Cryopreservation of the entire ovary of cynomolgus monkey in a magnetic field environment without using cryoprotectants

OBJECTIVE: In case of autotransplantation (AT) of the ovarian cortical fragments, a large proportion of follicles are lost and the ovarian functions exit a short period of time. Theoretically, the best way is the AT of an intact ovary with vascular anastomosis. However, cryopreservation(C) technique of the entire ovary has not been completed yet. Here, we describe the successful C technique of the entire ovary without the use of any cryoprotectants. DESIGN: Hormone data and menstruation records after heterotopic AT of the cryopreserved entire ovaries of five cynomolgus monkeys(CM) in the magnetic field environment(MFE). MATERIALS AND METHODS: The theoretical principle of C system in the MFE is the vibrating of the particle, avoids the formation of ice crystals and breakdown of the cells doesn't occur. All five CMs (a-e) used for the experiment had normal menstrual cycle(mc) at the start of the experiment. We removed both ovaries from five female CM on the first day of menses. The ovaries were immediately frozen in a MFE and cryopreserved for about 1 month in LN2. Frozen-thawed ovaries were transplanted in the skeletal muscle of the femur (two CMs) and under the kidney capsules (three CMs) of the same CMs. After each AT, five CM were recorded their menstruation and hormone level. RESULTS: The mc of one CM recovered soon after AT of the ovaries (a). However, after second mense, E2 and progesterone levels did not increase. When the ovaries of the other four CMs were stimulated by injection of FSH, two recovered the mc (b, c). One of these two CMs now has a regular mc, and the other's is irregular. One of the other two CMs recovered the mc about 3 months after AT (d); however, menses was confirmed only once. In the fifth CM, the mc did not recover after the ovaries were transplanted (e). After frozen-thawed ovarian AT, four of the five CMs recovered their ovarian function with hormone production and the mc. CONCLUSIONS: The advantages of this method do not need cryoprotectants, and can cryopreserve the whole ovary. In the near future, we hope to attempt the AT of an intact ovary with vascular anastomosis. This method of preserving intact internal organs would provide extra time for transportation of an organ for transplant anywhere in the world, and would make possible the creation of banks for frozen internal organs.