Effect of three-dimensional collagen membrane culture and presence of cumulus cells on maturation of bovine oocytes.

Objective: The use of animals as experimental models has been proposed to improve the techniques applied in human reproduction clinics. This prospective and observational study evaluates the effects of the use of cumulus cells and collagen membrane on the maturation process of bovine oocytes.

Methods: Design and Setting: Bovine oocytes with or without cumulus cells were cultured in maturation medium for 24 hours in the conventional system (2D), central well plates and in the three-dimensional (3D) system.

Ovarian tissue features assessed in bovine fetuses after vitrification and xenotransplantation procedures.

Cryopreservation and transplantation of ovarian tissue are proposed methods for the restoration of endocrine function and reproductive potential. Therefore, this study aimed to evaluate the effects of vitrification and xenotransplantation on follicle viability, activation, stromal cell integrity, vascularization, and micronuclei formation. Bovine fetal ovaries were fragmented and assigned to the following groups: Fresh control (FC), ovarian fragments immediately fixed; Vitrified control (VC), ovarian fragments vitrified; Vitrified xenotransplanted (VX), ovarian fragments vitrified and xenotransplanted; and Fresh xenotransplanted (FX), ovarian fragments xenotransplanted.

Three-dimensional levitation culture improves in-vitro growth of secondary follicles in bovine model.

Research Question: Does a three-dimensional culture system based on magnetic levitation with nanoparticles assembly maintain the follicular structure and viability with adequate growth rates leading to oocyte maturation after long-term culture?

Design: Randomized-controlled trial of treatments in a bovine model. Secondary follicles (n = 213) isolated from bovine ovaries were cultured in a two-dimensional system (two-dimensional control) or three-dimensional levitation system with different concentrations (three-dimensional 50 µl/ml, 100 µl/ml and 200 µl/ml) of magnetic nanoparticles. Follicular growth (diameter, daily growth and growth patterns), morphology (normal, degenerated and extruded follicles), antrum formation, oocyte viability and chromatin configuration were assessed.

Positive effect of resveratrol against preantral follicles degeneration after ovarian tissue vitrification.

This study aimed to evaluate whether the addition of resveratrol to vitrification/thawing medium improves the cryotolerance of preantral follicles enclosed in bovine ovarian fragments. Ovarian fragments were obtained from bovine fetuses and distributed to the following groups: fresh ovarian fragments (control), vitrified (VIT), and vitrified with resveratrol (VIT + RESV). Overall, the mean percentage of normal follicles was greater (P < 0.