Hydroxypropyl cellulose as an option for supplementation of cryoprotectant solutions for embryo vitrification in human assisted reproductive technologies

Abstract

Hydroxypropyl cellulose (HPC) was investigated as a replacement for serum substitute supplement (SSS) for use in cryoprotectant solutions for embryo vitrification. Mouse blastocysts from inbred (n = 1056), hybrid (n = 128) strains, and 121 vitrified blastocysts donated by infertile patients (n = 102) were used. Mouse and human blastocysts, with or without zona pellucida, were vitrified and warmed in either 1% or 5% HPC or in 5% or 20% SSS-supplemented media using the Cryotop (Kitazato BioPharma Co. Ltd, Fuji, Japan) method, and the survival and oxygen consumption rates were assessed. Viscosity of each vitrification solution was compared. Survival rates of mouse hybrid blastocysts and human zona pellucida-intact blastocysts were comparable among the groups. Mouse and human zona pellucida-free blastocysts, which normally exhibit poor cryoresistance, showed significantly higher survival rates in 5% HPC than 5% SSS (P < 0.05). The 5% HPC-supplemented vitrification solution showed a significantly higher viscosity (P < 0.05). The blastocysts were easily detached from the Cryotop strip during warming when HPC-supplemented vitrification solution was used. The oxygen consumption rates were similar between non-vitrified and 5% HPC groups. The results suggest possible use of HPC for supplementation of cryoprotectant solutions and provide useful information to improve vitrification protocols.

A combination of hydroxypropyl cellulose and trehalose as supplementation for vitrification of human oocytes: a retrospective cohort study

“…The potential use of HPC as a macromolecular supplement in oocyte and embryo vitrification solutions has been previously described [14,47,48]. Inoue et al first evaluated the use of HPC as a substitute for animal-derived serum and proteins in human oocytes, finding no differences in survival rate when compared with using SSS [14].…”

Effects of gonadotropin administration on clinical outcomes in clomiphene citrate‐based minimal stimulation cycle IVF

“…The embryos were cultured to the cleavage or blastocyst stage and vitrified for subsequent use in embryo transfer cycles. The embryo vitrification was performed using Cryotop ® (Kitazato Biopharma), as described previously …”

“…The embryo vitrification was performed using Cryotop ® (Kitazato Biopharma), as described previously. 13…”

Infertility treatment strategy involving combined freeze‐all embryos and single vitrified‐warmed embryo transfer during hormonal replacement cycle for in vitro fertilization of women with hypogonadotropic hypogonadism

“…Selected morphologically and developmentally competent embryos were vitrified for subsequent use in ET cycles. The Cryotop ® method of vitrification (Kitazato Corporation, Shizuoka, Japan) was used, as described previously . In the HR cycle, the administration of estradiol (Hisamitsu Pharmaceutical Co., Inc., Tokyo, Japan, or Bayer AG., Leverkusen, Germany) was started from day 2 or 3 of the cycle.…”