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Biomolecular Imaging of Cellular Uptake of Nanoparticles using Multimodal Nonlinear Optical Microscopy
Published on: May 16, 2022
Quantitative imaging of single upconversion nanoparticles in biological tissue
Annemarie Nadort1, Varun K A Sreenivasan, Zhen Song
1MQ Biofocus Research Centre, Macquarie University, Sydney, NSW, Australia.
Plos One
|May 22, 2013
Summary
New synthetic nanomaterials called upconversion nanoparticles (UCNPs) offer high-contrast biomedical imaging. Despite signal loss in deep tissue, UCNPs show promise for imaging biological liquids and subsurface layers.
Area of Science:
- Biomedical Imaging
- Nanomaterials Science
- Optical Physics
Background:
- Upconversion nanoparticles (UCNPs) possess unique luminescent properties beneficial for optical biomedical imaging.
- UCNPs overcome limitations of biological tissue autofluorescence and high light absorption, enabling high-contrast imaging.
- Their nonlinear luminescence dependence on excitation intensity poses challenges for deep tissue imaging.
Purpose of the Study:
- Investigate the trade-off between UCNP luminescence and tissue depth.
- Identify optimal application niches for UCNPs in biomedical imaging.
- Assess UCNP detectability in biological tissues for in vivo applications.
Main Methods:
- Experimental and theoretical investigation of UCNP luminescence under varying conditions.
- Single UCNP imaging through hemolyzed blood.
- Quantification of UCNP optical properties and theoretical modeling of detectability in human skin.
Main Results:
- UCNPs enable high-contrast imaging by suppressing background autofluorescence and tissue absorption.
- Signal reduction occurs at depths around 1 cm due to nonlinear luminescence dependence.
- Single 70-nm UCNPs are predicted detectable up to 400 µm in human skin, outperforming fluorescent dye molecules.
Conclusions:
- UCNPs are suitable for imaging biological liquids and subsurface tissue layers.
- UCNP-assisted imaging in the ballistic regime offers high sensitivity for specific biomedical applications.
- Further research can optimize UCNP utility for in vivo imaging despite tissue scattering and absorption.
