title: Serum- and xeno-free cryopreservation of human umbilical cord tissue as mesenchymal stromal cell source.
abstract: OBJECTIVE
  Human umbilical cord (UC) has become a notable source for mesenchymal stromal cells (MSCs) that can migrate to areas of inflammation and damaged tissue and can suppress excess immune reactions and to repair, respectively. Although UC is a solid tissue, there are several advantages, including repeatable uses from the same donor sample when needed and the possibility of future explorations for cells with unknown potential, if we could cryopreserve the UC as a living tissue material. However, because the cryoprotectants in the previous reports included animal- or allogeneic human-derived serum or no serum, the frozen-thawed UC-MSCs were inferior to fresh UC-MSCs in cell proliferation. The objective of this study was to find a suitable cryopreservation method of UC for clinical use.
  
  
  METHODS
  The UC was cut in cross-section and incised longitudinally, immersed in the cryoprotectant and frozen slowly. Later, it was thawed and minced rapidly, and the fragments of UC were cultured by improved explant method.
  
  
  RESULTS
  The highest yield of cells was obtained from frozen-thawed UC with serum- and xeno-free cryoprotectant, STEM-CELLBANKER, when compared with others. The cells derived from frozen-thawed UC stored in STEM-CELLBANKER expressed the phenotypes of MSCs, retained the immunosuppressive properties in allogeneic mixed lymphocyte reactions and the differentiation potentials (into adipocyte and chondrocytes) comparable to those derived from fresh UC.
  
  
  CONCLUSIONS
  UC can be cryopreserved in serum- and xeno-free cryoprotectant as a living tissue while keeping its growth and functions equivalent to fresh UC. Our method is simple and feasible for clinical use.
authors.affiliation: Department of Cell Processing and Transfusion, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Shimazu
authors.affiliation: Department of Cell Processing and Transfusion, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Mori
authors.affiliation: Department of Cell Processing and Transfusion, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Atsuko
authors.initials: A
authors.lastname: Takahashi
authors.affiliation: Department of Obstetrics, NTT Medical Center Tokyo Hospital, Tokyo, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Tsunoda
authors.affiliation: Department of Cell Processing and Transfusion, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan; Division of Molecular Therapy, Center for Advanced Medical Research, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
authors.forename: Arinobu
authors.initials: A
authors.lastname: Tojo
authors.affiliation: Department of Cell Processing and Transfusion, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan. Electronic address: tokikoni@ims.u-tokyo.ac.jp.
authors.forename: Tokiko
authors.initials: T
authors.lastname: Nagamura-Inoue
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000187:drug effects; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects; D002469:Cell Separation; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology; D016895:Culture Media, Serum-Free; D005615:Freezing; D006801:Humans; D007165:Immunosuppression Therapy; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects; D014470:Umbilical Cord / Q000166:cytology*
chemical_list: D015415:Biomarkers; D003451:Cryoprotective Agents; D016895:Culture Media, Serum-Free
keywords: cryopreservation; immunosuppression; mesenchymal stromal cell; umbilical cord