Adult Stem Cells (ASCs) are multipotent or unipotent cells, found in various adult tissues, and their primary role is to maintain or repair the tissue in which they reside. Moreover, ASCs are able to differentiate into specialized cells and consequently regenerate different tissues. Populations with a wider therapeutic application are present in the bone marrow: hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs). Other populations reside in the skin, intestine, dental tissues, central nervous system, mammary gland, and liver.

The ability of these cells to repair damaged tissues gives them tremendous potential for innovative therapeutic approaches in the treatment of illness or trauma. Regenerative medicine focuses on ASC technologies and tissue engineering. MSCs are already used for connective tissue regeneration, while HSCs represent a successful therapy for blood and bone marrow cancers. ASCs currently are currently an object of great interest in research, considering their wide range of possible applications for in vitro and/or in vivo studies. Some challenging aspects related to the use of these cells are represented by their low number and the necessity of providing them with the right niche able to mimic their natural complex microenvironment, supplying the appropriate stimuli for the correct growth and differentiation. Recent research progress has revealed that cell fate and commitment can be affected by several factors, including growth factors, small molecules or stimuli derived from the extracellular microenvironment, via direct cell-cell as well as cell-ECM interactions. All these factors could activate cellular signalling and subsequently assist or modulate the differentiation process of ASCs and this is the motivation that prompts researchers to actively look for the ideal molecule or biomaterial that could optimize cell adhesion, spreading, or proliferation processes leading to a proper regeneration of a tissue. An optimal biomaterial or scaffold is needed in order to create a niche, where cells can interact with each other, to obtain a complete tissue regeneration process and to be implanted in vivo.

This Special Issue welcomes both original research and review articles addressing the contribution of molecules or biomaterial technologies in shaping Adult Stem Cell fate and differentiation processes. There is a strong interest in approaching a characterization and elucidation of several biological mechanisms and possible future applications of biomaterials in this rapidly evolving scenario. We invite publications presenting every kind of molecular study in this field that could be of great attraction.

Potential topics include but are not limited to the following:

• Growth factors and cytokines stimulating adult stem cell (MSCs or HSCs) differentiation
• Molecules stimulating adult stem cell (MSCs or HSCs) expansion
• Molecules regulating stem cell adhesion and engrafting
• Scaffold geometry influencing stem cell differentiation
• Biomaterials and cytokines for stem cell chondrogenic differentiation
• Biomaterials and cytokines for stem cell osteogenic differentiation
• Extracellular microenvironment influencing stem cell adhesion
• Extracellular microenvironment influencing stem cell differentiation
• Biomaterials for culture, expansion, or differentiation of adult stem cells
• Future trends in the field of stem cells for biomaterial engineering applications