Preparation of chains of magnetosomes, isolated from Magnetospirillum magneticum strain AMB-1 magnetotactic bacteria, yielding efficient treatment of tumors using magnetic hyperthermia.
Chains of magnetosomes isolated from Magnetospirillum magneticum strain AMB-1 magnetotactic bacteria by sonication at 30 W during 2 h are tested for magnetic hyperthermia treatment of tumors. These chains are composed of magnetosomes, which are bound to each other by a filament made of proteins. When they are incubated in the presence of cancer cells and exposed to an alternating magnetic field of frequency 198 kHz and average magnetic field strength of 20 or 30 mT, they produce efficient inhibition of cancer cell proliferation. This behavior is explained by a high cellular internalization, a good stability in solution and a homogenous distribution of the magnetosome chains, which enables efficient heating. When the chains are heated during 5 h at 90°C in the presence of 1% SDS, the filament binding the magnetosomes together is denatured and individual magnetosomes are obtained. By contrast to the chains of magnetosomes, the individual magnetosomes are prone to aggregation, are not stable in solution and do not produce efficient inhibition of cancer cell proliferation under application of an alternating magnetic field.
Institut de minéralogie et de physique des milieux condensés, Université Pierre et Marie Curie, UMR CNRS 7590, 4 Place Jussieu, 75005 Paris, France. edouardalphandery@hotmail.com
Edouard
E
Alphandéry
François
F
Guyot
Imène
I
Chebbi
D045744:Cell Line, Tumor; D049109:Cell Proliferation; D006367:HeLa Cells; D006358:Hot Temperature; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D060526:Magnetic Fields; D055944:Magnetosomes / Q000737:chemistry*; D042201:Magnetospirillum / Q000737:chemistry; D009369:Neoplasms / Q000473:pathology / Q000628:therapy*; D013010:Sonication