Cryopreservation of oocyte and ovarian tissue

Abstract

Cryopreservation of reproductive cells (i.e., oocytes, spermatozoa) and tissues (i.e., ovarian and testicular tissue) is a developing technology that has tremendous implications for rapid advancement of biomedical research. Since the early 1980s, advances have been made in establishing optimal conditions for in vitro oocyte maturation, fertilization, and embryo culture. These in vitro systems have contributed significantly to utilization of thawed cells and tissues and have made it possible to evaluate protocols designed to cryopreserve such biomaterials more effectively. Although cryopreservation of preimplantation embryos from various species including mouse, human, and farm animals has been successful, cryopreservation of oocytes and ovarian tissue from most mammalian species has been more challenging due to their extreme sensitivity to suboptimal conditions during the cryopreservation process. Cryopreservation of mouse oocytes has been well documented and has resulted in greater success than studies with other mammalian species. Ovarian tissue cryopreservation and transplantation techniques have recently received much scientific and public attention due to their great potential for use in human infertility treatment, in safeguarding the reproductive potential of endangered species, and in genome banking of genetically important laboratory animal strains. A review of past and current research in the field of oocyte and ovarian tissue cryopreservation and transplantation and a discussion of possible strategies for oocyte and ovarian tissue banking are provided.