Human Sperm Cryopreservation Using Polyvinyl Alcohol as a Cryoprotectant

Cryopreservation is a procedure commonly used worldwide to keep a broad range of living cells and tissues, such as sperm, oocytes, and embryos, at extremely low temperatures for long periods while retaining the integrity of their structures. In order to preserve fertility during cancer treatment, sperm cryopreservation has become a common practice. Polyvinyl alcohol (PVA), a synthetic polymer, has shown to prevent the growth of ice crystals and inhibit ice recrystallization at lower concentrations. In the current investigation, the aim was to assess the PVA as a supplement to improve human sperm cryopreservation. Sperm from 21 normospermic males were collected and divided into five equal groups: Fresh, frozen control, 0.01% PVA, 0.1% PVA, and 0.5% PVA. After being frozen and thawed, the main sperm parameters were examined, such as motility, viability, morphology, malondialdehyde (MDA) level, and DNA fragmentation. Based on the results, human sperm motility and viability were increased by adding 0.01% PVA in comparison with the control group. Moreover, different concentrations of PVA did not affect morphology, MDA, or DNA fragmentation. It is reasonable to declare that using an optimal concentration of impermeable ice inhibitors, such as PVA, in conjunction with a permeable cryoprotectant significantly improves the enhancement of human sperm after thawing.