MXPA00002869A - Contrast-enhanced diagnostic imaging method for monitoring interventional therapies - Google Patents

Abstract

The present invention relates to a contrast-enhanced diagnostic imaging method for monitoring the efficacy of interventional therapies. The contrast agents useful in this method comprise an image-enhancing moiety (IEM) and a state-dependent tissue binding moiety (SDTBM). These contrast agents exhibit state-dependent binding to one or more components of a targeted tissue or tissue component and provide a detectable change in the signal characteristics of the agent once bound to the targeted tissue. As a result, these agents exhibit a binding affinity for, and thus image contrast of, the targeted tissue which changes as the tissue-state changes during therapy.

Description

METHOD FOR FORMING IMPROVED CONTRARY DIAGNOSTIC IMAGES, TO MONITOR INTERVENTION THERAPIES TECHNICAL CAMPQ OF THE INVENTION The present invention relates to methods for improved contrast diagnostic imaging. In particular, the present invention relates to methods of imaging by MRI and by optical means; which use contrast agents that target a specific tissue or specific tissue component and that allow the monitoring of state changes in white tissue (ie, denaturation, necrosis, tissue coagulation, apoptosis) that occur during or after intervention therapy. The contrast agents used in this invention exhibit a state-dependent binding to one or more components of a white tissue and provide a detectable change in the signal characteristics of the contrast agent bound to the tissue.

BACKGROUND OF THE INVENTION Diagnostic imaging techniques, such as magnetic resonance imaging (MRI), X-ray, imaging by nuclear radiopharmaceuticals, optical imaging (ultraviolet, visible and / or infrared), ultrasound imaging, have been used in medical diagnosis for several years. In some cases, the use of contrast media to improve the quality of the image or to provide specific information has been common for many years. In other cases, such as imaging or ultrasound, the introduction of contrast agents is imminent or recent. The methods of imaging by MRI and optical means are unique among imaging modalities, since they produce complex signals that are sensitive to the chemical environment and the state of the target tissue. When the X-ray signal or radionuclide agents remain the same, if the agents are free of plasma, bound to proteins or trapped within the bone, certain agents for MRI and optical imaging will have different signal characteristics in different physiological environments and pathological states. For example, when administering tissue components, MRI contrast agents can show changes in induced relaxation rates or chemical changes of nearby or joined nuclei. Similarly, an optical dye may exhibit changes in its absorbance, reflectance, fluorescence, phosphorescence, chemiluminescence, dispersion or other spectral properties at the junction. In general, to provide diagnostic data, the contrast agent must interfere with the wavelength of the electromagnetic radiation used in the imaging technique, alter the physical properties of the tissue to produce an altered signal or, as in the case of radiopharmaceuticals, provide the radiation source itself. Commonly used materials include organic molecules, metal ions, salts or chelates, including metal chelates, particles (particularly iron particles), or labeled peptides, antibodies, proteins, polymers or liposomes. After administration, some agents diffuse nonspecifically throughout the compartments of the body before they are metabolized and / or excreted; these agents are generally known as non-specific agents. Alternatively, other agents have a specific affinity for a particular body compartment, cell, cell component, organ or tissue; these agents can be referred to as white agents. One application of diagnostic imaging techniques has been the monitoring of intervention therapies. Common intervention therapies include targeting a non-desired tissue or tissue component with high thermal energy using focused ultrasound (e.g., Cline et al., "MR Temperature Mapping of Focused Ultrasound Surgery", Mag. Resn. Med., 31: 628-636 (1994)), radiofrequency generators (eg, Rossi et al., "Percutaneous RF Interstitial Thermal Ablation in the Treatment of Hepatic Cancer", AJE, 167: 759-768 (1996)). , microwave antennas (eg, Schwarzmaier et al., "Magnetic Resonance Imaging of Microwave Induced Tissue Heating", Mag. Resn. Med., 33: 729-731 (1995)), and lasers (eg, Vogl et al. ., "Recurrent Nasopharyngeal Tumors: Preliminary Clinical Results with Interventional MR Imaging-Controlled Laser-Induced Thermotherapy", Radiology, 196: 725-733 (1995); the use of cryoablation (ie, liquid nitrogen) and the injection of denaturing fluids (eg, ethanol, hot saline) directly into the unwanted tissue (eg, Nagel et al., "Contrast -Enhanced MR Imaging of Hepatic Lessions Treated with Percutaneous Ethanol Ablation Therapy ", Radiolocry, 189: 265-270 (1993) and Honda et al.," Percutaneous Hot Saline Injection Therapy for Hepatic Tumors: An Alternative to Percutaneous Ethanol Injection Therapy ", Radiology, 190: 53- 57 (1994)); the injection of P1012 chemotherapeutic and / or chaotropic agents in tissue (eg, Pauser et al., "Evaluation of Efficient Chemoembolization Mixtures by Magnetic Resonance Imaging of Therapy Monitoring: An Experimental Study on the VX2 Tumor in the Rabbit Liver", Cancer Res., 56: 1863-67 (1996)); and photodynamic therapies, wherein a cytotoxic agent is activated in vivo by irradiation with light (for example, Dodd et al., "MRI Monitoring of the Effects of Photodynamic Therapy on Prostate Tumors", Proc. Soc. and Mag. Resn., 3: 1368, ISSN 1065-9889 (August 19-25, 1995)). The shared goal of all interventional therapies is the treatment of the tissue or unwanted tissue component (i.e., tissue or component of cancerous, tumorous, neoplastic tissue) by causing necrosis, ablation, coagulation or denaturation of the tissue. To obtain maximum benefit from these intervention methods and to minimize side effects (eg, damage to adjacent tissues), it is essential to monitor in vivo the effectiveness of the therapy. In fact, to be truly effective, intervention therapy must continue until the absolute "death" of the tissue or unwanted tissue component (non-viability after removal or termination of therapy). In this way, not only should you be able to accurately monitor the progress of the therapy, to avoid P1012 excessive treatment and possible damage to adjacent tissue, but must also be able to distinguish exactly between truly necrotic tissue and those that may have been damaged to a certain degree but, nonetheless, remain viable. One way to monitor the effectiveness of intervention therapy is to form an image of the tissue or unwanted tissue component during or after that therapy. However, any method of diagnostic imaging must be able to increase the contrast between tissues of different disease states (native versus denatured, viable versus necrotic) and such a way to provide two basic classes of information: 1) Data from Detection. This includes the spectroscopic information necessary to determine the pathological state of the tissue represented in the image. The ability to provide this kind of information is related to the "specificity" and "sensitivity" of the agent. 2) Feedback and Resolution. These kinds of information provide the monitoring of therapeutic intervention procedures that destroy or degrade tissue or tissue components. It is contemplated that with some intervention methods, "real-time" feedback is preferred (approximately 1-10 P1012 seconds) of the progress of the therapy, while with other methods, a post-therapeutic assessment is adequate. With all interventional therapies, precise spatial resolution (approximately 1-5 mm) of the treated tissue and any effects on the surrounding tissues during treatment are desirable. Current methods based on MRI to monitor the effectiveness of intervention therapies are generally one of two classes: (1) those that do not use an exogenous contrast agent but that depend on some other observable MR parameter (vide infra); and (2) those that use contrast agents, extracellular, non-specific. However, these methods provide virtually non-direct information regarding the pathological state of the tissue or tissue component that is being subjected to intervention therapy (eg, whether it is native or denatured, necrotic or viable). Additionally, these methods are largely limited to the monitoring of thermal ablation therapies and provide limited sensitivity to thermally induced tissue temperature changes. Several of these MRI-based methods for monitoring thermal ablation therapies depend on temperature-dependent NMR parameters such as relaxation times (i and / or T2), and the frequency of P1012 proton resonance (PRF) of water, phase changes, and diffusion coefficient. However, these methods suffer from a number of limitations. For example, such a method comprises monitoring the effect of temperature on the relaxation time T_. of the tissue. See, for example, Cline et al., "MR Temperature Mapping of Focused Ultrasound Surgery," Mag. Resp. Med., 31: 628-636 (1994). However, this approach is inadequate because each tissue has a unique Ti temperature profile, and in this way, this method requires Ti calibration for each type of tissue. The method of i is limited to sensitivity, with a change dependent on Ti in only 0.01% to 1.5% per 1 ° C. Another method that uses temperature measurement involves monitoring the effect of temperature on the resonance frequency of the proton (or chemical change) of the water. This method detects changes in hydrogen bonding and molecular movement of water molecules induced by changes in temperature. See, for example, J.D. ~ Poorter, et al., "Noninvasive MRI Thermometry with the Proton Resonance Frequency (PRF) Method: In Vivo Results in Human Muscle," Mag. Resp. Med., 33: 74-81 (1995). However, the low sensitivity of this method (0.01 ppm / ° C) requires the use of high magnetic field strengths (it is P1012 say, > 4.7 T) what is clinically undesirable. Additionally, determining the chemical change of the water requires absolute stability of the magnetic field and is also highly dependent on the magnetic susceptibility of the tissue that varies dramatically between different types of tissue. In this way, this method, like the Ti method, also requires extensive calibration for each type of tissue. Finally, this method does not provide information regarding tissue induced necrosis or degradation, thermally induced. Another known method requires monitoring the effect of temperature on the diffusion coefficient of the water proton. See, for example, H. Saint Jaimes, "Precision in Temperature Measurement via i or Diffusion Imaging". Proc Soc 'and Mag. Resn. , 2: 1072, ISSN 1065-9889 (August 19-25, 1995). This method, however, is also limited because the diffusion coefficient is sensitive to tissue movement and tissue perfusion. In all of the above methods, physiological tissue changes due to increased blood flow, tissue metabolism, or induced edema, may result in unpredictable signal variations. (that is, changes in magnetic susceptibility). These effects place normal thermal calibration curves that are of little or no value for accurate monitoring of thermal ablation therapy. In addition, the measurement of the temperature alone may be insufficient to accurately determine the efficiency of tissue ablation or side effects in the surrounding tissues. Other methods that monitor the effect of temperature on chemical change of other magnetic cores have also been reported. For example, the chemical change of cobalt NMR is a very sensitive temperature cell. However, the low receptivity of 59Co requires high field strengths (= 4.7 T), high concentrations, and long measurement time. See, A.G. Webb et al., "Measurement of Microwave Induced Heating of Breast Tumors in Animal Models Using Cobalt Based NMR", Proc. Soc 'and Mag. Resn. , 1:72, ISSN 1065-9889 (August 19-25, 1995). In addition, the toxicity of cobalt agents maintains a number of limitations for in vivo use. Fluorine NMR (19F) has also been used to monitor the temperature-dependent phase transitions of fluorocarbons encapsulated in liposomes and fluorinated polymers. See, for example, Webb et al., "Microencapsulation of Fluorine-Containing Phase Transition Agents for Monitoring Temperature Changes in vivo", Proc. Soc 'V Mag. Resn., 3: 1574, ISSN 1065-9889 (August 6-12, 1994). Clinically, however, 19F methods are not useful due to the limited biodistribution of fluorinated polymeric compounds, the dependence of the chemical change of fluorinated agents on the pH, and the type of tissue, and the need for large magnetic forces. These agents also do not report the thermally induced tissue necrosis. Certain contrast agents containing paramagnetic metal complexes have also been suggested to monitor the efficacy of intervention therapies. These agents can induce large changes in the chemical changes of the proton (20-40 ppm) of the chelating ligand in the normal range of water resonance frequency. By the paramagnetic displacement of the resonances away from the volumetric resonance of the water in vivo, these resonances can be observed. See, for example, Aime et al., "Yb (III) DOTMA as Contrast Agent in CSl and Temperature Probé in MRS", Proc. Soc 'and Mag. Resn. 2: 1109, ISSN 1065-98889 (August 19-25, 1995). Although these changed, hyperfine resonances are temperature dependent, they require the use of high concentrations of the paramagnetic complex and high magnetic fields, clinically impractical, to detect changes in temperature. These complexes also can not report thermally induced tissue necrosis.

More recently, a method has been described to distinguish between normal and necrotic tissue of the liver. Dupas et al., "Delineation of Liver Necrosis Using Double Contrast-Enhanced MRI", J. MRI, Vol. 7, no. 3, pp. 472-77 (1997). This method, however, involves the use of non-specific contrast agents that limit their ability to specifically monitor the change in state of the tissue or unwanted tissue component. Also, this method requires the administration of multiple contrast agents. Thus, known, diagnostic imaging methods are limited in that they can not provide accurate information on the state of the specific tissue or tissue component that undergoes intervention therapy (i.e., if the tissue is in its state). native or denatured, necrotic or viable). Accordingly, a need remains for a method of diagnostic imaging that can monitor in a non-invasive and accurate manner the state of a specific tissue or tissue component, which can optionally provide rapid feedback of tissue necrosis. , induced during intervention therapies.

SUMMARY OF THE NINETION The present invention provides a method for P1012 the enhanced diagnostic imaging of contrast, particularly for imaging by MRI and optical components, of a specific tissue or tissue component that is undergoing or has undergone intervention therapy. The method comprises the steps of: (a) administering to a patient a contrast agent capable of binding to a tissue or white tissue component that is undergoing or has undergone intervention therapy; (b) subjecting the patient to one of the imaging arrays by MRI, ultraviolet light, visible light or infrared light; and (c) monitoring a characteristic imaging signal of the contrast agent to determine if intervention therapy is complete. The contrast agents used in the present invention comprise an enhancer portion of the image (or signal generator) ("IEM") and a state-dependent tissue binding portion ("SDTBM"). These contrast agents are capable of demonstrating state-dependent binding to a woven or white woven component. This binding leads to a detectable change in the characteristics of the signal of the contrast agent, and in this way, allows the determination of changes of state within a white tissue (eg, ablation, degradation, or denaturation) that is being submitting or having undergone intervention therapy. In one aspect of this invention, the use of contrast agents allows "real time" monitoring during thermal intervention therapy of thermally induced necrosis. These contrast agents exhibit an increased contrast between the tissues of different states.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a graphical representation of the experimental data of the effects that changes in temperature have on the observed relaxation capacity (Ri) for HSA solutions with and without using a contrast agent. Figure 2 is a graphical representation of the experimental data of the loss in ROI signal intensity over time for MRI images generated using HSA solutions with and without a contrast agent. Figure 3 is a graphical representation of the experimental data on the effects that changes in ethanol concentration have on the observed relaxation capacity (Rx) for HSA solutions with and without P1012 contrast agents.

DETAILED DESCRIPTION OF THE INVENTION In order that the invention described herein may be more fully understood, the following detailed description is set forth. The present invention provides a non-invasive method for accurately monitoring the efficacy of interventional therapies (ie,, monitoring the state of a tissue or unwanted tissue component). In particular, the invention provides a method of diagnostic imaging and comprises the use of a contrast agent that demonstrates state-dependent binding to a white tissue or white woven component and whose signal characteristics are altered when joins the white tissue. The imaging methods useful in this invention are MRI imaging (which includes magnetic resonance spectroscopy techniques) and optical means. As used herein, the term "interventional therapy" refers to any of several therapeutic methods wherein the goal is to induce or cause necrosis, ablation or coagulation of any unwanted tissue or tissue component (cancerous, tumorous, neoplastic).

P1012 Also, as used herein, the terms "pathological state" or "condition" are used herein to broadly describe two physiological conditions of the woven or woven component that undergo intervention therapy. A state can be considered alive, native or viable. This "initial" state usually describes the tissue before it is subjected to any intervention therapy and in which the tissue and / or cellular mechanisms such as metabolism and respiration are functional. The "second" state, which describes the tissue during or after it has undergone successful therapy, can be considered non-viable, denatured, necrotic or apoptotic and in which this tissue and / or cellular mechanisms are abnormal, non-functional or they have stopped. The inventive method described herein comprises the steps of: (a) administering to a patient a contrast agent capable of binding to a tissue or tissue component, which objective is being subjected to or has undergone intervention therapy; (b) subjecting the patient to one of the imaging arrays by MRI, ultraviolet light, visible light or infrared light; and (c) monitor a signal of the formation of P1012 characteristic images of the contrast agent, to determine if intervention therapy is complete. The contrast agents used in the present invention comprise an enhancer portion of the (signal generator) ("IEM") and a state dependent tissue binding portion ("SDTBM"). Due to the combination of these portions, which are defined in more detail below, the contrast agents are able to show state-dependent binding to a tissue or white tissue component, and to demonstrate the signal characteristics that are altered when join the objective. The state-dependent binding refers to the relative affinity demonstrated by the contrast agent for the tissue or white tissue component that is dependent on the state of the target tissue. In this manner, the agents used in the present invention have a greater or lesser binding affinity for one or more tissue components in their denatured or necrotic state compared to the binding affinity of the native or viable tissue agent. This state-dependent change in the union results in a location of the agent to the tissue of one state over the tissue of the other state, while at the same time changing the signal characteristics of the state.

P1012 agent to improve the detection of the change of state that is presenting. For example, if the agent expresses a higher binding affinity for viable or native tissue, where the increased binding affinity results in a more intense signal, then viable tissue is imaged (or detected) as a "hot spot". " During the course of intervention therapy, this hot spot will become "cold" as viable tissue becomes necrotic, due to the reduced binding affinity of the agent to the necrotic tissue. Conversely, if the agent expresses a higher binding affinity for necrotic or non-viable tissue, then that tissue will be revealed as a hot spot during the course of therapy. It is preferred that the binding affinity dependent on the state of the agent exhibit a high sensitivity to the change in physiological state. Preferred agents are those that have a binding affinity and corresponding signal changes that are sensitively readjusted to correspond to the state change that the tissue or tissue component is undergoing. In one aspect of the invention, by monitoring and changing the signal during the course of the therapeutic procedure in the intervention, real-time, sensitive monitoring of the efficiency and degree of tissue ablation is improved.

P1012 STRUCTURE OF CONTRAST AGENTS The contrast agents used in the present invention should comprise at least one enhancing portion of the image (or signal generator) ("IEM") and a state-dependent tissue binding portion ("SDTBM"). "). An optionally physiologically compatible ("L") linking group can be used to link the IEM to the SDTBM. Examples of suitable linking groups include linear alkyl, branched or cyclic, alkyl, aryl, ether, polyhydroxyl, polyether, polyamine, heterocyclic, peptide, peptoid, phosphate, sulfate or other physiologically compatible covalent bonds. The linkage group can provide an important physico-chemical stability to the complex by improving the half-life in blood or other biological fluids and compartments. Also, the linking group can provide a means for biodegradation and subsequent expression of the agent. 1. Intensifying Image Serial (IEM) The first domain of the contrast agents used in the present invention is an IEM that can be any chemical or substance used to provide the signal or contrast in the imaging. The IEM may be able to generate a P1012 different signal characteristic when the agent binds to a tissue or tissue component compared to that of the free agent. For optical imaging, this may be a change in absorbance, reflectance, fluorescence, scattering, phosphorescence, chemiluminescence, an increase in the number of absorbance peaks or any change in their wavelength peaks, or any other change that by external detection will correspond to a joined IEM. By MRI, this may be a change in the induced relaxation rates of the water protons (1 / T? Or 1 / T2) or any other nearby nucleus, or a change of one or more peaks in the NMR spectrum of already be the IEM or peaks that appear from the nuclei in the binding site for the SDTBM. Accordingly, the IEM can be an organic molecule, metal ion, salt or chelate, including metal chelates, a metal or particle cluster (particularly iron particle); or a labeled peptide, protein, polymer or liposome. For the formation of images by optical means (using ultraviolet, visible or infrared light), the IEM can also be any organic or inorganic dye. Examples of useful organic dyes include indocyanine green and fluorescein. Examples of inorganic dyes include P1012 luminescent metal complexes, such as those of Eu (III), Tb (III) and other lanthanide ions (atomic numbers 57-71). See, W. Dew. Horrocks & M. Albin, Progr. Inorg. Chem. 1984, 31, pp. 1-104. A particularly useful IEM is a physiologically compatible metal chelate compound consisting of one or more organic, cyclic or acyclic chelating agents rendered complex to one or more metal ions. For optical imaging, preferred metal ions include those with atomic numbers 13, 21-31, 39-42, 44-50, or 57-83. By MRI, the preferred metal ions include those with atomic numbers 21-29, 42, 44 or 57-83, and more preferably a paramagnetic form of a metal ion with atomic numbers 21-29, 42, 44, or 57- 83 When the IEM comprises a paramagnetic metal chelate, the preferred paramagnetic metal is selected from the group consisting of Gd (III), Fe (III), Mn (II and III), Cr (III), Cu (II), Dy (III), Tb (III and IV), Ho (III), Er (III), Pr (III) and Eu (II and III). The most preferred is Gd (III). If the IEM is a metal chelate, it should not disintegrate to any significant degree as long as the agent passes through the body, including the white tissue. The significant release of free metal ions, and in particular paramagnetic metal ions, P1012 free, can result in toxicity, which would only be acceptable in pathological tissues. In general, the degree of toxicity of a metal chelate is related to its degree of dissociation in vivo before excretion. In general, the toxicity increases with the amount of free metal ion. For complexes in which the kinetic marking capacity stands out, a high thermodynamic stability (a constant deformation of at least 1015 M "1 and more preferably at least 1020 M" "1) is desirable to minimize dissociation, and its attached toxicity For complexes in which the kinetic marking capacity is comparatively lower, dissociation can be minimized with a lower formation constant, ie 1010 M "1 or greater. Toxicity is also a function of the number of coordination sites opened in the complex. In general, few water coordination sites decrease the tendency for the chelating agent to release the paramagnetic metal. Preferably, therefore, the complex contains two, one, or zero open coordination sites. The presence of more than two open sites in general will unacceptably increase toxicity by releasing the metal ion in vivo. In order to effectively improve the images by MRI, the complex must be able to improve the P1012 1 / T relaxation speeds? (longitudinal, or reticulum of the spin) and / ol / T2 (transverse, or spin-spin) of water protons or other spectroscopic imaging cores, including protons, P-31, C-13, Na-23 , or F-19 in the IEM, other biomolecules, or injected biomarkers. The relaxation capacities R and R2 are defined as the capacity to increase 1 / T? or l / T2, respectively, per mM of the metal ion (ie, mM "1s" 'L). For the most common form of MRI clinic, MRI water proton, the relaxivity is optimal where the paramagnetic ion bound to the chelating ligand still has one or more open coordination sites for exchange with water (RB Lauffer, Chemical Reviews, 87, pp. 901-927 (1987)). However, this must be compensated for by the stability of the metal chelate (vide infra) which decreases in general with increasing numbers of the open coordination sites. More preferably, therefore, the complex contains only one or two open coordination sites. The type of chelating ligand can greatly affect the rate of water exchange for an MRI agent. In particular, the rate of water exchange can play a significant role in contrasting the tissue generated in thermal ablation therapies. In general, a higher water exchange rate gives a P1012 greater Ri due to the large number of water molecules that interact with the paramagnetic center; conversely, a lower exchange rate gives a lower Ri. In this way, a metal chelate complex having a slow water exchange rate (kex-298K = 500-10,000 ns) will generally show an increase in l / Ti (Ri) as the temperature increases, reflecting the positive effects of the increased thermal movement of the water molecules and the increased exchange of water near the paramagnetic center; Ri then usually reaches a maximum contrast value at temperatures over physiological. At the same temperature, the contrast will then fall to minimum values, since the beneficial effect of the increased exchange of water is decompensated by the insufficient amount of time that each water molecule passes near the paramagnetic center. A metal chelate with a moderately fast water exchange rate (kex-298K 10-100 ns) will show a relatively linear dependency of 1 / T_. (Ri) in the temperature, which will then fall at some higher temperature, again due to an insufficient amount of time that each water molecule passes near the paramagnetic metal under these conditions. A metal chelate with a very fast water exchange rate (kex-298K 0.1-10 ns) a P1012 and higher physiological temperatures will show a decreasing 1 / T, since the increased thermal movement of the water molecules further limits the time each water molecule passes near the paramagnetic center. However, this chelate will show an increase in 1 / T? at lower temperatures (ie, cryogenic) due to an increased time that each water molecule passes in the vicinity of the paramagnetic metal. When the method of the present invention is used to monitor thermal ablation therapies, it is preferred that the moderately fast water exchange chelates are used as the IEM, in order to maximize the contrast between the initial state of the native tissue or viable (initial Ri) and the state of the denatured or necrotic tissue (Ri second). For those therapies that use cryogenic techniques, it may be preferable to use chelates of very fast water exchange rates, in order to take selective advantage of the increase in 1 / T? (Ri) as the temperature decreases. In all methods of interventional therapy, it is preferred that the sensitivity of the R profile with respect to the tissue state coincide precisely with the denaturing profile of the tissue or tissue component of interest.

In addition to increasing the 1 / T? or l / T2 of the tissue nuclei via dipole-dipole interactions, MRI agents can affect two other magnetic properties and thus be of clinical use: 1) an iron or metal chelate particle of high magnetic susceptibility, particularly Dy, Gd, or Ho chelate can alter the intensity of the tissue MRI signal by creating microscopic magnetic susceptibility gradients (Villringer et al., Magn. Reson. Med. 6, pp. 164-174 (1988). )). No open coordination sites are required in a chelate for this application. 2) an iron or metal chelate particle can also be used to change the resonance frequency of water protons or other spectroscopic or imaging cores, including protons, P-31, C-13, Na-23, or F-19 in the injected agent or the woven component to which they are attached. Here, depending on the cores and strategy used, zero to three open coordination sites can be used. The chelating, organic ligand can be physiologically compatible. The molecular size of the chelating ligand must be compatible by the size of the paramagnetic metal. In this way Gd (III), which has a crystal ionic radius of 0.938A, requires a greater P1012 chelating ligand that iron (III), having a crystal ionic radius of 0.64 A. Many chelating ligands, suitable for MRI agents are known in the art. These can also be used for metal chelates for other forms of biological imaging. Preferred EMIs include: Magnevis Doratem gadopentetato-dimeglumina gadoterate-meglumina DTPA DOTA Omniscan ProHance gadodiamide gadoteridol DTPA-BMA HP-D03A It is known in the art that other metals can be replaced by Gd3 + in certain applications.

P1012 2, State-Dependent Tear-binding Portion (SDTBM) The second domain of the contrast agents used in this invention is a state-dependent tissue-binding portion (SDTBM) that provides the selection functionality of target the agent. The SDTBM can be highly variable, depending on the application of interest. In this way, the specific structure of the SDTBM will depend on the specific woven or woven component that is joined. However, in general, the SDTBM must equip the contrast agent with a state dependent change in binding affinity for the tissue or white tissue component. This state-dependent change in binding affinity should result in a detectable change in the characteristics of the contrast agent signal. The change in binding affinity must be sufficiently sensitive and the number of binding sites sufficiently large such that the contrast is generated when the state of the tissue changes. The SDTBM may comprise a small molecule or alternatively, a biomolecule. Biomolecules can vary in molecular weight and size, but they must share the same fundamental characteristic in that they are biologically derived or synthesized from subunits that occur naturally (ie, P1012 amino acids or nucleotides). Examples of biomolecules include receptor ligands, saccharides, lipids, hormones, peptides, proteins, nucleotides and nucleic acids (DNA, RNA) and antibodies including fragments thereof and monoclonal and genetically engineered versions. Small molecules, on the other hand, are synthetically derived, well-known organic molecules of relatively low molecular weight that have little or no chemical similarity to biomolecules. Small molecules typically do not include subunits of biomolecules and linkages (eg, natural amino acids linked by amide bonds). Examples of small molecules include synthetic drugs, lipophilic or amphiphilic organic molecules, and porphyrins. The most preferred SDTBMs are those that bind reversibly to proteins in the plasma, interstitial space (the fluid between the cells) or intracellular space. While any biomolecule or small molecule that binds to a protein could be used, the most useful are those that bind to proteins that either exist in high concentration or have a large number of binding sites for certain ligands. Since the native state of many proteins in tissues, plasma or interstitial or intracellular state is usually more structurally and chemically well defined than the denatured or undeployed state, it is a preferred aspect of the invention to design the SDTBM to bind with greater affinity to these native states that to the denatured states, corresponding. This difference in binding affinity between native and denatured states leads to a detectable change in the characteristics of the agent signal. A quantitative measurement of the ability of a contrast agent to relax the water protons, and consequently affect the MRI image, is provided by their ability to relax. As described above, the relaxation capacity is the dependence of the signal strength of the water proton on the concentration of the paramagnetic metal ion in solution. Relaxation capacity is defined as the ratio T or T2 induced per unit time (Rx or R2 in units of mM "1 sec-1) observed for a contrast agent, where the concentration of the agent is expressed in millimolar (mM) The physical properties of a gadolinium complex affect the ability of relaxation in a contrast agent.The number of water molecules joined to the gadolinium complete, the exchange rate of water molecule with volumetric solution, the relaxation time of seven electrons unpaired, and the time of collapse P1012 rotational (known as the rotational correlation time) of the contrast agent in solution all contribute to the observed, complete relaxation capacity. Alteration in these physical properties can dramatically alter the ability to relax. The effect of water exchange rate on relaxation capacity has been discussed previously. In addition, the binding of small gadolinium chelates of a relatively low molecular weight to large macromolecules slows down the rotational decay time and increases the relaxation improvement by factors of 3 to 10. The binding of the contrast agent to the protein causes the magnetic fluctuations between the paramagnetic ion and the water protons are presented in the same time scale as the Larmor frequency, generating the most efficient, possible longitudinal relaxation (Ti) and the highest possible relaxation capacity. In this way, the state-dependent binding of MRI contrast agents to large macromolecules, such as proteins, is an efficient way to increase the MRI signal (and contrast) in one state over the other. The contrast of the image is generated between areas that have different levels of binding to the contrast agent. In a preferred aspect of the invention, the contrast of the image is generated between areas of high binding affinity (the native state) and low P1012 binding affinity (the denatured state). To generate the contrast between the weaves or tissue components of different state, it is desired to cause the binding affinity of the contrast agent to change by at least 20% or more when the tissue changes state. For example, if the agent was 90% bound (ie, 10% free) to the viable state of a tissue or white tissue component (i.e., HSA), the agent must be 72% bound or less under the same conditions as the non-viable state (for example, denatured). A greater contrast will be generated if the difference in binding affinity is greater. It is desirable that the binding affinity of the contrast agent for the second tissue state (resulting from or during intervention therapy) should be 80% less than the binding affinity for the first tissue state compared to the affinity of union in the second state, preferably 50% or less, more preferably 30% or less, still more preferably 20% less, and most preferably 10% less. In the case where, the IEM is a chromophore suitable for use in optical imaging, the invention requires that there be a measurable difference between the optical properties of the drug not bound to the tissue and the contrast agent bound to the tissue. . For example, the maximum absorbance of green P1012 indocyanine shifts from 770-780 nm to 790-805 nm at the plasma or blood junction. This state-dependent binding can be used to detect tissue denaturation by monitoring the change in absorbance of the dye as the tissue denatures and the protein does not bind any longer. Those skilled in the art will appreciate that the optical agents useful in the invention will generally tend to provide greater sensitivity to the condition of the tissue. Therefore, in order to generate sufficient contrast, the optical agents may not require such a large binding affinity difference or as great a difference in signal between the two states of the woven as the MR agents of the present invention. The dependent binding of the weave must also result in a signal change characteristic of the contrast agent. In MRI, this contrast-dependent signal change can be manifested as a change in the induced relaxation velocities (l / Ti or l / T2) of the water protons, or the relaxation capacities Rx and R2. In a preferred aspect of the present invention, the relaxivity of the agent in the second tissue state (Ri second) is desirably 80% or less of the relaxation capacity (initial Rx) of the agent in the initial state of the tissue. Preferably, Rx second is 50% or less of the initial Rx, in more P1012 preferred 20% less, and even more preferably 10% or less. It is also preferred that after the intervention therapy is finished and the white tissue is returned to the physiological conditions (for example, in the case of thermal denaturation, after the temperature is returned to the physiological temperature), the capacity of agent relaxation R__ is still less than the agent's ability to relax in the initial state of the tissue (initial Ri), preferably 80% less than the initial Rx, more preferably 50% less than the initial Ri, in even more preferably 20% less, and more preferably 10% or less. It is also desirable that the Rx relaxation capacity of the contrast agent, after the intervention therapy is terminated and the target tissue is returned to the physiological conditions, is maintained at the agent's ability to relax immediately after it is terminated. intervention therapy. As indicated previously, the specific structure of the SDTBM will depend on the specific tissue or tissue component that is attached. Therefore, it is necessary to first determine what woven or tissue component is to be targeted. Several possible joining sites are contemplated.

P1012 These binding sites include nucleic acids, glycosaminoglycans (formerly known as acid mucopolysaccharides), calcified tissue, bone, fat, synovial fluid, cell membranes, proteins, lipoproteins, enzymes, proteoglycans, amyloids and ceroids. Preferred binding sites are proteins, with serum and structural / connective proteins that are most preferred. When the target is a protein, suitable proteins include human serum albumin (HSA, 0.7 mM in plasma, lower concentrations in interstitial space); fatty acid binding protein (FABP, also known as protein Z or protein A, approximately 0.1 mM in the primary cells of the liver, kidney, heart and other tissues); glutathione-S-transferase (GST, also known as ligand, approximately 0.1 mM in the primary cells of the liver, kidney, heart and other tissues) glycoprotein, alpha-1-acid (AAG, PM 41000, 0.55 g-1.4 g / L ), as well as lipoproteins (for example, those concentrated in the atherosclerotic plaque). Other examples include the structural proteins of the extracellular matrix (collagens, laminin, elastin, fibronectin, entactin, vitronectin), amyloid (including the beta-2-amyloid (A4) protein of Alzheimer's disease), ceroid (or lipofuscin), and glycoproteins (e.g., osteonectin, tenascin, and thrombospondin). A preferred protein target for positively charged contrast agents or contrast agents containing the basic SDTBMs will be alpha-1-acid glycoprotein (AAG). The plasma levels of the acute-phase, positive protein vary significantly with the state of the disease. For example, AAG concentrations are increased two to four times after the inflammatory stimulus and plasma levels of AAG have been suggested as a prognostic aid for glioma, metastatic breast and other carcinoma, neonatal infection and chronic pain. Elevated levels have been reported in -therosclerosis, Chron's disease, myocardial infarction, nephritis, and bacterial, viral and post-operative infections. The highly soluble AAG has an individual polypeptide chain of 183 amino acids and is characterized by several unusual properties, including a high content of carbohydrates and sialic acid (45% and 12%, respectively) and a low isoelectric point of pH 2.7. Alpha-1-acid glycoprotein has been implicated in the binding of numerous basic drugs, including propranolol (Ka = 11.3 X 105), imipramine (Ka = 2.4 x 105), and chloropromazine (Ka = 35.4 x 105). The percentage of free lignocaine has been correlated with the concentration of AAG in patients (0.4 to 3 gl "1), implying that the union P1012 selective AAG over other proteins (eg, HSA) in the plasma could be discussed using rational drug design methods. Ligands for HSA, FABP, and GST are the most preferred SDTBMs since these are negatively charged molecules or tend to be neutral with negatively charged, partial groups (eg, in ester, an amide, or a ketone-carbonyl-oxygen); These compounds are generally thought to be less toxic to positively charged molecules. Of these three proteins, HSA may be the most preferred in some cases, since the ligands for FABP and GST will require some intracellular admission before binding. In general, intracellular admission for contrast agents (except in the liver) is avoided to minimize toxicity. HSA is present in substantial amounts in many extracellular fluid environments including plasma, the interstitial space of normal and cancerous tissues, synovial fluid, cerebral spinal fluid, and inflammatory or abscess fluid. In many pathological tissues such as tumors, inflammation, atherosclerotic plaque, or the walls of the atherosclerotic arteries, the capillary spleens are permeable, resulting in even higher levels of SAH. This can improve the usefulness of the agents of this invention since a large number of intervention therapies can target sick tissues. HSA is also preferred because it is known to have good affinity and high ability to bind to a wide variety of structurally different molecules, usually at a large number of binding sites. In this way, there is more flexibility in the design of contrast agents. For the binding to the native state of the HSA, a wide range of hydrophobic or amphiphilic substances can be useful as the SDTBM (U. Kragh-Hansen, Pharm. Rev., 33, pp. 17-53 (1981); XM He et al., Nature, 358, pp. 209-215 (1992), DC Carter, Adv. Protein Chem., 45, pp. 153-203 (1994) These include, but are not limited to, small molecules that comprise at least one aliphatic group , alkoxy, alkylthio, alkylcarbonyl, alkylcarbonyloxy, aryl or heterocyclic with 1 to 60 carbon atoms and optionally one or more nitn atoms, oxygen, sulfur, halogen, aliphatic amide, ester-sulfonamide, acyl, sulfonate, phosphate, hydroxyl or substituents organometallics.Alternatively, but less preferred, SDTBM can be a biomolecule such as a peptide containing hydrophobic amino acid residues and / or substituents with or without hydrophobic or hydrophilic terminating groups.

P1012 As discussed above, for the binding to HSA, a wide range of hydrophobic substances such as SDTBM may be useful. In general, the binding affinity to HSA and possibly other proteins will be increased with the hydrophobicity of the SDTBM. Theoretical estimates of the hydrophobicity of a substituent such as an SDTBM can be obtained by calculating the contribution to the log of the octanol-water (or octanol-buffer) partition coefficient (log P) for the same TBM using the Hansch constant 1 for the substituents. See, A. Leo and C. Hansch, "Partition Coefficients and their Uses", Chemical Reviews, 71, pp. E525-616 (1971); K.C. Chu, "The Quantitative Analysis of Structure-Activity Relationships," Burger's Medicinal Chemistry, Part 1, pp. 393-418 (4th ed 1980). The binding affinity will increase with the increase in the contributions of log P. For example, for substituents in aliphatic groups, the following constants 1 can be used: Group 1-aliphatic CH3 0.50 Phenyl 2.15 For substituents on aryl groups, the following constants can be used: P10X2 Group 1-aliphatic CH2 0.56 CH2CH3 1.02 Phenyl 1.96 In this way, the contribution of log P for a p-methylbenzyl group bound to an IEM will be calculated as follows (using the value of 1-aliphatic for CH3 as an estimate for the -CH2- group): contribution of log P = 0.50 + 2.15 + 0.56 = 3.2 In binding to HSA, a minimum contribution of log P of 2 (equivalent to 4 CH3 groups or a phenyl ring) is required to achieve significant binding. More preferred is a log p contribution of 3. Even more preferred is a log p contribution of 4. The binding of HSA by equilibrium dialysis or ultrafiltration using 4.5% w / v HSA in pH buffer can be assessed. 7.4. Preferably, at least 10%, and more preferably at least 50%, and more preferably at least 80% and most preferably at least 95% of the contrast agent binds to the native state of HSA to concentrations P1012 relevant physiological (0.01-10 mM plasma for MRI and optical imaging). In this application, the measurement of the percent binding of the contrast agent to HSA has an error of about +/- 5%. Protein binding to other proteins or serum can be assessed in a similar way. The addition of lipophilic groups in a contrast agent will probably decrease the solubility of the agent. To retain an efficient solubility of the contrast agent at clinically effective or higher dose levels, it may be preferred to incorporate one or more hydrogen-bonding groups (oxygen, nitrogens, etc.) into the SDTBM. While purely aliphatic groups can be used as in SDTBMs, these are not as preferred as aliphatic, mixed aryl groups or purely aryl groups. Especially when a negative charge binds to purely aliphatic groups, particularly long and flexible ones, the contrast agent may interfere with the metabolism of endogenous molecules such as fatty acids or the interactions between proteins and membrane lipids. This can increase the toxicity of the agent. In this way, it is preferred that the SDTBM contain at least one aryl ring. In the case of MRI agents linked to HSA, of P1012 native state for the improvement of the tumor or tissue, it is especially preferable that the contrast agent have two or more different lipophilic groups to completely immobilize the agent when it binds to the protein. These groups can be in an SDTBM, or as much as two or more separate chemical groups attached to the contrast agent. Due to its volumetric nature and stiffness, it is preferable that the two or more groups each consist of an aromatic ring, with the two or more rings in the complete molecule arranged in a rigid, non-planar orientation. The magnetic efficiency, or relaxation capacity, of an MRI agent is generally greater when the agent has a rotational correlation time approximately equal to HSA (R.B. Lauffer, Chemical Reviews, 87, pp. 901-927 (1987)). Whereas a small molecule such as Gd-DTPA has a rotational correlation time of about 0.1 nanoseconds (nseg), the HSA has a correlation time of more than 5-10 nseconds, - if a chelate has this longer correlation time, the magnetic fluctuations between the paramagnetic ion and the water protons in the same scale will be presented. time as the Larmor frequency, generating the most efficient longitudinal relaxation (Ti) possible and in this way the highest possible relaxation capacity. Any flexibility of the P1012 chelate when bound to the protein is expected to decrease the effective rotational correlation time and thus decrease the ability to relax. Since a protein binding site can still produce flexibility in several directions, additional binding sites may be preferred. As previously indicated, the state-dependent binding must also result in a signal change characteristic of the contrast agent. In MRI, this change of state-dependent signal can be modified with a change in induced relaxation rates (1 / T? Or l / T2) in water protons, or the relaxation capacities of Ri and R2. Thus, when HSA is the target, the degree to which an agent has been readjusted for maximum relaxation capacity can be assessed by measuring the union of state-dependent relaxation capacity (Rx bound) in the presence of HSA in its two physiological states: native and denatured. In a preferred aspect of the present invention, the ability of the agent to relax in the second state of the tissue (Ri second) is desirably 80% or less in the relaxation capacity (initial Ri) of the agent in the initial state of the tissue. Preferably, Ri second is 50% or less of the initial Rx, preferably 20% or less, more preferably 10% or less.

This requires the measurement of the relaxation capacity of the free chelate (Ri-free) as well as the relaxation capacity (Ri-observed) and percent binding of the agent in 4.5% HSA in its two physiological states. In a preferred aspect of the invention, Rx-free corresponds to R_. observed in the denatured state. The R_. observed is a weighted average of the molar fraction of the free Rx and the Rx-bound: Ri-observed = (fraction-free * Ri-free) + (fraction-bound * Ri-linked) In this way: i-joined = l "R? -observed - (f action-free * Rt_-free) 1 Fraction -united State-Dependent Union to HSA As indicated above, the preferred protein for contrast agents to be used in this invention is HSA. For this application, it is desirable that the contrast agent exhibits an improved blood half-life to increase the degree to which the agent remains in the blood (ie, bound to HSA) and thus, available throughout the course of intervention therapy. The prolonged blood half-life can be achieved by including a linking group (L) that functions as an extension portion of the P1012 blood half-life ("BHEM") to reduce the admission rate of hepatocytes of the contrast agent. See, U.S. Patent Application Serial No. 08 / 382,317, filed February 1, 1995, which is incorporated herein by reference. BHEMs are extremely hydrophilic groups that can be bound to hydrogen with water. The presence in a contrast agent of the hydrophilic BHEM reduces the admission of the hepatocytes of the agent. Examples of chemical groups that can serve as a BHEM include atoms of carbon, phosphorus, tungsten, molybdenum or sulfur having charged or neutral heteroatoms, attached such as oxygen, nitrogen, sulfur or halogens (especially fluorine), which possess two or more single electron pairs (ie partial full negative charge) or electropositive hydrogen atoms (i.e., protonated amine) for hydrogen bonding with water (these include groups such as sulfone, ether, urea, thio-urea, amine- sulfonamide, carbamate, peptide, ester, carbonate and acetals Preferred groups include those that have one or more partial or complete negative charges in aqueous solution at physiological pH where the negatively charged atoms can not be used partially or completely by the covalent bond or covalent coordinated to the IEM. Examples of these preferred BHEMs P1012 include negatively charged groups such as phosphate mono-ester, phosphate diester, carboxylate and sulfonate. More preferred are those having phosphonate groups or any of the ester forms thereof. Even more preferred are the phosphonate diesters, since a) they are highly hydrophilic with four hydrogen-binding oxygens; b) they are synthesized relatively easily using techniques mixed later; c) serve as excellent linkers between the IEM and the SDTBM; and d) because phosphate compounds exist and are metabolized naturally in the body, contrast agents containing phosphate diester are expected to be non-toxic. The incorporation into a contrast agent of this invention of a BHEM results in prolonged blood retention of the agent. Blood retention is preferably measured when calculating, in a rat plasma pharmacokinetic experiment, the area under the concentration curve against time in plasma ("area under the curve" or "AUC-conc.") For a specific period of time (for example, 0-10 minutes, 0-30 minutes, 0-60 minutes, 0-120 minutes or 0 -infinite). Blood retention (as measured by AUC-conc) can be evaluated experimentally by the administration of a contrast agent to rats, rabbits or higher mammals. It has been observed that the extension of blood half-life is higher in rabbits and P1012 higher mammals than in rats. In this application, the data of the blood half-life, as measured by AUC-conc., Represent experimentation in rats. The error associated with this data is approximately +/- 10%. The reason why a measurement of same half life is not used is that the mathematical definition of this amount is often not clear and the resulting estimates are variable depending on the pharmacokinetic model used and the length of time in which the blood samples were obtained. For example, the average plasma concentrations observed after tail vein injection of 0.1 mmol / kg Gd-DTPA labeled with Gd153 in two rats is shown below. Using the KaleidaGraph Macintosh program, this AUC-conc from 0 to 10 minutes was calculated as 3.5 mM min. time (min) P1012 The contrast agents of this invention, useful in targeting serum proteins such as HSA, exhibit an increase in AUC-conc of at least 20% when BHEM is added to the IEM and SDTBM. They preferably exhibit an increase in AUC-conc of at least 40%, more preferably at least 70% and even more preferably at least 100%. In general, the increase in AUC-conc caused by a BHEM is greater when the binding in significant plasma, for example, 20% -50% or greater. The percent of the increase calculated in AUC-conc may be different for the AUC-conc determined during different time periods. In general, the percent increase in AUC-conc. caused by BHEM is greater for AUC-conc taken for prolonged periods, for example, 0-30 minutes, instead of 0-10 minutes. Since the structural and physical characteristics of the composite molecule of the contrast agent will govern its binding in plasma, it is important to select the IEM and the BHEMs that are compatible with the desired junction. For example, to achieve binding to positively charged binding sites to HSA, it is preferred to have net negative or neutral net charge BHEM to reduce the possibility of repulsion and perhaps even an increased binding affinity. For binding to the alpha-acid glycoprotein, at least some portion of the contrast agent must be P1012 charge positively. For binding to globulins, at least some portion of the contrast agent must be spheroidal in nature. For lipoprotein binding, at least a portion of the contrast agent must be lipophilic or fatty acid type. It is contemplated that the BHEM can be arranged in a variety of positions with respect to the IEM and SDTBM. However, the position of the portions can not be such that one portion interferes with the proposed function of the other. For example, in an HSA-binding contrast agent, the placement of the BHEM should not block the ability of the STDBM to bind the agent to HSA. Since the main binding sites in HSA are medium type (XM He et al., Nature, 358, 00. 209-215 (1992); DC Cárter, adv. Protein Chem., 45, pp. 153-203 (1994 )), with hydrophobic interiors (especially near the "toe" region) and positively charged "ankle" regions, the binding affinity of an STDBM will decrease if the distal portion of the STDBM becomes extremely hydrophilic.As an illustrative example, if the STDBM is a phenyl ring, the most preferred BHEM position in the ring is ortho, followed by meta.A hydrophilic group in the para position will reduce the binding affinity of STDBM to HSA For the IEM consisting of a chelate metallic, it is preferred that the BHEM and the STDBM do not join P1012 the IEM to significantly reduce the strength of the bond between the metal ion and the chelating ligand. For example, where the chelating arm is acetate, the BHEM or the STDBM does not preferentially bind to the acetate oxygen. Another positional requirement is that the negatively charged BHEM atoms can be neutralized partially or completely by the covalent or covalent binding coordinated to the IEM; this ensures that highly hydrophilic atoms of BHEM will be highly solvated in aqueous systems. For example, when the IEM is a metal chelate, it is important to place the negatively charged atoms of the BHEM so that they can not be neutralized by the positively charged metal ion (Mn +) of the IEM through the coordinated covalent bond and the formation of 5 or 6-membered chelate rings, the most stable ring sizes. Since 5-membered chelate rings are the most stable for metal ions of interest for IEMs (such as gadolinium), it is very important to prevent their formation. In this manner, as shown in the drawing below, a BHEM of phosphinate (-P02-) or phosphonate (-P03-) can not be attached to the nitrogen atom of an aminocarboxylate chelating agent via a -CH2- linker. since it will form a very stable 5-membered chelate ring. Similarly, a phosphodiester BHEM (-OPO3-) should not be attached to the nitrogen atom of an aminocarboxylate chelating agent via the -CH2- linker since this could form a 6-membered chelate ring. However, both of these BHEMs can be linked to other positions, such as the ethylene structure of the ligand. In some cases, as shown, it may be preferred to increase the length of the linker group to ensure that 5- or 6-membered rings can not be formed.

BHEM of Phosphine or Strongly disadvantaged (5-member chelate ring, neutralized charge) Disadvantaged (6-member chelate ring, neutralized charge) More preferred (no possibility of 5 or 6 membered chelate rings or charge neutralization P1012 It is contemplated that the portions of this invention can be placed in the contrast agent so that the following structures can result: (1) IEM - [(__,) "-. { (BHEM), - (SDTBM) 0} p] q (2) IEM - [(SDTBM) "I (BHEM). ] r (3) where m can be equal to 0-4, s, o, and p the same or different ones equal to 1-4, and r and q are at least one. If the portions of this invention are placed in the contrast agent as in structure (1) above, the BHEM is preferably sulfone, urea, thio-urea, amine, sulfonamide, carbamate, peptide, ester, carbonate, acetals and so more preferred or ester forms Y2-R, where Z = P,, Mo, or S Yi Y2 = O or S Y3, Y4 = O, S or not present P1012 R2 = H, alkyl of 1 to 6 carbon atoms or is not present. More preferably, BHEM is a phosphate group. If the portions of this invention are placed in the contrast agent as the structure (2) above, the BHEM is preferably sulfone, urea, thio-urea-, amine, sulfonamide, carbamate, peptide, ester, carbonate, acetals and so more preferred, BHEM has the following formula Y1 II Y - ZY "or ester forms I Y2-R2 where Z = P, W or Mo Yi Y2 = O or S Y3, Y4 = O, S or R2 = H, alkyl of 1 to 6 carbon atoms is not present or is not present. More preferably, BHEM is a phosphate group. If the portions of this invention are placed on the contrast agent as in structure (3) above, the BHEM is preferably S03"or forms of ester, sulfone, urea, thio-urea-, amine, sulfonamide, carbamate, peptide, ester, carbonate, acetal and more preferably, P1012 Y3-Z-Y "Or forms of ester Y? -R2 where Z = P, W or Mo Y3, Y4 = O, S or R2 = H, alkyl of 1 to 6 carbon atoms is not present or is not present. More preferably, BHEM is a phosphate group. It is contemplated that if the portions of this invention are placed in the contrast agent as in structure (3) above, the preferred contrast agents have the formula: G 3+ OR P1012 where Ri, R2, R3, R4, R5, R6, R ?, Rs, Rg, Rio, R11 Y Ri6 may be the same or different and are selected from the group consisting of H, SDTBM, BHEM and alkyl of 1 to 6 carbon atoms, with the proviso that at least one of the R is SDTBM and at least one other is BHEM. R12, 33 and R14 may be the same or different and is selected from the group consisting of O "and N (H) R 7 7, Ris = H, CH2CH (0H) CH3, hydroxy-alkyl or CH (4) 6) COR12 and R17 = H or alkyl of 1 to 6 carbon atoms For contrast agents comprising the formulas shown above, BHEM is preferably sulfone, ether, urea, thio-urea, amine, amide, sulfonamine, carbamate , peptide, ester, carbonate, acetal and more preferably COO "or ester forms, S03" or ester forms and P1012 Y1 II Y3-Z-Y < or forms of ester I Y2-R2 where Z = P, W, Mo, or S Y1, Y2 = O or S Y3, Y4 = O, S or R2 = H, alkyl of 1 to 6 carbon atoms is not present or is not present. In the case of an HSA binding contrast agent, the BHEM can be placed between the IEM and the SDTBM as shown above in structure (1) or in the IEM away from the SDTBM as shown above in the structure ( 3) . In this way, the complete binding potential of the hydrophobic SDTBM group can be displaced without interference from the hydrophilic BHEM group. The contrast agents useful in the present invention exhibit state-dependent binding to HSA are disclosed in the United States patent application.

Serial No. 08 / 382,317 filed on February 1, 1995.

For example, the following agents are useful: P1012 P1012where n is equal to 1-4 wherein R comprises an aliphatic group and / or at least one aryl ring, or comprises a peptide comprising hydrophobic amino acid residues and / or substituent with or without hydrophobic or hydrophilic terminating groups. Preferred contrast agents useful in the invention are: P1012 - MS-313 MS-317 MS-32S MS-326 M3-327 The most preferred contrast agents with state-dependent binding to HSA are MS-317, MS-322, MS-325 and MS-328. The most preferred is MS-325.

Use of the Contrast Agents The agents used in this invention are defined to include pharmaceutically acceptable derivatives thereof. The pharmaceutically acceptable derivative means any salt, ester, salt of an ester, or other pharmaceutically acceptable derivative of a compound of this invention, which, upon administration to a recipient, is capable of providing (directly or indirectly) a compound of this invention or a metabolite or inhibitoryly active residue thereof. Particularly favored derivatives are those that increase the bioavailability of the compounds of this invention when these compounds are administered to a mammal (for example, by allowing an orally administered compound to be more readily absorbed in the blood) or a compound distribution is improved of origin to a biological compartment (for example, the brain or lymphatic system). It is also contemplated that the agents used in this invention may comprise a pharmaceutically salt P1012 acceptable. The pharmaceutically acceptable salts of this invention include those derived from inorganic or organic acids and bases. Included among these acid salts are the following: acetate, adipate, alginate, asparate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorrate, camphorsulfonate, cyclopentanepropionate, digluconate, dodecyl sulfonate, ethanesulfonate, fumarate, glucoheptanoate, glycerophosphate, hemisulfate, heptanoate, hexanoate , hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, oxalate, pamoate, pectinate, persulfate, 3-phenylpropionate, picrate, pivalate, propionate, succinate, tartrate, thiocyanate, tosylate and undecanoate. Basic salts include ammonium salts, alkali metal salts, such as sodium and potassium salts, alkaline earth metal salts, such as calcium, magnesium and zinc salts, salts with organic bases such as dicyclohexylamine, N-methyl salts -D-glucamine, and salts with amino acids such as arginine, lysine and so on. Also, groups containing basic hydrogen can be quaternized with agents such as lower alkyl halides, such as methyl, ethyl, propyl and butyl chloride, bromides and iodides; dialkyl sulfates, such as dimethyl, diethyl, dibutyl and diamyl sulfates, long chain halides such as chlorides, P1012 decyl, lauryl, myristyl and stearyl bromides and iodides, aralkyl halides, such as benzyl and phenethyl bromides and others. The soluble or dispersible products in water or oil are obtained in this way. The preferred salts of this invention are the N-methyl-D-glucamine, calcium and sodium salts. The pharmaceutical compositions of this invention comprise any of the complexes of the present invention, or pharmaceutically acceptable salts thereof, together with any pharmaceutically acceptable carrier, adjuvant or vehicle. The pharmaceutically acceptable carriers, adjuvants and vehicles that can be used in the pharmaceutical compositions of this invention include, but are not limited to, ion exchangers, alumina, aluminum stearate, lecithin, serum proteins, such as human serum albumin, buffer substances, such as phosphates, glycine, sorbic acid, potassium sorbate, TRIS (tris (hydroxymethyl) amino-methane), and partial mixtures of glyceride of saturated vegetable fatty acids, water, salts or electrolytes, such as protamine sulfate, disodium acid phosphate, potassium acid phosphate, sodium chloride, zinc salts, colloidal silica, magnesium trisilicate, polyvinylpyrrolidone, cellulose-based substances, polyethylene glycol, sodium carboxymethylcellulose, polyacrylates, waxes, polyethylene-polyoxypropylene block polymers, polyethylene glycol and wool grease. In accordance with this invention, the pharmaceutical compositions may be in the form of an injectable, sterile preparation, for example, an injectable, sterile, aqueous or oleaginous suspension. This suspension can be formulated according to techniques known in the art using suitable wetting or dispersing agents and dispersing agents. The preparation is injectable, sterile it can also be a sterile injectable solution or suspension in a non-toxic, parenterally acceptable diluent or solvent, for example, as a solution of 1,3-butanediol. Among the acceptable vehicles and solvents that can be used is water, Ringer's solution and isotonic sodium chloride solution. In addition, fixed, sterile oils are conventionally used as a solvent or suspension medium. For this purpose, any fixed, blended oil including synthetic mono- or di-glycerides can be employed. Fatty acids, such as oleic acid and its glyceride derivatives are useful in the preparation of injectables, such as natural pharmaceutically acceptable oils, such as olive oil or castor oil, especially in their polyoxyethylated versions. These solutions or oily suspensions may also contain P1012 a long chain alcohol diluent or dispersant, such as Ph. Helv or similar alcohol. Since the contrast agents of this invention can bind to plasma proteins, in some cases depending on the dose and speed of injection, the binding sites in the plasma proteins may become saturated. This will lead to a decreased union of the agent and could compromise the half-life or tolerability. In this way, it may be desirable to inject the pre-bound agent with a sterile albumin or plasma replacement solution. Alternatively, a syringe apparatus containing the contrast agent can be used and mixed with the blood drawn into the syringe, this is then re-injected into the patient. The compounds and pharmaceutical compositions of the present invention can be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir in dosage formulations containing carriers, adjuvants and vehicles. pharmaceutically acceptable, non-toxic, conventional. The term "parenteral" as used herein includes subcutaneous, intravenous, intramuscular, intra-articular, intra-synovial, intrasternal, intratracheal, intraepitial, intralesional, and intracranial injection or infusion techniques.

P1012 When administered orally, the pharmaceutical compositions of this invention can be administered in any orally acceptable dosage form including, but not limited to, capsules, tablets, suspensions or aqueous solutions. In the case of tablets for oral use, carriers that are commonly used include lactose and corn starch. Lubricating agents such as magnesium stearate are also typically added. For oral administration in a capsule form, useful diluents include lactose and dried corn starch. When aqueous suspensions are required for oral use, the active ingredient is combined with emulsifying and dispersing agents. If desired, certain sweetening, flavoring or coloring agents may also be added. Alternatively, when administered in the form of suppositories for rectal administration, the pharmaceutical compositions of this invention can be prepared by mixing the agent with a suitable non-irritating excipient which is solid at room temperature but liquid at the rectal temperature and therefore it will melt in the rectum to release the drug. These materials include cocoa butter, beeswax and polyethylene glycols. As noted above, the P1012 pharmaceutical compositions of this invention can also be administered topically, especially when the purpose of the treatment includes easily accessible areas or organs by topical application, including the eye, the skin or the lower intestinal tract. Suitable topical formulations are easily prepared for each of these areas or organs. Topical application to the lower intestinal tract may be performed in a rectal suppository formulation (see, above) or in a suitable enema formulation. You can also use transdermal patches, applied topically. For topical applications, the pharmaceutical compositions can be formulated in a suitable ointment containing the active component dispersed or dissolved in one or more carriers. Carriers for topical administration of the compounds of this invention include, but are not limited to, mineral oil, liquid petrolatum, white petrolatum, propylene glycol, polyoxyethylene, polyoxypropylene compound, emulsifying wax and water. Alternatively, the pharmaceutical compositions can be formulated in a suitable lotion or cream containing the active components dispersed or dissolved in one or more pharmaceutically acceptable carriers. Suitable carriers include, but are not limited to, oil P1012 mineral, sorbitol monostearate, polysorbate 60, cetyl esters wax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water. For ophthalmic use, the pharmaceutical compositions can be formulated as micronized suspensions in sterile saline, pH adjusted, isotonic, or preferably as solutions in sterile saline, pH adjusted, isotonic, either with or without a preservative such as bencialconium chloride. Alternatively, for ophthalmic uses, the pharmaceutical compositions can be formulated into an ointment such as petrolatum. For administration by nasal spray or inhalation, the pharmaceutical compositions of this invention are prepared according to techniques well known in the pharmaceutical formulating art and can be prepared as solutions in saline, employing benzyl alcohol or other suitable preservatives, promoters of absorption to improve bioavailability, fluorocarbons and / or other conventional solubilizing or dispersing agents. The dose depends on the sensitivity of the diagnostic imaging instrument, as well as the composition of the contrast agent. For example, for imaging by MRI, a contrast agent P1012 containing a highly paramagnetic substance, for example, gadolinium (III), generally requires a lower dose than a contrast agent containing a paramagnetic substance with a low magnetic moment, for example, iron (III). Preferably, the dose will be in the range of about 0.001 to 1 mmol / kg body weight per day of the active metal-binding complex. More preferably, the dose will be in the range of about 0.005 and about 0.05 mmol / kg of body weight per day. In the case where optical imaging is used to monitor intervention therapy, the agent doses will be approximately equal to those in MRI (0.001-10 mmol / kg). Also, as with MRI contrast agents, the administration of optical agents is well known in the art. However, it should be understood that a specific dose regimen for any particular patient will also depend on a variety of factors, including age, body weight, general health, sex, diet, time of administration, rate of excretion, combination of drugs and the judgment of the attending physician. After administration of the appropriate dose of the contrast agent, the patient is then P1012 undergoes imaging either by MRI or by optical means (imaging by ultraviolet light, visible or infrared light). Appropriate adjustments and appropriate imaging parameters to perform these imaging techniques, as well as the collection and analysis of the data (i.e., monitoring of the agent signal characteristics) are well known or commonly understand principles. accepted The final step of the method of this invention is to monitor a signal characteristic of the imaging of the administered contrast agent. For optical image formation, these signal characteristics include absorbance, reflectance, fluorescence or phosphorescence and / or their lifetimes, chemiluminescence, dispersion, or other spectral properties. For MRI image formation, these signal characteristics include the reflection capacities Rx and R2 (1 / T? And l / T2, respectively). In a more preferred aspect of this invention, "real-time" monitoring is possible where an image is generated and in this way the signal characteristic is monitored periodically throughout the course of intervention therapy. The frequency at which images are generated and monitored will depend on the type and P1012 duration of therapy. In order that this invention can be more fully understood, the following examples are set forth. These examples are for illustration purposes only and should not be considered as limiting the scope of the invention in any way.

EXAMPLES The following is a synthetic scheme for the preferred contrast agents useful in the method of the invention, and in particular for that of MS-325. See the U.S. Patent Application Serial Number 08 / 833,745, filed April 11, 1997 and incorporated herein by reference. Another synthetic scheme, useful though not so preferred, for these contrast agents is described in the Patent Application of the United States Serial No. 08 / 382,317 filed February 1, 1995 incorporated herein by reference. First, a ROH alcohol is reacted with PC13, preferably at a molar ratio of 1: 1, to form a reaction product of dichlorophosphine (I): PCI3, solvent (I) ROH-ROPCI2 The R group can be a group of organic chelating agent, linear, branched or cyclic aliphatic, aryl, heterocyclic, peptidic, peptoid, deoxyribo- or ribo-nucleotide or nucleosidic, or cyclic organic or acyclic, which may be optionally substituted with one or more of nitrogen, oxygen, sulfur, halogen, aliphatic, amide, ester, sulfonamide, aryl, acyl, sulfonate, phosphate, hydroxyl, or organometallic substituents. This reaction takes place in the presence of an ethereal or hydrocarbon solvent and is carried out at a temperature from about -50 ° C to about 15 ° C, preferably from about -10 ° C to about -5 ° C, for a period from about 30 minutes to about 3 hours, preferably from about 1 to about 1.5 hours. The solvent may be any ethereal or hydrocarbon solvent, it may be selected from the group consisting of heptanes, methyl t-butyl ethers, dioxanes, tetrahydrofurans, diethyl ethers and dialkyl ethers of ethylene glycol. More preferably, the solvent is tetrahydrofuran. The dichlorophosphine (I) is then reacted with from about 5 to about 6 equivalents of an amine base to form a reaction product of bis (amino) phosphino (II): This reaction takes place in the presence of an ethereal or hydrocarbon solvent, as described above, and is carried out at a temperature from about -50 ° C to about 15 ° C, preferably from about -10 ° C. to about -5 ° C, for a period from about 30 minutes to about 3 hours, preferably from about 15 to about 30 minutes. The base used to form the reaction product (II) can be any amine base, preferably a base having a pKa value from about 5 to about 11, and more preferably is selected from the group consisting of imidazole , 2,4-dimethylimidazole, 1H-tetrazole, dialkylamines (methyl, ethyl, butyl), pyridine, piperazine, piperidine, pyrrole, 1H-1, 2, 3-triazole, and 1, 2,4-triazole. In a more preferred embodiment, the base is imidazole. The bis (amino) phosphino (II) compound is then reacted with from about 0.75 to about 1.0 equivalents of a second alcohol R1OH, where R1 can be any of the substituents defined above for the R group, to form a product of reaction of (amino) phosphino (III): amino solvent. (II) RO? (Aminoh + R! 0II ROP; \::? This reaction takes place in the presence of an ethereal solvent or hydrocarbon and is carried out at a temperature of from about -50 ° C to about 15 ° C, preferably from about -10 ° C to about -5 ° C, for a period of approximately minutes to about 3 hours, preferably from about 1.0 to about 1. 5 hours. The solvent can be any ethereal or hydrocarbon solvent and can be selected preferentially from the group consisting of heptanes, methyl t-butyl ethers, dioxanes, tetrahydrofurans, 1,3-dioxolanes, diglymes, diethyl ethers, dialkyl ethers, and dialkyl ethers of ethylene glycol. More preferably, the solvent is tetrahydrofuran. Finally, the (amino) phosphino (III) compound is reacted with about one equivalent of acidic water, preferably having a pH of about 2.5 to about 5, and about 1 or more equivalents of an oxidant to form the phosphodiester compound desired (IV): The oxidant can be any peroxide-type oxidant and is preferably selected from the group consisting of periodates. More preferably, the oxidant is sodium periodate. The above hydrolysis and oxidation is carried out in a solvent mixture at a temperature of from about -15 ° C to about 25 ° C, preferably from about 0 ° C to about 2 ° C, for a period from about 10 to about about 24 hours, preferably from about 10 to about 15 hours. The solvent mixture comprises any combination of solvents selected from the group consisting of ethereal or hydrocarbon solvents. Preferably, the solvent mixture comprises tetrahydrofuran, heptane and toluene in the volume ratio of 10: 10: 1. According to this synthetic scheme, the ligand P1012 chelate in the MS-325 complex is prepared as follows.

Preparation of [(4,4-diphenylcyclohexyl) -fQSfQoxymethyl] diethylenetriaminepta-acetic acid The preparation of the chelating ligand used in the MS-325 complex is shown below in Scheme I: Scheme I i H20 NtlO < P1012 In a single reaction vessel containing a solution of phosphorus trichloride (13.2 mL, 0.151 mol) in tetrahydrofuran (202 mL) was added a solution of 4,4-diphenyl-cyclohexane (1.) (38.34 g, 0.152 mol). ) in tetrahydrofuran (243 ml) while stirring and maintaining an internal temperature of -6.2 ° C to -5.3 ° C for 1.5 hours. The mixture was then stirred for an additional 34 minutes yielding a reaction product of dichlorophosphine (2.), which has a 31P NMR chemical change of 174.28 ppm. To this solution, imidazole (51.34 g, 0.753 mol) in tetrahydrofuran (243 ml) was added while stirring and kept at an internal temperature of -7.8 ° C to -3.6 ° C for 37 minutes. The resulting mixture is then stirred for an additional 20 minutes yielding a solution of a bis (amino) phosphino reaction product (3.) having a 31P NMR chemical change of 106.36 ppm. To this mixture was added a solution consisting of the penta-t-butyl ester (4) of 2- (R) -hydroxymethyl-diethylenetriamine-pentaacetic acid (160.0 g, 0.128 mol, purity: 56.32% by weight) in heptane (114 ml) ) while stirring and holding at an internal temperature of -6.8 ° C to -4.8 ° C for 1 hour and 6 minutes. This mixture was then stirred for an additional 23 minutes producing a solution (5_) having a 31P NMR chemical change of 123.8.

P1012 ppm. Finally, water (202 ml) was added for a period of about 1 minute while maintaining an internal temperature of -6.5 ° C to 6.5 ° C. The mixture was stirred for 5 minutes followed by the addition of heptane (620 ml), toluene (70 ml) and 5N aqueous hydrochloric acid (202 ml) for 5 minutes while maintaining an internal temperature of 1.0 ° C to 12.1 ° C. Then, sodium periodate (22.6 g, 0.106 mol) was added during a period of 3 minutes while maintaining an internal temperature of 10.5 ° C. The reaction mixture was warmed to room temperature over 35 minutes and stirred an additional 2.5 hours yielding a solution (6.) with a chemical change of 31 P NMR of 4.27 ppm. The layers were separated and the organic layer was washed with 10% aqueous sodium thiosulfate (2 X 809 mL). To the above organic layer was added tetraoctylammonium bromide (8.21 g, 0.015 mol). Concentrated hydrochloric acid (11.51 M, 405 mL) was then added over a period of 22 minutes while maintaining an internal temperature of 22.8 ° C at 25.0 ° C. This mixture was stirred for 16.0 hours producing a compound (7) with a 31P NMR chemical change of 7.78 ppm. The layers were separated and the organic layer was discarded. To the above aqueous layer was added 8M aqueous sodium hydroxide (630 mL) until a pH of 6.56 was recorded. The solution was concentrated under reduced pressure (50 ° C to 55 ° C, evacuated to 85 mm Hg) until 400 mL of solvent was collected (approximately 1 hour). The solution was cooled to room temperature and amberlite XAD-4 resin (92.0 g) was added. The suspension was stirred for 50 minutes at room temperature and filtered to give a light yellow aqueous solution (1.1 L). The previous solution was loaded on inverted phase silica gel C-18 (271 g, wet packed in methanol and then washed in 800 mL of methanol / water, 1: 1 and 800 mL of water) and eluted with water. The first 1.0 L of the eluent collected was discarded and the next 1.3 L collected were retained. To the retained solution was added 6N aqueous hydrochloric acid (60 mL at a pH = 2.15) and 3N aqueous hydrochloric acid (30 mL at a pH of 1.63). The slurry was stirred for 1.25 hours and filtered. The solid was washed with aqueous solution of pH 1.67 (500 mL) and dried (48-50 ° C, 4-6 mm Hg) at a constant weight (18.0 hours) to obtain a completely white solid, the compound of the formula: P1012 (65.5 g, yield: 68.89% purity: 99.45% by weight, 98.95% in area, 3.02% of water and 97.81% of chelated products.

Experimental Part Three types of samples were prepared and evaluated. The first was a control sample containing human serum albumin (HSA) without a contrast agent. The other two samples contained HSA and the non-specific agent Gd-DTPA and the specific agent of HSA, MS-325, respectively. In these examples, the longitudinal relaxation capacities (Rx, mM "1 sec" 1) were monitored and obtained at 20 MHz by determining the relaxation rate (l / Tx) of the water protons in phosphate buffered saline (PBS) , 150 mM NaCl, 10 mM phosphate, pH = 7.4), PBS solutions containing 4.5% by weight HSA, or P1012 gels containing HSA at 4.5% by weight and 1% Agar. The dependence of temperature on the ability to relax (Ri) was observed by varying the temperature of the samples with a circulating water bath and monitoring the temperature of the sample with a thermocouple.

Example 1; Monitoring of Thermal Necrosis of HSA to 4. 5 %. The following three samples were prepared in 4.5% HSA solutions: (1) a control sample without a contrast agent; (2) a comparative sample with Gd-DTPA; and (3) a sample with MS-325. Samples with Gd-DTPA and MS-325 were prepared by adding an aqueous formulation (pH = 7), comprising either Gd-DTPA or MS-325 to the 4.5% HSA solution. The resulting mixtures had a concentration of 0.3 mM Gd-DTPA and 0.1 mM MS-325, respectively. The three samples were then used to monitor the thermal denaturation of the 4.5% HSA solutions. To be this, the data of Tx (and in this way the data of Ri (= 1 / T?)) For each sample were collected at 20 MHz over a temperature range of 20-60 ° C. Each sample was then removed from the NMR and heated at 85 ° C for 15 minutes to induce thermal denaturation of the HSA. Subsequently, the sample was returned to P1012 NMR and data from i were collected at this higher temperature. See Table 1 below and Figure 1.

Table 1 As shown in Table 1 and Figure 1, after the thermal denaturation of the three solutions containing HSA, the sample that also contained the agent of P1012 specific HSA contrast, the MS-325, demonstrated a significant decrease in the observed Ri (a loss of 26.7 mM "1 sec" 1) during the denaturing of the HSA as measured from immediately before the denaturation (56.2 ° C ) to immediately after denaturation (85 ° C). However, the sample containing the non-specific contrast agent Gd-DTPA, even at a concentration of three times that used for the MS-325 sample, showed little change in R_. (a loss of only 0.1 mM "1 sec" 1) during denaturation. This indicates that Gd-DTPA does not bind to negative or denatured HSA. After the above data were obtained, the denatured samples were allowed to cool to physiological temperature (37 ° C) and the turn data was collected again. The sample with MS-325 maintained a significant loss in Ri (a net loss of 25 mM "1 sec" 1) while the sample with Gd-DTPA showed only small changes in R_. (a net loss of 0.5 mM "1 sec" 1).

Example 2; Formation of MRI images of Thermal Denaturation of HSA at 1.0 Tesla. The following samples were prepared on 1% agar gels containing 4.5% HSA: (1) a sample of P1012 control without a contrast agent; (2) a comparative sample with Gd-DTPA; and (3) a sample with MS-325. The contrast agents were added in a sufficient amount such that the concentration of Gd-DTPA and MS-325 was 0.3 mM Gd-DTPA and 0.1 mM MS-325, respectively. These agar gels containing 4.5% HSA were referred to as "ghosts" Weighted MRI scans, initials (FISP-3D, TR = 15, TE = 4, alpha = 30) at 1.0 Tesla of the agar ghosts were then obtained at a temperature of approximately 25 ° C. Initial scans revealed that ghosts containing MS-325 were brighter than ghosts containing Gd-DTPA (comparative sample) or 4.5% HSA alone (control sample); this result was as expected due to the specific binding of MS-325 to HSA. The ghosts were then heated in a circulating water bath with additional i-weighted MRI scans obtained over time. As the temperature increased, the ghosts containing MS-325 remained much brighter (less loss of signal strength as measured in% ROI loss). (region of interest)) than ghosts containing Gd-DTPA or 4.5% HSA alone. See Table 2 below and Figure 2.

Table 2 As the ghosts were heated above 50-60 ° C, they came to have an opaque color, which corresponds to the thermal denaturation of the HSA. At the same time, as shown in Table 2 and Figure 2, the dramatic loss of signal strength was observed for the ghosts that contained MS-325 (76% loss in intensity). However, the ghosts that contained Gd-DTPA or HSA alone, produced only a modest change in signal strength. Ghosts of Gd-DTPA, even at a concentration of Gd-DTPA that was three times that used P1012 for the ghosts of MS-325, remained as constant dark images during the MRI scans after thermal denaturation. After the above data were collected, the denatured samples were then allowed to cool to normal physiological temperature (37 ° C). The ghosts containing MS-325 maintained their loss of signal strength (32% loss). Control ghosts and ghosts containing Gd-DTPA still showed only a 5% and 10% decrease in signal intensity, respectively, after denaturation. According to these results, the contrast agents useful in the method of this invention can provide a very sensitive indication of the thermal denaturation of the HSA. In fact, even when the concentration of another contrast agent was used three times, this higher concentration could not provide the sensitivity required to monitor the thermal denaturation of the HSA.

Example 3: Ethanol Denaturing of HSA The following three samples were prepared in 4.5% HSA solutions: (1) a control sample without a contrast agent; (2) a comparative sample with Gd-DTPA; and (3) a sample with MS-325. The samples with Gd- P1012 DTPA and MS-325 were prepared by adding an aqueous formulation (pH = 7) comprising either Gd-DTPA or MS-325 to the 4.5% HSA solution. The resulting mixtures had a concentration of 0.31 mM Gd-DTPA and MS-325 and 0.08, respectively. Then, pure ethanol was titrated to each of the samples. The Ti data were collected (and thus the Rx data (= l / Tx)) at 20 MHz and 37 ° C after each addition of ethanol. See Table 3 below and Figure 3.

Table 3 P1012 As shown in Table 3 and Figure 3, during the ethanol ablation of the 4.5% HSA solutions, the sample containing MS-325 showed a significant decrease in the observed relaxation capacity (33 mM "1 sec" 1) and in this way, allowed the detection of ethanol-induced necrosis. However, the sample that contained Gd-DTPA (still at almost four times the concentration of MS-325) showed only a minor change in the observed relaxation capacity (0.3 mM "1 sec" 1).

P1012

Claims (35)

1. CLAIMS 1. A method for enhancing diagnostic contrast imaging of a specific tissue or tissue component that is undergoing or has undergone intervention therapy, comprising the steps of: (a) administering to a patient a contrast agent capable of binding to the woven or white woven component and having a specific affinity for the tissue or tissue component, wherein the contrast agent comprises an enhancing portion of the image (IEM) and a portion of state-dependent attachment to the web (SDTBM); (b) subjecting the patient to a deformation of images by MRI, ultraviolet light, visible light or infrared light; and (c) monitoring a signal characteristic of the imaging of the contrast agent to determine whether it completes the intervention therapy. The method according to claim 1, wherein the IEM is selected from the group consisting of organic molecules, metal ions, salts and chelates, particles, agglomerates, iron particles, labeled peptides, proteins, polymers, liposomes, dyes organic and inorganic dyes. P1012 3. The method according to claim 1, wherein the IEM comprises physiologically compatible chelate comprising at least one organic chelating agent, cyclic or acyclic, complexed with one or more metal ions with atomic numbers 13, 21-34, 39-42 , 44-50 or 57-83. 4. The method according to claim 3, wherein the metal ion is a paramagnetic metal ion with atomic numbers 21-29, 42, 44 or 57-83. The method according to claim 4, wherein the paramagnetic metal ion is selected from the group consisting of Gd (III), Fe (III), Mn (II), Mn (III), Cr (III), Cu (II), Dy (III), Tb (III), Ho (III), Er (III) and Eu (III). 6. The method according to claim 5, wherein the metal ion is Gd (III). The method according to claim 5, wherein the chelating agent is selected from the group consisting of DTPA, DOTA, DTPA-BMA and HP-D03A. The method according to claim 1, wherein the IEM comprises a luminescent metal complex. 9. The method according to claim 1, wherein the IEM comprises a metal particle or iron chelate of Dy, Gd, or Ho. The method according to claim 1, wherein the SDTBM is selected from the group that ÍO12 consists of small molecules and biomolecules. The method according to claim 10, wherein the SDTBM comprises a small molecule comprising at least one aliphatic, alkoxy, alkylthio, alkylcarbonyl, alkylcarbonyloxy, aryl or heterocyclic group having 1 to 60 carbon atoms and optionally, one or more substituents of nitrogen, oxygen, sulfur, halogen, aliphatic amide, ester-sulfonamide, acyl, sulfonate, phosphate, hydroxyl or organometallic. The method according to claim 11, wherein the SDTBM comprises at least one aryl ring. The method according to claim 11, wherein the SDTBM comprises at least two aryl rings. The method according to claim 10, wherein the SDTBM comprises a biomolecule comprising a peptide containing hydrophobic amino acid residues and / or substituents, with or without hydrophobic or hydrophilic terminating groups. 15. The method according to claim 1, wherein the contrast agent exhibits a state-dependent binding affinity for a woven tissue component in plasma, intersytial space, synovial fluid, cerebrospinal fluid, inflammatory fluid, fluid abscess or intracellular space. 16. The method according to claim 1, in P1012 wherein the contrast agent exhibits a state-dependent binding affinity for a protein selected from the group consisting of human serum albumin, fatty acid binding protein, glutathione-S-transferase and lipoproteins. The method according to claim 1, wherein the contrast agent further comprises a portion for prolonging blood half-life (BHEM) which possesses one or more full or partial negative charges in aqueous solution at physiological pH, where the negative charge can not be completely or partially neutralized by the covalent or covalent link coordinated to the IEM. 18. The method according to claim 17, wherein the contrast agent exhibits a state-dependent binding affinity for human serum albumin. The method according to claim 18, wherein at least 10% of the agent binds to human serum albumin in its native state. The method according to claim 18, wherein at least 50% of the agent binds to human serum albumin, in its native state. The method according to claim 18, wherein at least 80% of the agent binds to the human serum albumin in its native state. 22. The method according to claim 18, in P1012 where at least 95% of the agent binds to serum, human albumin in its native state. The method according to claim 18, wherein the contrast agent exhibits the binding affinity for human serum albumin in its denatured state which is less than about 80% of the binding affinity of the contrast agent for human serum albumin in its native state. The method according to claim 18, wherein the contrast agent exhibits a binding affinity for human serum albumin in its denatured state which is less than about 50% of the binding affinity of the contrast agent for human serum albumin in its native state. The method according to claim 18, wherein the contrast agent exhibits a binding affinity for human serum albumin in its denatured state which is less than about 20% of the binding affinity of the contrast agent for human serum albumin in its native state. The method according to claim 18, wherein the contrast agent exhibits a binding affinity for human serum albumin in its denatured state which is less than about 10% of the binding affinity of the contrast agent for serum albumin P1012 human in its native state. The method according to claims 1 or 18, wherein the contrast agent exhibits a relaxivity of Ri when it is attached to the tissue or tissue component in its denatured state which is less than about 80% of the relaxivity R_ . of the contrast agent when it is attached to the tissue tissue component in its native state. The method according to claims 1 or 18, wherein the contrast agent exhibits a relaxivity of Ri when it is attached to the tissue or tissue component in its denatured state which is less than about 50% of the relaxation capacity Rx of the contrast agent when it is attached to the tissue tissue component in its native state. The method according to claims 1 or 18, wherein the contrast agent exhibits a relaxivity of R ± when it is attached to the tissue or tissue component in its denatured state which is less than about 20% of the relaxivity R_. of the contrast agent when it is attached to the tissue or tissue component in its native state. 30. The method according to claims 1 or 18, wherein the contrast agent exhibits a relaxivity of Ri when it is bound to the tissue or component of P1012 tissue in its denatured state which is less than about 10% of the relaxivity Ri of the contrast agent when bound to the tissue tissue component in its native state. 31. The method according to claims 1 or 18, wherein the contrast agent exhibits a relaxivity of Ri. When the intervention therapy is complete and the tissue or woven component returns to physiological conditions, which is less than approximately 80% of the relaxation capacity Ri of the contrast agent when it is attached to the woven or woven component in its native state. 32. The method according to claims 1 or 18, wherein the contrast agent exhibits a relaxivity of Ri. When the intervention therapy is complete and the tissue or tissue component returns to physiological conditions, which is less than about 50. % of the relaxation capacity R_. of the contrast agent when it joins the woven fabric component in its native state. The method according to claims 1 or 18, wherein the contrast agent exhibits a Rx relaxivity when the intervention therapy is complete and the tissue or tissue component is returned to physiological conditions that is less than about 20. P1012% of the relaxation capacity Ri of the contrast agent when it binds to the woven or woven component in its native state. 34. The method according to claims 1 or 18, wherein the contrast agent exhibits a relaxivity of Rl r when the intervention therapy is complete and the woven or woven component returns to physiological conditions, which is less than about 10% of the Rx relaxation capacity of the contrast agent when it joins the woven or woven component in its native state. 35. A method for imaging enhanced contrast imaging, of a specific tissue or tissue component that is undergoing or has undergone intervention therapy, comprising the steps of: (a) administering to a patient a contrast agent that has one of the following formulas: MS-315 P1012 WS-323 MS-325 P1012 MS-326 MS-327 MS-328 P1012 P1012 wherein n can be from 1 to 4, and R comprises an aliphatic group and / or at least one aryl ring; (b) subjecting the patient to imaging by MRI, ultraviolet light, visible light or infrared light; Y (c) monitoring a signal characteristic of the imaging of the contrast agent to determine if intervention therapy is complete. P1012