Developmental Competence of Domestic Cat Vitrified Oocytes in 3D Enriched Culture Conditions

Abstract

Cryoinjuries severely affect the competence of vitrified oocytes (VOs) to develop into embryos after warming. The use of culture conditions that provide physical and chemical support and resemble the in vivo microenvironment in which oocytes develop, such as 3D scaffolds and coculture systems, might be useful to improve VOs outcomes. In this study, an enriched culture system of 3D barium alginate microcapsules was employed for the in vitro embryo production of domestic cat VOs. Cryotop vitrified-warmed oocytes were in vitro matured for 24 h in the 3D system with or without fresh cumulus-oocyte complexes (COCs) in coculture, whereas a control group of VOs was cultured in traditional 2D microdrops of medium. After in vitro fertilization, presumptive embryos were cultured in 3D or 2D systems according to the maturation conditions. Vitrified oocytes were able to mature and develop into embryos in 3D microcapsules (17.42 ± 11.83%) as well as in 2D microdrops (14.96 ± 8.80%), but the coculture with companion COCs in 3D resulted in similar proportions of VOs embryo development (18.39 ± 16.67%; p = 1.00), although COCs presence allowed for blastocyst formation (0.95 ± 2.52%). In conclusion, embryos until late developmental stages were obtained from cat VOs, and 3D microcapsules were comparable to 2D microdrops, but improvements in post-warming conditions are still needed.

Granulosa cells in three‐dimensional culture: A follicle‐like structure for domestic cat vitrified oocytes

“…Trying to restore VOs impaired competence, the combination of physical (presence of companion cells) and chemical (intercellular signalling) factors in the form of co-culture systems has been tested in different species with variable results (Attanasio et al, 2010;Casillas, Ducolomb, Lemus, Cuello, & Betancourt, 2015;Casillas et al, 2014). In our last study, an enriched culture system comprising a 3D environment (barium alginate microcapsules) and a co-culture with companion COCs gave some possibilities for domestic cat VOs development (Colombo, Morselli, Tavares, Apparicio, & Luvoni, 2019). Inspired by these results and convinced of the advantages given by the combination of physical and chemical factors in in vitro microenvironments, a 3D follicle-like structure was applied.…”

One-step automated bioprinting-based method for cumulus-oocyte complex microencapsulation for 3D in vitro maturation

“…biomaterial has also been reported for oocyte IVM [15,[32][33][34][35][36]. The clinical interest in IVM is constantly urged by the World Health Organization since infertility affects about 15% of couples [15].…”

“…COC-microbeads and assessing its validity on oocyte nuclear and cytoplasmic maturation. Indeed, most of the studies published to date described two-step or manual procedures [32][33][34][35][36]. Dorati et al [15] described alginate microbead preparation by the diffusion setting gelation technique in which, using a mouth-controlled hand-pulled glass Pasteur micro-pipette, single COCs were transferred into the alginate solution in culture medium and dropped into single wells of a 96-well plate containing the cross-linking agent.…”

“…Among biocompatible materials, alginate hydrogels have been successfully used for culturing and studying different cell types [17] and have been widely employed in long-term in vitro culture of ovarian follicles [18][19][20][21][22][23][24][25][26][27][28][29][30][31]. In recent years, IVM culture of COCs in 3D alginate microenvironments has been reported in various animal models with encouraging results [18,[32][33][34][35][36]. Methods for fabricating microbeads containing a COC, namely "COC-microbeads", need to be chosen according to their ability to control microbead shape and dimensions and generate reproducible 3D IVMs.…”

Follicular extracellular vesicles enhance meiotic resumption of domestic cat vitrified oocytes

“…Data from mouse and human studies have shown that vitrification better protects oocytes from structural damage and sustains gametes' developmental competence than slow freezing 12,14 . For the domestic cat, although both slow-freezing and vitrification have been used to preserve immature oocytes 4,13,15,16 , the rates of cryopreserved immature oocytes that complete nuclear maturation are much lower than for fresh gametes (0-38%) 3,4,13,16,17 . Different approaches have been used to improve the survival and developmental competence of mature and immature vitrified oocytes.…”