medicine, Kagoshima University, 21-24 Korimoto 1-chome, Kagoshima, 890-0065, Japan. kawagu@vet.kagoshima-u.ac.jp.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kawaguchi
authors.affiliation: Veterinary Pathology, Department of Pathological and Preventive Sciences, Joint Faculty of Veterinary Medicine, Kagoshima University, 21-24 Korimoto 1-chome, Kagoshima, 890-0065, Japan. miyoshi@vet.kagoshima-u.ac.jp.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Miyoshi
authors.affiliation: Veterinary Surgery, Department of Veterinary Clinical Science, Joint Faculty of Veterinary Medicine, Kagoshima University, 21-24 Korimoto 1-chome, Kagoshima, 890-0065, Japan. makotofjk@vet.kagoshima-u.ac.jp.
authors.forename: Makoto
authors.initials: M
authors.lastname: Fujiki
authors.affiliation: Department of Advanced Technology Fusion, Graduate School of Science and Engineering, Saga University, Honjyo 1-chome, Honjyo-cho, Saga, 840-8502, Japan. nakayama@me.saga-u.ac.jp.
authors.forename: Koichi
authors.initials: K
authors.lastname: Nakayama
authors.affiliation: Veterinary Surgery, Department of Veterinary Clinical Science, Joint Faculty of Veterinary Medicine, Kagoshima University, 21-24 Korimoto 1-chome, Kagoshima, 890-0065, Japan. kaz_msm@vet.kagoshima-u.ac.jp.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Misumi
mesh_terms: D000273:Adipose Tissue / Q000166:cytology; D000818:Animals; D001861:Bone Regeneration; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation; D010003:Osteoarthritis / Q000628:therapy*; D010865:Pilot Projects; D011859:Radiography; D013552:Swine; D013556:Swine, Miniature