Magneto-motive detection of nanoparticles and hemoglobin

Magneto-motive diagnostic systems combining optical coherence tomography (OCT) and ultrasonography (US) can be used to detect magnetic nanoparticles and red blood cells (RBCs) containing iron in response to an external magnetic field. Magnetic force on magnetic nanoparticles and hemoglobin iron may be varied by applying an external current to a solenoid containing a conical iron core that substantially increases and focuses a magnetic field (Bmax = 2 Tesla). In studies using superparamagnetic iron oxide (SPIO) and monocrystalline iron oxide (MION) nanoparticles, the hypothesis of this research is that tissue-based macrophage cells can be detected in an external magnetic field after taking up SPIO nanoparticles in liver and MION nanoparticles in the atherosclerotic high-risk plaque. Therefore, magneto-motive OCT (MM-OCT) and magneto-motive ultrasound (MM-US) can detect iron-laden tissue motion in response to an external magnetic field. Important parameters of magnetic force-induced displacement are optical path length change (Δp) in MM-OCT and Doppler frequency shift (fd) in MM-US. Variations of these parameters in response to an external magnetic field may aid understanding and identification of lesions in biomedical engineering applications, especially inflammatory diseases such as cancer and atherosclerosis. In studies involving human red blood cells (RBCs), the hypothesis of the proposed research is that magnetic permeability of deoxygenated RBCs is sufficient such that when positioned in a high magnetic field gradient, translational and rotational motion is modified. Moreover, our hypothesis states that a high magnetic field can increase blood viscosity, resulting in reduction of blood flow rate, enabling not only imaging and measurement of small caliber vessels, but also providing improved laser treatment for port wine stains (PWS), telangiectasias, and hemangiomas.