Stem cells are progenitor cells that are capable of self-renewal and differentiation into various cells. Especially, pluripotent stem cells (PSCs) have in vivo and in vitro differentiation capacity into three germ layers and can proliferate infinitely. The differentiation ability of PSCs can be applied for regenerative medicine and tissue engineering. In domestic animals, their PSCs have a potential for preclinical therapy as well as the production of transgenic animals and agricultural usage such as cultured meat. Among several domestic animals, a pig is considered as an ideal model for biomedical and agricultural purposes mentioned above. In this reason, studies for pig PSCs including embryonic stem cells (ESCs), embryonic germ cells (EGCs) and induced pluripotent stem cells (iPSCs) have been conducted for decades. Therefore, this review will discuss the history of PSCs derived from various origins and recent progress in pig PSC research field.

In this study, a nanofibrous scaffold was obtained by co-electrospinning poly (3-hydroxybutyrate- co-3-hydroxyvalerate) (PHBV) and collagen in 2,2,2-trifluoroethanol at a ratio of 3/7. The fiber diameters were in the range of 250-600 nm. It was found that PHBV/Collagen (PHCP) nanofibrous scaffold showed greater proliferation than the PHBV nanofibrous scaffold induced by oxidant in NIH3T3 cells. Otherwise, in the early-stage wound-healing mouse model, wound closure was evaluated according to wound size reduction and histology of regenerated skin on the backs of mice. Each of the tissues removed on day 0, 3, 6, 9, 12, 15, and 18 was used for analysis of biochemical and pathological changes. None of the nanofiber-attached mice showed significant difference on the third day, however, from the third day until the ninth day, significantly faster healing was observed in PHCP-attached mice, compared to control wounds in epithelialization, wound contraction, and histopathological examinations. These results strongly support the beneficial effects of biomedical application of PHCP nanofiber in acceleration of the initial phase of wound healing through α-SM actin contraction.