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Visualizing implanted tumors in mice with magnetic resonance imaging using magnetotactic bacteria.

ABSTRACT: To determine if magnetotactic bacteria can target tumors in mice and provide positive contrast for visualization using magnetic resonance imaging.The ability of the magnetotactic bacterium, Magnetospirillum magneticum AMB-1 (referred to from here as AMB-1), to confer positive magnetic resonance imaging contrast was determined in vitro and in vivo. For the latter studies, AMB-1 were injected either i.t. or i.v. Bacterial growth conditions were manipulated to produce small (approximately 25-nm diameter) magnetite particles, which were observed using transmission electron microscopy. Tumor targeting was confirmed using 64Cu-labeled bacteria and positron emission tomography and by determination of viable cell counts recovered from different organs and the tumor.We show that AMB-1 bacteria with small magnetite particles generate T1-weighted positive contrast, enhancing in vivo visualization by magnetic resonance imaging. Following i.v. injection of 64Cu-labeled AMB-1, positron emission tomography imaging revealed increasing colonization of tumors and decreasing infection of organs after 4 hours. Viable cell counts showed that, by day 6, the bacteria had colonized tumors but were cleared completely from other organs. Magnetic resonance imaging showed a 1.22-fold (P = 0.003) increased positive contrast in tumors on day 2 and a 1.39-fold increase (P = 0.0007) on day 6.Magnetotactic bacteria can produce positive magnetic resonance imaging contrast and colonize mouse tumor xenografts, providing a potential tool for improved magnetic resonance imaging visualization in preclinical and translational studies to track cancer.

SUBMITTER: Benoit MR

PROVIDER: S-EPMC3409839 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature

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Visualizing implanted tumors in mice with magnetic resonance imaging using magnetotactic bacteria.

Benoit Michael R MR Mayer Dirk D Barak Yoram Y Chen Ian Y IY Hu Wei W Cheng Zhen Z Wang Shan X SX Spielman Daniel M DM Gambhir Sanjiv S SS Matin A A

Clinical cancer research : an official journal of the American Association for Cancer Research 20090811 16

<h4>Purpose</h4>To determine if magnetotactic bacteria can target tumors in mice and provide positive contrast for visualization using magnetic resonance imaging.<h4>Experimental design</h4>The ability of the magnetotactic bacterium, Magnetospirillum magneticum AMB-1 (referred to from here as AMB-1), to confer positive magnetic resonance imaging contrast was determined in vitro and in vivo. For the latter studies, AMB-1 were injected either i.t. or i.v. Bacterial growth conditions were manipulat ...[more]

PMID: 19671860

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Dataset Information

Visualizing implanted tumors in mice with magnetic resonance imaging using magnetotactic bacteria.

Publications

Visualizing implanted tumors in mice with magnetic resonance imaging using magnetotactic bacteria.

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