title: Assessment of the Safety of Chondrocyte Sheet Implantation for Cartilage Regeneration.
abstract: We have previously studied the effects of chondrocyte sheets on the repair and regeneration of articular cartilage by using temperature-responsive culture inserts. On the basis of this work, we succeeded in rapid fabrication of chondrocyte sheets with the use of a coculture method in which inserts were placed between synoviocytes and chondrocytes. Treatment of cartilage defects using layered chondrocyte sheets promotes repair and regeneration; this method is compatible with in vivo osteoarthritis models that reproduce partial-thickness defects. In human stem cell clinical research guidelines, the Ministry of Health, Labour and Welfare (MHLW) approved several applications related to this technology. Indeed, its translation to a clinical setting is already yielding favorable results. In this study, we evaluated the risk of tumorigenesis associated with this treatment and characterized the dynamics of biological processes associated with the posttransplantation cell sheets in vivo. Furthermore, we also confirmed the safety of the procedure by using array comparative genomic hybridization (array CGH) and G-band staining to screen for deleterious genetic aberrations during prolonged subculture of cells. The safety of chondrocytes that were cultured for longer than normal was confirmed by the array CGH and G-band staining results. In addition, tumorigenicity testing confirmed that culture chondrocyte sheets are not tumorigenic. Furthermore, from the evaluation of bioluminescence imaging following implantation of the cell sheets, it was confirmed that the transplanted chondrocytes and synoviocytes remained in the knee joint and did not transfer elsewhere over time. We believe that the technique used in this study is a highly useful method for evaluating the safety of not only chondrocytes but also extensive subculturing in general.
authors.affiliation: 1 Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine , Kanagawa, Japan .
authors.forename: Miyuki
authors.initials: M
authors.lastname: Yokoyama
authors.affiliation: 1 Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine , Kanagawa, Japan .
authors.forename: Masato
authors.initials: M
authors.lastname: Sato
authors.affiliation: 2 Division of Regenerative Technology, Department of Reproductive Biology and Pathology, National Research Institute for Child Health and Development , Tokyo, Japan .
authors.forename: Akihiro
authors.initials: A
authors.lastname: Umezawa
authors.affiliation: 1 Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine , Kanagawa, Japan .
authors.forename: Genya
authors.initials: G
authors.lastname: Mitani
authors.affiliation: 1 Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine , Kanagawa, Japan .
authors.forename: Tomonori
authors.initials: T
authors.lastname: Takagaki
authors.affiliation: 1 Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine , Kanagawa, Japan .
authors.forename: Munetaka
authors.initials: M
authors.lastname: Yokoyama
authors.affiliation: 3 CellSheed, Inc. , Tokyo, Japan .
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kawake
authors.affiliation: 1 Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine , Kanagawa, Japan .
authors.forename: Eri
authors.initials: E
authors.lastname: Okada
authors.affiliation: 4 Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University , Tokyo, Japan .
authors.forename: Mami
authors.initials: M
authors.lastname: Kokubo
authors.affiliation: 5 DNA Chip Research, Inc. , Kanagawa, Japan .
authors.forename: Noriko
authors.initials: N
authors.lastname: Ito
authors.affiliation: 6 Department of Anesthesiology and Critical Care Medicine, Jichi Medical University School of Medicine , Tochigi-ken, Japan .
authors.forename: Yuko
authors.initials: Y
authors.lastname: Takaku
authors.affiliation: 6 Department of Anesthesiology and Critical Care Medicine, Jichi Medical University School of Medicine , Tochigi-ken, Japan .
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Murai
authors.affiliation: 5 DNA Chip Research, Inc. , Kanagawa, Japan .
authors.forename: Ryo
authors.initials: R
authors.lastname: Matoba
authors.affiliation: 2 Division of Regenerative Technology, Department of Reproductive Biology and Pathology, National Research Institute for Child Health and Development , Tokyo, Japan .
authors.forename: Hidenori
authors.initials: H
authors.lastname: Akutsu
authors.affiliation: 3 CellSheed, Inc. , Tokyo, Japan .
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamato
authors.affiliation: 3 CellSheed, Inc. , Tokyo, Japan .
authors.forename: Teruo
authors.initials: T
authors.lastname: Okano
authors.affiliation: 1 Department of Orthopaedic Surgery, Surgical Science, Tokai University School of Medicine , Kanagawa, Japan .
authors.forename: Joji
authors.initials: J
authors.lastname: Mochida
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000254:growth & development* / Q000473:pathology* / Q000503:physiopathology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000473:pathology* / Q000502:physiology / Q000637:transplantation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D048091:Guided Tissue Regeneration / Q000009:adverse effects* / Q000295:instrumentation*; D008297:Male; D016513:Mice, SCID; D051381:Rats; D011917:Rats, Inbred Lew; D012038:Regeneration / Q000502:physiology; D054457:Tissue Scaffolds / Q000009:adverse effects; D016896:Treatment Outcome