Chains of Magnetosomes Extracted from AMB-1 Magnetotactic Bacteria for Application in Alternative Magnetic Field Cancer Therapy

Abstract

International audienceChains of magnetosomes extracted from magnetotactic bacteria are shown to be highly efficient for alternative magnetic field cancer therapy. The viability of MDA-MB-231 breast cancer cells is relatively unaffected by the presence of less than ∼ 1 mg of chains of magnetosomes. When these cells are exposed to an oscillating magnetic field of frequency 183 kHz and field strengths of 20 to 60 mT, up to 100 % of them are destroyed. We show that it is possible to fully eradicate a tumor xeno-greffed on a mouse by administering a suspension containing ∼ 1 mg of chains of magnetosomes within the tumor and by exposing the mouse to three heat cycles of 20 minutes, during which the tumor temperature is raised to ∼ 43°C. We demonstrate the higher efficiency of the chains of magnetosomes compared with various other materials, i. e. whole inactive magnetotactic bacteria, individual magnetosomes not organized in chains and two different types of chemically synthesized nanoparticles currently tested for alternative magnetic field cancer therapy. The efficiency of the chains of magnetosomes is attributed to three factors, (i), a high magnetosome specific absorption rate (SAR), (ii), a homogenous distribution of the chains of magnetosomes within the tumor yielding uniform heating and (iii), the faculty of the chains of magnetosomes to penetrate within the cancer cells following the application of the alternative magnetic field, which enables intra-cellular heating. Biodistribution studies reveal that chains of magnetosomes administered directly within xeno-greffed breast tumors progressively leave the tumors during the 14 days following their administration and are then eliminated in the feces

Tailoring the interplay between electromagnetic fields and nanomaterials toward applications in life sciences: a review

“…165 Interestingly, magnetosomes produced by magnetotactic bacterium have been reported to produce unusually large SAR values compared to similar magnetic NPs produced by synthetic colloidal methods. 166,167 This indeed indicates that there is still space for improving synthetic methods to produce more efficient materials.…”

Controlled cobalt doping in the spinel structure of magnetosome magnetite: new evidences from element- and site-specific X-ray magnetic circular dichroism analyses

“…Tailored synthesis of MNPs by which the physical and magnetic properties are well controlled is essential for determining the technological and biomedical applications that they are suitable for. For instance, MNPs with single-domain (SD) sizes and one-dimensional (1D) arrays have advantages in magnetic memory devices [4] and magnetic hyperthermia [5] due to their stronger magnetic anisotropy and hysteresis than their random assemblages [6][7][8].…”

Ganglioside-magnetosome complex formation enhances uptake of gangliosides by cells

“…In addition, because magnetosomes are comprised of Fe 3 O 4 , the magnetic field could accelerate the process that the particles entering into cells. 35,36 Therefore, the effects described above were further enhanced by the presence of a magnetic field, because of the magnetic characteristics of magnetosomes. Our findings provide a basis for the application of magnetosomes in the delivery of specific gangliosides into cells, and the new strategy will be useful in studies of carbohydrate-protein interactions in vitro and in vivo.…”