Magnetosome-inspired synthesis of soft ferrimagnetic nanoparticles for magnetic tumor targeting

Abstract

Magnetic targeting is one of the most promising approaches for improving the targeting efficiency by which magnetic drug carriers are directed using external magnetic fields to reach their targets. As a natural magnetic nanoparticle (MNP) of biological origin, the magnetosome is a special “organelle” formed by biomineralization in magnetotactic bacteria (MTB) and is essential for MTB magnetic navigation to respond to geomagnetic fields. The magnetic targeting of magnetosomes, however, can be hindered by the aggregation and precipitation of magnetosomes in water and biological fluid environments due to the strong magnetic attraction between particles. In this study, we constructed a magnetosome-like nanoreactor by introducing MTB Mms6 protein into a reverse micelle system. MNPs synthesized by thermal decomposition exhibit the same crystal morphology and magnetism (high saturation magnetization and low coercivity) as natural magnetosomes but have a smaller particle size. The DSPE-mPEG–coated magnetosome-like MNPs exhibit good monodispersion, penetrating the lesion area of a tumor mouse model to achieve magnetic enrichment by an order of magnitude more than in the control groups, demonstrating great prospects for biomedical magnetic targeting applications.

The role of tumor model in magnetic targeting of magnetosomes and ultramagnetic liposomes

“…This could make a difference in treatment, with a 2- to 3-fold increase in the quantity of nanomaterials in OT tumors thanks to magnet application, and similar to results obtained in in vivo brain 43 and colon 29 tumor models. The %ID/g obtained with magnetic targeting of magnetosomes is also comparable to that recently reported for this kind of nanoparticles after magnetic targeting in breast cancer tumor models 37 , 38 .…”

“…Magnetic liposomes 30 have been tested for such a purpose in several in vitro 31 and in vivo 32 models, generally subcutaneous tumor models, resulting in an improved therapeutic efficiency when the liposomes were co-vectorized with a chemotherapeutic drug 33 , 34 . Among highly magnetic theranostic materials are the naturally synthesized magnetosomes 35 , 36 , which have only recently been tested for in vivo magnetic targeting 37 , 38 . In addition, the role of tumor model, and especially orthotopic versus subcutaneous tumors, is yet to be investigated in relation with magnetic targeting feasibility and efficiency.…”

Boosting SARS-CoV-2 Enrichment with Ultrasmall Immunomagnetic Beads Featuring Superior Magnetic Moment

“…Figure a shows the TEM image of Mal-NPs, which exhibited good monodispersity and homogeneity. The TEM images revealed distinct lattice stripe patterns (Figure S1), indicating a well-defined cubic octahedron structure, which is consistent with the natural magnetosome . Meanwhile, the commercially available magnetic beads, which were used as Ct-NPs, displayed a spherical shape with aggregation and poor monodispersity (Figure b).…”

“…In our previous study, we successfully incorporated the Mms6 protein into the reverse micelle system, creating a nanoreactor that emulates the natural magnetosome vesicles. , This innovative approach enabled us to recreate the microenvironment of magnetotactic bacteria magnetosome biomineralization in vitro. By utilizing this method, we were able to biomimetically synthesize small-sized magnetosome-like crystals with a cubic octahedral crystal structure that closely resembles natural magnetosomes.…”

“…Synthesis of Magnetosome-like Nanoparticles. Based on the previous work, 37 the synthesis procedure is as follows: First, 0.05 mmol iron acetylacetonate and 0.25 mmol 1,2hexadecanediol are weighed and mixed together. The resulting mixture is dissolved in 5 mL of diphenyl ether solution containing 0.1% water.…”