An Investigation of the Sensing Capabilities of Magnetotactic Bacteria

We investigate the sensing capabilities of magnetotactic bacteria (Magnetospirillum gryphiswaldense strain MSR-1) to MCF-7 breast cancer cells. Cancer cells are allowed to grow inside a capillary tube with depth of 200 μm and motion of magnetotactic bacteria is investigated under the influence of oxygen gradient and geomagnetic field. The influence of cancer cells is modeled to predict the oxygen gradient within the capillary tube in three-dimensional space. Our experimental motion analysis and count of motile magnetotactic bacteria indicate that they migrate towards less-oxygenated regions within the vicinity of cancer cells. Bands of magnetotactic bacteria with average concentration of 18.8±2.0% are observed in close proximity to MCF-7 cells (h = 20 μm), whereas the concentration at proximity of 190 μm is 5.0 ± 6.8%.