ARS | Publication request: In Vitro Elongation of Porcine Embryos Using Alginate Hydrogels as a Three-Dimensional Extracellular Matrix

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 8, 2010
Publication Date: N/A

Technical Abstract: In the pig, the pre-implantation period of pregnancy is highly influential on sow productivity and therefore the profitability of swine production. Between Day 11 and 12 of gestation, the embryo undergoes a significant morphological change, during which it transforms from an ovoid structure of about 1 cm in length to a long, thin filament that can grow to greater than 10 cm in length. This transformation process is known as elongation and is critical for maternal recognition of pregnancy. It has been found that about 20% of embryonic loss is associated with the elongation process that occurs before implantation. An effective in vitro culture system could help us develop a clear understanding of the pre-implantation period of porcine embryos, in particular elongation, which in turn can allow us to identify physiological components that could be manipulated to improve pregnancy outcomes. So far, attempts to elongate porcine embryos in vitro have been unsuccessful. We hypothesize that this failure to elongate is, at least in part, caused by an inadequate culture system which lacks three-dimensional structure. Therefore, our objective is to use tissue engineering principles (i.e. scaffolds) to provide a 3D matrix in which to culture the embryos, in an attempt to establish an effective culture system that can support pig embryo elongation in vitro. In particular, we have been using alginate hydrogels as a three-dimensional scaffold. Alginate, a polysaccharide derived from brown algae that gels in the presence of a divalent cation, is an inert material that allows for gentle encapsulation of cells and tissue without any specific interaction between the cells/tissue and the surrounding hydrogel. We have investigated different hydrogel formation and encapsulation techniques with live embryos, including a bead method using alginate and calcium chloride solution, a slurry method using alginate and calcium sulfate solution, and a method of boring into pre-made alginate hydrogels. We have obtained promising data indicating embryo survival as well as evidence of elongation in vitro within the alginate hydrogels.