title: Nanoliter droplet vitrification for oocyte cryopreservation.
abstract: OBJECTIVE
  Oocyte cryopreservation remains largely experimental, with live birth rates of only 2-4% per thawed oocyte. In this study, we present a nanoliter droplet technology for oocyte vitrification.
  
  
  METHODS
  An ejector-based droplet vitrification system was designed to continuously cryopreserve oocytes in nanoliter droplets. Oocyte survival rates, morphologies and parthenogenetic development after each vitrification step were assessed in comparison with fresh oocytes.
  
  
  RESULTS
  Oocytes were retrieved after cryoprotectant agent loading/unloading, and nanoliter droplet encapsulation showed comparable survival rates to fresh oocytes after 24 h in culture. Also, oocytes recovered after vitrification/thawing showed similar morphologies to those of fresh oocytes. Additionally, the rate of oocyte parthenogenetic activation after nanoliter droplet encapsulation was comparable with that observed for fresh oocytes. This nanoliter droplet technology enables the vitrification of oocytes at higher cooling and warming rates using lower cryoprotectant agent levels (i.e., 1.4 M ethylene glycol, 1.1 M dimethyl sulfoxide and 1 M sucrose), thus making it a potential technology to improve oocyte cryopreservation outcomes.
authors.affiliation: Demirci Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhang
authors.forename: Imran
authors.initials: I
authors.lastname: Khimji
authors.forename: Lei
authors.initials: L
authors.lastname: Shao
authors.forename: Hooman
authors.initials: H
authors.lastname: Safaee
authors.forename: Khanjan
authors.initials: K
authors.lastname: Desai
authors.forename: Hasan Onur
authors.initials: HO
authors.lastname: Keles
authors.forename: Umut Atakan
authors.initials: UA
authors.lastname: Gurkan
authors.forename: Emre
authors.initials: E
authors.lastname: Kayaalp
authors.forename: Aida
authors.initials: A
authors.lastname: Nureddin
authors.forename: Raymond M
authors.initials: RM
authors.lastname: Anchan
authors.forename: Richard L
authors.initials: RL
authors.lastname: Maas
authors.forename: Utkan
authors.initials: U
authors.lastname: Demirci
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents; D005260:Female; D051379:Mice; D009865:Oocytes
chemical_list: D003451:Cryoprotective Agents