Friday, 01 November, 2013
A fast analysis method to quantify nanoparticle uptake on a single cell level
A. Torrano, J. Blechinger, C. Osseforth, C. Argyo, A. Reller, T. Bein, J. Michaelis, and C. Bräuchle -
Nanomedicine, Vol. 8 (11), pp. 1815-1828 (2013)
Aim: This study examines the absolute quantification of particle uptake into cells. Methods: We developed a novel method to analyze stacks of confocal fluorescence images of single cells interacting with nano-and micro-particles. Particle_in_Cell-3D is a freely available ImageJ macro. During the image analysis routine, single cells are reconstructed in 3D and split into two volumes intracellular and the membrane region. Next, particles are localized and color-coded accordingly. The mean intensity of single particles, measured in calibration experiments, is used to determine the absolute number of particles. Results: Particle_in_Cell-3D was successfully applied to measure the uptake of 80-nm mesoporous silica nanoparticles into HeLa cells. Furthermore, it was used to quantify the absolute number of 100-nm polystyrene nanoparticles forming agglomerates of up to five particles; the accuracy of these results was confirmed by super-resolution, stimulated emission depletion microscopy. Conclusion: Particle_in_Cell-3D is a fast and accurate method that allows the quantification of particle uptake into cells.