Effects of sodium alginate capsules as 3D scaffolds on hormones and genes expression in preantral follicles of mice compared to 2D medium: An experimental study

Background: The improvement of in vitro maturation methods, which can activate the preantral follicle growth, plays a crucial role in the production of mature oocytes in reproductive technology.
Objective: To evaluate the different concentrations of 3D scaffolds of sodium alginate on hormones and gene expression in mice preantral follicles.
Materials and Methods: Immature female BALB/c mice (12-14 days) were sacrificed. The follicles were removed mechanically and transferred into α minimal essential medium with 5% fetal bovine serum. The preantral follicles were incubated with different concentrations of sodium alginate (0.25%, 0.5%, and 1%) and 2D medium for 12 days. The follicles were examined for antral formation following the 10th day and the diameter on days 6^th and 12^th. The levels of hormones (AMH, androstenedione, 17𝛽-estradiol, and progesterone) and the expression of genes (CYP11a1, CYP17a1, CYP19a1, AMH, and GnRH) at the end of the 12^th day.
Results: Maximum follicle diameter and highest percentage of antrum formation were related to 0.5% concentration (p = 0.00). The levels of hormones in different doses of sodium alginate were increased significantly compared to the control group (p = 0.00). The highest and lowest levels of these hormones were related to 0.5% concentration and 2D medium, respectively. The highest level of genes expression was observed in 0.5% sodium alginate, which showed a significant increase compared to the control group (p = 0.00).
Conclusion: Proper concentration of alginate hydrogel increases follicle growth, causes follicle maturation, produces steroid hormones, and increases appropriate expression of steroidogenesis-related genes.