In the present study, the applicability of hyaluronic acid-alginate (HAA) hydrogel and ovarian cells (OCs) for the culture of mouse ovarian follicles were investigated, and the results were compared with those of alginate (ALG) and fibrin-alginate (FA) hydrogels.
In the first step of this experimental study, mechanically isolated preantral follicles from the ovaries of two-week-old mice were encapsulated in the absence or presence of OCs in ALG, HAA, and FA hydrogels and cultured for 14 days. The morphology, diameter, survival and antrum formation rates of the follicles and the maturation and quality of the oocytes were evaluated during culture. In the second step, preantral follicles were cultured similar to the first step but for 13 days, and their genes expression and hormonal secretion were assessed on the last day of culture.
In the absence of OCs, higher numbers of ALG- and HAA-encapsulated follicles reached the antral stage compared to FA-encapsulated (P<0.05). However, a higher percentage of HAA-developed oocytes resume meiosis up to germinal vesicle break down (GVBD)/metaphase II (MII) stages in comparison with ALG-developed (P<0.05). Additionally, HAA-encapsulated follicles were significantly overexpressed most of the growth and differentiation genes, and secreted higher levels of estradiol compared to ALG- and FA-encapsulated (P<0.05). The co-culture condition increased the diameter of ALG-encapsulated follicles, on day 13 of culture (P<0.05). It also increased the survival and maturation rates of ALG- and FA-encapsulated follicles, respectively (P<0.05). Moreover, co-culture condition improved cortical granule distribution in all groups, increased estradiol and progesterone secretions in ALG and FA groups, and androstenedione secretion in the FA group (P<0.05).
The present study showed that the applied HAA hydrogel is a promising hydrogel for follicle culture and OCs utilization could ameliorate the culture conditions regardless of the type of hydrogel.