title: Slow-freezing versus vitrification for human ovarian tissue cryopreservation.
abstract: OBJECTIVE
  Ovarian tissue can be cryopreserved prior to chemotherapy using either the slow-freezing or the vitrification method; however, the data on the equality of the procedures are still conflicting. In this study, a comparison of the cryo-damage of human ovarian tissue induced by either vitrification or slow-freezing was performed.
  
  
  METHODS
  Ovarian tissue from 23 pre-menopausal patients was cryopreserved with either slow-freezing or vitrification. After thawing/warming, the tissue was histologically and immunohistochemically analyzed and cultured in vitro. During tissue culture the estradiol release was assessed.
  
  
  RESULTS
  No significant difference was found in the proportion of high-quality follicles after thawing/warming in the slow-freezing and vitrification group, respectively (72.7 versus 66.7 %, p = 0.733). Estradiol secretion by the ovarian tissue was similar between groups during 18 days in vitro culture (area-under-the-curve 5,411 versus 13,102, p = 0.11). Addition of Sphingosine-1-Phosphate or Activin A to the culture medium did not alter estradiol release in both groups. The proportion of Activated Caspase-3 or 'Proliferating-Cell-Nuclear-Antigen' positive follicles at the end of the culture period was similar between slow-freezing and vitrification.
  
  
  CONCLUSIONS
  Slow-freezing and vitrification result in similar morphological integrity after cryopreservation, a similar estradiol release in culture, and similar rates of follicular proliferation and apoptosis after culture.
authors.affiliation: Department of Gynecological Endocrinology and Reproductive Medicine, University Clinic of Schleswig-Holstein, Ratzeburger Allee 160, 23538, Lübeck, Germany, silke.klocke@web.de.
authors.forename: Silke
authors.initials: S
authors.lastname: Klocke
authors.forename: Nana
authors.initials: N
authors.lastname: Bündgen
authors.forename: Frank
authors.initials: F
authors.lastname: Köster
authors.forename: Ursula
authors.initials: U
authors.lastname: Eichenlaub-Ritter
authors.forename: Georg
authors.initials: G
authors.lastname: Griesinger
mesh_terms: D000328:Adult; D017209:Apoptosis / Q000502:physiology; D053148:Caspase 3 / Q000378:metabolism; D015925:Cryopreservation / Q000379:methods*; D004958:Estradiol / Q000378:metabolism; D005260:Female; D005615:Freezing; D006801:Humans; D008246:Lysophospholipids / Q000378:metabolism; D006080:Ovarian Follicle / Q000378:metabolism*; D013110:Sphingosine / Q000031:analogs & derivatives / Q000378:metabolism; D058989:Vitrification; D055815:Young Adult
chemical_list: D008246:Lysophospholipids; C060506:sphingosine 1-phosphate; D004958:Estradiol; D053148:Caspase 3; D013110:Sphingosine