Prevention of zona hardening in non‐human primate oocytes cultured in protein‐free medium

Abstract

These results indicate that fertilization failure occurs when macaque oocytes are cultured in medium without protein, but can be prevented with PVA.

Primate Follicular Development and Oocyte Maturation In Vitro

“…Bovine serum albumin used in early studies (Xu, 2009a) was replaced by human serum protein supplement (SPS; Xu, 2010, 2011a) for relevance to future clinical application. The culture media also contains fetuin, a major glycoprotein in serum and follicular fluid, which reportedly prevents “hardening” of the zona pellucida in a serum-free culture environment (VandeVoort, 2007; Schroeder, 1990). Bovine fetuin is used currently due to unavailability of human protein.…”

Reliable preimplantation genetic diagnosis in thawed human embryos vitrified at cleavage stages without biopsy

“…On the other hand, a setback in biopsying thawed embryos is the hardening of zona pellucida due to freezing and thawing [24] probably because of irreversible denaturation of some unidentified proteins located in the zona. However, assisted hatching [25] or culturing embryos in protein-free medium [26] may improve implantation rates lowered due to zona hardening. The small hole that must be created in the zona for embryo biopsy after thawing may also help the embryo to hatch.…”

Zinc PVA versus potassium dichromate for preservation of microsporidian spores of human origin

“…Zinc sulphate incorporated in zinc PVA has been shown to selectively concentrate viable Cryptosporidium oocysts in the floatation technique (Bukhari and Smith 1995). PVA is widely used in cell culture and tissue engineering and it has been shown to improve the extracellular conditions for cell survival (Cheng and LeDuc 2006;Vandevoort et al 2007). Concerning aqueous potassium dichromate, a concentration of 2-2.5 % at 22°C provides the optimum laboratory conditions for sporulation of Cyclospora, Isospora and Eimeria oocysts.…”

“…Saavedra et al (2003) reported that PVA in cell culture promotes preservation of long-term hepatocytic functions. Vandevoort et al (2007) reported that in vitro maturation of the female ovarian oocysts cultured in a medium enriched with PVA was significantly better than cultures without PVA and the incidence of fertilisation and embryo development to blastocyst stage was better. Moreover, Deters et al (2003) found that zinc sulphate, a constituent of zinc PVA, is a potent stimulator for keratinocyte differentiation and increased cell proliferation in vitro.…”