A. Water Exchange 2326 B. Proton Exchange 2327 C. Electronic Relaxation 2327 D. Relaxivity 2331 E. Outerand Second-Sphere Relaxivity 2334 F. Methods of Improving Relaxivity 2336 V. Macromolecular Conjugates 2336 A. Introduction 2336 B. General Conjugation Methods 2336 C. Synthetic Linear Polymers 2336 D. Synthetic Dendrimer-Based Agents 2338 E. Naturally Occurring Polymers (Proteins, Polysaccharides, and Nucleic Acids) 2339

https://mriquestions.com/uploads/3/4/5/7/34572113/lauffer_1999_review.pdf

Gadolinium(III) Chelates as MRI Contrast Agents: Structure, Dynamics, and Applications

Anion recognition chemistry has grown from its beginnings in the late 1960s with positively charged ammonium cryptand receptors for halide binding to, at the end of the millennium, a plethora of charged and neutral, cyclic and acyclic, inorganic and organic supramolecular host systems for the selective complexation, detection, and separation of anionic guest species. Solvation effects and pH values have been shown to play crucial roles in the overall anion recognition process. More recent developments include exciting advances in anion-templated syntheses and directed self-assembly, ion-pair recognition, and the function of anions in supramolecular catalysis.

Anion Recognition and Sensing: The State of the Art and Future Perspectives

Fluorogenic and chromogenic chemosensors and reagents for anions.

http://nathan.instras.com/MyDocsDB/doc-557.pdf

Photosensitized singlet oxygen and its applications

A coated implantable medical device 10 includes a structure 12 adapted for introduction into the vascular system, esophagus, trachea, colon, biliary tract, or urinary tract; at least one layer 18 of a bioactive material positioned over the structure 12; and at least one porous layer 20 positioned over the bioactive material layer 18. Preferably, the structure 12 is a coronary stent, and the bioactive material is at least one of heparin, dexamethasone or a dexamethasone derivative. The device 10 includes layers 18 and 22 of heparin and dexamethasone, the layer 22 of dexamethasone being positioned above the layer 18 of heparin. The layers of bioactive material also can be individual materials or a combination of different materials. Unexpectedly, the more soluble heparin markedly promotes the release of the less soluble dexamethasone above it. The porous layer 20 is composed of a polymer applied by vapor or plasma deposition and provides a controlled release of the bioactive material. It is particularly preferred that the polymer is a polyimide, parylene or a parylene derivative, which is deposited without solvents, heat or catalysts, merely by condensation of a monomer vapor.

Coated implantable medical device

Texaphyrins are provided for use as radiation sensitizers. Advantageous properties of texaphyrins for use as a radiation sensitizer include: i) a low redox potential which allows radiation-induced hydrated electrons to flow to texaphyrin rather than neutralizing hydroxyl radicals, allowing hydroxyl radicals to cause cellular damage, ii) a relatively stable texaphyrin radical that reacts readily to covalently modify neighboring molecules causing further cellular damage, iii) intrinsic biolocalization, and iv) indifference to the presence or absence of O 2 . These properties allow texaphyrins to be particularly effective for treating the hypoxic areas of solid neoplasms. Methods of treatment for an individual having a neoplasm or atheroma include the use of a texaphyrin as a radiation sensitizer and as an agent for photodynamic tumor therapy, or the use of a texaphyrin for internal and for external ionizing radiation. Novel texaphyrins are provided.

Texaphyrin-oligonucleotide conjugates

Texaphyrin metal complexes having improved functionalization include the addition of electron-donating groups to positions 2, 7, 12, 15, 18 and/or 21 and/or the addition of electron-withdrawing groups to positions 15 and/or 18 of the macrocycle. Electron-donating groups at positions 2, 7, 12, 15, 18 and/or 21 contribute electrons to the aromatic π system of the macrocycle which stabilizes the metal complex to demetallation and the imine bonds to hydrolysis. The addition of substituents to the 12 and 21 positions of the macrocycle offer steric protection for the imine bonds against possible in vivo enzyme hydrolysis. Electron-withdrawing groups at positions 15 and/or 18 render the macrocycle more readily reduced, i.e. the redox potential is lower and the macrocycle more readily gains an electron to form a radical. Such texaphyrins having a low redox potential and imine bond stabilization are useful in a variety of applications.

Texaphyrin compounds having improved functionalization

Texaphyrins: Synthesis and Applications

Gadolinium(III) texaphyrin (Gd-tex2+) is representative of a new class of radiation sensitizers detectable by magnetic resonance imaging (MRI). This porphyrin-like complex has a high electron affinity [E1/2 (red.) approximately = -0.08 V versus normal hydrogen electrode] and forms a long-lived pi-radical cation upon exposure to hydrated electrons, reducing ketyl radicals, or superoxide ions. Consistent with these chemical findings, Gd-tex2+ was found to be an efficient radiation sensitizer in studies carried out with HT29 cells in in vitro as well as in in vivo single and multifraction irradiation studies with a murine mammary carcinoma model. Selective localization of Gd-tex2+ in tumors was confirmed by MRI scanning.

https://www.pnas.org/content/pnas/93/13/6610.full.pdf

Gadolinium(III) texaphyrin: a tumor selective radiation sensitizer that is detectable by MRI

The synthesis and characterization of several lanthanide(III) texaphyrin complexes of 4, 5, 9, 24-tetraethyl-16, 17-dimethoxy-10, 23-dimethyl-13, 20, 25, 26, 27-pentaazapentacyclo[20.2.1.1 heptacosa]-1, 3, 5, 7, 9, 11(27),-12, 14, 16, 18, 20, 22(25), 23-tridecaene (2), 4, 5, 9, 24-tetraethyl-16, 17-bis((3-hydroxypropyl)oxy)-10, 23-dimethyl-13, 20, 25, 26, 27-pentaazapentacyclo-[20.2.1.1] heptacosa-1,3, 5, 7, 9, 11(27), 12, 14(19), 15, 17, 20, 22(25),-20, 25, 26, 27-pentaazapentacyclo[20.2.1.1] heptacosa-1,3, 5, 7, 9, 11(27), 12, 14, 16, 18, 20, 22(25), 23-tridecaene (30), respectively, are reported. Single crystals suitable for X-ray diffraction were obtained for the La(III) complex 3, the Gd(III) complexes 9 and 37, the Eu(III) complex 36, and the Lu(III) complex 22, by dissolving the respective complex in MeOH/CHCl[sub 3] and layering with diethyl ether. The five lanthanide(III) texaphyrin complexes all crystallize in the triclinic space group, P[bar 1] (No. 2), with Z = 2. The complexes are characterized by five-coordination from the texaphyrin, a coordinated methanol molecule on one side and at least one symmetrically bidenate NO[sub 3][sup [minus]] ion opposite the methanol. The 10-coordinate La(III) complex 3 has two bidentate NO[sub 3][sup [minus]] ions on the same side of the macrocycle. The europium(III) and gadolinium(III) texaphyrins 36 and 37 are structurally isomorphous and are 9-coordinate species with a bidentatemore » NO[sub 3][sup [minus]] ion and a methanol molecule on the top side of the macrocycle. On the other hand, the lutetium(III) texaphyrin is 8-coordinate with only a single bidentate NO[sub 3][sup [minus]] ion chelated on the [open quotes]top[close quotes] side of complex. In an unusual case of disorder, the gadolinium(III) texaphyrin 9 has both 9- and 10-coordinate species present in the solid state. The geometry of the 9-coordinate species is like that found in 36 and 37, while the 10-coordinate Gd(III) species similar to the La(III) species 3.« less

Tarak D. Mody

Papers

Texaphyrin-oligonucleotide conjugates

Texaphyrin compounds having improved functionalization

Texaphyrins: Synthesis and Applications

Gadolinium(III) texaphyrin: a tumor selective radiation sensitizer that is detectable by MRI

Synthesis and structural characterization of lanthanide(III) texaphyrins