The invention relates to an enzymatically responsive product that includes an amino acid residue conjugated to a magnetic particle, wherein the amino acid residue is phosphorylated or sulfated or comprises an ester-moiety linked via peptide bond. Compositions containing the enzymatically responsive product, and the use thereof for separating distinct types of mammalian cells (e.g., cancer cells from normal cells), for treating a cancerous condition, and imaging cancer cells are also disclosed.

A particle usable as T.sub.1 and T.sub.2 contrast agents is provided. The particle is a gadolinium silicide (Gd.sub.5Si.sub.4) particle that is ferromagnetic at temperatures up to 290 K and is less than 2 m in diameter. An MRI contrast agent that includes a plurality of gadolinium silicide (Gd.sub.5Si.sub.4) particles that are less than 1 m in diameter is also provided. A method for creating gadolinium silicide (Gd.sub.5Si.sub.4) particles is also provided. The method includes the steps of providing a Gd.sub.5Si.sub.4 bulk alloy; grinding the Gd.sub.5Si.sub.4 bulk alloy into a powder; and milling the Gd.sub.5Si.sub.4 bulk alloy powder for a time of approximately 20 minutes or less.

Provided are a method for simultaneously detecting fluorescence and Raman signals for multiple fluorescence and Raman signal targets, and a medical imaging device for simultaneously detecting multiple targets using the method. The method includes: injecting at least one marker particle comprising Raman markers and receptors into the body of an animal, which can be a human; irradiating a laser beam onto the body of the animal; and detecting the optical signals emitted by the marker particle after the irradiation of the laser beam separately as fluorescence signals and Raman signals. The simultaneous detection of multiple targets may be performed even without scanning optical signals emitted by the marker particle individually with different optical fibers. As an examination may be performed by injecting surface-enhanced Raman marker particles, weak Raman signals may be augmented so as to obtain a more accurate diagnosis result in real time.

Erythrocytes exposed to dialysis with an hypotonic buffer stably take up superparamagnetic iron oxide nanoparticles and may be used MRI contrast agents. Such erythrocytes may also be used as drug delivery vehicles.

The method comprises: a) receiving a plurality of imaging signals of the object over a period of time; b) measuring the signal intensity in each of the plurality of imaging signals corresponding to a point on the object; and c) curve fitting the measured signal intensity of the point on the object to a bi-exponential function comprising a first and a second exponential term, the first exponential term representing the decrease in concentration of the contrast agent which is free over time and the second exponential term representing a decrease in concentration of the contrast agent which is retained on the object over time.

The invention relates to aqueous dispersions, comprising particles based on a magnetic iron oxide with dimensions of 20 nm, the surface of which is modified by the grafting of aminated groups R with a covalent bonding to the surface of said particles, wherein the isoelectronic point of particles with such a modified surface is 10. The invention further relates to a method for production of said aqueous suspensions and a method for modification of the surface of the particles present in said dispersions, in particular, by the immobilisation of polysaccharides such as dextrans, particularly for the formulation of magnetic compositions which may be administered in vivo and in particular for the formulation of injectable compositions of contrast agents for MRI.

Provided herein are therapeutic nanoparticles having a diameter of between 10 nm to 30 nm, and containing a polymer coating, and a nucleic acid containing a sequence complementary to a sequence within a micro-RNA identified as having a role in cancer cell metastasis or anti-apoptotic activity in a cancer cell (e.g., miR-10b) or a sequence within an mRNA encoding a pro-apoptotic protein that is covalently linked to the nanoparticle. Also provided are pharmaceutical compositions containing these therapeutic nanoparticles. Also provided herein are methods of decreasing cancer cell invasion or metastasis in a subject having a cancer and methods of treating a metastatic cancer in a lymph node in a subject that require the administration of these therapeutic nanoparticles to a subject.

A magnetic nanoparticle includes a magnetic core and a superparamagnetic outer shell, in which the outer shell enhances magnetic properties of the nanoparticle. The enhanced magnetic properties of the magnetic nanoparticle allow for highly sensitive detection as well as diminished non-specific aggregation of nanoparticles.

A multimodal contrast and radiopharmaceutical agent for an imaging and a targeted therapy guided by imaging.

The present invention relates to a composition for target substance detection using a magnetic nanoparticle having a Curie temperature which is within a biocompatible temperature range, a target substance detection system, and a method for obtaining an image of a living body or specimen. As the magnetic nanoparticle of the present invention has a Curie temperature within the temperature range of 0 C. to 41 C., the ferromagnetic and paramagnetic properties of the magnetic nanoparticle may be controlled within a biocompatible temperature range at a temperature at which a biological control agent is not destroyed, and the temperature of the magnetic nanoparticle is adjusted to control the magnetic properties thereof such that the properties of the magnetic nanoparticle may be used only when ferromagnetic properties are required, such as in the case of signal amplification in detecting, separating, and delivering biological control agents. Accordingly, the present invention can provide a biological substance detection system which satisfies both a decrease in non-specific binding and signal amplification using a magnetic nanoparticle having a Curie temperature which is within a biocompatible temperature range, and can be reused after detection.