title: Modified vitrification method for cryopreservation of human ovarian tissues.
abstract: BACKGROUND
  Vitrification is a prospective technology in ovarian tissue cryopreservation, but it is still in an initial stage. This study was conducted to investigate a modified vitrification protocol for human ovarian tissue, which can be used as an alternative to preserve fertility for young women with cancer who have to undergo cytotoxic therapy and sterilization.
  
  
  METHODS
  Ovarian tissue samples were collected from 15 patients and randomly allocated to groups of fresh, vitrification, and conventional slow freezing. A modified carrierless vitrification method was applied. The proportion of morphologically intact follicles in fresh ovarian tissues was compared with that in warmed/thawed tissues. The initial growth of the follicles and the concentrations of estradiol and progesterone were detected to determine the viability and endocrine function of the cryopreserved tissues.
  
  
  RESULTS
  The proportion of morphologically intact primordial follicles in the fresh group (97.6%) was significantly higher than that in the other two groups (vitrification group 80.3% and slow-freezing group 72.6%, P < 0.001). In both the vitrification and slow-freezing groups, estradiol and progesterone were secreted continuously during 2-week culture in vitro, the proportion of primary follicles were both significantly increased compared to the fresh group. No statistically significant differences existed between the two groups after cryopreservation in the proportion of both primordial and primary follicles, and the concentrations of estradiol and progesterone (P > 0.05).
  
  
  CONCLUSIONS
  The modified vitrification method for cryopreservation of human ovarian tissues is effective, simple, and inexpensive.
authors.affiliation: Center of Reproductive Medicine, First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China.
authors.forename: Yu-bin
authors.initials: YB
authors.lastname: Li
authors.forename: Can-quan
authors.initials: CQ
authors.lastname: Zhou
authors.forename: Guo-fen
authors.initials: GF
authors.lastname: Yang
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wang
authors.forename: Yu
authors.initials: Y
authors.lastname: Dong
mesh_terms: D000328:Adult; D015925:Cryopreservation / Q000379:methods*; D004958:Estradiol / Q000096:biosynthesis; D005260:Female; D006801:Humans; D010053:Ovary / Q000166:cytology* / Q000378:metabolism; D011374:Progesterone / Q000096:biosynthesis; D046509:Tissue Culture Techniques
chemical_list: D011374:Progesterone; D004958:Estradiol