Carboxylated Poly-<span style="font-variant: small-caps">l</span>-Lysine as a Macromolecular Cryoprotective Agent Enables the Development of Defined and Xeno-Free Human Sperm Cryopreservation Reagents

In human sperm cryopreservation, test yolk buffer and human serum albumin have been used as permeating macromolecular-weight cryoprotectants. In clinical reproductive medicine, human serum albumin is frequently used because of low risks of zoonoses and allergic reactions. However, the risk of alloge...

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Bibliographic Details
Main Authors: Hiroki Takeuchi, Mikiko Nishioka, Tadashi Maezawa, Yuko Kitano, Kento Terada-Yoshikawa, Ryota Tachibana, Manabu Kato, Suong-hyu Hyon, Yuki Gen, Kayo Tanaka, Kuniaki Toriyabe, Masafumi Nii, Eiji Kondo, Tomoaki Ikeda
Format: Article
Language:English
Published: MDPI AG 2021-06-01
Series:Cells
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Online Access:https://www.mdpi.com/2073-4409/10/6/1435
Description
Summary:In human sperm cryopreservation, test yolk buffer and human serum albumin have been used as permeating macromolecular-weight cryoprotectants. In clinical reproductive medicine, human serum albumin is frequently used because of low risks of zoonoses and allergic reactions. However, the risk of allogeneic infectious diseases exists, and the supply may be unstable because human serum albumin is derived from human blood. Therefore, the development of xeno-free human sperm cryopreservative reagents that could overcome the aforementioned problems is warranted. We succeeded in developing a new xeno-free and defined sperm cryopreservation reagent containing glycerol, carboxylated poly-<span style="font-variant: small-caps;">l</span>-lysine, and raffinose. The cryopreservation reagent was not significantly different in terms of sperm motility, viability, and DNA fragmentation and was comparable in performance to a commercial cryopreservation reagent containing human serum albumin. Moreover, the addition of saccharides was essential for its long-term storage. These results may help elucidate the unknown function of macromolecular-weight permeating cryoprotective agents.
ISSN:2073-4409