Examination of the safety of intracytoplasmic injection procedures by using bovine zygotes

Abstract

We have evaluated the safety of intracytoplasmic sperm injection(ICSI) procedures by using bovine zygotes. Bovine zygotes were injected with a small amount (2-3 pl) of either medium alone or medium containing polyvinylpyrrolidone (PVP) (sham-ICSI, without spermatozoon) using the same procedure as ICSI, and the subsequent in-vitro embryonic development and embryo quality (number of cells/blastocyst) were examined. Control zygotes which had not been injected were similarly evaluated after in-vitro development. The sham-ICSI of either medium alone or medium containing PVP into bovine zygotes had no harmful effects on the rate of normal fertilization and on the rate of development to hatched blastocyst stage compared with those of controls (P > 0.05). In addition, no harmful effects were observed in the number of cells per blastocyst (embryo quality). The results suggest, for the first time, that the ICSI procedures currently used for animal and human ICSI are neither detrimental to embryonic development nor detrimental to embryo quality.

Effect of polyvinylpyrrolidone on sperm function and early embryonic development following intracytoplasmic sperm injection in human assisted reproduction

“…However, our results showed that the direct injection of PVP into IVF embryos resulted in a reduction in the rates of cleavage and blastocyst formation, along with a reduction in the number of cells in blastocysts, relative to control IVF embryos. The reason for this was the smaller volume used by Motoishi et al [44] compared to that used by Kato et al [29]. Motoishi et al injected only 2–3 pl of PVP into the bovine zygote while Kato et al injected 24–32 pl of PVP.…”

Stallion Sperm Selection: Past, Present, and Future Trends

“…At first, Percoll was used for processing spermatozoa, mixing the colloid with various salt solutions, such as Tyrodes with lactate, albumin, and pyruvate to achieve different densities for the density gradient [3]. Concern was expressed about the potential toxicity of PVP for spermatozoa [9], although reports varied [10,11], which may reflect species differences in sperm susceptibility or even differences in the PVP from various sources [12]. Subsequently, some batches of Percoll were found to have high endotoxin levels, necessitating the testing of each batch to identify those that were nontoxic to spermatozoa [13], which was not conducive to widespread use of density gradient centrifugation (DGC) of semen.…”

Comparison of Blastulation and Pregnancy Rates of Fertilized Human Oocytes Obtained after Conventional In Vitro Fertilization and Intracytoplasmic Sperm Injection.

“…However, Motoishi et al [20] suggested that the ICSI procedures currently used for animal and human ICSI are neither detrimental to embryonic development nor detrimental to embryo quality (blastulation and number of cells per blastocyst). On the other hand, it has been suggested that toxicity of PVP is related to its impurities.…”