The effect of high-throughput vitrification of human ovarian cortex tissue on follicular viability: a promising alternative to conventional slow freezing?

Abstract

Background The standard procedure most frequently used for ovarian tissue cryopreservation (OTC) is slow freezing, while vitrification has been proposed as promising alternative and has built an impressive catalog of success in fertility laboratories regarding cryopreservation of oocytes and embryos. Methods We developed and evaluated a high-throughput protocol for vitrification of human ovarian tissue suitable for clinical processing. Follicular viability was assessed via calcein staining prior and after cryopreservation analyzing ovarian tissue of a cohort of 30 patients. Results We found no significant differences regarding follicular viability between slow frozen and vitrified cortex tissue samples 24 h after thawing and rapid warming. Follicular viability of thawed and rapid warmed samples was not significantly different in comparison to fresh samples, indicating high proportions of follicular survival rates with both methods. Conclusions High-throughput vitrification is a promising option in a clinical setting. More research is required to determine the status of other tissue-specific quality indicators potentially influencing on autotransplantation.

Investigating the impact of vitrification on bovine ovarian tissue morphology, follicle survival, and transcriptomic signature

“…The extent of this cell damage could be linked to the freezing protocol applied. Previous research has shown that vitrification protocols are better at preserving ovarian stromal cells compared to slow freezing protocol [ 49 , 50 ]. However, no significant differences in follicular viability have been observed among fresh, vitrified, and slow-frozen ovarian samples [ 50 ].…”

“…Previous research has shown that vitrification protocols are better at preserving ovarian stromal cells compared to slow freezing protocol [ 49 , 50 ]. However, no significant differences in follicular viability have been observed among fresh, vitrified, and slow-frozen ovarian samples [ 50 ]. Despite these findings, the precise impact of vitrification protocols on follicles has remained largely unknown.…”

Comparison of angiogenic potential in vitrified vs. slow frozen human ovarian tissue

“…Preparation of vitrification and rapid warming solutions were performed according to Suzuki and colleagues with modifications described elsewhere 7 , 8 . In brief, tissue was equilibrated in different solutions with varying concentrations of 10%, 20% and finally 35% ethylene glycol (Merck, Darmstadt, Germany) in GMOPS+ (Vitrolife, Gothenburg, Sweden) supplemented with 10% SSS (Serum substitute supplement, Fujifilm Irvine scientific, Santa Ana, USA) for 5 min each.…”

“…The majority of centers performing OTC use the slow freezing method while the optimal protocol regarding vitrification of ovarian tissue has yet to be determined 7 .…”

“…In our recent study, we describe a high throughput vitrification protocol suitable for clinical routine without detecting significant differences regarding follicular viability in comparison to the slow freezing standard protocol 7 . In this prospective study, we analysed the secretion of 10 angiogenic factors after 48 h of hypoxic tissue culture of human ovarian tissue.…”