TY  - EJOU
AU  - Lemmon, Christopher A.  
AU  - Sniadecki, Nathan J.  
AU  - Ruiz, Sami Alom  
AU  - Romer, John L. Tan, Lewis H.  
AU  - Chen, Christopher S.  

TI  - Shear Force at the Cell-Matrix Interface: Enhanced Analysis for Microfabricated Post Array Detectors
T2  - Molecular \& Cellular Biomechanics

PY  - 2005
VL  - 2
IS  - 1
SN  - 1556-5300

AB  - The interplay of mechanical forces between the extracellular environment and the cytoskeleton drives development, repair, and senescence in many tissues. Quantitative definition of these forces is a vital step in understanding cellular mechanosensing. Microfabricated post array detectors (mPADs) provide direct measurements of cell-generated forces during cell adhesion to extracellular matrix. A new approach to mPAD post labeling, volumetric imaging, and an analysis of post bending mechanics determined that cells apply shear forces and not point moments at the matrix interface. In addition, these forces could be accurately resolved from post deflections by using images of post tops and bases. Image analysis tools were then developed to increase the precision and throughput of post centroid location. These studies resulted in an improved method of force measurement with broad applicability and concise execution using a fully automated force analysis system. The new method measures cell-generated forces with less than 5% error and less than 90 seconds of computational time. Using this approach, we demonstrated direct and distinct relationships between cellular traction force and spread cell surface area for fibroblasts, endothelial cells, epithelial cells and smooth muscle cells.
KW  - cell adhesion
KW  -  stress
KW  -  mechanical
KW  -  mechanosensors
KW  -  cytoskeleton
KW  -  focal adhesions
KW  -  actomyosin
KW  -  shear force
KW  -  image analysis
KW  -  PDMS
KW  -  microfabricated post array detectors

DO  - 10.3970/mcb.2005.002.001