Figure 3.

Application of nanotechnology on mechanotransduction research.

A: Measurement of mechanics and mechanical forces of aliving cell. Magnetic tweezers and optical tweezers measure mechanics of a cell using a magnetic bead and microscopic objects coated with specific ligand that attaches to cell surface receptor. Atomic forcemicroscopy (AFM) measures cell mechanics by directly touching a cell. Force sensor fused into adhesion molecule or attached on substrate measure traction force of a cell. Traction force microscopy measuresdisplacement of microbeads embedded in the substrate to determine traction force. Other methods, not shown in this figure, includemicropillar array to detect traction force and fluorescent resonance energy transfer (FRET)-based probe to map stress within a cell. B:Measurement of mechanical properties of a single molecule using magnetic and optical tweezers. AFM can be used for a single molecular analysis but loading rate is much higher than that used in the magnetic and optical tweezers. Fusing an internal control molecule whose mechanical property is known to a test molecule can be used to warrant single molecular analysis. C: Pattern of nanoscale scaffold regulates cell behaviors. D: Stiffness of nanoscale scaffold and mechanical stimulation regulate cell differentiation. For example, nanoparticles can be mechanically manipulated to activate a specific signaling pathway to induce differentiation, growth, and death.