Traditional 2D cell culture systems used in biology do not accurately reproduce the 3D structure, function, or physiology of living tissue. Resulting behaviour and responses of cells are substantially different from those observed within natural extracellular matrices (ECM). The early designs of 3D cell-culture matrices focused on their bulk properties, while disregarding individual cell environment. However, recent findings indicate that the role of the ECM extends beyond a simple structural support to regulation of cell and tissue function. So far the mechanisms of this regulation are not fully understood, due to technical limitations of available research tools, diversity of tissues and complexity of cell-matrix interactions.The main goal of this project is to develop a versatile and straightforward method, enabling systematic studies of cell-matrix interactions. 3D CAD matrices will be produced by femtosecond laser-induced polymerization of hydrogels with cells in them. Cell embedment results in a tissue-like intimate cell-matrix contact and appropriate cell densities right from the start.A unique advantage of the LeBMEC is its capability to alter on demand a multitude of individual properties of produced 3D matrices, including: geometry, stiffness, and cell adhesion properties. It allows us systematically reconstruct and identify the key biomimetic properties of the ECM in vitro. The particular focus of this project is on the role of local mechanical properties of produced hydrogel constructs. It is known that, stem cells on soft 2D substrates differentiate into neurons, stiffer substrates induce bone cells, and intermediate ones result in myoblasts. With LeBMEC, a controlled distribution of site-specific stiffness within the same hydrogel matrix can be achieved in 3D. This way, by rational design of cell-culture matrices initially embedding only stem cells, for realisation of precisely defined 3D multi-tissue constructs, is possible for the first time.