Treating ram sperm with cholesterol-loaded cyclodextrins improves cryosurvival.

Area of Science:

• Reproductive Biology
• Sperm Cryopreservation
• Animal Science

Background:

• Current ram sperm cryopreservation limits fertility to laparoscopic intrauterine insemination.
• Improving cryosurvival is key to enabling more practical artificial insemination methods.
• Cholesterol loading of cyclodextrins (CLC) is explored as a method to enhance sperm quality.

Purpose of the Study:

• To determine if treating ram sperm with cholesterol-loaded cyclodextrins (CLC) improves cryosurvival.
• To assess the feasibility of using CLC with neat semen for cryopreservation.
• To evaluate the effects of CLC on sperm cholesterol content, osmotic tolerance, post-thaw survival, and zona pellucida binding.

Main Methods:

• Ram sperm were treated with six different cyclodextrins pre-loaded with cholesterol (CLC) before cryopreservation.
• Evaluated sperm motility, viability, cholesterol content, osmotic tolerance, and zona pellucida binding post-thaw.
• Optimized CLC concentration and application to neat semen were determined.

Main Results:

• Sperm treated with 2-hydroxypropyl-beta-cyclodextrin showed significantly higher post-thaw motility (62%) compared to controls (43%).
• Methyl-beta-cyclodextrin also improved motile and viable sperm percentages.
• CLC treatment increased sperm cholesterol content, enhanced osmotic tolerance, and improved zona pellucida binding capacity.

Conclusions:

• Treating ram sperm with CLC significantly increases cryosurvival rates and post-thaw longevity.
• CLC enhances sperm cholesterol content, osmotic tolerance, and zona-binding capabilities.
• The application of CLC to neat semen is feasible for practical cryopreservation of ram sperm.