Comparative evaluation of two density gradient preparations for sperm separation for medically assisted conception.

Area of Science:

• Reproductive biology andrology
• Biomaterials science
• Medical laboratory science

Background:

• Conventional sperm separation methods often utilize polyvinylpyrrolidone (PVP)-coated silica beads (Percoll).
• Concerns regarding PVP content have led to the withdrawal of Percoll for assisted reproduction.
• Novel silane-coated silica beads (Puresperm) offer a potential alternative for sperm separation.

Purpose of the Study:

• To evaluate and optimize the sperm separation efficiency of Puresperm.
• To compare Puresperm with Percoll across different gradient configurations and semen loading volumes.
• To assess the suitability of Puresperm as an alternative for assisted reproduction.

Main Methods:

• Comparative analysis of sperm parameters (concentration, motility, vitality, morphology) using manual and computer-assisted semen analysis.
• Evaluation of three-layer (90%-70%-40%) vs. two-layer (90%-45%) gradients for both Puresperm and Percoll.
• Assessment of large (3.0 ml) vs. small (0.75 ml) semen loading volumes on three-layer Puresperm gradients.
• 12 replicates for each experimental condition using normozoospermic semen samples.

Main Results:

• Percoll demonstrated superior performance over Puresperm in concentration, motility, vitality, and yield in three-layer gradients.
• No significant differences were observed between two- and three-layer Percoll gradients.
• Three-layer Puresperm gradients performed significantly better than two-layer Puresperm gradients.
• Large semen volumes on three-layer Puresperm gradients yielded higher sperm concentration, motility, vitality, and normal morphology.
• Small semen volumes on three-layer Puresperm gradients produced higher yields of good-quality spermatozoa.

Conclusions:

• While Percoll outperformed Puresperm in direct comparison, Puresperm shows promise as an alternative for sperm separation.
• Optimizing Puresperm gradients with large semen loading volumes can enhance sperm quality parameters.
• Three-layer Puresperm gradients with large semen volumes represent an attractive option for sperm separation in assisted conception, especially given Percoll's unavailability.