Cellular microcompartments comprising human cells undergoing cardiac differentiation, tissues obtained from said microcompartments and uses thereof

A three-dimensional cellular microcompartment (10) successively comprising, organized around at least one lumen (18):

• at least one inner layer (16) of human cells undergoing cardiac differentiation, expressing at least one gene chosen from PDGFRα, MESP-1, NKX2-5, GATA4, MEF2C, TBX20, ISL1, and TBX5,
• at least one intermediate layer (14) of isotonic aqueous solution, and
• at least one outer hydrogel layer (12),
• the inner layer having a variable thickness and the ratio between the largest thickness (t2) and the smallest thickness (t1) of the inner layer being greater than or equal to 2, the smallest thickness (t1) and the largest thickness (t2) of the inner layer being the smallest and the largest of the inner layer thicknesses measured along a segment (22) passing through the geometric center of the cellular object formed by the inner layer and the one or more lumen(s) (18, 18-1, 18-2), between the interface of the inner layer and of the intermediate layer and the interface of the inner layer and of a lumen (18, 18-1, 18-2), and/or between the interface of the inner layer and of a lumen (18-1) and the interface of the inner layer and of another lumen (18-2).