The present disclosure provides a pH and oxygen dual-sensitive magnetic resonance imaging contrast agent and a preparation method thereof, which is a dual-modal nanoparticle contrast agent with .sup.19F signal and CEST dual signal (.sup.19F-CEST), a CEST contrast agent that is dual-sensitive to pH and oxygen. The preparation method comprises: mixing a variety of phospholipid surfactants and cholesterol well to obtain a blend of phospholipid surfactants, which is dissolved in chloroform or a mixed solvent of chloroform and methanol, evaporated to dryness with a rotary evaporator and dried overnight in a vacuum oven at 40 C. after adding rhodamine, finally, it is dispersed in water containing glycerin by mechanical dispersion or ultrasonic vibration to obtain a lipid modifier; mixing perfluorocarbon, the lipid modifier obtained in step (1), glycerin, and water and ultrasonically mixing well with a probe, and extruding with an extruder to prepare a perfluorocarbon nanoemulsion.

The disclosure relates in some aspects to imaging agents, and in particular, imaging agents for sensing of calcium signaling. According to some embodiments of the disclosure, contrast agents for magnetic resonance imaging and related technologies are provided, and methods of making and using the contrast agents.

Provided herein are MRI contrast agents that are conditionally activated by an enzyme from a reporter gene coupled to a gene of interest. In some embodiments, provided herein is a platform where a substrate (blocking access of water to a Gd(III) ion) is removed by an enzyme that can be changed to accommodate a number of gene therapy targets.

An object of the present invention is to provide a halogenated biotin-modified dimer, which is capable of imaging diagnosis or treatment by labeling with a halogen, a biotin-modified dimer having a high affinity for a mutant streptavidin with a low affinity for natural biotin. The present invention provides a compound represented by the following formula (1) or a salt thereof:

##STR00001##

wherein the meaning of each symbol is the same as that described in the specification.

Provided herein are examples of metal chelating ligands that have high affinity for manganese. The resultant metal complexes can be used as MRI contrast agents, and can be functionalized with moieties that bind to or cause relaxivity change in the presence of biochemical targets.

The invention relates to the use of tetrapyrroles conjugated compounds as contrast agent in magnetic resonance imaging (MRI). In particular conjugates of natural hemin that can be embedded in gels and implants to image local delivery in MRI.

Alkylphosphocholine analogs incorporating a chelating moiety that is chelated to gadolinium are disclosed herein. The alkylphophocholine analogs are compounds having the formula:

##STR00001##

or a salt therof. R.sub.1 includes a chelating agent that is chelated to a gadolinium atom; a is 0 or 1; n is an integer from 12 to 30; m is 0 or 1; Y is H, OH, COOH, COOX, OCOX, or OX, wherein X is an alkyl or an arylalkyl; R.sub.2 is N.sup.+H.sub.3, N.sup.+H.sub.2Z, N.sup.+HZ.sub.2, or N.sup.+Z.sub.3, wherein each Z is independently an alkyl or an aroalkyl; and b is 1 or 2. The compounds can be used to detect solid tumors or to treat solid tumors. In detection/imaging applications, the gadolinium emits signals that are detectable using magnetic resonance imaging. In therapeutic treatment, the gadolinium emits tumor-targeting charged particles when exposed to epithermal neutrons.

The present invention relates to compounds that are useful as metal ligands and which either contain a molecular recognition moiety or can be bound to a molecular recognition moiety and methods of making these compounds. Once the compounds that contain a molecular recognition moiety are coordinated with a suitable metallic radionuclide, the coordinated compounds are useful as radiopharmaceuticals in the areas of radiotherapy and diagnostic imaging. The invention therefore also relates to methods of diagnosis and therapy utilising the radiolabelled compounds of the invention.

An imaging nanoparticle comprising a plant virus particle having an interior surface and an exterior surface, an imaging agent that is linked to the interior and/or exterior surface, and a layer of biocompatible mineral such as silica coated over the exterior surface, is described. The imaging nanoparticle can be used in method of generating an image of a tissue region of a subject, by administering to the subject a diagnostically effective amount of an imaging nanoparticle and generating an image of the tissue region of the subject to which the imaging nanoparticle has been distributed.

Silica nanocarriers hybridized with superparamagnetic iron oxide nanoparticles (SPIONs) and curcumin through equilibrium or enforced adsorption technique. Methods for dual delivery of SPIONs and curcumin to a target for diagnosis or therapy, for example, for SPION-based magnetic resonance imaging or for targeted delivery of curcumin to a cell or tissue. The technique can be extend to co-precipitation of mixed metal oxide involving Ni, Mn, Co and Cu oxide. The calcination temperature can be varied from 500-900 C. The nanocombination is functionalized with chitosan, polyacrylic acid, PLGA or another agent to increase its biocompatibility in vivo.