[Ultra-rapid cryopreservation of human spermatozoa with different concentrations of sucrose].

Objective: To explore the feasibility of ultra-rapid freezing of human spermatozoa in the cryogenic vial with different concentrations of sucrose solution.Methods: We divided 40 normal semen samples prepared with the routine swim-up technique into 6 aliquots,1 as the control and the other 5 cryopreserved with sucrose solution at the concentrations of 0.15,0.20,0.25 and 0.30 mol/L,respectively.After thawing,we determined and compared the motility,progressive motility and plasma membrane integrity of the sperm among the 6 groups.Results: The motility,progressive motility and plasma membrane integrity of the sperm were significantly lower after thawing than before cryopreservation([96.2±1.8]%,[93.8±2.8]% and [99.0±0.8]%)(P0.05).Post-thawing sperm motility was(55.5±6.3)% in the 0.20 mol/L sucrose group,significantly higher than in the 0.15,0.25 and 0.30 mol/L groups([45.9±6.6]%,[50.4±9.4]% and [45.5±11.2]%)(P0.05),and it was(53.6±5.0)% in the conventional freezing group,with no statistically significant difference from the 0.20 and 0.25 mol/L sucrose cryopreservation groups(P0.05),but remarkably higher than in the 0.15 and 0.30 mol/L groups(P0.05).Post-thawing progressive sperm motility exhibited no statistically significant differences between the 0.20 mol/L sucrose and conventional freezing groups([44.4±7.4]% vs [42.3±8.1]%,P0.05),but markedly higher in both than in the 0.15,0.25 and 0.30 mol/L sucrose groups([37.1±8.3]%,[33.1±9.2]% and [22.0±9.1]%)(P0.05).Post-thawing plasma membrane integrity was significantly higher in the 0.20 mol/L sucrose cryopreservation group([70.1±6.9]%) than in either the conventional freezing group([63.1±6.8]%) or the 0.15,0.25 and 0.30 mol/L sucrose groups([57.7±8.3]%,[63.5±10.7]% and [57.8±12.9]%)(P0.05).Conclusion: As a simple,safe and effective method,ultra-rapid freezing with sucrose solution at the final concentration of 0.20 mol/L can be used for the cryopreservation of human spermatozoa.