Hyaluronic acid substantially increases the retention of motility in cryopreserved/thawed human spermatozoa

Abstract

We have demonstrated previously that hyaluronic acid (HA) improves the velocity and the retention of motility in freshly ejaculated human spermatozoa. In the present work, we examined the effect of HA on cryopreserved/ thawed spermatozoa in four paradigms: (i) effect of HA on sperm motility and velocity in semen; (ii) stabilizing effect of HA after 4 h of incubation when the decline of sperm motility is already detectable; (iii) the duration of improved motility after the separation of spermatozoa from HA by Percoll gradient centrifugation; and (iv) motility of sperm cryopreserved in the presence of HA. HA improved the retention of sperm motility in thawed spermatozoa. Indeed, the motility values after 30 h were approximately 100% higher in the HA compared with the control samples. This effect of HA was also evident in the stabilization of spermatozoa with already declining motility. After removal of the HA from the incubation medium, significantly increased motility in the HA-exposed spermatozoa was still detectable for at least 4 h. Cryopreservation of spermatozoa in the presence of HA did not improve the recovery of motility. The data indicate that HA improves the retention of motility of cryopreserved/thawed spermatozoa, even after the removal of HA from the incubation medium. The utilization of HA will probably prove beneficial in assisted reproduction: in intrauterine insemination and in in-vitro fertilization (IVF), the extended sperm motility and velocity will enhance the fertilizing efficiency; in intracytoplasmic sperm injection (ICSI), the improved motility will facilitate the identification of viable spermatozoa. Because HA is a physiological component of the cumulus and of the female and male reproductive tracts, administration of HA should not cause ethical concerns.

Cryopreservation of Ram Semen in Extenders Containing Soybean Lecithin as Cryoprotectant and Hyaluronic Acid as Antioxidant

“…In parallel, some studies have found positive effects of this molecule for the refrigerated storage, cryopreservation and incubation of human (Sbracia et al. ) and boar spermatozoa (Yeste et al. ).…”

Evaluation of a transfer medium containing high concentration of hyaluronan in human in vitro fertilization

“…It attracts water, thus forming a highly hydrated gel, which in turn promotes expansion of the extracellular surfaces (19). It is interesting that HA also improves motility (20) in fresh and frozen/thawed human sperm (21) and promotes capacitation and acrosome reaction in mammalian sperm (22).…”

Effectiveness of Assisted Reproduction Techniques as an Answer to Male Infertility

“…Human spermatozoa are not very sensitive to damage caused by rapid initial cooling (cold shock) and they may be more resistant than other cells to cryopreservation damage because of their low water content (50%). Nevertheless, the postthaw motility of human spermatozoa can be ranged between 20 and 50 percent (Sbracia et al 1997). It is believed that the cause of this decrease could be multiple including diminished integrity of the membranes and cryodamage to the membranes of the intracellular compartments, which affects energy metabolism and synthesis.…”