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Updated: Sep 29, 2025
Modified MicroSecure Vitrification: A Safe, Simple and Highly Effective Cryopreservation Procedure for Human Blastocysts
Published on: March 2, 2017
Cryoprotectants-Free Vitrification and Conventional Freezing of Human Spermatozoa: A Comparative Transcript Profiling
Mengying Wang1, Plamen Todorov2, Wanxue Wang1
1Department of Obstetrics and Gynaecology, Medical Faculty, Cologne University, 50931 Cologne, Germany.
Introduction:
Spermatozoa cryopreservation is an important technique to preserve fertility for males. This study aimed at exploring the stability of epigenetics information in human spermatozoa, manipulated by two different technologies, freezing and vitrification.
Methods:
Spermatozoa samples were distributed into three groups: 1. Fresh spermatozoa (control group), 2. Frozen spermatozoa, 3. Vitrified spermatozoa. Epigenetic differences of fresh and cryopreserved spermatozoa were evaluated using high-throughput RNA sequencing.
Results:
Differentially expressed genes (DEGs) in frozen (1103 genes) and vitrified (333 genes) spermatozoa were evaluated. The bioinformatical analysis identified 8 and 15 significant pathways in groups of frozen and vitrified spermatozoa, respectively. The majority of these pathways are most relevant to immune and infectious diseases. The DEGs of the fertilization process are not detected during vitrification. The freezing process induces more down-regulation of genes and is relevant to apoptosis changes and immune response.
Conclusion:
Cryopreservation of human spermatozoa is an epigenetically safe method for male fertility preservation. Cryoprotectant-free vitrification can induce more minor biological changes in human spermatozoa, in comparison with conventional freezing.
