Magnetic particle detection (MPD) for in-vitro dosimetry

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Cell Biology

Background:

• Accurate cell dose measurement is crucial for reproducible in-vitro health effect studies of magnetic nanoparticles.
• Current methods for quantifying nanoparticle uptake are often time-consuming and labor-intensive.
• Standardized dosimetry is essential for reliable interpretation of biological responses to nanomaterials.

Purpose of the Study:

• To develop a simple, low-cost inductive sensor for rapid quantification of magnetic nanoparticle mass.
• To assess the sensor's performance in measuring nanoparticle uptake by cultured cells.
• To provide a more accessible and efficient method for magnetic particle detection in in-vitro assays.

Main Methods:

• Development of a low-cost inductive sensor utilizing an oscillating magnetic field (250 kHz).
• Exploitation of nonlinear particle magnetization to generate a harmonic signal (750 kHz) proportional to mass.
• Validation of sensor sensitivity and linearity (R(2)>0.999) for carboxyl-coated iron-oxide nanoparticles.
• Application of the sensor to measure nanoparticle uptake in RAW 264.7 macrophages.

Main Results:

• The sensor accurately determines the total mass of magnetic nanoparticles bound to and internalized by cells.
• Achieved sensitivity allows detection of approximately 100 ng of nanoparticles in under one second.
• Dosimetric performance is comparable to more expensive and labor-intensive analytical techniques.
• Linear correlation (R(2)>0.999) between sensor signal and nanoparticle mass was established.

Conclusions:

• The developed inductive sensor offers a fast, low-cost solution for quantifying magnetic nanoparticle cell dose in in-vitro settings.
• This technology can improve the consistency and interpretation of biological response data.
• The sensor is well-suited for high-throughput screening and routine laboratory use in nanomaterial safety assessments.