Cryopreservation of Limited Sperm Using A Combination of Sucrose and Taurine, Loaded on Two Different Devices, and Thawed at Two Different Temperatures

BACKGROUND

Cryopreservation of sperm is essential for patients with low sperm counts and couples undergoing infertility treatment. The aim of this study was to compare the effects of Taurine (T) and Sucrose (S) in individual sperm cryopreservation utilizing cryotop and petri dish and thawing at 37 and 42°C.

MATERIALS AND METHODS

In this experimental study, 17 normospermic semen samples were processed using the "Swim-up" procedure and progressively motile sperm were then isolated from these samples using an inverted microscope. Sperm were added to droplets of "sucrose medium" with 25 mM Taurine antioxidant (S+T) and the commercial cryoprotectant "Sperm Freeze" (CPA), loaded on a petri dish and cryotop. After rapid freezing of the samples, they were thawed at two different temperatures (37°C and 42°C), and the sperm classical parameters, viability, and DNA fragmentation were assessed.

RESULTS

Statistical analysis displayed a significant increase in total and progressive motility in individual sperm freezing on cryotop with CPA and thawing at 42°C (P<0.05). Other parameters did not show any differences between the CPA and S+T groups and two thawing temperatures in either of the cryopreservation methods.

CONCLUSION

Although, both cryoprotectants (CPA and S+T) may preserve individual sperm effectively using cryotop, the CPA and thawing at 42°C showed a better effect on the motility percentage of the small number of sperm.

A 3-D printed vitrification device integrated with French straws

The goal of this work was to develop prototypes of open-hardware vitrification devices for sperm cryopreservation that can be integrated with existing straw platforms. The open-hardware Vitrification Device for French Straws (VD-FS) is low-cost, customizable, 3-D printable, standardized, and allows long-term sample storage and identification. The feasibility was shown for vitrifying and storing samples with multiple configurations. The results can be improved by design alternation and evaluation of various vitrification solutions. This is the first complete open-hardware vitrification device that can be integrated with existing French-straw storage systems, providing a foundation for future community-level modifications and improvements.

Effect of lactoferrin on ram sperm motility after cryopreservation

Objective

The objective of this study was to analyse the differentially abundant proteins caused by freeze-thawing of ram sperm and explore candidate proteins of interest for their ability to improve ram sperm cryopreservation outcomes in vitro .

Methods

Sperm were from three mature Dorper. Fresh and frozen sperm proteins were extracted, and the differentially abundant proteins were analysed by mass spectrometry (MS). Among these proteins, lactoferrin（LTF) was selected to be added before cryopreservation. Next, sperm samples were diluted in Tris extender, with the addition of 0μg/ml,10 μg/ml, 100 μg/ml, 500 μg/ml, 1000 μg/ml of LTF. After thawing, sperm quality evaluated by motility, plasma membrane integrity, mitochondrial activity and reactive oxygen species (ROS).

Results

Cryopreservation significantly altered the abundance of 40 proteins; the abundance of 16 proteins was increased, while that of 24 proteins was decreased. Next, LTF was added to Tris extender applied to ram sperm. The results showed that sperm motility and plasma membrane integrity were significantly improved (p<0.05) by supplementation with 10 μg/ml LTF compared to those in the control group. There was no significant difference in mitochondrial activity between the 0μg/ml group and other groups (p>0.05). Supplementation of the cryoprotective extender with 10 μg/ml LTF led to decreased reactive oxygen species (ROS) levels compared with those in the control and other groups (p<0.05).

Conclusion

LTF is an important protein during cryopreservation, and the addition of 10 μg/ml LTF to a cryoprotective extender can significantly improve the function of frozen ram sperm.