Platform for the differentiation of cells

An in vitro method for islet cell expansion, which comprises the steps of:

• a) inducing cystic formation in cells in or associated with post-natal islets of Langerhans to obtain a duct-like structure;
• b) expanding cells of said duct-like structure;
• and
• c) inducing islet cell differentiation of said expanded cells of said duct-like structure to become insulin-producing cells;
• wherein step a) and step b) are concurrently effected using a solid matrix, basement membrane constituents, basal feeding medium and appropriate growth factors to permit the development, maintenance and expansion of a duct-like structure cell population with at least bipotentiality;
• wherein step c) is effected by removing cells from said matrix and resuspended in a basal liquid medium containing soluble matrix proteins and growth factors selected from the group consisting of fibronectin, IGF-1, IGF-2, insulin, and NGF.