Reviving vacuum-dried encapsulated ram spermatozoa via ICSI after 2 years of storage

Front Vet Sci. 2023 Nov 30:10:1270266. doi: 10.3389/fvets.2023.1270266. eCollection 2023.

Abstract

Introduction: Freeze-drying techniques give alternative preservation mammalian spermatozoa without liquid nitrogen. However, most of the work has been conducted in the laboratory mouse, while little information has been gathered on large animals that could also benefit from this kind of storage.

Methods: This work adapted a technique known as vacuum-drying encapsulation (VDE), originally developed for nucleic acid conservation in anhydrous state, to ram spermatozoa, and compared it to canonical lyophilization (FD), testing long-term storage at room temperature (RT) and 4°C.

Results and discussion: The results demonstrated better structural stability, namely lipid composition and DNA integrity, in VDE spermatozoa than FD ones, with outcomes at RT storage comparable to 4°C. Likewise, in VDE the embryonic development was higher than in FD samples (12.8% vs. 8.7%, p < 0.001, respectively). Our findings indicated that in large mammals, it is important to consider dehydration-related changes in sperm polyunsaturated fatty acids coupled with DNA alterations, given their crucial role in embryonic development.

Keywords: ICSI; encapsulation; lipidomics; ovine; polyunsaturated fatty acids.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work received funding from the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Skłodowska-Curie grant agreements No. 734434. The present study was carried out in the framework of the Project “Demetra” (Dipartimenti di Eccellenza 2018–2022, CUP_C46C18000530001), funded by the Italian Ministry for Education, University and Research. LP and MC acknowledge support from the National Science Centre, Poland, through Grant No. 2016/21/D/NZ3/02610 (Sonata) and 2019/35/B/NZ3/02856 (Opus). This work has been funded by the European Union - NextGenerationEU under the Italian Ministry of University and Research (MUR) National Innovation Ecosystem grant ECS00000041 - VITALITY - CUP C43C22000380007.