Abstract: A process of differentiation of stem cells through the use of specific oxygen concentrations, provided that the stem cells are not human embryonic stem cells, and seeded on a support, in an appropriate culture medium, wherein the differentiation leads to: a. either a first group of specialized differentiated cells under normoxic conditions, and in an appropriate culture medium, b. or a second group of specialized differentiated cells under hypoxic conditions, in a culture medium of the same nature as the one used for obtaining the first group of specialized differentiated cells; the first and second groups of specialized differentiated cells retaining the functional properties of the corresponding specialized differentiated cells respectively obtained through a biological natural process.

Abstract: The invention relates to the use of a unit including a substrate and polyelectrolyte multilayer films deposited thereon in order to: carry out a method involving the proliferation of initial stem or differentiated cells that are brought into contact with the unit; and cover the unit with confluent viable adherent cells resulting from the proliferation of the initial cells, the cover being obtained at the end of a period of no more than one month, such as 14 days, 11 days or, in particular, 7 days, after the initial cells are brought into contact with the unit.