Enhancing effects of serum-rich and cytokine-supplemented culture conditions on developing blastocysts and deriving porcine parthenogenetic embryonic stem cells

The present study was conducted to develop an effective method for establishment of porcine parthenogenetic embryonic stem cells (ppESCs) from parthenogenetically activated oocyte-derived blastocysts. The addition of 10% fetal bovine serum (FBS) to the medium on the 3rd day of oocyte culturing improved the development of blastocysts, attachment of inner cell masses (ICMs) onto feeder cells, and formation of primitive ppESC colonies. ICM attachment was further enhanced by basic fibroblast growth factor, stem cell factor, and leukemia inhibitory factor. From these attached ICMs, seven ppESC lines were established. ppESC pluripotency was verified by strong enzymatic alkaline phosphatase activity and the expression of pluripotent markers OCT3/4, Nanog, and SSEA4. Moreover, the ppESCs were induced to form an embryoid body and teratoma. Differentiation into three germ layers (ectoderm, mesoderm, and endoderm) was confirmed by the expression of specific markers for the layers and histological analysis. In conclusion, data from the present study suggested that our modified culture conditions using FBS and cytokines are highly useful for improving the generation of pluripotent ppESCs.

Stem cell maintenance in a different niche / 대한생식의학회지

To overcome the difficulty of controlling stem cell fate and function in applications to regenerative medicine, a number of alternative approaches have been made. Recent reports demonstrate that a non-cellular niche modulating the biophysical microenvironment with chemical factors can support stem cell self-renewal. In our previous studies, early establishment was executed to optimize biophysical factors and it was subsequently found that the microgeometry of the extracellular matrix made huge differences in stem cell behavior and phenotype. We review here a three-dimensional, non-cellular niche designed to support stem cell self-renewal. The characteristics of stem cells under the designed system are further discussed.

Cryopreservation of Human Embryos / 대한산부인과학회잡지

Technology for the long-term preservation of gamete and embryo has improved greatly over the past 20 years and currently is used for supporting various assisted reproductive technologies (ART). Recent progress in cryobiology and its related sciences have made it possible to preserve human embryos effectively, and several cryopreservation methods also have been developed. Successful freezing of supernumerary embryos has allowed patients undergoing ART the opportunity to achieve pregnancies from more than one embryo transfer without being subjected to controlled ovarian hyperstimulation and oocyte retrieval each time. It also allows a delay in embryo transfer where certain adverse conditions exist for fresh transfer, e.g. when the patient is at risk for ovarian hyperstimulation syndrome or when there is poor endometrial development during the retrieval cycle. Cryopreservation of all available embryos from retrieval is utilized when an oocyte recipient is not properly synchronized with oocyte donor's cycle. In this paper is to review the current status and perspectives of embryo cryopreservation in ART program. Also, briefly discuss the oocyte cryopreservation for the establishment of ovum bank.