The Synthesis and Design of Nanoparticles for Measuring Traction Forces in Living Cells

In the cytoplasm of mammalian cells, there are diverse and continuous intracellular movements essential for cell physiology, such as the transport of vesicles and other organelles. It is crucial to determine varied mechanical behaviours of the cell from viscous, viscoelastic, and poroelastic to pure elastic for differing physiological cell processes. In this project, poly(N-isopropylacrylamide), PNIPAM nanoparticles were synthesised and designed to measure traction forces in living cells via the passive microrheology method. Confocal microscopy was used for characterisation of the nanoparticles such as its size and shape. Subsequently, the nanoparticles were injected into a living cell’s cytoplasm and intracellular movement was observed. The video was then analysed to determine the traction forces in the cells using the passive microrheology method. The nanoparticles were found to be non-toxic to the cells and were able to successfully permeate through the cell membrane. Thus, these nanoparticles can be used to further comprehend the mechanics of cells. By expanding on our knowledge of the intricacies of cell physiology, nanoparticle-based monitoring of cells paves the way for understanding the effect of cancer mutations on normal cells.