Indirect MPI-based detection of superparamagnetic nanoparticles transported by computer-controlled magneto-aerotactic bacteria

MC-1 strain magneto-aerotactic bacteria recently used in cancer therapy and labeled with superparamagnetic nanoparticles are localized by magnetic particle imaging (MPI) spectrometry. A 8.5 mT drive field oscillating at 150 kHz is generated in a solenoid coil and placed near two receiving coils connected in series in a gradiometric configuration. The magnetic behavior of superparamagnetic particles attached to the MC-1 bacteria using MC-1 antibodies allowed the indirect detection of the MC-1 bacteria. It is moreover validated that the drive field does not break the covalent bond between the MC-1 antibodies coating the superparamagnetic particles and the MC-1 bacteria. The results presented here demonstrate the usability of a MPI device to provide a real-time evaluation of the evolution of cancer treatment using MC-1 bacteria as delivery vectors.