Kazuhisa Tomita1,2, Shinji Sakai3, Mehdi Khanmohammadi3, Takayuki Yamochi4, Shu Hashimoto4, Masayuki Anzai5, Yoshiharu Morimoto6, Masahito Taya3, Yoshihiko Hosoi5. 1. IVF Namba Clinic, 1-17-28 Minamihorie, Nishi-ku, Osaka, 550-0015, Japan. tomita@ivfnamba.com. 2. Laboratory of Molecular Developmental Biology, Graduate School of Biology-Oriented Science and Technology, Kinki University, Wakayama, 649-6493, Japan. tomita@ivfnamba.com. 3. Division of Chemical Engineering, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka, 560-8531, Japan. 4. IVF Namba Clinic, 1-17-28 Minamihorie, Nishi-ku, Osaka, 550-0015, Japan. 5. Laboratory of Molecular Developmental Biology, Graduate School of Biology-Oriented Science and Technology, Kinki University, Wakayama, 649-6493, Japan. 6. HORAC Grand Front Osaka Clinic, 3-1 Ofuka-cho, Kita-ku, Osaka, 530-0011, Japan.
Abstract
PURPOSE: We investigated whether enzymatically fabricated hyaluronan (HA) microcapsules were feasible for use in the cryopreservation of a small number of sperm. METHODS: HA microcapsules were fabricated using a system of water-immiscible fluid under laminar flow. Three sperm were injected into a hollow HA microcapsule using a micromanipulator. Capsules containing injected sperm were incubated in a freezing medium composed of sucrose as the cryoprotectant and then placed in a Cryotop® device and plunged into liquid nitrogen. After thawing, the capsule was degraded by hyaluronidase, and the recovery rate of sperm and their motility were investigated. RESULTS: The HA microcapsule measuring 200 μm in diameter and with a 30-μm thick membrane was handled using a conventional intracytoplasmic sperm injection (ICSI) system, and the procedure involved the injection of sperm into the capsule. The HA microcapsules containing sperm were cryopreserved in a Cryotop® device and decomposed by the addition of hyaluronidase. The recovery rate of sperm after cryopreservation and degradation of HA microcapsules was sufficient for use in clinical practice (90 %). CONCLUSIONS: Hollow HA microcapsules can be used for the cryopreservation of a small number of sperm without producing adverse effects on sperm quality.
PURPOSE: We investigated whether enzymatically fabricated hyaluronan (HA) microcapsules were feasible for use in the cryopreservation of a small number of sperm. METHODS:HA microcapsules were fabricated using a system of water-immiscible fluid under laminar flow. Three sperm were injected into a hollow HA microcapsule using a micromanipulator. Capsules containing injected sperm were incubated in a freezing medium composed of sucrose as the cryoprotectant and then placed in a Cryotop® device and plunged into liquid nitrogen. After thawing, the capsule was degraded by hyaluronidase, and the recovery rate of sperm and their motility were investigated. RESULTS: The HA microcapsule measuring 200 μm in diameter and with a 30-μm thick membrane was handled using a conventional intracytoplasmic sperm injection (ICSI) system, and the procedure involved the injection of sperm into the capsule. The HA microcapsules containing sperm were cryopreserved in a Cryotop® device and decomposed by the addition of hyaluronidase. The recovery rate of sperm after cryopreservation and degradation of HA microcapsules was sufficient for use in clinical practice (90 %). CONCLUSIONS: Hollow HA microcapsules can be used for the cryopreservation of a small number of sperm without producing adverse effects on sperm quality.
Entities:
Keywords:
Human sperm cryopreservation; Hyaluronan; ICSI; Microcapsule; Small number of sperm
Authors: E Isachenko; V Isachenko; I I Katkov; G Rahimi; T Schöndorf; P Mallmann; S Dessole; F Nawroth Journal: Hum Reprod Date: 2004-03-11 Impact factor: 6.918
Authors: Vladimir Isachenko; Eugenia Isachenko; Igor I Katkov; Markus Montag; Salvatore Dessole; Frank Nawroth; Hans Van Der Ven Journal: Biol Reprod Date: 2004-06-02 Impact factor: 4.285