A fast analysis method to quantify nanoparticle uptake on a single cell level

• Published in: Nanomedicine (London, England) Vol. 8; no. 11; pp. 1815 - 1828
• Main Authors: Torrano, Adriano A, Blechinger, Julia, Osseforth, Christian, Argyo, Christian, Reller, Armin, Bein, Thomas, Michaelis, Jens, Bräuchle, Christoph
• Format: Journal Article
• Language: English
• Published: London Future Medicine Ltd 01.11.2013; Future Medicine
• Subjects: Biological and medical sciences; Cellular control mechanisms; cellular uptake; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; fluorescence microscopy; ImageJ; Imaging systems; Investigative techniques, diagnostic techniques (general aspects); Materials science; Medical sciences; Miscellaneous. Technology; Models, Theoretical; nanomedicine; nanoparticle; Nanoparticles; Nanoparticles - chemistry; Nanoscale materials and structures: fabrication and characterization; nanotoxicology; Observations; Particle Size; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Physics; Properties; STED; super-resolution microscopy; Toxicology; Nanotoxicology; STED; nanoparticle; In vitro; Uptake; super-resolution microscopy; cellular uptake; Nanoparticles; ImageJ; Analysis method; Isolated cell; Fast; Nanomedicine; Quantitative chemical analysis; Fluorescence microscopy; Nanotechnology
• ISSN: 1743-5889; 1748-6963
• DOI: 10.2217/nnm.12.178

This study examines the absolute quantification of particle uptake into cells. 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. 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. Particle_in_Cell-3D is a fast and accurate method that allows the quantification of particle uptake into cells. Original submitted 10 May 2011; Revised submitted 15 October 2012; Published online 5 February 2013