What was utilized to investigate the potential differentiation of ASCs to AF phenotype?

The ability of adipose-derived stem cells (ASCs) to differentiate into the annulus fibrosus (AF) phenotype is significantly influenced by mechanical cues, including strain. Strain refers to the deformation experience by a material or cell in response to applied forces. In the context of tissue engineering, applying specific levels of strain to ASCs can mimic the physiological environment of the annulus fibrosus, which is subjected to mechanical loads in the intervertebral disc.

Research has shown that mechanical strain can promote cell differentiation by providing biological signals that encourage ASCs to adopt specific phenotypes, such as that of the AF. This process occurs because the cells' mechanical environment can activate intracellular signaling pathways linked to differentiation. Therefore, utilizing strain as a parameter in experiments allows researchers to effectively encourage and study the differentiation of ASCs into a cell type that participates in the structural integrity and function of the annulus fibrosus.

While stress, elasticity, and Young’s modulus are also important mechanical properties in tissue engineering, strain directly relates to the application of forces that influence differentiation. Stress is a measure of the force acting on a unit area, but strain describes the resultant deformation due to that stress. Elasticity refers to the material's ability to return to its