the effect of hyaluronan on morphology, motility and vitality of mouse sperm before cryopreservation and after the thawing

introduction: sperm cryopreservation is widely used as a way of preserving the male sperm used in future artificial insemination and fertilization. despite all the recent advances in cryopreservation technology, sperm motility is negatively affected by freezing and the thawing afterwards. yet hyaluronic acid is believed to improve the vitality and motility of the sperm, enhancing the physiological functions of spermatozoa for the conception.  this study investigates the effects of hyaluronan (ha) supplementation on characteristics of morphology, motility and vitality of mice sperm before the freezing and after the thawing. materials and methods: 6 male mice were randomly selected for the purpose of this study. semen samples were removed from the animals and then were divided into four groups. the first was control group without freezing. the second was the frozen control group. for the third, hyaluronan was added before the freezing, while it was used after the thawing for the last one. semen was frozen in 1.8 ml cryotubes with %18 raffinose and % 3 skim milk. sperm morphology was examined through papa nicolao staining. eosin b was used to analyses viability. motility parameters were assessed through observation under inverted microscope.  data were analyzed using the t- test. results: based on the results of the study, ha supplementation (750 µg / ml) improved the motility and vitality parameters (p<0.05) when it was added after the thawing, while no effect was observed when it was added before the freezing.  ha did not change the sperm morphology when it was added either before the freezing or after the thawing. conclusion: based on the results of the study, ha supplementation (750 µg / ml) after the thawing of the frozen sperm improves the motility and the vitality of the sperms.