Changes on membrane integrity and ultrastructure of human sperm after freeze-drying

• Published in: Journal of reproduction and contraception Vol. 27; no. 2; pp. 76 - 81
• Main Authors: ZHU, Wei-jie, LI, Jing, XIAO, Luan-juan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2016
• Subjects: freeze-drying; human sperm; lyophilization; membrane integrity; ultrastructure; 人精子; 冷冻干燥法; 形态异常; 扫描电镜; 男性不育症; 精子头部; 膜完整性; 超微结构; human sperm; freeze-drying; membrane integrity; lyophilization; ultrastructure
• ISSN: 1001-7844
• DOI: 10.7669/j.issn.1001-7844.2016.02.0076

Objective To observe changes on membrane integrity and ultrastructure of human sperm after freeze-drying.Methods Semen samples from both normospermic donors（group A, n=15） and infertile men with abnormal sperm parameters（group B, n=15） were enrolled into this study. These samples were freeze-dried by using a freeze-drying method. The membrane integrity in the head and tail regions of individual spermatozoon was examined by using the combined hypo-osmotic swelling-eosin Y exclusion test. Sperm ultrastructure in groups A（n=3） and B（n=3） was observed by scanning electron microscopy（SEM）.Results After freeze-drying, all spermatozoa were types I（damaged both head and tail membranes） and III（damaged head membrane and intact tail membrane） membrane integrity in groups A and B. Type III of group B had lower value than that of group A（P〈0.01）. Under SEM, intact freeze-dried spermatozoa including abnormal morphology and normal-looking morphology were observed in both groups A and B. A few freezedried sperm heads had unsmooth or fuzzy surface. Isolated sperm heads, bent tails,broken sperm tails or fragmentary tails were more frequently seen in group B than those in group A.Conclusion Freeze-dried human spermatozoa could have intact structural components. However, freeze-drying resulted in severe damage on membrane integrity and ultrastructure of sperm. Samples from infertile men would have less resistance to freeze-drying.