Strategies towards standardizing calibration methods for magnetic particle imaging (MPI) signal quantification: solution vs. cellular environments

Ureña Horno, E ORCID: 0000-0003-2496-7809, Maguire, ML ORCID: 0009-0004-5578-7231, Ozkan, S ORCID: 0000-0001-7854-4735, O'Brien, L ORCID: 0000-0002-0136-8603, Murray, P ORCID: 0000-0003-1316-148X, Poptani, H ORCID: 0000-0002-0593-3235 and Giardiello, M ORCID: 0000-0003-0560-4711 (2025) Strategies towards standardizing calibration methods for magnetic particle imaging (MPI) signal quantification: solution vs. cellular environments Nanoscale, 17 (41). pp. 24060-24071. ISSN 2040-3364, 2040-3372

Text Giardiello_Nanoscale 2025.pdf - Open Access published version Download (2MB) | Preview

Abstract

Magnetic Particle Imaging (MPI) is a powerful technique for non-invasive imaging and iron quantification using superparamagnetic iron oxide nanoparticles (SPIONs), with applications ranging from in vivo cell tracking to tracer distribution and biodistribution studies. As the MPI community continues to grow and diversify, there is an increasing recognition of the need for standardized approaches in signal quantification to ensure reproducibility, comparability, and reliable interpretation of results across studies. A key area where standardization is particularly needed is in the construction of calibration curves for quantitative MPI. In this study, we demonstrate that calibration curves derived from SPIONs in solution differ markedly from those obtained in cellular environments. We therefore propose calibrating MPI signal against the number of labelled cells, a strategy that accounts for altered SPION behaviours in the cellular environment and enables more accurate estimation of intracellular iron content. Another critical but often overlooked factor in MPI quantification is the influence of SPION concentration and spatial distribution within the sample. We show that even modest variations in concentration can significantly affect MPI signal intensity, challenging the commonly assumed linear relationship between signal and iron content. Our findings reveal that variations in concentration can introduce nonlinearities in signal response, thereby altering calibration curves and impacting the accuracy and reproducibility of MPI-based quantification. By systematically examining the effects of environmental context and SPION concentration, our study provides a framework for biologically relevant MPI calibration strategies and supports the development of more standardized, reproducible quantification protocols.

Item Type:	Article
Uncontrolled Keywords:	Humans, Iron, Calibration, Magnetite Nanoparticles, Magnetic Iron Oxide Nanoparticles
Divisions:	Faculty of Health & Life Sciences Faculty of Science & Engineering Faculty of Science & Engineering > School of Physical Sciences Faculty of Science & Engineering > School of Physical Sciences > Chemistry Faculty of Science & Engineering > School of Physical Sciences > Physics Faculty of Health & Life Sciences > Inst. Life Courses & Medical Sciences Faculty of Health & Life Sciences > Inst. Life Courses & Medical Sciences > Inst. Life Courses & Medical Sciences (T&R staff) Faculty of Health & Life Sciences > Inst. Life Courses & Medical Sciences > Women's & Children's Health Faculty of Health & Life Sciences > Inst. Systems, Molec & Integrative Biology Faculty of Health & Life Sciences > Inst. Systems, Molec & Integrative Biology > Inst. Systems, Molec & Integrative Biology (T&R Staff) Faculty of Health & Life Sciences > Inst. Systems, Molec & Integrative Biology > Molecular & Clinical Cancer Medicine Faculty of Health & Life Sciences > Tech, Infrastructure & Env Directorate Faculty of Health & Life Sciences > Tech, Infrastructure & Env Directorate > Liverpool Shared Research Facilities
Depositing User:	Symplectic Admin
Date Deposited:	17 Nov 2025 08:48
Last Modified:	28 Feb 2026 01:05
DOI:	10.1039/d5nr03025k
Related Websites:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3195435
Disclaimer:	The University of Liverpool is not responsible for content contained on other websites from links within repository metadata. Please contact us if you notice anything that appears incorrect or inappropriate.