Eroglu Ali, Toner Mehmet, Toth Thomas L
Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
Fertil Steril. 2002 Jan;77(1):152-8. doi: 10.1016/s0015-0282(01)02959-4.
To determine the effectiveness of trehalose as an intracellular cryoprotectant for the cryopreservation of human oocytes.
In vitro comparative study.
Clinical and academic research environment at a medical school teaching hospital.
PATIENT(S): Women undergoing in vitro fertilization (IVF).
INTERVENTION(S): Discarded human oocytes, obtained from IVF patients, were randomly distributed into three groups: control group (no trehalose), extracellular trehalose group (0.5 M extracellular trehalose), and intracellular trehalose group (0.15 M intra- and 0.5 M extracellular trehalose). Trehalose was introduced into oocytes by microinjection. The oocytes in each group were cooled to different temperatures (i.e., -15 degrees C, -30 degrees C, and -60 degrees C) at rate of 1 degrees C/minute and thawed at ambient air temperature. Survival was examined after overnight culture.
MAIN OUTCOME MEASURE(S): Survival of human oocytes cryopreserved in the presence and absence of trehalose.
RESULT(S): The majority of oocytes in the intracellular trehalose group survived cooling to -15 degrees C (63%), -30 degrees C (53%), and -60 degrees C (66%). In contrast, only a small number of oocytes in both the control (13%) and extracellular trehalose group (22%) survived cooling to -15 degrees C, while all oocytes degenerated when cooled to -30 degrees C and -60 degrees C.
CONCLUSION(S): Small amounts of intracellular trehalose in the absence of any other cryoprotectant provide a significant protection against freeze-associated stresses. Our results suggest that sugars such as trehalose should be considered as intracellular cryoprotectants for cryopreservation of human oocytes.
