Development and validation of a sperm-freezing device created using 3D printer technology.

Area of Science:

• Reproductive biology
• Biomedical engineering
• Cryopreservation technology

Background:

• Semen cryopreservation is crucial for assisted reproduction.
• Standardized and reproducible freezing protocols are essential for maintaining sperm viability.
• Current methods may lack consistency in cooling rates and handling safety.

Purpose of the Study:

• To develop and evaluate a novel 3D-printed prototype for holding semen straws during cryopreservation.
• To assess the safety, reproducibility, and effectiveness of the 3D-printed prototype compared to conventional supports.

Main Methods:

• A 3D-printed prototype and an expanded polyethylene (EPS) support were used to hold ten semen straws each.
• Temperature monitoring was performed using thermocouples within straws during freezing in liquid nitrogen vapor.
• Sperm parameters including motility, vitality, and DNA fragmentation were analyzed before and after freezing.

Main Results:

• The 3D-printed prototype demonstrated highly reproducible temperature cooling curves.
• The prototype material proved durable, withstanding over 300 freezing cycles without degradation.
• Sperm recovery rates for motility, vitality, and DNA integrity were comparable between the 3D-printed prototype and the EPS support.

Conclusions:

• The 3D-printed prototype facilitates homogeneous, quantifiable, and reproducible cooling in liquid nitrogen vapor.
• The device enhances safe handling of semen straws and provides explicit freezing conditions.
• The prototype offers improved intra-operator and inter-laboratory reproducibility for sperm cryopreservation.