MRI of a Surgical Guidewire in a Hydrogel Phantom: Effects of Ferric Ion Chelated Natural MNPs

Abstract

Magnetic resonance imaging (MRI) presents an alternative imaging method over conventional X-ray based modalities for guiding minimal invasive surgeries. However, lack of commercial MRI safe and functional interventional instruments and devices is the main obstacle for the realization of interventional procedures under MRI. Herein, as a novel passive tracking method, Fe3+ ions binded melanin nanoparticles (MNPs) were used as a coating to enhance the visibility of a commercial MRI safe nitinol guidewire. Fe3+ chelating ability of MNPs was found to be approximately 95% using inductively coupled plasma mass spectroscopy (ICP-MS). The spherical shapes of MNPs were evaluated and measured by scanning electron analysis with a mean diameter of 134± 21 nm for MNPs before $Fe3+ chelation and $144 ± 34$ nm after. NIH 3T3 cells incubated with MNPs-Fe3+ solutions at levels up to 1000 ng/ml and MNPs-Fe3+ solutions indicated negligible cytotoxic effect. The traceability of MNPs-Fe+ coated surgical nitinol guidewire was confirmed inside a custom-made hydrogel phantom model in a 3T MRI scanner. A conspicuous bright signal from coated nitinol guidewire was obtained for axial, sagittal, and coronal planes with MRI. This pilot study showed that both the tracking of an interventional guidewire and the degradation level of a hydrogel used for the therapeutic response of a drug can be imaged by MRI during minimal invasive operations. © 2024 Elsevier B.V., All rights reserved.