zn(ii)-phthalocyanine and Hemolysis

Poly(l-lactide)-b-poly(ethylene oxide) block copolymer (mPEG-b-PLLA) micelles were fabricated and applied as a new biodegradable and biocompatible nanocarrier for solubilization of hydrophobic zinc (II) phthalocyanine (ZnPc). The nanocarrier demonstrated a good colloidal stability and its in vitro sustained cargo release profile was assessed. Photobleaching of ZnPc, both in its native form and encapsulated in the obtained polymeric micelles, was studied by means of spectroscopic measurements. The photodynamic reaction (PDR) protocol for cyto- and photocytotoxicity was performed on metastatic melanoma cells (Me45), normal human keratinocytes (HaCaT) being used for comparison. The intracellular accumulation of free and encapsulated ZnPc was visualized at various time periods (1, 3 and 24h). The proapoptotic potential of the encapsulated phthalocyanine was evaluated by monitoring DNA double strand break damage fragmentation (TUNEL assay) and caspase 3/7 activity. In addition, in vitro biocompatibility studies were conducted by determining hemolytic activity of Zn-Pc-loaded mPEG-b-PLLA micelles and their lack of cytotoxicity against macrophages (P388/D1) and endothelial cells (HUV-EC-C). Our results suggest that the PDR using Zn-Pc-loaded mPEG-b-PLLA micelles can be effective in inhibiting tumor cell growth and apoptosis induction with higher responses, observed for Me45 cells. Additionally, the ZnPc-loaded micelles appear to be hemato-biocompatible and safe for normal keratinocytes, macrophages and endothelial cells.

Topics: Animals; Apoptosis; Biocompatible Materials; Caspase 3; Caspase 7; Cell Line; Cell Survival; DNA Breaks, Double-Stranded; Drug Carriers; Dynamic Light Scattering; Hemolysis; Humans; Indoles; Isoindoles; Lactates; Mice; Micelles; Microscopy, Atomic Force; Microscopy, Confocal; Nanostructures; Organometallic Compounds; Particle Size; Photochemotherapy; Photosensitizing Agents; Polyethylene Glycols; Zinc Compounds

The present work reports the synthesis, photophysical and photochemical characterization and photodynamic evaluation of zinc, aluminum and metal free-base tetracarboxy-phthalocyanines (ZnPc, AlPc and FbPc, respectively). To evaluate the possible application of phthalocyanines as a potential photosensitizer the photophysical and photochemical characterization were performed using aqueous (phosphate-buffered solution, PBS) and organic (dimethyl sulfoxide, DMSO) solvents. The relative lipophilicity of the compounds was estimated by the octanol-water partition coefficient and the photodynamic activity evaluated through the photooxidation of a protein and photohemolysis. The photooxidation rate constants (k) were obtained and the hemolytic potential was evaluated by the maximum percentage of hemolysis achieved (Hmax) and the time (t50) to reach 50% of the Hmax. Although these phthalocyanines are all hydrophilic and possess very low affinity for membranes (log PO/W=-2.0), they led to significant photooxidation of bovine serum albumin (BSA) and photohemolysis. Our results show that ZnPc was the most efficient photosensitizer, followed by AlPc and FbPc; this order is the same as the order of the triplet and singlet oxygen quantum yields (ZnPc>AlPc>FbPc). Furthermore, together, the triplet, fluorescence and singlet oxygen quantum yields of zinc tetracarboxy-phthalocyanines suggest their potential for use in theranostic applications, which simultaneously combines photodiagnosis and phototherapy.

Topics: Animals; Cattle; Dimethyl Sulfoxide; Erythrocyte Membrane; Hemolysis; Humans; Hydrophobic and Hydrophilic Interactions; Indoles; Isoindoles; Light; Models, Molecular; Organometallic Compounds; Oxidation-Reduction; Photolysis; Photosensitizing Agents; Serum Albumin, Bovine; Singlet Oxygen; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Water; Zinc Compounds

Combination therapies for cancer aim to exploit either additive or synergistic effects arising from the action of two species with the final goal to maximize the therapeutic efficacy. In this work, we develop multifunctional nanoparticles (NPs) for co-delivery of the conventional anticancer drug docetaxel (DTX) and the second generation photosensitizer zinc-phthalocyanine (ZnPc) as potential dual carrier system for the combination of chemotherapy and photodynamic therapy (PDT). Biodegradable and amphiphilic block copolymers based on poly(ε-caprolactone) (PCL=B) and poly(ethylene oxide) (PEO=A), with AB and ABA architectures, were assembled in "core-shell" NPs and loaded with both DTX and ZnPc employing the melting/sonication method. Hydrodynamic diameters within the range 60-100nm and low polydispersity indexes were obtained. Zeta potential was negative for all the formulations and unaffected by drug encapsulation. Concerning drug loading ability of NPs, the entrapment efficiency was related to initial ZnPc/DTX ratio. Steady-stationary and time-resolved emission fluorescence measurements pointed out the embedding of monomeric ZnPc in the NPs, excluding the presence of ZnPc self-supramolecular oligomers. The release of DTX was biphasic whereas ZnPc remained mainly associated with NPs. Singlet oxygen generation was observed when ZnPc-loaded NPs were irradiated at 610nm within a 45min time range, despite that ZnPc was not released in the medium. Stability of NPs in the presence of serum proteins and plasma was excellent and no toxicity toward red blood cells was found. NPs cytotoxicity was evaluated in HeLa cells irradiated for 30min with a halogen lamp. After 72h, viability of cells treated with ZnPc/DTX-loaded NPs strongly decreased as compared to NPs loaded only with DTX, thus showing a combined effect of both DTX and ZnPc. Superior antitumor activity of ZnPc/DTX-loaded NPs as compared to DTX-loaded NPs was confirmed in an animal model of orthotopic amelanotic melanoma, thus pointing to the application of PEO-PCL NPs in the combined chemo-photodynamic therapy of cancer.

Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Line, Tumor; Cell Survival; Docetaxel; Drug Carriers; Drug Stability; Female; Hemolysis; Humans; Indoles; Isoindoles; Melanoma, Amelanotic; Mice; Mice, Nude; Nanoparticles; Organometallic Compounds; Photochemotherapy; Photosensitizing Agents; Plasma; Singlet Oxygen; Skin Neoplasms; Taxoids; Tumor Burden; Zinc Compounds

The photodynamic inactivation (PDI) of Escherichia coli and Streptococcus mitis sensitized by cationic phthalocyanines was studied in different media containing blood derivatives. First, the activity of zinc(II) tetramethyltetrapyridino[3,4-b:3',4'-g:3'',4''-l:3''',4'''-q]porphyrazinium (ZnAPc4+), zinc(II) 2,9,16,23-tetrakis[4-(N-methylpyridyloxy)]phthalocyanine (ZnPPc4+) and zinc(II) 2,9,16,23-tetrakis[2-(N,N,N-trimethylamino)ethoxy]phthalocyanine (ZnEPc4+) were compared to photoinactivate these bacteria in saline solutions. After visible light irradiation, a higher photoinactivation of E. coli cells was found for ZnPPc4+, while ZnEPc4+ was the more effective sensitizer to eradicate S. mitis cells. In the presence of human red blood (HRB) cells, two aspects were analyzed: the photohemolysis induced by these cationic phthalocyanines and the PDI of bacteria in medium containing erythrocytes. The highest photohemolytic damage was produced by ZnPPc4+, which can be avoided using azida ion as photoprotective quencher. In both bacteria, the photoinactivation is possible in presence of HRB cells. Mainly, ZnEPc4+ is effective to photoinactivate S. mitis with a low hemolysis of erythrocytes. However, inactivation of E. coli by ZnPPc4+ decreases in medium with HRB cells, further when azide ion is added to avoid hemolysis. The presence of plasma considerable reduces the photocytotoxic effect, which mainly affects the eradication of E. coli. However, the PDI of S. mitis by ZnEPc4+ is even possible in presence of blood derivatives.

Topics: Blood; Erythrocytes; Escherichia coli; Hemolysis; Humans; Indoles; Isoindoles; Organometallic Compounds; Phosphates; Photosensitizing Agents; Sodium Chloride; Streptococcus mitis; Wound Infection; Zinc Compounds

The synergistic effect of ultrasound (US) and chemicals on cells is known as sonodynamic therapy. In this work, two phthalocyanines (zinc and chloroaluminum) have been tested as potential sonosensitizers for sonodynamic therapy. We studied the effect of US and phthalocyanines on carp erythrocytes, as a nucleated cell model. The level of hemolysis, osmotic fragility, lipid peroxidation and oxidation of hemoglobin were the markers of these reactions. Red blood cells were preincubated with phthalocyanines and exposed to 1 MHz continuous wave at the intensity of 2.44 W/cm2 for 5 min. It was noticed that US and phthalocyanines exposure led to an increase in the level of hemolysis, lipid peroxidation product and osmotic fragility in comparison to US alone and phthalocyanines alone. However, these factors did not cause changes in the degree of hemoglobin oxidation. The results lead to the conclusion that phthalocyanines caused synergistic effect with US, and it can be used as a sonosensitizer for sonodynamic therapy, but the mechanism of this action is still unclear.

Topics: Animals; Carps; Cells, Cultured; Combined Modality Therapy; Erythroblasts; Hemolysis; Indoles; Isoindoles; Lipid Peroxidation; Methemoglobin; Models, Animal; Organometallic Compounds; Osmotic Fragility; Photosensitizing Agents; Ultrasonic Therapy; Zinc Compounds

Two octa-substituted phthalocyanines, namely 1,4,8,11,15,18,22,25-octakis(decyl)phthalocyaninato zinc(II) (ZnODPc) and 1,4,8,11,15,18,22,25-octakis(pentyl)phthalocyaninato zinc(II) (ZnOPPc), were investigated for their use in photodynamic therapy (PDT) after topical application. Both substances exhibited favourable properties as photosensitisers in vitro: absorption maxima around 700 nm with absorption coefficients of about 190000 (M(-1) cm(-1)), a singlet oxygen quantum yield of 0.47 +/- 0.02 (ZnODPc), and good accumulation in keratinocytes and fibroblasts. Cell death after phthalocyanine-photosensitisation appeared to occur mainly via apoptosis. The in vivo experiments demonstrated a good accumulation of the phthalocyanines after topical application in a tetrahydrofuran-azone formulation onto the dorsal skin of Balb/c mice: [(4.6-4.7) +/- 1.0]% of deposited dye could be recovered after 3 h from deposition. ZnODPc showed significantly better skin-photosensitising properties than ZnOPPc and is therefore a potential candidate for the treatment of psoriasis.

Topics: 3T3 Cells; Administration, Topical; Animals; Apoptosis; Caspase 3; Caspases; Cell Survival; Erythrocytes; Female; Fibroblasts; Hemolysis; Humans; Indoles; Isoindoles; Keratinocytes; Mice; Mice, Inbred BALB C; Organometallic Compounds; Photochemotherapy; Photosensitizing Agents; Singlet Oxygen; Skin; Spectrophotometry; Zinc Compounds