DEVELOPMENT OF AN ACOUSTO-MICROFLUIDIC STRATEGY FOR IMPROVING BOVINE SPERM FUNCTIONALITY

Abstract

Cryopreservation of bovine spermatozoa is a common practice that is widely used in artificial insemination (AI) in the cattle breeding industry. However, post-thaw motility, viability and other important functional parameters that play crucial role in fertilization success are often significantly reduced due to cryodamage or other stress to the cells. This issue creates fertilization success inconsistent, although the consistency of fertilization success is crucial for farmers and their economic well-being. While certain solutions have been developed to address this problem none of them aimed to improve the existing semen, maintaining a balance between the cost, effectiveness and biocompatibility. To address this issue, this study aimed to develop an acoustofluidic device that can improve the functional parameters of bovine spermatozoa using surface standing acoustic waves (sSAW). The acoustofluidic device was fabricated using the nanofabrication and photolithography techniques creating interdigital transducers (IDTs) on the surface of the lithium niobate (LiNbO3) substrate with an attached polydimethylsiloxane (PDMS) flow chamber. The experimental procedure was done using fluorescent microscopy, and imaging flow cytometry (IFC) techniques, and using mitochondrial membrane potential (MMP) as a viability marker. The results demonstrated a significant increase in tetramethylrhodamine methyl ester (TMRM)+ subpopulation after exposure to sSAW, which suggests that sSAW has positive impact on the MMP. These findings position the acoustofluidic approach of the spermatozoa treatment as an advanced, biocompatible, and non-invasive tool that may contribute to the higher fertilization rates for the cattle breeding industry resulting in economic benefits