Vitrification of Rattus norvegicus immature cumulus-oocyte complexes using hyaluronic acid

Abstract

The aim of this study was to assess in vitro meiosis resumption and nuclear maturation of Rattus norvegicus oocytes after vitrification with different cryoprotective solutions. Cumulus-oocyte complexes (COCs) were exposed to an equilibration solution for 4 min placed in cryoprotective solutions for 1 min and vitrified in open pulled straws. Cryoprotective solutions were prepared with 15% ethylene glycol + 15% dimethyl sulfoxide + 0.5 M sucrose and different supplements, to form the following groups: G1, 20% fetal bovine serum in modified phosphate-buffered saline (mPBS); G2, 0.4% bovine serum albumine in mPBS; G3, 1% hyaluronic acid in mPBS; and G4, 0.4% polyvinyl alcohol in mPBS. Seven days after vitrification, the COCs from G1 to G4 were warmed and in vitro matured for 30 h along with the control group. Hoechst staining was performed to assess meiosis resumption and nuclear maturation rates. Control group showed higher meiosis resumption (77.88%) and nuclear maturation rates (55.75%) compared to all vitrified groups. Among the vitrified COCs, G3 showed the highest meiosis resumption and nuclear maturation rates (G1, 26.5 and 15.38%; G2, 22.12 and 11.54%; G3, 34.55 and 20%; G4, 20.17 and 9.24%). Supplementation of the vitrification solution with 1% hyaluronic acid provided better results, compared to the other supplements. Hyaluronic acid can be useful to vitrify rat COCs associated with other cryoprotectant agents.

Biomaterials and advanced technologies for the evaluation and treatment of ovarian aging

“… Parisa Jamalzaei [ 222 ] 2020 A HAA composed of HA and ALG Mouse preantral follicles Promoted the development of preantral follicles and oocyte maturation in mice and enhanced estrogen secretion. L M G Paim [ 224 ] 2015 A vitrification solution with 1% hyaluronic acid The cumulus oocyte complex Improved the meiotic recovery rate and nuclear maturation rate of norvegicus oocytes. Somayeh Tavana [ 225 ] 2016 The HABH Ovariectomized rats Prevented or reduced early ischemia-induced follicular loss, promoted follicular survival and angiogenesis.…”

“…Vitrification of embryos has been successful, while cryopreservation of oocytes has still failed to achieve the expected results [ 223 ]. Paim et al used a vitrification solution with 1% hyaluronic acid to freeze the cumulus oocyte complex (COC) for 7 days and then heated and matured it in vitro for 30 h [ 224 ]. The results showed that adding 1% hyaluronic acid to vitrified frozen solution could improve the meiotic recovery rate and nuclear maturation rate of Rattus norvegicus oocytes in vitro.…”