Biocompatibility of Bacterial Magnetosomes as MRI Contrast Agent: A Long-Term In Vivo Follow-Up Study

Abstract

Derived from magnetotactic bacteria (MTB), magnetosomes consist of magnetite crystals enclosed within a lipid bilayer membrane and are known to possess advantages over artificially synthesized nanoparticles because of the narrow size distribution, uniform morphology, high purity and crystallinity, single magnetic domain, good biocompatibility, and easy surface modification. These unique properties have increasingly attracted researchers to apply bacterial magnetosomes (BMs) in the fields of biology and medicine as MRI imaging contrast agents. Due to the concern of biosafety, a long-term follow-up of the distribution and clearance of BMs after entering the body is necessary. In this study, we tracked changes of BMs in major organs of mice up to 135 days after intravenous injection using a combination of several techniques. We not only confirmed the liver as the well-known targeted organs of BMs, but also found that BMs accumulated in the spleen. Besides, two major elimination paths, as well as the approximate length of time for BMs to be cleared from the mice, were revealed. Together, the results not only confirm that BMs have high biocompatibility, but also provide a long-term in-vivo assessment which may further help to forward the clinical applications of BMs as an MRI contrast agent.

Why Does Not Nanotechnology Go Green? Bioprocess Simulation and Economics for Bacterial-Origin Magnetite Nanoparticles

“…Recently, a long-term (135 days) in vivo study on the biocompatibility of BMNs, showed that even at concentrations 10–50 times higher than previously tested for synthetic nanoparticles, tissue damage was negligible. This biocompatibility trend was maintained even in the liver and spleen where BMN concentration was greater ( Nan et al, 2021 ). The same work also suggested that BMN clearance from the body occurred through biliary excretion, within 1 week from administration, and urinary excretion, up to 120 days ( Nan et al, 2021 ).…”

“…This biocompatibility trend was maintained even in the liver and spleen where BMN concentration was greater ( Nan et al, 2021 ). The same work also suggested that BMN clearance from the body occurred through biliary excretion, within 1 week from administration, and urinary excretion, up to 120 days ( Nan et al, 2021 ). Given these elimination routes are already well-described for other drugs ( Bardal et al, 2011 ), the pharmacological behavior of BMNs becomes more predictable.…”

Polysaccharide-Based Theranostic Systems for Combined Imaging and Cancer Therapy: Recent Advances and Challenges

“…Current research in the field of developing T 2 contrast agent development investigates the application of metal-alloy particles and magnetosomes. Because of their biological origin, magnetosomes are of particular interest in developing contrast agents, as they promise a high degree of biocompatibility …”

“…Because of their biological origin, magnetosomes are of particular interest in developing contrast agents, as they promise a high degree of biocompatibility. 35 Hyperpolarization. Another option in MRI to increase signal in general is to use the effect of hyperpolarization.…”

Biomanufacturing Biotinylated Magnetic Nanomaterial via Construction and Fermentation of Genetically Engineered Magnetotactic Bacteria

“…BMPs are biocompatible, without cytotoxic, genotoxic, immunotoxic, and hemolytic effects [ 31 , 32 , 33 , 34 ]. Compared with artificial NPs, BMPs have higher transverse relaxivity (r2) and more effective signal decay, and they can be used as magnetic resonance imaging (MRI) contrast agents [ 35 , 36 ]. Moreover, the outer membrane of BMPs makes them easily modified with drugs, antibodies, and nucleic acids, widely used in drug delivery, antigen recovery and detection, and gene transfection [ 37 , 38 , 39 ].…”