Investigation of Polymer Functional Groups and Their Impact on Sperm Viability

We have observed that the viability of sperm decreases depending on the polymer materials used in assisted reproductive technologies. We have done some preliminary studies and have determined that sperm can be negatively impacted by either the functional groups present on polymers, surface charge, surface morphology, and other polymer properties. We have further noted increased incidence in gamete toxicity in contact materials that were recently purchased after product substitutions became necessary due to supply chain issues. We believe this is due to the use of additives, mold release agents, and other contaminants that are present on the polymer surfaces. In this study, we propose to investigate the polymer properties of contact materials used in assisted reproductive techniques (ART) to determine their impact on the viability of sperm after exposure to different polymers over time. Following sperm exposure to various materials, we will test sperm function using the hamster egg penetration test. In addition, the Phadnis lab has developed a “sperm racetrack”, an optically clear counter-current microfluidic channel that can be used as a sensitive assay to measure other functional aspects of sperm including linear velocity, swim efficiency and longevity of motility. In this study, we aim to examine the material properties that may affect sperm viability, to determine whether there are negative impacts on sperm after exposure to specific polymer materials and to identify materials that are most compatible with gametes, with the ultimate goal of optimizing the composition of contact materials used in ART.

Current Status

2024-02-15
The Utah Center for Reproductive Medicine research continues to focus on the cause of declining sperm viability and motility. Our previous investigations identified a potential link between sperm motility and material contaminants used to handle the samples. Further analysis using the Scanning Electron Microscope has provided insight into potential contaminants. We have identified specific elements, including aluminum, titanium, potassium, barium, and carboxylic groups, which may contribute to a decline in motility. This information helps understand potential contaminants found within all samples used for sperm collection and analysis. Preliminary motility tests were conducted to assess the impact of contaminants on sperm movement. Prior results indicate a correlation between certain materials and reduced sperm motility, specifically the syringes used. To delve deeper, we will expose sperm cells to syringes and other relevant samples, monitoring motility at 24 hours. If the findings result in an abnormal decrease in motility, we will test sperm motility every hour to determine the average time it takes to decrease.
Additionally, our team is actively developing a specialized “race track” for sperm to navigate. This controlled environment will allow us to isolate and study the effects of contaminants on sperm motility. First, we are working to determine the ideal human tubal fluid flow rate along the race track to facilitate optimal sperm forward movement. Next, we will extract sperm at specific locations along the race track and examine various characteristics. This approach allows us to identify potential patterns and correlations. In the subsequent phase, we will expose sperm to contaminants and compare their performance against a control group. This comparative analysis will help us discern which samples exhibit unfavorable conditions for sperm motility.












The image above shows the microfluidic device described as a “sperm race track” that will be used to compare sample data. There are two channels, each with two ends meant to run comparison tests side by side. There is an input end to insert human tubal fluid into and another to flow waste fluid. Additionally, ports are located to insert a syringe to extract the sperm at that location for further testing on each extraction.