Synthesis of trimethylammoniumphenylthio-substituted phthalocyanines with different pattern of substitution

Conjugatable water-soluble Pt(II) and Pd(II) porphyrin complexes: novel nano- and molecular probes for optical oxygen tension measurement in tissue engineering

Measurement of oxygen tension in compressed collagen sheets was performed using matrix-embedded optical oxygen sensors based on platinum(II) and palladium(II) porphyrins supported on polyacrylamide nanoparticles. Bespoke, fully water-soluble, mono-functionalised Pt(II) and Pd(II) porphyrin complexes designed for conjugation under mild conditions were obtained using microwave-assisted metallation. The new sensors display a linear response (1/τ vs. O2) to varying oxygen tension over a biologically relevant range (7.0 × 10(-4) to 2.7 × 10(-1) mM) in aqueous solutions; a behaviour that is maintained following conjugation to polyacrylamide nanoparticles, and following embedding of the nanosensors in compressed collagen sheets, paving the way to innovative approaches for real-time resolution of oxygen gradients throughout 3D matrices useful for tissue regeneration.

Synthesis of water-soluble cobalt and zinc phthalocyanines with cationic substituents

Hexadecasubstituted CoPc and ZnPc containing different number of N-methylpyridiniumoxy groups and chlorine atoms were synthesized. It was shown that increasing number of cationic groups leads both to increased solubility of complexes in dipolar aprotic organic solvents and in water, and to increased contribution of monomeric form in aggregation equilibrium in water up full disaggregation.

Synthesis of tetra(tricarbethoxy)- and tetra(dicarboxy)- substituted soluble phthalocyanines

Pd (II), Co (II), Cu (II) and Zn (II) phthalocyanines with a tricarbethoxyethyl substituent on each benzo group were prepared from 4-(1,1,2-tricarbethoxyethyl)-phthalonitrile and the corresponding divalent metal salt at 170°C. Transesterification occurred when the reaction was carried out in pentanol. Treatment of the palladium complex with sodium ethoxide at room temperature and further acidification resulted with tetra(1,2-dicarboxyethyl)phthalocyaninatopal-ladium. Its UV-vis spectrum in aqueous solution indicated dimeric and monomeric species at pH ≈ 12, but at pH ≈ 6 only the dimeric form were present.

Synthesis, characterization and spectroscopic properties of new fluorescent 7,8-dihexyloxy-3-(4-oxyphenyl)coumarin substituted phthalocyanines

The synthesis of metal-free and metallophthalocyanines ( M = Zn , Co ) obtained from 7,8-dihexyloxy-3-[p-(3',4'-dicyanophenoxy)phenyl]coumarin are described. The newly prepared compounds have been characterized by elemental analysis, IR, NMR, mass and UV-vis spectral data. Their electronic absorption and fluorescence spectral properties are reported. Cyclic voltammetry of the compounds have also been studied. In situ spectroelectrochemistry of the Co(II) complex in THF and DCM is included to identify the difference in its redox behavior, as compared with other complexes.

Zinc tetranitrophthalocyanine: isomer separation and photophysical photobiological evaluation in J774A tumor cells

The synthesis of zinc tetranitrophthalocyanine ( T 4 NO 2 ZnPc ) was carried out and two structural isomers ( C 2v and C s) were separated by column chromatography and characterized by 400 MHz proton nuclear resonance spectroscopy and absorption spectroscopy. The photophysical and photobiological parameters for isomers C 2v and C s were determined in solution and in the presence of macrophage cell culture (J774A). The results obtained clearly indicated that the photophysical, photochemical and photobiological properties of the two isomers were different and each isomer showed a different biological behavior.

Syntheses and properties of trimethylaminophenoxy-substituted Zn((II))-phthalocyanines

The syntheses, photophysical properties and in vitro biological behavior of a series of nine Zn((II))-phthalocyanines (ZnPcs) bearing one to eight positively-charged trimethylaminophenoxy groups are reported. All ZnPcs are highly soluble in polar organic solvents, and show fluorescence and singlet oxygen quantum yields in the ranges 0.11-0.21 and 0.16-0.47, respectively. The cytotoxicity of the ZnPcs depends on both the number of charges and their site of substitution (α vs. β) on the Pc isoindole units; the most promising for PDT application are the α-substituted di-cationic ZnPcs 6a and 17a.

Quaternary ammonium zinc phthalocyanine: inhibiting telomerase by stabilizing G quadruplexes and inducing G-quadruplex structure transition and formation

Water-soluble, octacationic zinc phthalocyanine (ZnPc) was found to be a very good G-quadruplex DNA stabilizer by using UV-melting studies and DNA polymerase stop assays, and a potent telomerase inhibitor by using the telomeric repeat amplification protocol (TRAP) assay. The compound's DNA-binding properties were also studied by surface plasmon resonance (SPR). Furthermore, CD experiments demonstrated that ZnPc could induce intramolecular G-quadruplex structure transition from the antiparallel to parallel form. More importantly, ZnPc was found to induce parallel structure formation in cation-deficient conditions. The stability of the induced structure was determined with CD melting assays.

Photodynamic therapy in the treatment of microbial infections: basic principles and perspective applications

BACKGROUND AND OBJECTIVES

Photodynamic therapy (PDT) appears to be endowed with several favorable features for the treatment of infections originated by microbial pathogens, including a broad spectrum of action, the efficient inactivation of antibiotic-resistant strains, the low mutagenic potential, and the lack of selection of photoresistant microbial cells. Therefore, intensive studies are being pursued in order to define the scope and field of application of this approach.

RESULTS

Optimal cytocidal activity against a large variety of bacterial, fungal, and protozoan pathogens has been found to be typical of photosensitizers that are positively charged at physiological pH values (e.g., for the presence of quaternarized amino groups or the association with polylysine moieties) and are characterized by a moderate hydrophobicity (n-octanol/water partition coefficient around 10). These photosensitizers in a micromolar concentration can induce a >4-5 log decrease in the microbial population after incubation times as short as 5-10 minutes and irradiation under mild experimental conditions, such as fluence-rates around 50 mW/cm2 and irradiation times shorter than 15 minutes.

CONCLUSIONS

PDT appears to represent an efficacious alternative modality for the treatment of localized microbial infections through the in situ application of the photosensitizer followed by irradiation of the photosensitizer-loaded infected area. Proposed clinical fields of interest of antimicrobial PDT include the treatment of chronic ulcers, infected burns, acne vulgaris, and a variety of oral infections.