Sperm quality metrics were improved by a biomimetic microfluidic selection platform compared to swim-up methods

Abstract

Sperm selection is an essential component of all assisted reproductive treatments (ARTs) and is by far the most neglected step in the ART workflow in regard to technological innovation. Conventional sperm selection methodologies typically produce a higher total number of sperm with variable motilities, morphologies, and levels of DNA integrity. Gold-standard techniques, including density gradient centrifugation (DGC) and swim-up (SU), have been shown to induce DNA fragmentation through introducing reactive oxygen species (ROS) during centrifugation. Here, we demonstrate a 3D printed, biologically inspired microfluidic sperm selection device (MSSP) that utilizes multiple methods to simulate a sperms journey toward selection. Sperm are first selected based on their motility and boundary-following behavior and then on their expression of apoptotic markers, yielding over 68% more motile sperm than that of previously reported methods with a lower incidence of DNA fragmentation and apoptosis. Sperm from the MSSP also demonstrated higher motile sperm recovery after cryopreservation than that of SU or neat semen. Experiments were conducted side-by-side against conventional SU methods using human semen (n = 33) and showed over an 85% improvement in DNA integrity with an average 90% reduction in sperm apoptosis. These results that the platform is easy-to-use for sperm selection and mimics the biological function of the female reproductive tract during conception.

Microfluidics: a concise review of the history, principles, design, applications, and future outlook

“…Additionally, the sperm recovered from this chip after cryopreservation showed higher motility compared to other methods like swim-up or neat semen. 156…”

Bio-inspired progressive motile sperm separation using joint rheotaxis and boundary-following behavior

“…They also used their device in conjunction with superparamagnetic beads for apoptotic sperm trapping. 41 In a similar approach, Xiao et al integrated the standard Petri dish used in the ICSI procedure with a two-layer film, consisting of a bottom layer film patterned with microchannels and a cover film. The microchannels promoted sperm boundary-following behavior and led to the isolation of motile sperms with high DNA integrity.…”

Embryonic development through in vitro fertilization using high-quality bovine sperm separated in a biomimetic cervix environment

“…In microfluidic technology, micro-structures formed in channels can separate sperm depending on their motility, 13–18 and the rheotaxis, which guides sperm's stream against the flow, can be utilized in microchannels to obtain highly motile sperm. 19,20 Moreover, by using the microfluidic platform, sperm can be sorted through chemotaxis effect, 21,22 the ability of sperm to detect chemical signals released by ovulated oocytes in the reproductive tract.…”