Microfluidic devices employing chemo‐ and thermotaxis for sperm selection can improve sperm parameters and function in patients with high DNA fragmentation

Abstract

Conventional sperm processing uses centrifugation has a negative effect on sperm parameters and DNA integrity. We designed and fabricated a novel microfluid device based on chemotaxis and thermotaxis, and compared it with the swim‐up method. Twenty normal samples with high DNA fragmentation were included. Each sample was divided into four groups: Group 1, control, Group 2: sperm selection by thermotaxis, Group 3: sperm selection by chemotaxis, and Group 4: sperm selection with thermotaxis and chemotaxis. We used cumulus cells in a microfluid device to create chemotaxis, and, two warm stages to form a temperature gradient for thermotaxis. The spermatozoa were assessed based on the concentration, motility, and fine morphology using Motile Sperm Organelle Morphology Examination, mitochondrial membrane potential (MMP), acrosome reaction (AR), and sperm DNA fragmentation. Concentration (22.40 ± 5.39 vs. 66.50 ± 19.21; p < 0.001) and DNA fragmentation (12.30 ± 3.96% vs. 17.95 ± 2.89%; p < 0.001) after selection in the chemotaxis and thermotaxis microfluid device were significantly lower than control group. The progressive motility (93.75 ± 4.39% vs. 75.55 ± 5.86%, p < 0.001), normal morphology (15.45 ± 2.50% vs. 10.35 ± 3.36, p < 0.001), MMP (97.65 ± 1.81% vs. 94 ± 3.89%, p = 0.02), and AR status (79.20 ± 5.28% vs. 31.20 ± 5.24%, p < 0.001) in the chemotaxis and thermotaxis microfluid device were significantly increased compared to control group. According to these findings, spermatozoa that have penetrated the cumulus oophorus have better morphology and motility, as well as acrosome reactivity and DNA integrity.

Microfluidic chip as a promising evaluation method in assisted reproduction: A systematic review

“…Twenty‐six studies focused on sperm motility (Figure 3a–c). 20,32–56 Among them, five tested sperm chemotaxis ability using ovarian fragments, 32 oviductal fluid, 54 cumulus cells, 34 acetylcholine, 55 or progesterone 45 . Four studies mimicked the female reproductive tract when assessing sperm motility, including the ovary, 34 cervix, 39,46 and fallopian tube, 51 aiming to simulate the natural in vivo conditions (Figure 3d–f).…”

Ultra-Rapid Freezing and Rapid Freezing Methods in Clinical ICSI Program: Effects on Sperm Biological Characteristics, DNA Methylation Stability, DNA Methyltransferase Activity, and Embryo Morphokinetics

“…The stained smears were washed indirectly with PBS and then allowed to dry completely. For evaluation of acrosomal status, fluorescence microscopy (Olympus Co, Tokyo, Japan) at 1,000 magnification and a U-MNIB3 filter was used with immersion oil [29].…”

Faster sperm selected by rheotaxis leads to superior early embryonic development in vitro

“…[21][22][23] Although sperm chemotaxis in mammals remains controversial, 24,25 recent strides toward sorting spermatozoa based on chemotaxis and thermotaxis has led to higher quality spermatozoa in humans. 26 Cells are attracted to the walls when swimming in confined spaces. 27 This hydrodynamic feature suggests that a significant amount of sperm motion takes place along the microenvironment walls within the FRT.…”

“…21–23 Although sperm chemotaxis in mammals remains controversial, 24,25 recent strides toward sorting spermatozoa based on chemotaxis and thermotaxis has led to higher quality spermatozoa in humans. 26…”