In vitro survival kinetics of microfluidic‐sorted bovine spermatozoa

Abstract

Background The isolation and characterization of sperm subpopulations that can achieve fertilization is a major challenge of assisted reproduction methods. We focused on the microfluidic sperm sorter as a novel tool for collecting highly motile spermatozoa from heterogeneous semen samples. Objectives This study primarily aims to obtain baseline information on sorted spermatozoa according to its characteristics and in vitro life span. Materials and Methods Frozen‐thawed bull semen was subjected to microfluidic sperm sorting using diffuser‐type microfluidic sperm sorter (DMSS). After sorting, samples were collected as the sorted spermatozoa and unsorted residual spermatozoa and incubated at 37°C for subsequent evaluation. The samples were assessed at different time points (0 or 1, 6, and 24 h) in terms of motility, which was measured by computer‐assisted sperm analysis (CASA), membrane integrity, mitochondrial function, and adenosine triphosphate (ATP) production after sorting (0 h). To determine the characteristics and efficiency of DMSS sorting, the sorted spermatozoa were compared with samples collected using the swim‐up method, a conventional method in motile sperm selection. Results A comparison between the sorted and residual spermatozoa demonstrated significantly higher motility parameters, membrane integrity, and mitochondrial function of the sorted spermatozoa until 6 h after incubation. The time course decrement of membrane and mitochondrial status were subjected to curve fitting and theoretically supported. Sperm ATP production measured immediately after sorting showed higher ATP generation of the sorted spermatozoa compared with the unsorted, frozen‐thawed spermatozoa. The motility parameters and mitochondrial activity of DMSS‐sorted spermatozoa were higher than the swim‐up‐collected spermatozoa (p < 0.05). Discussion and Conclusion These results indicate that DMSS sorting can strictly select highly motile spermatozoa with the ability to maintain its membrane integrity and mitochondrial function related to ATP production. We speculate that the device that is able to sort high‐quality spermatozoa can have great potential in assisted reproduction.

Mitochondria Content and Activity Are Crucial Parameters for Bull Sperm Quality Evaluation

“…Effective semen cryopreservation is one of the key elements contributing to the success of assisted reproductive technologies (ART) in cattle breeding and human reproductive medicine. Published studies often make comparisons between the ejaculates of different bulls/breeds or between the swim up fractions [ 31 , 42 , 43 ]. While investigating the topic, we have not come across works that would compare bulls with high and low semen evaluation scores.…”

Does using microfluidic sperm sorting chips in bovine IVEP affect blastocyst development?

“…Choosing morphologically better quality and motile spermatozoa allows for increased sperm capacitation ability and, as a result, more successful fertilization with oocyte (Mirsanei et al, 2022; Yildiz & Yuksel, 2019). Accordingly, the use of microfluidic sperm sorting devices allows the selection of spermatozoa that are more suitable for in vitro fertilization (Anbari et al, 2021; Asghar et al, 2014; Ogata et al, 2021; Pujol et al, 2022; Quinn et al, 2017). Moreover, Ogata et al (2021) reported that a diffuser‐type microfluidic sperm sorter, a different sperm‐separating device, can select highly motile spermatozoa with the ability to maintain its membrane integrity and mitochondrial function related to ATP production.…”

“…Accordingly, the use of microfluidic sperm sorting devices allows the selection of spermatozoa that are more suitable for in vitro fertilization (Anbari et al, 2021; Asghar et al, 2014; Ogata et al, 2021; Pujol et al, 2022; Quinn et al, 2017). Moreover, Ogata et al (2021) reported that a diffuser‐type microfluidic sperm sorter, a different sperm‐separating device, can select highly motile spermatozoa with the ability to maintain its membrane integrity and mitochondrial function related to ATP production. Thus, it is thought that the rate of reaching the blastocyst and the quality of the blastocyst may have increased after the selection of better quality and less damaged spermatozoa and successful fertilization of the oocyte and spermatozoa.…”

Microfluidics-A novel technique for high quality sperm selection for greater ART outcomes

“…In bovines, more functional and progressively motile spermatozoa with high DNA integrity have been obtained recently (Nagata et al, 2018), based on ability of sperm to cross laminar flow streamlines. Highly motile spermatozoa with intact membrane integrity and mitochondrial function from frozen-thawed bull semen have been successfully sorted using diffuser-type microfluidic sperm sorter (DMSS, Ogata et al, 2021). DMSS is now considered by many as a high-quality sperm selection method to achieve great potential of assisted reproduction in bovines.…”