Kim J, Jeong SY, Ju YM, Yoo JJ, Smith TL, Khang G, Lee SJ, Atala A. In vitro osteogenic differentiation of human amniotic fluid-derived stem cells on a poly(lactide-co-glycolide) (PLGA)-bladder submucosa matrix (BSM) composite scaffold for bone tissue engineering. Biomed Mater. 2013 Feb; 8(1):014107.