The research and development for biomedical applications are recently focused on multifunctional nanoparticles. To integrate various functionalities, different methods of modifying the particle’s physical properties are developed. Among the considered, nanodiamond (ND) is a promising candidate for the development of multifunctional complex due to its variable features in size, structure, surface chemistry, physical properties, and biocompatibility. In addition to its well-studied structural, surface, electrochemical and photonic properties, strong magnetism of ND can be observed. In the present work, magnetically modified ND is introduced in terms of its bioapplications. Along with the soft ferromagnetism of ND, the increased fluorescence at one- and two-photon excitation is realized. Utilizing the combined magnetic and fluorescence properties of the magnetically modified ND, fluorescence imaging, fluorescence lifetime imaging and manipulation of cells by magnetic field are demonstrated. The perspectives to use the magnetic ND for drug delivery, cells magnetic separation and filtration, in bioengineering to control the cell distribution combined with imaging and treatment are discussed.
Magnetic properties of biological particles are measured in high-gradient magnetic separation (HGMS) analysis, revealing the concentrating process of nucleoprotein particles, ferritin, red blood cells, and eggs. A magnetic force acting on micrometer and submicrometer biological particles having diamagnetic or paramagnetic susceptibility with respect to the solution causes their movement and accumulation in gradient magnetic fields dependent on the values of the magnetic moments. The methods developed enable us to obtain the magnetic moments values of single particles and their assembly directly from magnetic separation and image analyses without assuming the detection of sizes. Our precision methods for the measurement of the capture traveling (magnetic diffusion) time and the accumulation (magnetic sedimentation) radius in HGMS show that it is really possible to determine the weak dia- or paramagnetic shifts of magnetic susceptibility up to 0.7×10-10 (SI units). HGMS analysis of the concentrating process of nucleoprotein granules (microcells, DNA granules, or nucleosome core particles) with polarization microscopy reveals phase transitions for DNA in granules, and separation accumulation of particles enables the determination of the diamagnetic susceptibility and anisotropy properties. Magnetic concentration effects always occur in living systems because micrometer-located gradient magnetic fields inside an organism are strong enough to cause drifts of cellular complexes and organelles of micrometer and submicrometer sizes. We report the appearance of superparamagnetic contamination inside developing shrimp eggs. In the developing shrimps eggs, ferritin aggregates are observed under weak gradient magnetic fields and diaparaferromagnetic changes are detected. A significant interruption of egg development is revealed in such fields.
Magnetophoretic and optical methods combined with pulsating weak magnetic field 1-10 Hz were applied to observe resonant vibrations of biological microparticles with anisotropic magnetic properties. Modeling of oxidative disorders in tissues was realized using reactive oxygen species (ROS) initiation and ferritin incorporation into porous sorbent beads and blood cells. Microscopic video recording of cells in high gradient magnetic separation allowed to determinate changes of magnetic moments under stress activating influences.
In the present work, diamagnetic separation parameters for the porous beads are studied using optical video recording microscopy. The possible direct amount determination of single or double macromolecular layers immobilized in the meshes of the porous beads is demonstrated for the concentrations' range used in heterogenic immunotest and the affinity chromatography, where the direct rapid detection of ligands within sorbent particles is known to be the actual task. A gradient diamagnetic biosensor is described as suitable for rapid quantitative detection of single or double macromolecular layers in porous nonmagnetic beads. Measurements of capture traveling time or accumulation radius in gradient magnetic field have shown that it is possible to determine 0.20 mg/ml of macromolecular amount within several seconds. The portative devices were made on the base of the fabre optic technique to detect accumulation radius of collected beads in two gradient magnetic positions: diamagnetic and paramagnetic zones of magnetized wire with 55 μm in diameter and to registrate with a lot of fabre wires having 30 μm in diameters. The successive procedures of the present method can be described by: the obtaining of agarose immuno-beads, the incubation of beads with the ligand sample or the injection of sample through affinity mini-column, the submerging of the loaded beads into the glass cell containing Ni-wire or the narrow gap of magnetic poles; the computational obtaining of immuno- parameters; binding constants, accumulation radius. Several biotechnological applications of the biosensor are presented on sorbent beads, human lymphocytes.
Magnetic sedimentation processes near ferromagnetic wire were applied for the cellular and the biotechnological monitoring. Numerous biological applications of magnetic sedimentation, or high gradient magnetic separation (HGMS), achieved mainly for human blood cells, have shown that it is possible to distinguish between the diamagnetic Fe-zero-spin oxidized states and the paramagnetic Fe-high-spin reduced ones in red blood cells. The precision methods of the measurements of capture travelling (magnetic diffusion) time or accumulation (magnetic sedimentation) radius in HGMS have shown that it is really to determine the weak dia- or paramagnetic shifts of magnetic susceptibility up to 0.7 (DOT) 10-10 (SI). The capture and sedimentation of particles with 5 - 40 micrometers sizes on single magnetized wires were investigated using microscopic video-recording type. Magnetic susceptibility bars for cells in normal and disturbed states demonstrated the high reproducibility and narrow distribution patterns.
The speckle pulse-analyzer is used to measure the human resonant mechanovibrations under pulsating magnetic influences, to conduct their Fourier-spectra analysis and dynamical processes documentation. The fast coherent response of organisms on super weak ultra-low-frequency magnetic field was recorded on coherent cells vibrations. Possible biophysical mechanisms are suggested and proved on experiments with blood cells. In particular, gradient steady magnetic fields could reveal the vibrational potency of cells in pulsating magnetic fields provided of the appearance of cellular magnetic sign-difference and anisotropy under pathological situations in organism. From the disturbances oxidative process in cells which give the paramagnetic shift of cells magnetic susceptibility relatively the normal state, the single cells or certain parts of organs become more paramagnetic than other native tissue. Arising magnetic vectors of living system appear oscillations in pulsating magnetic fields.
Light microscopic dynamical images and amplitude-frequency spectra by computerized documentation were used for the experimental evidence that the biological rhythms and ciliary beating cycles can be used as relevant tool for the biomonitoring of environmental pollutants and influences. At present work some lower animals, invertebrates: Protozoa cells, Rotifera, Mollusca gill cilia epithelium, Polychaeta served the convenient model biosystem for investigations due there ciliary and contractile organs. The narrow Fourier- spectra bands were revealed for large number of organisms, which were shifted or diffused by heavy metal salts, ATP, Ca-, Mg-ions and organic mixture in concentrations 10-2-10-6 M. The three phase of the ciliary beating were obtained for single cilium. The group of cilia with a good metachronal coordination gave the narrow characteristic Fourier bands, while the perturbances from the external influences led to the spreading and shifting of the main bands. These effects could serve as test-methods for the environmental biomonitoring of pollutants.
The precise magnetophoretic measurements of magnetic susceptibility of red blood cells and sorbent microparticles fulfilled with the video-camera observation and light scattering detection were applied for the identification of the cellular free radical excess under oxidative stress, paramagnetic ions changes and the immunospecific binding detection. The fast and sensitive assay allows to determine weak paramagnetic or diamagnetic shifts relatively surrounding solution connected with hematological and metabolic cellular disorders, external chemical influences by ions and organic molecules additions in range 10-4 - 10-6 M. The autoregistration of magnetophoresis facilitated the analysis of the functional states of cells and the macromolecular binding detection.
Some living biological objects were investigated with `AiryScan'--computer- aided Phase Microscope with spatial resolution up to 0.05 micrometers and time resolution 1 ms. Influence of ATP on the frequency and intensity of Infuzoria Paramecium Caudatum and Unio pictorium cilia beat were observed.
Some living biological objects were investigated with `AiryScan'-computer-aided Phase Microscope with spatial resolution up to 0.05 micrometers and time resolution 1 ms. Influence of ATP on the frequency and intensity of Infusoria Paramecium Caudatum and Unio pictorium cilia beat were observed.
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