Electromagnetic field in human sperm cryopreservation improves fertilizing potential of thawed sperm through physicochemical modification of water molecules in freezing medium

Abstract

Physicochemical properties of water molecules as the main compositions of the freezing media can be affected by the electromagnetic fled. The purpose of this study was to apply extremely low repetition rate electromagnetic fields (ELEFs) to change the molecular network of water molecules existing in freezing media used for human sperm cryopreservation. First, different time periods and pulsed electromagnetic fields were used to evaluate the physiochemical properties of water. The lowest rate of cluster size, surface tension, viscosity, and density was observed for water samples exposed to 1000 Hz ELEF for 60 min (P < 0.05) that could be results in small ice crystal formation. Therefore, this treatment was selected for further evaluations in human sperm freezing because there was minimal probability of amorphous ice crystallization in this group. To assess fertilizing potential, human semen samples were subjected to ELEF (1000 Hz) water-made freezing medium and cryopreserved. The highest percentage of total motility, progressive motility, viability, membrane integrity, mitochondrial membrane potential, DNA integrity, and TAC were obtained in frozen ELEF as compared to other groups. The percentage of viable spermatozoa (Annexin V - /PI - ) in frozen ELEF was significantly higher than in frozen control. The level of ROS was significantly lower in frozen ELEF when compared to frozen control. It can be concluded that the modification of physicochemical properties of water existing in cryopreservation media by ELEF is a suitable strategy to improve the outcome of cryopreservation.

Cryopreservation of Semen in Domestic Animals: A Review of Current Challenges, Applications, and Prospective Strategies

“…The magnetized extender also decreased ROS concentrations in post-thaw boar sperm [ 190 ]. In a recent study, cryopreserved human sperm was improved by exposing the freezing diluents to a 1000 Hz ELEF [ 191 ].…”

Sperm cryopreservation: current status and future developments

“…Other additives that can be included alongside CPAs and antioxidants include energy substrates (glucose, fructose, L-carnitine etc. ), antifreeze proteins, and other compounds that compensate for osmolarity changes, as well as minerals (higher or lower levels of NaCl and KCl) to manage the ionic composition of the sample (Nash 1962;Katkov 2000;Bilodeau et al 2001;Ghallab et al 2017;Gholami et al 2019;Zandiyeh et al 2020). However, the concentrations of these additives in cryopreservation media will have to be carefully monitored in futureformulations, as even clinically approved CPAs such as glycerol can become toxic above a critical threshold concentration (Pegg 2002;Best 2015).…”

“…The list of constituents given for each CPA and supplement reviewed for human publications If a specific amount was not given, a tick was used to acknowledge its use. (Mahadevan and Trounson 1983;Stanic et al 2000;Hammadeh et al 2001aHammadeh et al , 2001bBanihani et al 2014;Raad et al 2018;Gholami et al 2019;Zandiyeh et al 2020). If a specific amount was not given, a tick was used to acknowledge its use.…”

“…To avoid this inter-species variation, the majority of publications compared focused on the cryopreservation of human spermatozoa, with 32 detailed projects identified spanning 13 different CPA media, four supplements and three freezing programs. A full list of the CPA employed, supplements included and freezing method, can be found in Table 1 (Peek et al 1982;Mahadevan and Trounson 1983;Stanic et al 2000;Hammadeh et al 2001aHammadeh et al , 2001bThomson et al 2009;Raad et al 2018;Gholami et al 2019;Zandiyeh et al 2020). Similar to the animal models, the most commonly performed post-thaw test for human spermatozoa was the percentage of motility (21/32).…”

“…Comparison of human-focused papers demonstrating freezing method, DNA integrity and total motility results. (Mahadevan and Trounson 1983;Stanic et al 2000;Hammadeh et al 2001aHammadeh et al , 2001bBanihani et al 2014;Raad et al 2018;Gholami et al 2019;Zandiyeh et al 2020).…”