Nanoplastics internalization impairs mitochondrial activity in equine sperm

Area of Science:

• Environmental Toxicology
• Reproductive Biology
• Nanotechnology

Background:

• Global plastic pollution leads to nanoplastic (NP) accumulation in tissues.
• NP's adverse effects on fertility via inflammation and oxidative stress are known.
• The impact of NP on gametes, particularly spermatozoa, remains under-investigated.

Purpose of the Study:

• To assess the internalization of nanoplastics (NP) in mature equine spermatozoa.
• To evaluate the effects of NP exposure on sperm quality parameters.

Main Methods:

• Equine ejaculates were incubated with varying concentrations (10-200 μg/mL) of 30 nm polystyrene NP.
• Sperm viability, mitochondrial activity, intracellular ROS, and motility were assessed via flow cytometry and CASA.
• NP internalization was confirmed using confocal microscopy and fluorescent NP.

Main Results:

• Nanoplastics were internalized by live spermatozoa, localizing in the post-acrosomal and mid-piece regions.
• NP exposure significantly reduced sperm viability and mitochondrial activity.
• Increased intracellular reactive oxygen species (ROS) levels were observed in NP-exposed sperm.

Conclusions:

• Nanoplastic internalization compromises equine sperm quality.
• Mitochondrial activity is a primary target of NP toxicity in spermatozoa.
• Further research is needed to understand the full implications of NP exposure on equine fertility.