What is substrate stiffness?

For example, the extracellular matrix of bone (ECM) has higher stiffness modulus than that of brain. Thus, growth conditions customized for cells such as osteoblasts necessitates a stiff and rigid culture substrate compared to conditions for neural cells.

What is cellular stiffness?

Cell stiffness is described as Young’s modulus or elastic modulus, which is obtained by fitting the curve of force versus indentation, where force is determined by multiplying the deflection by the spring constant of the cantilever following Hooke’s law.

How do you measure cell stiffness?

The micropipette aspiration method applies negative pressure in a micropipette of diameter ranging from 1 to 5 μm to suck a small piece of cell membrane into the pipette. Cell stiffness is calculated from the applied negative pressure and cell membrane deformation.

What is substrate rigidity?

Using substrates of identical chemical composition but different flexibility, we show that this process is controlled by substrate rigidity: on stiff substrates, cells migrate away from one another and spread on surfaces, whereas on soft substrates they merge to form tissue-like structures.

What causes cell stiffness?

The reorganization and reorientation of these fibers determines the stiffness and elasticity of the modified extracellular matrix. Increased collagen deposition, fiber misalignment, and crosslinking during extracellular matrix reorganization leads to increased stiffness.

What makes ECM stiff?

Cancer-associated fibroblasts (CAFs) are the main contributors to ECM stiffness and degradation. The cells interact with almost all cells within the tumor microenvironment (TME) that could enable them to modulate ECM components for tumorigenic purposes.

What are possible cell shape changes when grown on soft and stiff substrates?

In vitro, cells cultured on soft, two-dimensional ECM substrates become relatively small and round, whereas on stiffer ECMs the cells assume elongated shapes. On highly rigid substrates such as glass, cells spread out and flatten.

What does rigidity mean in medical terms?

Rigidity – meaning stiff or inflexible muscles – is one of the main motor symptoms of Parkinson’s, along with tremor and slowness of movement (bradykinesia). Muscles become rigid because of their inability to relax.

How do you increase cell stiffness?

Cell stiffness (G) increases linearly with increasing cytoskeletal contractile prestress (P).

How do you increase cell adhesion?

Various groups have reported the enhancement of cell adhesion by increasing surface roughness at the nanometer scale using techniques such as sand blasting. It has also been shown that cell adhesion may be improved by chemical grafting of adhesion peptides such as Arg-Gly-Asp to material surfaces.

What is extracellular matrix stiffness?

Abstract. Tissues stiffen during aging and during the pathological progression of cancer, fibrosis, and cardiovascular disease. Extracellular matrix stiffness is emerging as a prominent mechanical cue that precedes disease and drives its progression by altering cellular behaviors.