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Updated: Jul 28, 2025
Fabricating Optical-quality Glass Surfaces to Study Macrophage Fusion
Published on: March 14, 2018
Three-dimensional label-free visualization of the interactions of PM2.5 with macrophages and epithelial cells using
Wang Sik Lee1, Inha Kang2, Sung-Jin Yoon1
1Environmental Disease Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-gu Daejeon, 34141, Republic of Korea.
Abstract:
Particulate matter ≤ 2.5 µm (PM2.5) poses health risks related to various diseases and infections. However, the interactions between PM2.5 and cells such as uptake and cell responses have not been fully investigated despite advances in bioimaging techniques, because the heterogeneous morphology and composition of PM2.5 make it challenging to employ labeling techniques, such as fluorescence. In this work, we visualized the interaction between PM2.5 and cells using optical diffraction tomography (ODT), which provides quantitative phase images by refractive index distribution. Through ODT analysis, the interactions of PM2.5 with macrophages and epithelial cells, such as intracellular dynamics, uptake, and cellular behavior, were successfully visualized without labeling techniques. ODT analysis clearly shows the behavior of phagocytic macrophages and nonphagocytic epithelial cells for PM2.5. Moreover, ODT analysis could quantitatively compare the accumulation of PM2.5 inside the cells. PM2.5 uptake by macrophages increased substantially over time, but uptake by epithelial cells increased only marginally. Our findings indicate that ODT analysis is a promising alternative approach to visually and quantitatively understanding the interaction of PM2.5 with cells. Therefore, we expect ODT analysis to be employed to investigate the interactions of materials and cells that are difficult to label.
Insights
Optical diffraction tomography visualizes particulate matter (PM2.5) interactions with cells without labeling. This method reveals how macrophages and epithelial cells uptake PM2.5, offering a new way to study cell-material interactions.
Area of Science:
- Biophysics
- Cell Biology
- Environmental Health
Background:
- Particulate matter ≤ 2.5 µm (PM2.5) presents health risks, but its cellular interactions are poorly understood.
- Challenges in labeling heterogeneous PM2.5 hinder visualization of its cellular uptake and effects.
- Advances in bioimaging are needed to overcome these limitations.
Purpose of the Study:
- To visualize and quantify the interaction of PM2.5 with cells using optical diffraction tomography (ODT).
- To investigate cellular uptake dynamics and behaviors of PM2.5 in macrophages and epithelial cells.
- To establish ODT as a viable technique for studying challenging cell-material interactions.
Main Methods:
- Utilized optical diffraction tomography (ODT) to generate quantitative phase images based on refractive index distribution.
- Visualized PM2.5 interactions with macrophages and epithelial cells without requiring labeling techniques.
- Analyzed intracellular dynamics, uptake, and cellular responses to PM2.5.
Main Results:
- ODT successfully visualized PM2.5 interactions, including intracellular dynamics and uptake, in both cell types.
- Demonstrated distinct PM2.5 uptake behaviors: significant accumulation in macrophages over time versus marginal uptake in epithelial cells.
- Quantitatively compared PM2.5 accumulation within cells, highlighting differences between phagocytic and nonphagocytic cells.
Conclusions:
- ODT provides a powerful, label-free approach for visualizing and quantifying cellular interactions with PM2.5.
- The findings highlight ODT's potential for studying interactions involving difficult-to-label materials and cells.
- ODT analysis is a promising tool for advancing our understanding of environmental health impacts at the cellular level.
