The effect of vitrified ovarian tissue autotransplantation encapsulated with hyaluronic acid hydrogen on VEGF, CD31 and CD34 gene expression in rat

One of the problems after cryopreservation and ovarian tissue transplantation is ischemia followed by follicles mortality. In the present study, hyaluronic acid hydrogel was used to improve angiogenesis in vitrified ovarian tissue transplantation in rat.

In this experimental study, 22 adult female rats (~8 weeks old) with normal estrous cycles were ovariectomized, then their right ovaries were vitrified and warmed into two groups without hyaluronic acid hydrogel (VT) and encapsulated with hyaluronic acid hydrogel (VT+HA) was autotransplanted into the dorsal muscle. Daily vaginal monitoring was performed until re-initiation of first full oestrus cycles. The ovaries were removed at the end of the first estrus cycle and angiogenesis genes VEGF, CD31 and CD34 evaluated by real time PCR. Data were analyzed by Mann-Whitney test and the significance level was considered P<0.05.

All transplants were completely successful (100% successful transplant). There was no statistically significant difference in CD34 and CD31 genes between two groups. But VEGF gene expression was significantly lower in VT+HA group (0.25±0.06) than VT group (1.00±0.05) (P<0.05). Thus, the VT group appeared more successful than the VT+HA group in expressing angiogenic genes at the end of the first estrus cycle.

Hyaluronic acid hydrogel does not play any effective role in the growth and improvement of angiogenesis after transplantation in the short term. But due to the angiogenic property of hyaluronic acid, increasing the expression of angiogenic genes in the VT + HA group may need more time.