Compositions and methods are provided for culturing
in vitro potentially regenerative cells (PRCs) from which functional tissue-organs are regenerated. In one aspect of the invention, a
tissue culture medium is provided which comprises at least 50% of water and a
sterol compound that is dissolved in a
fatty acid-containing oil at a concentration at least 0.1% by weight based on the weight of the oil and added to the water. The culture medium can be used to culture PRCs that are isolated from the body of a
mammal to generate functional tissue-organs
in vitro with substantially the same physiological
structure and function as the corresponding ones existing
in vivo and in situ. The cultured PRCs, tissues, and tissue-organs can serve as valuable models for scientific investigation in life sciences,
nutraceutical discovery,
drug screening, pharmacokinetic studies, medical devices and tissue /
organ transplantation.