Comparison of agarose gel support system and conventional methods for in vitro culture of bovine preantral follicles.

We evaluated the efficiency of two-dimensional (2D) and three-dimensional (3D) systems for in vitro culture of preantral follicles from the bovine species. Ovarian cortex fragments were obtained from a local slaughterhouse and randomly distributed into four groups: i) standard culture, directly on a culture plate (2D), ii) supported culture, on a gel monolayer (2D), iii) immersed culture on agarose gel (plating coated) covered in a medium (3D) and iv) Millicell-Biopore culture (3D), tested at 6 or 14 days. The following parameters were evaluated: follicular morphology and morphometry, reactive oxygen species production and granulosa cell proliferation. After 6 days of culture, follicles cultured on a gel monolayer (2D) showed a higher proportion of intact follicles than those cultured using other methods (P < 0.05). After 14 days of growth, standard culture on a culture plate (2D) and supported culture on a gel monolayer (2D) had a higher percentage of morphologically intact follicles (P < 0.05) than the 3D culture. An assessment of the redox status revealed that superoxide anion levels and antioxidant capacity of the samples cultured using the four methods were lower than those of the control group (non-cultured; P < 0.05). Taken together, these findings suggest that the agarose gel support system offers distinct advantages for bovine preantral follicle culture by maintaining morphological integrity and stabilising the redox environment, although further studies incorporating functional endpoints are warranted to fully confirm these observations.