Hydroxyaluminum Phthalocyanine Research Articles

Efficacy of photodynamic therapy in an experimental mice tuberculosis model

The objective: to study the efficacy of antimicrobial photodynamic therapy (APDT) using hydroxyaluminum phthalocyanine (Photosens) as a photosensitizer in the experimental model of tuberculosis infection in mice.Subjects and Methods. Balb/cmice were infected with the multiple drug resistant (MDR) strain of M. tuberculosis Beijing BO/W148. APDT with hydroxyaluminum phthalocyanine and red laser light exposure were started on Day 45. A total of 4 sessions of APDT on the projection of both lungs, liver and spleen were performed. On Day 60, the therapeutic eff ect of APDTwas assessed by evaluation of severity of mycobacterial load and specific granulomatous infiltration in the lungs, liver and spleen. The absorption of light energy of laser radiation by the chest and abdominal walls, as well as tissues of lungs, liver and spleen was determined by photometry using afluovisor.Results. The tissues of the experimental animal retain a significant amount of light energy, however, the residual value of light transmission is sufficient to provide a pronounced therapeutic effect which manifests itself as a significant decrease of mycobacterial load and specific inflammatory process in all the studied internal organs.Conclusion. APDT may be an effective tool to treat some forms of tuberculous infection including those caused by M. tuberculosis with MDR.

Prion Strains Differ in Susceptibility to Photodynamic Oxidation.

Prion disorders, or transmissible spongiform encephalophaties (TSE), are fatal neurodegenerative diseases affecting mammals. Prion-infectious particles comprise of misfolded pathological prion proteins (PrPTSE). Different TSEs are associated with distinct PrPTSE folds called prion strains. The high resistance of prions to conventional sterilization increases the risk of prion transmission in medical, veterinary and food industry practices. Recently, we have demonstrated the ability of disulfonated hydroxyaluminum phthalocyanine to photodynamically inactivate mouse RML prions by generated singlet oxygen. Herein, we studied the efficiency of three phthalocyanine derivatives in photodynamic treatment of seven mouse adapted prion strains originating from sheep, human, and cow species. We report the different susceptibilities of the strains to photodynamic oxidative elimination of PrPTSE epitopes: RML, A139, Fu-1 > mBSE, mvCJD > ME7, 22L. The efficiency of the phthalocyanine derivatives in the epitope elimination also differed (AlPcOH(SO3)2 > ZnPc(SO3)1-3 > SiPc(OH)2(SO3)1-3) and was not correlated to the yields of generated singlet oxygen. Our data suggest that the structural properties of both the phthalocyanine and the PrPTSE strain may affect the effectiveness of the photodynamic prion inactivation. Our finding provides a new option for the discrimination of prion strains and highlights the necessity of utilizing range of prion strains when validating the photodynamic prion decontamination procedures.

Liposomal Composition Based on Hydroxyaluminum Phthalocyanine and Gold Nanoparticles for Combined Photodynamic and Photothermal Therapy

Liposomal Composition Based on Hydroxyaluminum Phthalocyanine and Gold Nanoparticles for Combined Photodynamic and Photothermal Therapy

Optimization of the photodynamic inactivation of prions by a phthalocyanine photosensitizer: The crucial involvement of singlet oxygen.

Prion disorders are fatal neurodegenerative diseases caused by the autocatalytic conversion of a natively occurring prion protein (PrPC ) into its misfolded infectious form (PrPTSE ). The proven resistance of PrPTSE to common disinfection procedures increases the risk of prion transmission in medical settings. Herein, we present the effective photodynamic inactivation (PDI) of prions by disulfonated hydroxyaluminum phthalocyanine (AlPcOH(SO3 )2 ) utilizing two custom-built red light sources. The treatment eliminates PrPTSE signal in infectious mouse brain homogenate with efficiency that depends on light intensity but has a low effect on the overall protein content. Importantly, singlet oxygen (O2 (1 Δg )) is the only species significantly photogenerated by AlPcOH(SO3 )2 , and it is responsible for the PDI of prions. More intensive light conditions show not only higher O2 (1 Δg ) production but also decreases in AlPcOH(SO3 )2 photostability. Our findings suggest that PDI by AlPcOH(SO3 )2 -generated O2 (1 Δg ) represents a promising approach for prion inactivation that may be useful in future decontamination strategies for delicate medical tools.

Effects of nanoparticles of hydroxy-aluminum phthalocyanine on markers of liver injury and glucose metabolism in diabetic mice.

Photodynamic therapy, by reducing pain and inflammation and promoting the proliferation of healthy cells, can be used to treat recurrent lesions, such as diabetic foot ulcers. Studies using the photosensitizer phthalocyanine, together with the nanostructured copolymeric matrix of Pluronic® and Carbopol® for the treatment of diabetic foot ulcers and leishmaniosis lesions, are showing promising outcomes. Despite their topical or subcutaneous administration, these molecules are absorbed and their systemic effects are unknown. Therefore, we investigated the effect of the subcutaneous administration of the hydroxy-aluminum phthalocyanine hydrogel without illumination on systemic parameters, markers of liver injury, and liver energy metabolism in type 1 diabetic Swiss mice. Both the hydrogel and the different doses of phthalocyanine changed the levels of injury markers and the liver glucose release, sometimes aggravating the alterations caused by the diabetic condition itself. However, the dose of 2.23 µg/mL caused less marked plasmatic and metabolic changes and did not change glucose tolerance or insulin sensitivity of the diabetic mice. These results are indicative that the use of hydroxy-aluminum phthalocyanine hydrogel for the treatment of cutaneous ulcers in diabetic patients is systemically safe.

Enhancement of photo-bactericidal effect of tetrasulfonated hydroxyaluminum phthalocyanine on Pseudomonas aeruginosa.

At the present time, photodynamic inactivation (PDI) is receiving considerable interest for its potential as an antimicrobial therapy. The results of our study indicate that enhancement of the phototoxic effect on Pseudomonas aeruginosa can be achieved by combination of tetrasulfonated hydroxyaluminum phthalocyanine (AlPcS4) and bimetallic gold/silver nanoparticles (Au/Ag-NPs) synthesized by the cell-free filtrate of Aureobasidium pullulans. The bimetallic nanoparticles were characterized by a number of techniques including UV-vis, XPS, TEM, and SEM-EDS to be 14±3nm spherical particles coated with proteins. The effect of diode lasers with the peak-power wavelength ʎ=650nm (output power of 10 and 40mW; radiation intensity of 26 and 105mW/cm2) in combination with the AlPcS4 and the bimetallic nanoparticles mixture on the viability of P. aeruginosa rods was shown. Particularly high efficiency of killing bacterial cells was obtained for the light intensity of 105mW/cm2, after 20, 30, and 40min of irradiation corresponding to 126, 189, and 252J/cm2 energy fluences. For AlPcS4+Au/Ag-NPs treatment, the viable count reduction were equal to 99.90, 99.96, and 99.975%, respectively. These results were significantly better than those accomplished for irradiated separated assays of AlPcS4 and Au/Ag-NPs.

Tetra(3,4-pyrido)porphyrazines Caught in the Cationic Cage: Toward Nanomolar Active Photosensitizers.

Investigation of a series of tetra(3,4-pyrido)porphyrazines (TPyPzs) substituted with hydrophilic substituents revealed important structure-activity relationships for their use in photodynamic therapy (PDT). Among them, a cationic TPyPz derivative with total of 12 cationic charges above, below and in the plane of the core featured a unique spatial arrangement that caught the hydrophobic core in a cage, thereby protecting it fully from aggregation in water. This derivative exhibited exceptionally effective photodynamic activity on a number of tumor cell lines (HeLa, SK-MEL-28, A549, MCF-7) with effective concentrations (EC50) typically below 5 nM, at least an order of magnitude better than the EC50 values obtained for the clinically approved photosensitizers verteporfin, temoporfin, protoporphyrin IX, and trisulfonated hydroxyaluminum phthalocyanine. Its very low dark toxicity (TC50 > 400 μM) and high ability to induce photodamage to endothelial cells (EA.hy926) without preincubation suggest the high potential of this cationic TPyPz derivative in vascular-targeted PDT.

P-0036 - Experimental Topical Photodynamic Therapy of Tongue and Colon Carcinoma

Background: Photodynamic therapy (PDT) is an experimental strategy for cancer, typically used for superficial tumors. PDT induces selective cell death of neoplastic tissue and connecting vasculature by combining photosensitizers with light. Preclinical studies of topical administration of hydroxy-aluminum phthalocyanine (AlOH-PC) entrapped in liposomes against tongue and colon carcinoma are presented.

Preparation and characterization of aluminum phthalocyanine acetate, propionate, and benzoate

Aluminum phthalocyanine acetate, propionate and benzoate were prepared by the reaction of hydroxy aluminum phthalocyanine and the corresponding acetic, propionic, and benzoic anhydrides. The reaction products were characterized by 1H and 13C NMR spectroscopy and mass spectrometry. The thermal behavior of the products was determined by thermal analysis of particular samples.

Reactive oxygen species produced by irradiation of some phthalocyanine derivatives

A comparative study of the reliability of methods used for the determination of singlet oxygen was carried out. The water iodide method, as well as the methods using 9,10-dimethylanthracene (DMA) and 1,3-diphenylisobenzofuran (DPIBF) in dimethylformamide (DMF) solutions, was used for the detection of singlet oxygen 1O 2 production in eight phthalocyanine photosensitizers. The iodide method is not only selective for the determination of 1O 2 but can also be used for the determination of other oxygen species. In addition, the results of the iodide method are affected by a possible formation of phthalocyanine dimers and by post-irradiation reactions. On the other hand, both the methods using indicators in DMF are highly selective for the determination of 1O 2. The quantum yield of the singlet oxygen production was determined for eight phthalocyanine derivatives; the following sequence was obtained: 5 ∼ 4 > 7 ∼ 2 ∼ 8 (standard) > 6 > 3 ∼ 1, where 5 represents the ammonium salt of disulphonated zinc phthalocyanine, 4 sulphonated zinc phthalocyanine [(3-diethylammonium)-propylsulphonamide] citrate, 7 tetrakis(trimethylammonium)zinc phthalocyanine tetraiodide, 2 tetrakis( N-methylpyridinium-3-oxy)zinc phthalocyanine tetraiodide, 8 zinc phthalocyanine, 6 sodium salt of disulphonated aluminum phthalocyanine, 3 sulphonated aluminum phthalocyanine [( N-2-hydroxyethyl)aminoethylsulphonamide] and 1 tetra-methylenepyridinium chloride of hydroxyaluminum phthalocyanine.

Photodynamic Therapy of Human Colorectal Carcinoma Cell Line

Colorectal cancer is one of the most common cancers in Europe and North America and it is the most common gastrointestinal carcinoma. The population in the Czech Republic has a higher incidence of colorectal carcinoma compared to other countries. Efforts are underway to develop better screening strategies and novel therapies to improve patient survival rates. Despite all efforts, colorectal cancer remains one of the leading causes of death from cancer. Photodynamic therapy (PDT) is an established modality for the treatment of various diseases. The PDT procedure involves the administration of a photosensitizer followed by illumination. The anti-tumor effects result from direct killing of malignant cells, shutting down of the tumor's vasculature, and the promotion of an immune response. In our experiment, we examined the effects of phototherapy with disulfonated hydroxyaluminum phthalocyanine (Al(OH)S2Pc) on the growth of colorectal carcinoma cells, in an effort to offer a new treatment modality for patients with this disease.

Photoelectrochemical behavior of a hydroxyaluminum phthalocyanine polyvinylpyridine–iodine electrode

A complex of poly-4-vinylpyridine with iodine is formed when a thin film of the polymer is immersed in a I/I− redox couple solution. A hydroxyaluminum phthalocyanine photoelectrochemical cell presents short-circuit current up to 107.3 μA cm−2 for a conversion efficiency of 0.035% when the organic film is coated with the polymer layer in an iodine/iodide electrolyte. This improvement is assigned to the contribution of the complex itself and to the decrease in the series resistance of the cell.

A new form of hydroxyaluminum phthalocyanine by acid treatment. Characterization and photoactivity

A new polymorph of hydroxyaluminum phthalocyanine (PcAlOH) was obtained when PcAlOH thin film was exposed to aqueous acid solutions. The new polymorph, which is characterized by infrared, near-infrared, and visible absorption spectrometry and X-ray diffractometry, shows enhanced photoactivity in a photoelectrochemical solar cell device.

Spectral Cosensitization in Phthalocyanine‐Porphyrin Photoelectrochemical Cells

An organic multilayer photoelectrochemical cell was fabricated by sequential vacuum deposition of hydroxyaluminum phthalocyanine (PcAlOH) and hydroxyaluminum tetraphenylporphyrin (TPPAlOH). Absorption and action spectra of the cell cover the entire visible spectrum up to 900 nm. In the reverse deposition sequence, only photoelectrochemical cell with very thin organic layers showed a sensitization effect. The cosensitization effects are probably due to the porosity of the organic thin films, allowing the contact of the electrolyte with each semiconductor.

Improvement of the Performance of a Hydroxyaluminum Phthalocyanine Photoelectrochemical Cell by a Phthalic Acid Treatment

Effects of a phthalic acid treatment on the performance of hydroxyaluminum phthalocyanine photoelectrochemical cells have been investigated. thin films have been prepared by vacuum deposition on tin oxide substrates. The acid treatment induces a dimorphic transformation of the α‐form to a new polymorph absorbing on a larger range (550–900 nm). Photoelectrochemical studies with BQ/HQ and redox couples showed that the phthalic acid treatment improved strongly the performance of cells.

Cellules photoélectrochimiques de phtalocyanine d'hydroxyaluminium déposées par rotation

The spin-coating technique was used to produce hydroxyaluminum phthalocyanine (PcAlOH) photoelectrochemical cells. The spectral and electrical behavior of NESA/PcAlOH/BQ/HQ/Pt cells is studied and comparisons are made with cells based upon sublimed PcAlOH films. Due to the weak solubility of PcAlOH in volatile organic solvents, the DMSO used in the spin-coating method seems to be trapped in the solid film, and leads to a decrease in the photoelectrochemical cell efficiency. Studies on the influence of the counter-electrode showed that a vanadium counter-electrode gave higher values of Jsc, Voc, and η than a platinum one, but corrision phenomena were observed in that case.

A New Polymorph of Hydroxyaluminum Phthalocyanine. Characterization and Photoactivity

Abstract Sublimed films of α-form hydroxyaluminum phthalocyanine (α-PcAlOH) can be transformed into a novel polymorph by a treatment with aqueous acid solutions. The spectroscopic characterization of the new polymorph, showing its particular visible and IR spectra and X-ray diffraction pattern was achieved by comparing with other polymorphs. The dimorphic transformation of PcAlOH is also associated with a dramatic enhancement in photoactivity as shown in the performance of a photoelectrochemical cell based upon a PcAlOH/redox junction.