Gellan gum-based gels with tunable relaxation properties for MRI phantoms

Pawel Brzozowski; Kalin I Penev; Francisco M Martinez; Timothy J Scholl; Kibret Mequanint

doi:10.1016/j.mri.2018.10.017

Gellan gum-based gels with tunable relaxation properties for MRI phantoms

Magn Reson Imaging. 2019 Apr:57:40-49. doi: 10.1016/j.mri.2018.10.017. Epub 2018 Oct 28.

Authors

Pawel Brzozowski¹, Kalin I Penev², Francisco M Martinez³, Timothy J Scholl⁴, Kibret Mequanint⁵

Affiliations

¹ School of Biomedical Engineering, The University of Western Ontario, London, Canada.
² Department of Chemical and Biochemical Engineering, The University of Western Ontario, London, Canada.
³ Department of Medical Biophysics, and the Robarts Research Institute, The University of Western Ontario, London, Canada.
⁴ Department of Medical Biophysics, and the Robarts Research Institute, The University of Western Ontario, London, Canada; Ontario Institute for Cancer Research, Toronto, Canada.
⁵ School of Biomedical Engineering, The University of Western Ontario, London, Canada; Department of Chemical and Biochemical Engineering, The University of Western Ontario, London, Canada. Electronic address: kmequani@uwo.ca.

PMID: 30394298
DOI: 10.1016/j.mri.2018.10.017

Abstract

Object: The research follows the analysis of gellan gum-based gels as novel MRI phantom material with the implementation of a design of experiments model to obtain tunable relaxation properties.

Materials and methods: Gellan gum gels doped with newly synthesized superparamagnetic iron oxide nanoparticles (SPIONs) and either MnCl₂ or GdCl₃ were prepared and scanned from 230 μT to 3 T. Nineteen gel samples were formulated with varying concentrations of contrast agents to determine the linear, quadratic, and interactive effects of the contrast agents by a central composite design of experiment. To inhibit microbial growth in the gels and to enable long-term use, methyl 4‑hydroxybenzoate (methylparaben) was utilized.

Results: The model containing SPIONs and metal salts relaxivity was analyzed with ANOVA, and the resulting significant coefficients were tabulated. The mathematical model was able to accurately predict the intended relaxation property from the concentration of the contrast agent with adjusted R² values > 0.97 for longitudinal (R₁) relaxation rates and 0.87 for transverse (R₂) relaxation rates.

Conclusion: The gel material maintained physical, chemical, and biological stability for at least four months and contained controllable relaxation properties while maintaining optical clarity.

Keywords: Design of experiments; Gellan gum; MRI phantom; Paramagnetic ions; SPIONs.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Contrast Media / chemistry*
Ferric Compounds / chemistry
Gels
Humans
Magnetic Fields
Magnetic Resonance Imaging*
Magnetic Resonance Spectroscopy
Magnetite Nanoparticles / chemistry
Metal Nanoparticles / chemistry
Parabens / chemistry
Particle Size
Phantoms, Imaging*
Polysaccharides, Bacterial / chemistry*
Regression Analysis
Temperature

Substances

Contrast Media
Ferric Compounds
Gels
Magnetite Nanoparticles
Parabens
Polysaccharides, Bacterial
ferric oxide
gellan gum
methylparaben

Grants and funding

CIHR/Canada