A fast and reproducible method to quantify magnetic nanoparticle biodistribution.

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Analytical Chemistry

Background:

• Quantifying superparamagnetic iron oxide nanoparticles (SPIONs) in vitro and in vivo is crucial.
• Existing methods like ICP and Prussian Blue titration measure total iron, requiring sample destruction and long measurement times.
• These methods are also susceptible to interference from endogenous iron.

Purpose of the Study:

• To introduce and evaluate magnetic susceptibility measurements (MSM) as a novel quantification technique for SPIONs.
• To compare the advantages of MSM against traditional iron oxide titration methods.
• To assess the accuracy, sensitivity, and robustness of MSM for SPION biodistribution studies.

Main Methods:

• Utilized magnetic susceptibility measurements (MSM) for SPION concentration and biodistribution analysis in rat organs.
• Compared MSM performance with established methods such as induced coupled plasma (ICP) spectroscopy and Prussian Blue (PB) UV-visible titration.
• Evaluated MSM's sensitivity, reproducibility, and robustness against SPION coating, environmental factors, and endogenous iron.

Main Results:

• MSM provides a simpler, faster (1-second measurements), and highly reproducible method for SPION detection.
• Achieved a minimal detection limit of approximately 2 μgFe mL(-1).
• MSM is unaffected by SPION coating or surrounding environment and robustly distinguishes SPIONs from endogenous iron, reducing the need for control samples.

Conclusions:

• MSM is a superior technique for SPION quantification, offering significant advantages over ICP and PB titration.
• MSM enables accurate determination of SPION biodistribution in biological tissues without interference.
• This method is easily implemented and suitable for standard use in various research settings.