title: Direct comparative analysis of conventional and directional freezing for the cryopreservation of whole ovaries.
abstract: OBJECTIVE
  To compare conventional slow equilibrium cooling and directional freezing for cryopreservation of whole ovaries.
  
  
  METHODS
  Experimental animal study.
  
  
  METHODS
  Academic research environment.
  
  
  METHODS
  Adult ewes.
  
  
  METHODS
  Eighty-one ovaries were randomly assigned to fresh control, conventional freezing (CF), and directional freezing (DF) group. Ovaries of CF and DF groups were perfused via the ovarian artery with Leibovitz L-15 medium, 10% fetal bovine serum, and 1.5 M dimethyl sulfoxide for 5 minutes. Each ovary was inserted into a glass test tube containing 10 mL of the same solution and cooled to -100°C or -70°C, respectively. Ovaries were stored in liquid nitrogen for a minimum of 2 weeks.
  
  
  METHODS
  Structural integrity of cortical and medulla regions, vascular integrity, follicle in vitro development, cell proliferation, and DNA damage and repair.
  
  
  RESULTS
  All examined parameters indicate that the structure of DF ovaries remains largely intact and comparable to fresh controls, whereas significant damages were observed in CF ovaries.
  
  
  CONCLUSIONS
  Directional freezing allows good preservation of whole ovaries, with most of the parameters taken into consideration almost identical to those recorded in fresh control samples. This encourages a reconsideration of the possible use of whole-ovary cryopreservation as a viable alternative to cortical fragments.
authors.affiliation: Laboratory of Biomedical Embryology, Università degli Studi di Milano, Milan, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Maffei
authors.forename: Maike
authors.initials: M
authors.lastname: Hanenberg
authors.forename: Georgia
authors.initials: G
authors.lastname: Pennarossa
authors.forename: José Roberto V
authors.initials: JR
authors.lastname: Silva
authors.forename: Tiziana A L
authors.initials: TA
authors.lastname: Brevini
authors.forename: Amir
authors.initials: A
authors.lastname: Arav
authors.forename: Fulvio
authors.initials: F
authors.lastname: Gandolfi
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D002470:Cell Survival; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology; D004249:DNA Damage; D004260:DNA Repair; D005260:Female; D005615:Freezing; D005786:Gene Expression Regulation; D010053:Ovary / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D012756:Sheep; D013997:Time Factors; D046509:Tissue Culture Techniques; D014022:Tissue Survival
chemical_list: D003451:Cryoprotective Agents
keywords: Whole ovary; cryopreservation; directional freezing; sheep