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Paramagnetic Relaxation Enhancement for Detecting and Characterizing Self-Associations of Intrinsically Disordered Proteins
Published on: September 23, 2021
How cellular processing of superparamagnetic nanoparticles affects their magnetic behavior and NMR relaxivity
Michael Lévy1, Claire Wilhelm, Martin Devaud
1Laboratoire Matière et Systèmes Complexes, UMR CNRS/Université Paris - Diderot, France.
Cellular processing alters iron oxide nanoparticle magnetic properties and NMR relaxivity. Nanoparticle clustering within cells changes their behavior, impacting biomedical applications.
Area of Science:
- Nanomedicine
- Biophysics
- Materials Science
Background:
- Cellular uptake modifies nanoparticle physical properties, crucial for biomedical uses.
- Intracellular concentration changes nanoparticle responsiveness to stimuli.
Purpose of the Study:
- Investigate how cellular uptake affects iron oxide nanoparticle magnetic properties.
- Analyze changes in Nuclear Magnetic Resonance (NMR) relaxivity post-cellular processing.
Main Methods:
- Characterized superparamagnetic behavior using SQUID measurements.
- Analyzed NMRD R(1) profiles in colloidal suspension and within cells (tumor, stem, macrophages).
- Utilized Transmission Electron Microscopy (TEM) for intracellular distribution analysis.
Main Results:
- Temperature-dependent magnetization and NMRD profiles changed after cellular uptake.
- Field-dependent magnetization at room temperature remained consistent.
- Intracellular magnetic coupling in lysosomes explained magnetic behavior changes.
- NMR longitudinal relaxivity correlated with intracellular nanoparticle distribution.
Conclusions:
- Cellular processing significantly alters iron oxide nanoparticle magnetic and NMR relaxivity properties.
- Changes are linked to intracellular organization and endocytosis stage.
- This study establishes a link between magnetic properties and NMR characterization of nanoparticles before and after cellular processing.
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