title: Needle immersed vitrification can lower the concentration of cryoprotectant in human ovarian tissue cryopreservation.
abstract: OBJECTIVE
  To investigate whether needle immersed vitrification (NIV) can further lower the concentration of cryoprotective agent (CPA).
  
  
  METHODS
  Experimental cross-sectional controlled in vitro study.
  
  
  METHODS
  University teaching hospital.
  
  
  METHODS
  Human ovarian biopsy tissues were obtained from ten women undergoing gynecology operations.
  
  
  METHODS
  Ovarian cortical tissues were cryopreserved using slow freezing or vitrification. The vitrification solutions used were as follows: group A: 2.69 mol/L ethylene glycol (EG)+2.11 mol/L dimethylsulfoxide (DMSO)+0.5 mol/L sucrose; group B: 2.42 mol/L EG+1.90 mol/L DMSO+0.5 mol/L sucrose; group C: 2.15 mol/L EG+1.69 mol/L DMSO+0.5 mol/L sucrose; and group D: 1.88 mol/L EG+1.48 mol/L DMSO+0.5 mol/L sucrose.
  
  
  METHODS
  Histologic evaluations were performed using light and electron microscopy. Apoptosis was assessed by TUNEL staining. Tissue damage after cryopreservation was measured by the levels of lactate dehydrogenase (LDH) in culture.
  
  
  RESULTS
  The proportion of normal ultrastructure of granulosa cells and stromal cells in groups B and C was higher than that in group A. The proportion of TUNEL-positive primordial follicles and stromal cells in the NIV groups decreased with reduction of concentration. Additionally, LDH levels in groups B and C were lower than in group A.
  
  
  CONCLUSIONS
  The NIV method could further lower the concentration of CPA. Therefore, we can use the CPA of group C as an optimal concentration for NIV.
authors.affiliation: Reproductive Medical Center of West China Second University Hospital, Sichuan University, Chengdu, People's Republic of China.
authors.forename: Zhun
authors.initials: Z
authors.lastname: Xiao
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.forename: Shan
authors.initials: S
authors.lastname: Luo
authors.forename: Shang-Wei
authors.initials: SW
authors.lastname: Li
mesh_terms: D000328:Adult; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D003430:Cross-Sectional Studies; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007101:Immersion; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D009339:Needles; D009994:Osmolar Concentration; D010053:Ovary / Q000166:cytology / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D055815:Young Adult
chemical_list: D003451:Cryoprotective Agents; D007770:L-Lactate Dehydrogenase