In vivo Preclinical Tumor-Specific Imaging of Superparamagnetic Iron Oxide Nanoparticles Using Magnetic Particle Imaging for Cancer Diagnosis.

Purpose: Magnetic particle imaging (MPI) is an emerging radiation-free, non-invasive three-dimensional tomographic technology that can visualize the concentrations of superparamagnetic iron oxide nanoparticles (SPIONs). To verify the applicability of the previously proposed point-of-care testing MPI (PoCT-MPI) in medical diagnosis and therapeutics, we imaged SPIONs in animal tumor models.

Methods: CT26 or MC38 mouse colon carcinoma cells (2 × 10 cells) were subcutaneously injected into the right flank of BALB/c mice.

A novel three-dimensional magnetic particle imaging system based on the frequency mixing for the point-of-care diagnostics.

The magnetic particle imaging (MPI) is a technology that can image the concentrations of the superparamagnetic iron oxide nanoparticles (SPIONs) which can be used in biomedical diagnostics and therapeutics as non-radioactive tracers. We proposed a point-of-care testing MPI system (PoCT-MPI) that can be used for preclinical use for imaging small rodents (mice) injected with SPIONs not only in laboratories, but also at emergency sites far from laboratories. In particular, we applied a frequency mixing magnetic detection method to the PoCT-MPI, and proposed a hybrid field free line generator to reduce the power consumption, size and weight of the system.

Construction of 3D-rendering imaging of an ischemic rat brain model using the planar FMMD technique.

Occlusion of the major cerebral artery usually results in brain hypoxic-ischemic injury, which evokes neuroinflammation and microglial activation. Activated microglia are considered a source of multiple neurotoxic factors, such as reactive oxygen species (ROS), in the central nervous system (CNS). We herein present a 3D-rendering brain imaging technique in an experimental rodent model of cerebral ischemia based on 2D magnetic images of superparamagnetic iron oxide nanoparticles (SPIONs) using the planar frequency mixing magnetic detection (p-FMMD) technique.

Frequency Mixing Magnetic Detection Scanner for Imaging Magnetic Particles in Planar Samples.

The setup of a planar Frequency Mixing Magnetic Detection (p-FMMD) scanner for performing Magnetic Particles Imaging (MPI) of flat samples is presented. It consists of two magnetic measurement heads on both sides of the sample mounted on the legs of a u-shaped support. The sample is locally exposed to a magnetic excitation field consisting of two distinct frequencies, a stronger component at about 77 kHz and a weaker field at 61 Hz.

Magnetic immunoassay platform based on the planar frequency mixing magnetic technique.

We represent the experimental results of our planar-frequency mixing magnetic detection (p-FMMD) technique to obtain 2D superparamagnetic images for magnetic immunoassay purpose. The imaging of magnetic beads is based on the nonlinear magnetic characteristics inherent in superparamagnetic materials. The p-FMMD records the sum-frequency components originating from both a high and a low frequency magnetic field incident on the magnetically nonlinear nanoparticles.

Optoelectronic Characterization of Infrared Photodetector Fabricated on Ge-on-Si Substrate.

We report on the optoelectronic characterization of Ge p-i-n infrared photodetector fabricated on Ge-on-Si substrate using rapid thermal chemical vapor deposition (RTCVD). The phosphorous doping concentration and the root mean square (RMS) surface roughness of epitaxial layer was estimated to be 2 x 10(18) cm(-3) and 1.2 nm, respectively.

Is the biotransformation of chlorinated dibenzo-p-dioxins by Sphingomonas wittichii RW1 governed by thermodynamic factors?

Density functional theory (DFT) calculations were used to explore the relationship between the biotransformation of dibenzo-p-dioxin and selected chlorinated derivatives by resting cells of Sphingomonas wittichii RW1 and measuring the thermodynamic properties of the biotransformation substrates. Sphingomonas wittichii RW1 can aerobically catabolize dibenzo-p-dioxin as well as 2,7-dichloro-, 1,2,3-trichloro-, 1,2,3,4-tetrachloro-, and 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin; however, neither the 2,3,7-trichloro- nor the 1,2,3,7,8-pentachlorodibenzo-p-dioxin was transformed to its corresponding metabolic intermediate. The experimental biotransformation rates established were apparently governed by the selected thermodynamic properties of the substrates tested.

Magnetic particle imaging with a planar frequency mixing magnetic detection scanner.

We present the first experimental results of our planar-Frequency Mixing Magnetic Detection (p-FMMD) technique to obtain Magnetic Particles Imaging (MPI). The p-FMMD scanner consists of two magnetic measurement heads with intermediate space for the analysis of the sample. The magnetic signal originates from the nonlinear magnetization characteristics of superparamagnetic particles as in case of the usual MPI scanner.

In situ measurement of superoxide and hydroxyl radicals by frequency mixing detection technique.

Frequency mixing magnetic detection (FMMD) was used to detect superoxide from hypoxanthine and xanthine reaction and to detect hydroxyl radical from the Fenton reaction. FMMD was also applied to measure the reactive oxygen species (ROS) level released from microglial cells. We could assess the formation and extinction of the free radicals without a spin trap reagent.

Analysis of beta amyloid peptides employing the small probe molecules.

We herein describe an analytical method employing a small molecule array for the characterization of similar proteins based on ligand binding. In this study, 2 different beta amyloids (Abeta(1-40) and (1-42)) were selected as the model compounds. Their primary structures are identical except for 2 additional C-terminal amino acids.

Detection of two different influenza A viruses using a nitrocellulose membrane and a magnetic biosensor.

Here we describe a new analytical method for the detection of two influenza A viruses by nitrocellulose membrane and magnetic sensors that employ a special frequency mixing technique. The combination of the nitrocellulose membrane and magnetic bead detection permits a rapid assay procedure and excludes two steps (the development of color and the stop reaction) required for usual immunochemical detection methods such as ELISA. Quantitative virus detection was performed using magnetic beads conjugated with secondary antibody.

Effect of heavy metals on the biodegradation of dibenzofuran in liquid medium.

The effect of heavy metals on the degradation of dibenzofuran by Sphingomonas wittichii RW1 was determined in liquid cultures. The results showed that 10mg/L cadmium, mercury and copper not only affected the growth of RW1 with dibenzofuran but also the ability of resting cells to degrade this compound. Growth and degradation were strongly inhibited by mercury, even at 1mg/L, while the inhibitory effect of cadmium and copper at the same concentration or at 5mg/L were negligible.

Biological removal of polychlorinated dibenzo-p-dioxins from incinerator fly ash by Sphingomonas wittichii RW1.

The ability of Sphingomonas wittichii strain RW1 to remove polychlorinated dibenzo-p-dioxins (PCDDs) from fly ash was investigated. All experiments were carried out in a slurry-phase system. Preliminary studies with resting cells of strain RW1 in a model fly ash system showed the complete removal of dibenzofuran (DF) and 81% of dibenzo-p-dioxin (DD).

Biodegradation of dibenzo-p-dioxin, dibenzofuran, and chlorodibenzo-p-dioxins by Pseudomonas veronii PH-03.

The dioxin-degrading strain Pseudomonas veronii PH-03 was isolated from contaminated soil by selective enrichment techniques. Strain PH-03 grew on dibenzo-p-dioxin and dibenzofuran as a sole carbon source. Further, 1-chlorodibenzo-p-dioxin, 2-chlorodibenzo-p-dioxin and other dioxin metabolites, salicylic acid, and catechol were also metabolized well.

Adsorption of halogenated aromatic pollutants by a protein released from Bacillus pumilus.

Previous studies of the biosorption of halogenated aromatic pollutants (HAPs) have focused on the sorption of these compounds by cell bodies. However, in this study we investigated the adsorption of HAPs by biocompounds released from a bacterium, Bacillus pumilus. When B.

Biotransformation of 2,7-dichloro- and 1,2,3,4-tetrachlorodibenzo-p-dioxin by Sphingomonas wittichii RW1.

Aerobic biotransformation of the diaryl ethers 2,7-dichlorodibenzo-p-dioxin and 1,2,3,4-tetrachlorodibenzo-p-dioxin by the dibenzo-p-dioxin-utilizing strain Sphingomonas wittichii RW1, producing corresponding metabolites, was demonstrated for the first time. Our strain transformed 2,7-dichlorodibenzo-p-dioxin, yielding 4-chlorocatechol, and 1,2,3,4-tetrachlorodibenzo-p-dioxin, producing 3,4,5,6-tetrachlorocatechol and 2-methoxy-3,4,5,6-tetrachlorophenol; all of these compounds were unequivocally identified by mass spectrometry both before and after N,O-bis(trimethylsilyl)-trifluoroacetamide derivatization by comparison with authentic standards. Additional experiments showed that strain RW1 formed a second metabolite, 2-methoxy-3,4,5,6-tetrachlorophenol, from the original degradation product, 3,4,5,6-tetrachlorocatechol, by methylation of one of the two hydroxy substituents.