Chapter 4 Magnetobiology Magnetobiology is an approach in radiobiology of non-ionizing radiation; the line of investigation in biophysics that studies biological effects of mainly weak static and low-frequency magnetic fields, which do not cause heating of tissues. Magnetobiology corresponds to somewhat more general term bioelectromagnetics, which should not be mixed up with the term bioelectromagnetism

Magnetic Resonance Imaging MRI Magnetic resonance imaging (MRI), or nuclear magnetic resonance imaging (NMRI), is primarily a medical imaging technique most commonly used in radiology to visualize the structure and function of the body

The Advantages and Disadvantages of MRI MRI scan is a painless radiology technique Its precise accuracy in detecting structural abnormalities of the body Disadvantages Patients who have heart pacemakers, metal implants, or metal chips or clips in or around the eyeballs cannot be scanned with an MRI because of the risk that the magnet may move the metal in these areas. patients with any history of claustrophobia should relate this to the practitioner

MRI versus CT MRI CT uses non-ionizing radio frequency (RF) signals to acquire its images uses X-rays, a type of ionizing radiation, to acquire its images for non-calcified tissue, though MR images can also be acquired from bones and teeth as well as fossils. examining tissue composed of elements of a higher atomic number than the tissue surrounding them, such as bone and calcifications (calcium based) CT may be enhanced by use of contrast agents containing elements of a higher atomic number than the surrounding flesh such as iodine or barium. Contrast agents for MRI are those which have paramagnetic properties, e.g. gadolinium and manganese For purposes of tumor detection and identification in the brain, MRI is generally superior In the case of solid tumors of the abdomen and chest, CT is often preferred due to less motion artifact MRI is also best suited for cases when a patient is to undergo the exam several times successively in the short term CT usually is more widely available, faster, much less expensive, and may be less likely to require the person to be sedated or anesthetized

Nanotechnology What is nano ? This piece is 1 nm If we divided the width into 100000 piece Then we took one piece from these pieces This piece is 1 nm Single hair 0.1mm width

The Relevance of Nano New properties enable new applications Size-Dependent Properties At the nanometer scale, properties become size-dependent. For example, Thermal properties – melting temperature (2) Mechanical properties – adhesion, capillary forces (3) Optical properties – absorption and scattering of light (4) Electrical properties – tunneling current New properties enable new applications

Magnetic Nanoparticles for Biological and medical Applications In recent years an increasing interest in using magnetic nanoparticles for biological and medical applications developed. The size of the particles can range from a few nanometers to several micrometers and thus is compatible with biological entities ranging from proteins (a few nm) to cells and bacteria (several μm). Generally the magnetic particles are coated with a suitable ligand, which allows chemically binding of the particles to different biological systems. This combination of biology and magnetism is useful, because the biochemistry enables a selective binding of the particles, while the magnetism enables easy manipulation and detection.

Fighting cancer using magnetic nanoparticles The center piece of the MagForce nano cancer therapy is the nanoparticle consisting of iron oxide. The particle is covered by a paint coating which insure the good stability and division of iron oxide particles in the tumor tissues. It additionaly support the process by which the particles are absorbed into the cancer cells. The small size of the particles is decided for theraby the diameter measure some 20nm and this is 500 times smaller than red blood cell. One milliliter of particle solution contains nearly 17 trillion single nanoparticles. This high density made efficient treatment possible. At the beginning of the therapy nanoparticles are injected directed to the tumor. The tumor in this particular case is glioblastoma a malignant brain tumor characterized by aggressive growing cells. After being injected the nanoparticles are spread out in the spaces between the tumor cells. The patient now entering the therapy device in which is alternating magnetic field is produced which has no dangerous to humans. This field effect is 1000 times alternation of the magnetic poles within the particles per second creating north which is precise regulated from outside. The warm forces the particles into spaces between tumor cells which make it easy for them to be absorb into the cells. The application is repeated and the thermal effect increases visibly. The particles begin to oscillate causing the cancer cells to die either from active self destruction or from swelling until they little burst. Tumor growth stopped and the destroyed cells as well as the nanoparticles are discharged by the body in a natural process. As a rule the one hour minimum invasive treatment is repeated six times however the particles only injected once, thus making the therapy is specially gentile on the patient.

New Approach to Biomagnetic Sensors The ability to tag biological molecules with functionalized magnetic particles has been already exploited for biological sensors. Traditionally many biological sensors, like a DNA-microarray, use fluorescent markers for the detection of specific biological molecules. The magnetic particles can be used as tags and the binding can thus be identified by detecting the stray magnetic field of the particles. Advantages of using magnetic particles vs. fluorescent molecules are that Magnetic particles typically have an unlimited shelf-life (unlike fluorescent marker, which deteriorate with time) The sensitivity of the sensors based on magnetic vs. fluorescent tagging are already comparable. The magnetic tags allow for manipulation of the target molecules such that they can be moved towards the magnetic field sensor using magnetic field gradients