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Applications of magnetosomes synthesized by magnetotactic bacteria in medicine.

Alphandéry E - Front Bioeng Biotechnol (2014)

Bottom Line: Different methods that can be used to prepare the magnetosomes for these applications are described.The toxicity and biodistribution results that have been published are summarized.The advantageous properties of the magnetosomes compared with those of chemically synthesized nanoparticles of similar composition are also highlighted.

View Article: PubMed Central - PubMed

Affiliation: Nanobacterie SARL , Paris , France † ; Institut de Minéralogie et de Physique des Milieux Condensés, Université Pierre et Marie Curie , Paris , France.

ABSTRACT
Magnetotactic bacteria belong to a group of bacteria that synthesize iron oxide nanoparticles covered by biological material that are called magnetosomes. These bacteria use the magnetosomes as a compass to navigate in the direction of the earth's magnetic field. This compass helps the bacteria to find the optimum conditions for their growth and survival. Here, we review several medical applications of magnetosomes, such as those in magnetic resonance imaging (MRI), magnetic hyperthermia, and drug delivery. Different methods that can be used to prepare the magnetosomes for these applications are described. The toxicity and biodistribution results that have been published are summarized. They show that the magnetosomes can safely be used provided that they are prepared in specific conditions. The advantageous properties of the magnetosomes compared with those of chemically synthesized nanoparticles of similar composition are also highlighted.

No MeSH data available.


Related in: MedlinePlus

Schematic diagram showing the treatment of a mouse using magnetic hyperthermia. The mouse has a breast tumor xeno-grafted under its skin. A suspension of magnetosomes is administered at the center of the tumor; the mouse is then positioned inside a coil where an alternating magnetic field is applied three times during 20 min. The tumor disappears 30 days following the treatment as can be seen in the bottom right photograph.
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Figure 2: Schematic diagram showing the treatment of a mouse using magnetic hyperthermia. The mouse has a breast tumor xeno-grafted under its skin. A suspension of magnetosomes is administered at the center of the tumor; the mouse is then positioned inside a coil where an alternating magnetic field is applied three times during 20 min. The tumor disappears 30 days following the treatment as can be seen in the bottom right photograph.

Mentions: In order to evaluate the anti-tumor activity of the magnetosomes (Alphandéry et al., 2011b), 100 μL of suspensions containing either individual magnetosomes or chains of magnetosomes at a concentration of 10 mg/mL were administered at the center of MDA-MB-231 breast tumors xeno-grafted under the skin of mice following the protocol illustrated in the schematic diagram of Figure 2. The mice were then exposed to an alternating magnetic field of average field strength ~20 mT and frequency 198 kHz three times during 20 min. This produced an increase in the tumor temperature up to ~43°C. The treatment with the chains of magnetosomes yielded the total disappearance of the tumor 30 days following the treatment in several mice (Figure 2), while that using the individual magnetosomes did not produce significant anti-tumor activity (Alphandéry et al., 2011b). The efficacy of the treatment was attributed on the one hand to the internalization of the chains of magnetosomes inside the tumor cells that enabled intracellular heating and hence efficient tumor cell destruction. On the other hand, the efficacy of the chains of magnetosomes was reported to arise from their homogenous distribution throughout the tumor, which is mostly due to their low level of aggregation.


Applications of magnetosomes synthesized by magnetotactic bacteria in medicine.

Alphandéry E - Front Bioeng Biotechnol (2014)

Schematic diagram showing the treatment of a mouse using magnetic hyperthermia. The mouse has a breast tumor xeno-grafted under its skin. A suspension of magnetosomes is administered at the center of the tumor; the mouse is then positioned inside a coil where an alternating magnetic field is applied three times during 20 min. The tumor disappears 30 days following the treatment as can be seen in the bottom right photograph.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126476&req=5

Figure 2: Schematic diagram showing the treatment of a mouse using magnetic hyperthermia. The mouse has a breast tumor xeno-grafted under its skin. A suspension of magnetosomes is administered at the center of the tumor; the mouse is then positioned inside a coil where an alternating magnetic field is applied three times during 20 min. The tumor disappears 30 days following the treatment as can be seen in the bottom right photograph.
Mentions: In order to evaluate the anti-tumor activity of the magnetosomes (Alphandéry et al., 2011b), 100 μL of suspensions containing either individual magnetosomes or chains of magnetosomes at a concentration of 10 mg/mL were administered at the center of MDA-MB-231 breast tumors xeno-grafted under the skin of mice following the protocol illustrated in the schematic diagram of Figure 2. The mice were then exposed to an alternating magnetic field of average field strength ~20 mT and frequency 198 kHz three times during 20 min. This produced an increase in the tumor temperature up to ~43°C. The treatment with the chains of magnetosomes yielded the total disappearance of the tumor 30 days following the treatment in several mice (Figure 2), while that using the individual magnetosomes did not produce significant anti-tumor activity (Alphandéry et al., 2011b). The efficacy of the treatment was attributed on the one hand to the internalization of the chains of magnetosomes inside the tumor cells that enabled intracellular heating and hence efficient tumor cell destruction. On the other hand, the efficacy of the chains of magnetosomes was reported to arise from their homogenous distribution throughout the tumor, which is mostly due to their low level of aggregation.

Bottom Line: Different methods that can be used to prepare the magnetosomes for these applications are described.The toxicity and biodistribution results that have been published are summarized.The advantageous properties of the magnetosomes compared with those of chemically synthesized nanoparticles of similar composition are also highlighted.

View Article: PubMed Central - PubMed

Affiliation: Nanobacterie SARL , Paris , France † ; Institut de Minéralogie et de Physique des Milieux Condensés, Université Pierre et Marie Curie , Paris , France.

ABSTRACT
Magnetotactic bacteria belong to a group of bacteria that synthesize iron oxide nanoparticles covered by biological material that are called magnetosomes. These bacteria use the magnetosomes as a compass to navigate in the direction of the earth's magnetic field. This compass helps the bacteria to find the optimum conditions for their growth and survival. Here, we review several medical applications of magnetosomes, such as those in magnetic resonance imaging (MRI), magnetic hyperthermia, and drug delivery. Different methods that can be used to prepare the magnetosomes for these applications are described. The toxicity and biodistribution results that have been published are summarized. They show that the magnetosomes can safely be used provided that they are prepared in specific conditions. The advantageous properties of the magnetosomes compared with those of chemically synthesized nanoparticles of similar composition are also highlighted.

No MeSH data available.


Related in: MedlinePlus