Embryonic progenitor cells in adipose tissue engineering.

Adipose tissue is extensively used in facial plastic surgery as a soft tissue filler for small-to-large facial defects. Variable results with autologous fat grafting and lipoinjection has led to interest in alternative forms of adipose tissue, including tissue engineered adipose tissue. Tissue engineering combines cells, scaffolds, and bioactive signals to regenerate organs or tissue. Cell sources include preadipocytes, adult stem cells, and embryonic stem cells. Although adult cells may be easily accessible from a patient, embryonic progenitor cells have comparative advantages over adult stem cells including indefinite self-renewal (high proliferative and expansion capacity) and strong tissue-forming capacity. This article will describe the types of embryonic progenitor cells and the cell culture conditions, common biomaterials, signaling factors, and biomechanical forces used in adipose tissue engineering. We will identify optimal conditions to generate functional, long-lasting adipose-like tissue. Lastly, we will propose potential future directions for the rapidly expanding field of adipose tissue engineering.