The activity of stem cell processes is regulated by internal and external signals of the cell “niche”. In general, the niche of stem cells can be represented as the microenvironment of the cells, providing a signal complex, determining the properties of the cells. At the same time, the “niche” concept implies feedback. Cells can modify their microenvironment, supporting homeostasis or remodeling the composition and structure of the extracellular matrix. To ensure the regenerative potential of tissue engineering products the “niche” concept should be taken into account. To investigate interactions in an experimental niche, an original hydrogel biopolymer scaffold with encapsulated mesenchymal adipose-derived stem cells (ASCs) was used in this study. The scaffold provides for cell adhesion, active cell growth, and proliferative activity. Cells cultured within a scaffold are distinguished by the presence of a developed cytoskeleton and they form a cellular network. ASCs cultured within a scaffold change their microenvironment by secreting VEGF-A and remodeling the scaffold structure. Scaffold biodegradation processes were evaluated after previous culturing of the ASCs in the scaffolds for periods of either 24 h or six days. The revealed differences confirmed that changes had occurred in the properties of scaffolds remodeled by cells during cultivation. The mechanisms of the identified changes and the possibility of considering the presented scaffold as an appropriate artificial niche for ASCs are discussed.

The article updates the existing data on the use of scaffolds as target and controlled substance delivery systems. The prerequisites and grounds for using scaffolds as substance delivery systems are being considered. Current tissue-engineered strategies for developing target drug and bioactive substance delivery using scaffolds are being discussed. A classification of scaffold-based substance delivery systems is provided. Special attention is given to the development of two-phase substance delivery systems using various types of nanoparticles. A variety of nanoparticles and the benefits of their use as carriers of substances in a two-component delivery systems are shown. Recent developments in the substance delivery systems for regenerative medicine and future prospects are presented.