Long-term preservation of germ cells and gonadal tissues at ambient temperatures

Abstract

Objective: To present an overview of different approaches and recent advances for long-term preservation of germ cells and gonadal tissues at ambient temperatures. Methods: Review of the existing literature. Results: Preserving viable spermatozoa, eggs, embryos, and gonadal tissues for the long term is critical in human fertility treatment and for the management of animal populations (livestock, biomedical models, and wild species). The need and number of banked germplasms are growing very fast in all disciplines, but current storage options at freezing temperatures are often constraining and not always sustainable. Recent research indicates that structures and functions of gametes or gonadal tissues can be preserved for the long-term using different strategies based on dehydration and storage at supra-zero temperatures. However, more studies are needed in rehydration and reanimation of germplasms (including proper molecular and cellular evaluations). Conclusions: While a lot of research is still warranted to optimize drying and rehydration conditions for each sample type and each species, alternative preservation methods will change the paradigm in fertility preservation and biobanking. It will transform the way we maintain and manage precious biomaterials for the long term.

The distribution and current state of biobanking in Indonesian wildlife: a systematic review

“…One potential way to achieve this agenda is by using room temperature storage techniques that have recently been investigated by cryobiologists (Comizzoli et al ., 2022a, b). Methods such as lyophilization or gamete freeze‐drying have been studied in the wild with good results (Magalhães et al ., 2012; Kaneko et al ., 2014).…”

“…Methods such as lyophilization or gamete freeze‐drying have been studied in the wild with good results (Magalhães et al ., 2012; Kaneko et al ., 2014). Disruption of cell activity by mimicking the phenomenon of anhydrobiosis, which occurs naturally in tardigrades, is also being developed for long‐term preservation of gametes at temperatures above zero (Comizzoli et al ., 2022a, b). However, considerable further studies are needed before it will be feasible to successfully adopt these methods.…”

Study on the optimal time limit of frozen embryo transfer and the effect of a long-term frozen embryo on pregnancy outcome

“…Furthermore, ongoing studies investigate the possibility of preserving embryos and germ cells at ambient temperatures. [ 45 ] This potential advancement could revolutionize the maintenance and management of valuable biological materials. However, there is still much to explore in this field.…”

Damages and stress responses in sperm cells and other germplasms during dehydration and storage at nonfreezing temperatures for fertility preservation

“…Storage under vacuum at room temperature improves DNA stability and embryo formation rate of dried mouse sperm (Kamada et al, 2018). So far, diverse storage containers have been used (Comizzoli, He, et al, 2022); however, glass ampoules that are mainly used for lyophilized sperm are breakable and less secure for storage and transport. Instead, moisture barrier bags (Elliott et al, 2015; P. C. Lee et al, 2022) or plastic sheets (Ito et al, 2021) have the advantage of gaining space for storage, they also are easier to ship from one location to another.…”

“…As another alternative to lyophilization, microwave‐assisted drying has been developed in mammalian cells (Chakraborty et al, 2008) and successfully translated to germ cells (Table 1). Most storage methods and conditions following the dehydration methods mentioned above have all been at noncryogenic temperatures and ensured the preservation of samples for days, months, or even years in different types of containers (Comizzoli, He, et al, 2022). Interestingly, multiple dehydration studies have not included protectants like trehalose (Table 1).…”