Measurements of movement and diffusion coefficients of single cells on polymeric surface from image analysis

Time-lapse digital images were taken every 30 s of PC12 cells cultured on polystyrene dishes, collagen-coated dishes and poly(L-lysine)-coated dishes in high-serum medium, low-serum medium and neurite outgrowth factor (NGF)-containing medium to investigate their diffusion coefficients (i.e., self-diffusion coefficients), D and specific movement (i.e., specific frequent movement) using image analysis and Fast Fourier Transform (FFT) analysis. D for these cells was found to fluctuate as a function of time, D varying between 0 and 0.08 μm²/s. The trend observed upon examination of average D values was: D in high-serum medium ≤ D in low-serum medium ≤ D in NGF-containing medium. Image analysis and FFT analysis of single cells cultured on polymeric dishes in these three media did not have any specific frequency of cell movement between 0 and 0.0167 Hz. The high diffusion coefficient and high amplitude of power spectra of PC12 cells in high-serum medium might be attributed to the high energy necessary for their continual suppression of the mitogen-activated protein kinase (MAPK) cascade and for them to maintain their undifferentiated state.