Triplet-state photophysics of aluminium phthalocyanine sensitizer in murine cancer cells

Syntheses and photochemical properties of a tribenzo-naphtho-condensed porphyrazinatozinc complex

The synthesis of a zinc derivative of tribenzonaphthoporphyrazinato ( Zn -tri- PcNc ) obtained from 6-carboxymethyl-2,3-dicyanonaphthalene and phthalonitrile is described. This new phthalocyanine ( Pc ) compound was characterized by 1 H NMR, elemental analyses, IR and UV-vis. The spectroscopic analysis of this compound show an electronic spectrum in DMSO with characteristic bands in the Soret and ϱ region. Steady state and time-resolved spectral analysis revealed a fluorescence quantum yield and a fluorescence lifetime of Φf=0.22 and τf = 2.56 ns respectively, in agreement with other Pc derivatives. This compound also shows a triplet lifetime in air satured solutions of 1.06 μs and a transient with the maximum absortion located at 610 nm, 120 nm shifted to the red compared to the triplet observed by other Pc compounds.

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.

A synthetic approach towards novel octa-substituted zinc(II) phthalocyanines with different solubility and photophysical properties

The synthesis and behavior in homogeneous solutions of 2,3,9,10,16,17,23,24-octakis(3-phthalimidopropyloxy)phthalocyaninatozinc(II) (5) and 2,3,9,10,16,17,23,24-octakis(3-aminopropyloxy)phthalocyaninatozinc(II) (6) are reported.

Photophysicals and photochemicals studies of zinc(II) phthalocyanine in long time circulation micelles for photodynamic therapy use

Long time circulation systems, such as polymeric micelles, represent a growing area in biomedical research. These microparticles can be used in many biological systems to provide appropriate drug levels with a specific biodistribution. Long time circulation micelles (LTCM) were routinely prepared using PEG-5000-DSPE (polyethyleneglycol-5000-distearoil-phosphatidyl-ethanolamine) and zinc(II) phthalocyanine (ZnPc) as a photosensitizer and fluorescent probe. This compound belongs to a second generation of photoactive agents, mainly used in photodynamic therapy (PDT) of neoplasic tissues. Their high selectivity for tumoral target tissues as well as high phototoxicity based on singlet oxygen generation renders the utilization of these compounds feasible as an alternative therapy for cancer treatment. LTCM were characterized by classical spectroscopic techniques. Absorbance measurements indicated that the drug was s completely loaded into LTCM (epsilon = 2.41 x 10(5) cm(-1)). This was also verified by steady state and time-resolved fluorescence measurements. The lifetime profiles of ZnPc decay curves were fitted according to biexponential function (tau1 = 3.9 ns and tau2 = 15.5 ns) indicating different locations for ZnPc into LTCM. The time-resolved spectroscopy measurements for ZnPc triplet excited state lifetimes (tauT) were calculated from the kinetic analysis of transient decays at the absorption maximum (480 nm), by using laser flash photolysis technique. All the spectroscopy measurements performed allowed us to conclude that, ZnPc in LTCM is a promising drug delivery system (DDS) for PDT.

Fluorescence lifetime measurements of disulfonated aluminium phthalocyanine in the presence of microbial cells

The fluorescence lifetimes of disulfonated aluminium phthalocyanine (AlPcS2) in the presence of several different microbial cells are measured using the technique of time correlated single photon counting (TCSPC) employing front-face illumination. The microbes studied are: Escherichia coli, Porphyromonas gingivalis (Gram-negative bacteria), Streptococcus mutans (a Gram-positive bacterium), and the yeast Candida albicans. Complex fluorescence decays are observed when AlPcS2 is in the presence of these microbes; the fluorescence decay data can be fitted to a distribution of exponential lifetimes indicating that the AlPcS2 molecules experience a range of micro-environments The average fluorescence lifetimes of AlPcS2 in the presence of the microbes studied range from 4.85 to 5.95 ns, indicating differences in the cellular localisation of AlPcS2 with each of the microbes studied. These novel data are presented alongside a brief summary of existing AlPcS2 fluorescence lifetime data measured both in solution and in model biological systems.