Substratstiffness

Substrate stiffness refers to the rigidity or elastic modulus of a substrate or underlying surface upon which cells, tissues, or materials are placed or cultured. It is a critical physical property that influences various biological processes and material behaviors. In cell biology, substrate stiffness plays a significant role in cell adhesion, differentiation, migration, and proliferation. Cells can sense the mechanical properties of their environment through mechanotransduction pathways, which direct cellular responses and fate decisions.

The measurement of substrate stiffness is commonly expressed in terms of elastic modulus, typically in units of kilopascals (kPa). Common materials used in research include hydrogels, polyacrylamide, and other elastomers, which can be engineered to exhibit a range of stiffness levels. Soft substrates (e.g., brain tissue, approximately 0.1–1 kPa) promote certain cell behaviors, while stiffer substrates (e.g., bone, over 30 kPa) induce different responses.

In tissue engineering and regenerative medicine, controlling substrate stiffness is vital for designing environments that emulate native tissue properties, thereby guiding tissue development and healing. Similarly, understanding the effects of substrate stiffness is important in cancer research, as tumor stiffness is often associated with disease progression.

Overall, substrate stiffness is a fundamental parameter influencing both biological functions and material performance. Advances in biomaterials and measurement techniques continue to expand our understanding of its role across disciplines.