Embryonic germ cells are capable of adipogenic differentiation in vitro and in vivo

There is an extensive clinical need for soft tissue filler materials, such as adipose tissue, for plastic and reconstructive surgery. Due to limitations with autologous adipose transplantation, engineered adipose tissue provides a potential alternative therapy. Embryonic germ cells form embryoid bodies and subsequent embryoid body-derived (EBD) cells have the ability to differentiate toward multiple tissue types. The objective of this study was to demonstrate that EBD cells were capable of adipogenic differentiation in vitro and in vivo using a poly(ethylene glycol)-based hydrogel scaffold. EBD cells underwent adipogenic differentiation in vitro and in vivo. Results were directly compared to adipogenic differentiation of adult bone marrow-derived mesenchymal stem cells (MSCs). Differentiated EBD cells in both monolayer and three-dimensional in vitro culture demonstrated fat granules by light microscopy, stained positive for lipids with oil red-O, and expressed adipocyte-specific genes (lipoprotein lipase [LPL], peroxisome proliferator activated receptor γ2, and adipocyte-specific fatty acid binding protein [αP2]). In vivo constructs demonstrated adipogenic differentiation by αP2 and LPL gene expression and oil red-O staining of lipid granules. In conclusion, EBD cells are capable of differentiating toward an adipogenic lineage in vitro and in vivo. EBD cells' adipogenic differentiation is comparable to that of MSCs and demonstrate therapeutic potential for soft tissue augmentation and reconstruction.