title: Improving ovarian tissue cryopreservation for oncologic patients: slow freezing versus vitrification, effect of different procedures and devices.
abstract: OBJECTIVE
  To compare slow freezing (SF) with four vitrification techniques (VT) for cryopreservation of ovarian tissue (OT) and to evaluate the best protocol for human OT in a xenograft model.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Patients undergoing fertility preservation.
  
  
  METHODS
  Ovariectomized nude mice.
  
  
  METHODS
  Cryopreservation of bovine OT after SF and four VTs (VT1, VT2, VT3, and VT4) by combining two cryoprotectant vitrification solutions (VS1 and VS2) and two devices (metallic grid and ethyl vinyl acetate bag), after which the cryopreservation of human OT by SF and VT1 and xenograft into nude mice.
  
  
  METHODS
  Follicular densities, proliferation, vascularization, fibrosis, apoptosis, tissue viability.
  
  
  RESULTS
  The in vitro study in bovine OT showed a lower percentage of quiescent follicles in the SF group but not in the vitrification groups (VT1-VT4). Apoptosis increased and cell proliferation decreased in all the experimental groups except VT1 (20% ethylene glycol, 20% dimethyl sulfoxide, 0.5 M sucrose, and 20% synthetic serum substitute in HEPES-buffered M199 culture media with Cryotissue metallic grids). Tissue viability was diminished in VT3, and the SF-xenografted human samples showed reduced primordial and secondary densities and unbalanced follicular populations when compared with fresh and VT1 tissue.
  
  
  CONCLUSIONS
  VT1 offers similar conditions to fresh tissue for follicular density, proliferation, viability, and cell death and preserves a larger population of quiescent follicles than SF after transplantation, thus ensuring the maintenance of graft potential fertility.
authors.affiliation: Grupo de Investigación de Medicina Reproductiva, Instituto de Investigación Sanitario La Fe, Valencia, Spain; Unidad de Preservación de la Fertilidad, Área de Salud de la Mujer, Hospital Universitario y Politécnico La Fe, Valencia, Spain.
authors.forename: Sonia
authors.initials: S
authors.lastname: Herraiz
authors.affiliation: Grupo de Investigación de Medicina Reproductiva, Instituto de Investigación Sanitario La Fe, Valencia, Spain; Unidad de Preservación de la Fertilidad, Área de Salud de la Mujer, Hospital Universitario y Politécnico La Fe, Valencia, Spain; Unidad de Genética, Hospital Universitario y Politécnico La Fe, Valencia, Spain. Electronic address: edurnenovella@yahoo.es.
authors.forename: Edurne
authors.initials: E
authors.lastname: Novella-Maestre
authors.affiliation: Grupo de Investigación de Medicina Reproductiva, Instituto de Investigación Sanitario La Fe, Valencia, Spain; Unidad de Preservación de la Fertilidad, Área de Salud de la Mujer, Hospital Universitario y Politécnico La Fe, Valencia, Spain; Departamento de Pediatría, Obstetricia y Ginecología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Rodríguez
authors.affiliation: Grupo de Investigación de Medicina Reproductiva, Instituto de Investigación Sanitario La Fe, Valencia, Spain; Unidad de Preservación de la Fertilidad, Área de Salud de la Mujer, Hospital Universitario y Politécnico La Fe, Valencia, Spain; Departamento de Pediatría, Obstetricia y Ginecología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain.
authors.forename: César
authors.initials: C
authors.lastname: Díaz
authors.affiliation: Departamento de Obstetricia y Ginecología, Hospital Clínico Universitario, Valencia, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Sánchez-Serrano
authors.affiliation: Banco de Tejidos, Centro de Transfusión de la Comunidad Valenciana, Valencia, Spain.
authors.forename: Vicente
authors.initials: V
authors.lastname: Mirabet
authors.affiliation: Grupo de Investigación de Medicina Reproductiva, Instituto de Investigación Sanitario La Fe, Valencia, Spain; Unidad de Preservación de la Fertilidad, Área de Salud de la Mujer, Hospital Universitario y Politécnico La Fe, Valencia, Spain; Departamento de Pediatría, Obstetricia y Ginecología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Pellicer
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D001943:Breast Neoplasms / Q000473:pathology*; D002417:Cattle; D049109:Cell Proliferation; D015925:Cryopreservation / Q000379:methods* / Q000592:standards; D005260:Female; D059247:Fertility Preservation / Q000379:methods* / Q000592:standards; D006689:Hodgkin Disease / Q000473:pathology*; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D010053:Ovary / Q000502:physiology; D011897:Random Allocation; D013997:Time Factors; D016896:Treatment Outcome; D058989:Vitrification; D023041:Xenograft Model Antitumor Assays / Q000379:methods; D055815:Young Adult
keywords: Fertility preservation; ovarian cortex; slow freezing; vitrification