Magnetic microspheres can be used for magnetic particle imaging of cancer cells arrested in the mouse brain

Abstract

Cellular MRI combines the ability to obtain high-resolution MRI data with the use of magnetic contrast agents for labeling specific cells, thereby enhancing their detectability. 1,2 The most widely used cell-labeling agents for cell tracking are magnetite (Fe 3 O 4 )-based superparamagnetic iron oxide (SPIO) nanoparticles. Commonly used iron

Tracking the fates of iron-labeled tumor cells in vivo using magnetic particle imaging

“…The signal strength of the MPIO was not altered by cellular internalization, which is in agreement with Melo et al 11 Others have reported a loss in signal with internalization for other SPIO. 23 These different findings may be due to the differences in composition between the MPIO and SPIO particles; the MPIO is embedded in a polymer which may prohibit a change in the relaxation properties when exposed to different environments when compared to the SPIO.…”

“…Differences in composition may also have an effect on MPI resolution. While we identified no significant change in resolution between 1.63 μm, encapsulated MPIO and MPIO-labeled cells, Melo et al 11 found there was a decrease in resolution when 0.9 μm, unencapsulated MPIO were internalized into cells. Although we did detect some differences in resolution we do not expect this finding to lead to inaccurate quantification whether the MPIO is still within the cell or being cleared from the body.…”

“…However, MPI signals were identied in mice which received the same number of MPIO-labeled cells. 11 An advantage of using MPIO is that even non-phagocytic cells (i.e., cancer cells) readily take up MPIO without the need for assistance such as transfection 12,13 and incorporation of MPIO into cells does not affect cell proliferation and mitosis, motility and migration, differentiation or metastasis formation and growth. 14,15 For cancer cells the amount of iron per labeled cell decreases with cell division.…”

Applications of Magnetic Particle Imaging in Biomedicine: Advancements and Prospects

“…Moreover, circulating tumor cells have innate tumor selfhoming capabilities and are considered delivery vehicles for anticancer treatments (Parkins et al, 2020). The micro-sized iron oxide (MPIO) containing 1 pg Fe/particle, which is equivalent to 1.5 million standard SPIONs, is a magnetic microsphere for preclinical cell tracking (Melo et al, 2021). Parkins et al (2021) reported that MPIO-labeled circulating tumor cells emerged in the tumor region of breast cancer models via intracardiac injection and provided the possibility of visualizing the tumor self-homing process.…”

State of the Art in Carbon Nanomaterials for Photoacoustic Imaging

“…In biomedical studies, various imaging techniques such as magnetic resonance imaging (MRI) [ 6 ], positron emission tomography (PET), X-ray computed tomography (X-ray), ultrasound imaging (USI) [ 7 , 8 ], and optical imaging techniques have been used for monitoring biological response in small animals. Among the imaging techniques, photoacoustic imaging (PAI) has widely been explored in the last two decades since it has unique characteristics through inherited complementary advantages from optical imaging and USI [ 9 ].…”