Intracellular Detection and Localization of Nanoparticles by Refractive Index Measurement

The measuring of nanoparticle toxicity faces an important limitation since it is based on metrics exposure, the concentration at which cells are exposed instead the true concentration inside the cells. In vitro studies of nanomaterials would benefit from the direct measuring of the true intracellular dose of nanoparticles. The objective of the present study was to state whether the intracellular detection of nanodiamonds is possible by measuring the refractive index. Based on optical diffraction tomography of treated live cells, the results show that unlabeled nanoparticles can be detected and localized inside cells. The results were confirmed by fluorescence measurements. Optical diffraction tomography paves the way to measuring the true intracellular concentrations and the localization of nanoparticles which will improve the dose-response paradigm of pharmacology and toxicology in the field of nanomaterials.

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Label-free high-resolution 3-D imaging of gold nanoparticles inside live cells using optical diffraction tomography

10.1101/097113 ◽

2016 ◽

Cited By ~ 6

Author(s):

Doyeon Kim ◽

Nuri Oh ◽

Kyoohyun Kim ◽

SangYun Lee ◽

Chan-Gi Pack ◽

...

Keyword(s):

Gold Nanoparticles ◽

Refractive Index ◽

Quantitative Imaging ◽

Extended Period ◽

Optical Diffraction ◽

Live Cells ◽

Diffraction Tomography ◽

Label Free ◽

Optical Diffraction Tomography ◽

4T1 Cells

AbstractDelivery of gold nanoparticles (GNPs) into live cells has high potentials, ranging from molecular-specific imaging, photodiagnostics, to photothermal therapy. However, studying the long-term dynamics of cells with GNPs using conventional fluorescence techniques suffers from phototoxicity and photobleaching. Here, we present a method for 3-D imaging of GNPs inside live cells exploiting refractive index (RI) as imaging contrast. Employing optical diffraction tomography, 3-D RI tomograms of live cells with GNPs are precisely measured for an extended period with sub-micrometer resolution. The locations and contents of GNPs in live cells are precisely addressed and quantified due to their distinctly high RI values, which was validated by confocal fluorescence imaging of fluorescent dye conjugated GNPs. In addition, we perform quantitative imaging analysis including the segmentations of GNPs in the cytosol, the volume distributions of aggregated GNPs, and the temporal evolution of GNPs contents in HeLa and 4T1 cells.AbbreviationsGNPsgold nanoparticlesRIrefractive indexODToptical diffraction tomographyDMDdigital micromirror device

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Mitotic Chromosomes in Live Cells Characterized Using High-Speed and Label-Free Optical Diffraction Tomography

Cells ◽

10.3390/cells8111368 ◽

2019 ◽

Vol 8 (11) ◽

pp. 1368 ◽

Cited By ~ 3

Author(s):

Kim ◽

Lee ◽

Fujii ◽

Lee ◽

...

Keyword(s):

Diffusion Coefficient ◽

Three Dimensional ◽

Laser Scanning Microscopy ◽

Optical Diffraction ◽

Live Cells ◽

Confocal Laser ◽

Diffraction Tomography ◽

Label Free ◽

Mitotic Chromosomes ◽

Optical Diffraction Tomography

The cell nucleus is a three-dimensional, dynamic organelle organized into subnuclear compartments such as chromatin and nucleoli. The structure and function of these compartments are maintained by diffusion and interactions between related factors as well as by dynamic and structural changes. Recent studies using fluorescent microscopic techniques suggest that protein factors can access and are freely mobile in heterochromatin and in mitotic chromosomes, despite their densely packed structure. However, the physicochemical properties of the chromosome during cell division are not fully understood. In the present study, characteristic properties such as the refractive index (RI), volume of the mitotic chromosomes, and diffusion coefficient (D) of fluorescent probes inside the chromosome were quantified using an approach combining label-free optical diffraction tomography with complementary confocal laser-scanning microscopy and fluorescence correlation spectroscopy. Variations in these parameters correlated with osmotic conditions, suggesting that changes in RI are consistent with those of the diffusion coefficient for mitotic chromosomes and cytosol. Serial RI tomography images of chromosomes in live cells during mitosis were compared with three-dimensional confocal micrographs to demonstrate that compaction and decompaction of chromosomes induced by osmotic change were characterized by linked changes in chromosome RI, volume, and the mobilities of fluorescent proteins.

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Enhancement of optical resolution in three-dimensional refractive-index tomograms of biological samples by employing micromirror-embedded coverslips

Lab on a Chip ◽

10.1039/c8lc00880a ◽

2018 ◽

Vol 18 (22) ◽

pp. 3484-3491 ◽

Cited By ~ 1

Author(s):

Seungwoo Shin ◽

Jihye Kim ◽

Je-Ryung Lee ◽

Eun-chae Jeon ◽

Tae-Jin Je ◽

...

Keyword(s):

Refractive Index ◽

Biological Samples ◽

Three Dimensional ◽

Optical Resolution ◽

Optical Diffraction ◽

Diffraction Tomography ◽

Optical Diffraction Tomography

Resolution-enhanced optical diffraction tomography using a micromirror-embedded coverslips.

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Three-dimensional refractive index distributions of individual angiosperm pollen grains

10.1101/353243 ◽

2018 ◽

Author(s):

Chansuk Park ◽

SangYun Lee ◽

Geon Kim ◽

SeungJun Lee ◽

Jaehoon Lee ◽

...

Keyword(s):

Refractive Index ◽

Three Dimensional ◽

Pollen Grains ◽

Optical Diffraction ◽

Diffraction Tomography ◽

Optical Diffraction Tomography ◽

Internal Structures ◽

Quantitative Analyses ◽

Angiosperm Pollen ◽

Preparation Techniques

Three-dimensional (3D) refractive index (RI) imaging and quantitative analyses of angiosperm pollen grains are presented. Using optical diffraction tomography, the 3D RI structures of individual angiosperm pollen grains were measured without using labeling or other preparation techniques. Various physical quantities, including volume, surface area, exine volume, and sphericity, were determined from the measured RI tomograms of pollen grains. Exine skeletons, the distinct internal structures of angiosperm pollen grains, were identified and systematically analyzed.

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Label-free monitoring of 3D cortical neuronal growth in vitro using optical diffraction tomography

10.1101/2021.07.31.454602 ◽

2021 ◽

Author(s):

Ariel J. Lee ◽

DongJo Yoon ◽

SeungYun Han ◽

Herve Hugonnet ◽

WeiSun Park ◽

...

Keyword(s):

Optical Diffraction ◽

Neuronal Cultures ◽

Multiple Time ◽

Diffraction Tomography ◽

Label Free ◽

Neuronal Growth ◽

Monitoring Method ◽

Optical Diffraction Tomography ◽

Immunofluorescence Labeling

The highly complex central nervous systems of mammals are often studied using three-dimensional (3D) in vitro primary neuronal cultures. A coupled confocal microscopy and immunofluorescence labeling are widely utilized for visualizing the 3D structures of neurons. However, this requires fixation of the neurons and is not suitable for monitoring an identical sample at multiple time points. Thus, we propose a label-free monitoring method for 3D neuronal growth based on refractive index tomograms obtained by optical diffraction tomography. The 3D morphology of the neurons was clearly visualized, and the developmental processes of neurite outgrowth in 3D spaces were analyzed for individual neurons.

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Measuring three-dimensional refractive index maps of injection-molded plastic lenses using optical diffraction tomography

Asia Communications and Photonics Conference 2015 ◽

10.1364/acpc.2015.asu2a.156 ◽

2015 ◽

Author(s):

Kyoohyun Kim ◽

YongKeun Park

Keyword(s):

Refractive Index ◽

Three Dimensional ◽

Optical Diffraction ◽

Diffraction Tomography ◽

Optical Diffraction Tomography ◽

Injection Molded ◽

Injection Molded Plastic ◽

Index Maps

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Dual-wavelength cell’s refractive index analysis with partially coherent optical diffraction tomography

Imaging and Applied Optics Congress ◽

10.1364/cosi.2020.cf3c.3 ◽

2020 ◽

Author(s):

J. M. Soto ◽

J. A. Rodrigo ◽

T. Alieva

Keyword(s):

Refractive Index ◽

Optical Diffraction ◽

Dual Wavelength ◽

Diffraction Tomography ◽

Partially Coherent ◽

Optical Diffraction Tomography ◽

Index Analysis

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Optical Fiber Refractive Index Profiling by Iterative Optical Diffraction Tomography

Journal of Lightwave Technology ◽

10.1109/jlt.2018.2876070 ◽

2018 ◽

Vol 36 (24) ◽

pp. 5754-5763 ◽

Cited By ~ 10

Author(s):

Shengli Fan ◽

Seth Smith-Dryden ◽

Jian Zhao ◽

Stefan Gausmann ◽

Axel Schulzgen ◽

...

Keyword(s):

Refractive Index ◽

Optical Fiber ◽

Optical Diffraction ◽

Diffraction Tomography ◽

Optical Diffraction Tomography

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Investigation of limitations of optical diffraction tomography

Opto-Electronics Review ◽

10.2478/s11772-007-0006-8 ◽

2007 ◽

Vol 15 (2) ◽

Cited By ~ 19

Author(s):

T. Kozacki ◽

M. Kujawińska ◽

P. Kniażewski

Keyword(s):

Refractive Index ◽

Dynamic Range ◽

Tomographic Reconstruction ◽

Back Propagation ◽

Reconstruction Algorithm ◽

Optical Diffraction ◽

Diffraction Tomography ◽

Refractive Index Distribution ◽

Optical Diffraction Tomography ◽

Index Distribution

AbstractOptical diffraction tomography (ODT) applied to measurement of optical microelements is limited by low dynamic range, i.e., only objects with small deviations of refractive-index distribution can be measured. Therefore in this paper the limitations and errors of ODT are investigated throughout extensive numerical experiments. It is shown that these errors can be reduced by introduction of additional numerical focusing in the tomographic reconstruction algorithm. Additionally, new tomographic reconstruction algorithm using back propagation in reference medium for optical microelements measurement with known design is proposed. This hybrid reconstruction algorithm allows significant extension of ODT applicability in measurement of elements having large deviations of refractive-index distribution.

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