Phthalocyanine Chloride Research Articles

The Effect of the Indium(III) Phthalocyanine Chloride Films on the Behavior of Flexible Devices of Flat and Disperse Heterojunction

By means of flat-heterojunction structures based on small semiconductor molecules (MSCs), an analysis of the indium(III) phthalocyanine chloride (In(III)PcCl) film as a constituent of optoelectronic devices was performed. The study included the behavior of In(III)PcCl playing three different roles: a donor species, an electronic acceptor, and a hole layer carrier. The flat-heterojunction structures were prepared by vacuum deposition method that permits a controlled layer-by-layer growth of high purity films. The investigated structures were characterized by scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), UV-vis spectroscopy and optical bandgaps were obtained by Tauc’s and Cody’s methods. As the structures exhibit a large spectral absorption in the visible range, they were incorporated into flat-heterojunction devices based on flexible and rigid substrates. However, during the synthesis of those structures, the disperse heterojunction arrangement was found and indeed it showed to be more efficient than the initial flat-heterojunction. In order to complement these results, disperse heterojunction arrangement structure as well as its bandgap value were obtained by DFT calculations. Finally, the electronic behavior of both fabricated devices, disperse heterojunction and flat-heterojunction were compared.

Aluminum chloride phthalocyanine in MCF-7: Rationally accounting for state of aggregation of photosensitizers inside cells

Current limited understanding of the intracellular self-aggregation process of several photosensitizers is one of the obstacles in the progress of Photodynamic Therapy (PDT) as a clinically viable option to photomodulate the biological responses. This is further intensified by the higher in vitro experimental complexity as compared to the experiments carried out in simple solution. This study describes the monomer(photoactive)/aggregate(non-active) equilibrium of aluminum chloride phthalocyanine (AlClPc) within the human breast adenocarcinoma cell line, MCF-7. Steady-state fluorescence and fluorescence lifetime imaging microscopy demonstrated that there was an upper limit of the amount of monomeric AlClPc inside cells, which might be influenced by the high water content inside the biological tissue. In this process, high AlClPc concentrations triggered the aggregation process while lowering its monomeric active form. The monomer/aggregates equilibrium can be modulated even inside cell typically through cell replication process, which decreases the AlClPc content inside each cellular unit. The results underline the need for new strategies in order to enhance the AlClPc monomerization within cells, especially in key organelles for PDT including mitochondria and lysosome membrane. This study demonstrates a rational approach for the study of the state of aggregation of photosensitizers inside cells, which is a critical issue to be considered for PDT efficacy.

EXPERIMENTAL STUDY OF THE NEUROTOXIC EFFECTS OF PHOTODYNAMIC THERAPY ON THE SPINAL CORD

ABSTRACT Objective To evaluate the effects of photodynamic therapy (PDT) on the dura mater using the photosensitizers aluminum chloride phthalocyanine and methylene blue in in vivo assays. Methods Fifty-six male Wistar rats were divided into two groups; one submitted to PDT and the other submitted to the photosensitizers without their photoactivation (control). The photosensitizers were applied to the dura mater after laminectomy at the T10 level. The methods used for assessment were the Basso, Beattie and Bresnahan (BBB) functional evaluation scale and study of the dura mater by light microscopy. Results No changes in motor activity were observed in the animals submitted to PDT compared to control. Histological and pathological evaluation did not show any differences between the group exposed to activated photosensitizers and the control group with regard to the inflammatory process and tissue necrosis. Conclusion The joint use of PDT with the photosensitizing pharmaceuticals aluminum chloride phthalocyanine and methylene blue did not induce any clinical neurotoxic effects or histological changes in the dura mater of the animals studied. Level de evidence V; Expert Opnion.

Photodynamic inactivation of Candida albicans and Candida tropicalis with aluminum phthalocyanine chloride nanoemulsion

The in vitro susceptibilities of Candida albicans and Candida tropicalis to Antimicrobial Photodynamic Treatment with aluminum phthalocyanine chloride in nanoemulsion (ClAlPc/NE) were investigated. PS concentration- and fluence-dependent cell survival after APDT were compared before and after unbound extracellular PS had been washed out. The PS uptake and its subcellular localization were also determined. Exposure to light in the absence of the PS and treatment with the PS in the absence of light did not kill the fungi. APDT with ClAlPc/NE resulted in a reduction of five orders of magnitude in viability for C. albicans and between four and five orders of magnitude for C. tropicalis. Washing the cells to remove unbound PS before light exposure did not impair fungal inactivation, suggesting that cell photosensitization was mainly carried out by cell bound ClAlPc. The degree of ClAlPc uptake was dependent on its concentration. Internalization of ClAlPc by C. albicans and C. tropicalis was confirmed by confocal fluorescence microscopy that showed the PS does not penetrate the nucleus and instead accumulates in specific regions of the cytoplasm. Our results show that incorporating the water-insoluble ClAlPc into a nanoemulsion leads to an efficient formulation capable of photoinactivating both Candida species.

Effect of dose responses of hydrophilic aluminium (III) phthalocyanine chloride tetrasulphonate based photosensitizer on lung cancer cells

Photodynamic therapy (PDT) is a promising approach for the treatment of different types of cancer and has been brought into focus for its synergy, compatibility, repeatability, relatively inexpensive cost and it's typically more efficacious nature. Photosensitizers (PSs) play a major role in PDT and are the core of this specific therapy. Al (III) Phthalocyanine Chloride Tetra sulfonic Acid (AlPcS4Cl) PS is an aromatic macrocyclic metal-based compound that is synthetically derived. It aids in deep tissue penetration due to its far red light activation wavelength, low photo bleaching, increased quantum yields and stability. Lung cancer is a leading cause of cancer related deaths worldwide accounting for approximately 1 in 5 of all cancer-related deaths. In this study, we explored the photochemical properties of AlPcS4Cl, its uptake into lung cancer, the intracellular localization and photodynamic action on lung cancer (A549 cells). Results indicated that AlPcS4Cl is a stable PS that localizes in intracellular organelles including the mitochondrion and lysosomes. PDT using AlPcS4Cl indicated an increase in cell death and decrease in cell proliferation and viability. AlPcS4Cl showed to be effective in treating lung cancer in vitro, however the resulting PDT efficacy will finally depend on the biological features such as tumour vasculature and tumour specific accumulation when used as a clinical application. It is noted that PDT can be considered as an adjunct therapy until standard protocols for various tumour types along with a relevant PS has been validated.

Organic nanostructure sensing layer developed by AAO template for the application in humidity sensors

The present study demonstrates a novel nanoporous structure of aluminium 1,8,15,22-tetrakis 29H,31H phthalocyanine chloride (AlPcCl) prepared by template-assisted method for a humidity sensor. The nanoporous sensing layer was fabricated by solution wetting of anodic aluminium oxide template. The solutions of AlPcCl in different concentrations were spun cast over the template at various speeds. Both capacitive and resistive responses were measured as a function of different relative humidity levels. The sensor showed wide operating relative humidity range and responded at quite low humidity levels. Morphological changes were investigated by field emission scanning electron microscopy. The sensor showed wide operating relative humidity range. The sensor demonstrated better performance with improved sensing parameters, highlighting unique advantages of the low-molecular nanostructured sensing layer for the humidity sensors.

Double Ring‐Expanding Carbonylation Using an In Situ Generated Aluminum Phthalocyanine Cobalt Carbonyl Complex

AbstractThe ring‐expanding carbonylation of epoxides provides an efficient one‐step procedure for synthesizing β‐lactones and succinic anhydride derivatives. Although porphyrin‐based catalysts generally show excellent catalytic activities in the ring‐expanding carbonylation of epoxides, the application of porphyrin catalysts is limited owing to the low yield and high cost of preparing porphyrins. This study aims to propose a new and highly efficient catalytic system for the carbonylation of propylene oxide (PO) using an in situ generated active catalyst from cost‐effective and readily available aluminum phthalocyanine chloride (AlPcCl) and dicobalt octacarbonyl (Co2(CO)8). The catalyst showed not only excellent catalytic activities of single carbonylation but also double carbonylation resulting in anhydride by judicious choice of reaction parameters, such as reaction temperature and the ratio of PO to catalyst. This is the first report on the use of an in situ generated catalyst for the one‐pot double carbonylation of epoxide to anhydride.

{CpFeII(CO)2SnII(Macrocycle•3-)} Radicals with Intrinsic Charge Transfer from CpFe(CO)2 to Macrocycles (Cp: Cp or Cp*); Effective Magnetic Coupling between Radical Trianionic Macrocycles•3.

Neutral {CpFeII(CO)2[SnII(Pc•3–)]} {Cp is cyclopentadienyl (1, 2) or Cp* is pentamethylcyclopentadienyl (3); Pc: phthalocyanine}, {Cp*FeII(CO)2[SnII(Nc•3–)]} (4, Nc: naphthalocyanine), and {CpFeII(CO)2[SnII(TPP•3–)]} (5, TPP: tetraphenylporphyrin) complexes in which CpFeII(CO)2 fragments (Cp: Cp or Cp*) are coordinated to SnII(macrocycle•3–) have been obtained. The product complexes were obtained at the reaction of charge transfer from CpFeI(CO)2 (Cp: Cp or Cp*) to [SnII(macrocycle2−)] to form the diamagnetic FeII and paramagnetic radical trianionic macrocycles. As a result, these formally neutral complexes contain S = 1/2 spins delocalized over the macrocycles. This provides alternation of the C–Nimine or C–Cmeso bonds in the macrocycles, the appearance of new bands in the near-infrared spectra of the complexes, and blue shift of both Soret and Q-bands. The {CpFeII(CO)2SnII(macrocycle•3–)} units (Cp: Cp or Cp*, macrocycle: Pc or Nc) form closely packed π-stacking dimers in 1 and 3 or one-dimensional chains in 2 and 4 with effective π–π interaction between the macrocycles. Such packing allows strong antiferromagnetic coupling between S = 1/2 spins. Magnetic interaction can be described well by the Heisenberg model for the isolated dimers in 1 and 3 with exchange interaction J/kB = −78 and −85 K, respectively. Magnetic behavior of 2 and 4 is described well by the model that includes contributions from an antiferromagnetically coupled S = 1/2 dimer (Jintra) and a Heisenberg S = 1/2 chain with alternating antiferromagnetic spin exchange between the neighbors (Jinter). Compound 2 demonstrates large intradimer interaction of Jintra/kB = −54 K and essentially weaker interdimer exchange interactions of Jinter/kB = −6 K, whereas compound 4 shows strong magnetic coupling of spins within the dimers (Jintra/kB = −170 K) as well as between the dimers (Jinter/kB = −40 K). Compound {CpFeII(CO)2[SnII(TPP•3–)]} (5) shows no π–π interactions between the porphyrin macrocycles, and magnetic coupling is weak in this case (Weiss temperature is −5 K). Preparation of a similar complex with indium(III) chloride phthalocyanine yields {CpFe(CO)2[In(Pc2–)]} (6). In this complex, indium(III) atoms are reduced instead of the phthalocyanine macrocycles that explains electron paramagnetic resonance silence of 6 in the 4–295 K range.

Synthesis and Antifungal Activity of 3-substituted 5-ferrocenyl-1H-pyrazoles

A convenient method for the selective synthesis of functionalized 3-substituted 5-ferrocenyl-1 H -pyrazoles has been developed. Condensation reaction of α,β-unsaturated ferrocenyl ketones and tosylhydrazine in the presence of catalytic amount of iron(III) phthalocyanine chloride allowed to obtain nine new 3-substituted 5-ferrocenyl-1 H -pyrazoles. The synthesized products were evaluated for their antifungal activity against Gibberella nicotiancola , Fusarium oxysporum f. sp. niveum , and Gibberella saubinetii . Most of the compounds exhibited excellent antifungal activity.

Thermal and electrical characterization of indium phthalocyanine chloride bulk structure

Metallic phthalocyanines (M-Pcs) have superior structure, electrical and optical properties. Therefore, M-Pcs can be used as alternatives to traditional semiconductors. In the present work, indium phthalocyanine chloride (ClInPc) is compressed to form a bulk structure (pellet). The prepared ClInPc pellet is characterized by differential scanning Calorimetry (DSC), and impedance spectroscopy in the frequency range of 0.15–100 kHz and at different temperatures (293–393 K). The DSC analysis of the ClInPc shows only one order phase transition at 196 °C. Additionally, the impedance spectroscopy reveals that the capacitance, dissipation factor, dielectric constant, and ac electrical conductivity of the ClInPc are temperature and frequency dependent. The ClInPc also exhibits a high capacitance of order 2–12 nF. Further, the dielectric constant of such material increases by increasing the temperature which involves the distribution of relaxation times. Furthermore, the AC conductivity follows Jonscher’s universal power law σac = AωS. The temperature dependent exponents S and m also outweigh the correlated barrier hopping (CBH) model for conduction mechanism.

Nanosystem Integrated with Photosensitizer and Novel Targeting Chemotherapy Agent for Gastric Cancer Chemo-Photodynamic Combined Therapy.

The poor cell membrane penetration ability of photosensitizers resulted in the limited antitumor effect, thereby hampered their potential in clinical translation. The high toxic side effect and multidrug resistance of chemotherapeutic agents during in clinical chemical therapy should be resolved. Nanosystem integrated with photosensitizer and novel targeting chemotherapy agent may be an effective strategy for overcoming clinical or preclinical drawbacks of monotherapy and enhancing therapeutic effect. Therefore, a nanosized micelle F127 integrated with Apogossypolone (ApoG2) and Al(III) phthalocyanine chloride tetrasulfonic acid (AlPcS4) (referred as F127-ApoG2@AlPcS4) was synthesized to induce the cell death quickly for reducing the risk of resistance and enhancing gastric cancer therapeutic efficiency by combining AlPcS4/photodynamic therapy and ApoG2/chemotherapy. Hydrophobic of ApoG2 and hydrophilic of AlPcS4 self-assembled into this micelle to formation of core-shell structure based on the amphiphilic character of F127 micelle. The reactive oxygen species-dependent mitochondria membrane permeability was improved effectively because of reactive oxygen species generation of ApoG2, thereby resulting in a considerable amount of AlPcS4 and ApoG2 entering the mitochondrial. The AlPcS4 binding site was altered from the cytoplasm to the cell nucleus at higher concentration because of the existence of ApoG2. With irradiation, ApoG2 and AlPcS4 showed effective synergistic anti-tumor effect through inducing apoptosis due to singlet oxygen production regulated mainly by AlPcS4, reactive oxygen species accumulation and calcium overload regulated mainly by ApoG2. Intranuclear AlPcS4 caused cell death through necrosis. The apoptosis induced by AlPcS4 was earlier than ApoG2. In summary, F127-ApoG2@AlPcS4 quickly induced a long-lasting apoptosis that led to cell death, which could be a promising nanosized reagent for gastric cancer therapy based on chemo-photodynamic combined therapy.

Photophysical properties of pyridyloxy phthalocyanine encapsulated in nanoparticles

Two aluminum chloride phthalocyanines with pyridyloxy substitution at α/β positions were synthesized. Their structures were characterized by infrared spectroscopy, proton nuclear magnetic resonance as well as elemental analysis. Tetra-α(β)-(2-pyridyloxy) aluminum chloride phthalocyanines were encapsulated into a diblock copolymer methoxy-poly(ethylene glycol)-block-poly(L-lysine) through a cosolvent method. The morphologies and photophysical properties of phthalocyanines encapsulated in nanoparticles were studied by transmission electron microscope, ultraviolet-visible, and fluorescence spectroscopic methods. The photophysical properties of phthalocyanines encapsulated into nanoparticles exhibited substitution positions dependence. The phthalocyanines with substitution at α positions were found to be an excellent candidate for use as photosensitizers for treatment of cancer by photodynamic therapy.

Comparison of the synergistic anticancer activity of AlPcS4 photodynamic therapy in combination with different low‑dose chemotherapeutic agents on gastric cancer cells.

Limited cellular delivery and internalization efficiency of Al(III) phthalocyanine chloride tetrasulfonic acid (AlPcS4) induce poor penetration ability in cells and a slight photodynamic therapy (PDT) effect on gastric cancer. The combination treatment of AlPcS4/PDT with low-dose chemotherapeutic agents may provide a promising treatment strategy to increase the weak delivery efficiency of AlPcS4, reducing the dose of chemical agents without reducing efficacy, and improving apoptosis-inducing abilities, thereby increasing the antitumor effects and decreasing the noxious side effects on gastric cancer. We investigated and compared the synergistic antitumor growth effect on gastric cancer cells by combining AlPcS4/PDT treatment with different low-dose chemotherapeutic agents, namely, 5-fluorouracil (5-FU), doxorubicin (DOX), cisplatin (CDDP), mitomycin C (MMC), and vincristine (VCR). The inhibitory effect was increased in treatments that combined AlPcS4/PDT with all the aforementioned low-dose chemotherapeutic agents, to a different extent. An evident synergistic effect was obtained in the combination treatment of AlPcS4/PDT with low-dose 5-FU, DOX, and MMC by increasing AlPcS4 intracellular uptake ability, improving apoptosis-inducing abilities, and prolonging apoptosis-inducing time. The low-dose chemotherapeutic agents prolonged the apoptosis-inducing period of AlPcS4/PDT, and AlPcS4/PDT quickly improved apoptosis-inducing abilities of chemotherapy even at low doses. Generally, the combination treatment of AlPcS4/PDT with low-dose chemotherapeutic agents had significant antitumor growth effects in addition to a low dark-cytotoxicity effect on gastric cancer, thereby representing an effective and feasible therapy method for gastric cancer.

Evaluation of aluminum phthalocyanine chloride and DNA interactions for the design of an advanced drug delivery system in photodynamic therapy

The aim of this study was to evaluate the interaction of aluminum phthalocyanine chloride (AlClPc) with double-stranded DNA. Absorption and fluorescence spectra, resonance light scattering, and circular dichroism were evaluated in water and water/ethanol mixtures with different concentrations of DNA or AlClPc. AlClPc showed a high ability to bind to DNA in both water and 4/6 water/ethanol mixture (v/v), with a majority of monomeric and aggregated initial forms of AlClPc, respectively. In this interaction, AlClPc bound preferentially to the grooves of DNA. The monomeric/aggregate state of AlClPc in DNA was dependent on the AlClPc/DNA ratio. At low concentrations of AlClPc, the interaction of AlClPc with few DNA sites caused a curvature in the DNA structure that provided a favorable environment for the intercalation of AlClPc aggregates. Increase in AlClPc concentration induced interactions with a high number of binding sites on DNA, which prevented bending and therefore aggregation of AlClPc molecules throughout the double-stranded DNA. These results are relevant to the understanding of the behavior and interaction of AlClPc with double-stranded DNA in the design of novel drug delivery systems for clinical application in photodynamic therapy as a new approach to treat skin or oral cancer, scars, or wound healing.

Enhancing integration of articular cartilage grafts via photochemical bonding.

The integration of osteochondral grafts to native articular cartilage is critical as the lack of graft integration may lead to continued tissue degradation, poor load transfer and inadequate nutrient transport. Photochemical bonding promotes graft integration by activating a photosensitizer at the interface via a light source and avoids negative effects associated with other bonding techniques. We hypothesized that the bond strength depends on photosensitizer type and concentration in addition to light exposure. Photochemical bonding was evaluated using methylene blue (MB), a cationic phenothiazine photosensitizer, and two phthalocyanine photosensitizers, Al(III) phthalocyanine chloride tetrasulfonic acid (CASPc) and aluminum phthalocyanine chloride (AlPc). Exposure was altered by varying irradiation time for a fixed irradiance or by varying irradiance with a fixed irradiation time. MB was ineffective at producing bonding at the range of concentrations tested while CASPc produced a peak twofold bond strength increase over controls. AlPc produced substantial bonding at all concentrations with a peak 3.9-fold bond strength increase over controls. Parametric tests revealed that bond strength depended primarily on the total energy delivered to the bonding site rather than the rate of light delivery or light irradiance. Bond strength persisted for 1 week of in-vitro culture, which warrants further exploration for clinical applications. These studies indicate that photochemical bonding is a viable strategy for enhancing articular cartilage graft integration. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2406-2415, 2018.

Diagnostic and control of linear and nonlinear optical effects in selected self-assembled metallophthalocyanine chlorides nanostructures

In this paper we described a new self-assembly phenomenon of the metallophthalocyanine chlorides nanostructures and its influence on the linear optical properties as well as the Second Harmonic Generation process. The self-assembly phenomenon were achieved through an annealing process carried out immediately after the deposition process. The studied nanostructures were subjected to the annealing process for 24 h and the temperature of the process was equal to 525 K. We discussed experimental results and theoretical calculations of structural, linear and nonolinear optical properties for aluminum and gallium phthalocyanine chlorides. The linear and second-order nonlinear optical properties for these compounds were investigated at microscopic and macroscopic levels. The electric dipole moments and dispersion-free first hyperpolarizabilities were determined by quantum chemical calculations based on Density Functional Theory. Ab-initio quantum mechanical calculations (time-dependent Hartree-Fock method) for the studied metallophthalocyanine chlorides were carried out to compute the frequency-dependent first hyperpolarizabilities and second-order susceptibilities at the wavelengths used in SHG measurements. Our results shed light on the linear and nonlinear optical properties of the nanostructures. The results showed that second harmonic signal is strong and polarized, and this polarizing effect was achieved by controlling the arrangement of the molecules inside the formed nanostructures. Our results also reveal potential application of the nanostructures not only for nonlinear optics but also for thermal sensor devices.

Self-Assembly of the Nonplanar Fe(III) Phthalocyanine Small-Molecule: Unraveling the Impact on the Magnetic Properties of Organic Nanowires

In this article we show for the first time the formation of magnetic supported organic nanowires (ONWs) driven by self-assembly of a nonplanar Fe(III) phthalocyanine chloride (FePcCl) molecule. The ONWs grow by a crystallization mechanism on roughness-tailored substrates. The growth methodology consists of a vapor deposition under low vacuum and mild temperature conditions. The structure, microstructure, and chemical composition of the FePcCl NWs are thoroughly elucidated and compared with those of Fe(II) phthalocyanine NWs by a consistent and complementary combination of advanced electron microscopies and X-ray spectroscopies. In a further step, we vertically align the NWs by conformal deposition of a SiO2 shell. Such orientation is critical to analyze the magnetic properties of the FePcCl and FePc supported NWs. A ferromagnetic behavior below 30 K with an easy axis perpendicular to the phthalocyanine plane was observed in the two cases with the FePcCl nanowires presenting a wider hysteresis. These resul...

NIRF/PA/CT multi-modality imaging guided combined photothermal and photodynamic therapy based on tumor microenvironment-responsive nanocomposites.

In this study, we developed a novel chitosan (CS)-controlled and aluminum phthalocyanine chloride (AlPc)-loaded molybdenum disulfide (MoS2) nanocomposite as a single nanoplatform (AlPc-MoS2@SiO2-CS) for near-infrared fluorescence (NIRF), photoacoustic (PA), and X-ray computed tomography (CT) multi-modality imaging-guided photothermal and photodynamic combination therapy of tumors. The MoS2 nanodot was used as the PA/CT contrast as well as hyperthermal agent. The MoS2@SiO2 nanoparticles prepared by a facile one-pot approach can serve as drug-delivery vehicles to transport the NIR absorbing photosensitizer AlPc within the mesoporous cavities. Meanwhile, a natural cationic polysaccharide, CS, was introduced as a gatekeeper to avoid the premature release of loaded AlPc. What's more, CS as a tumor microenvironment-responsive agent can control the release of loaded drugs to the acidic local environment in the tumor. The in vivo multimodal imaging uncovered that the AlPc-MoS2@SiO2-CS nanocomposites showed enhanced tumor uptake and diagnosis abilities after intravenous injection. More importantly, the nanocomposites exhibited an evident near-infrared induced photothermal effect in the in vitro and in vivo experiments, which remarkably improved the photodynamic therapy efficiency by accelerating the blood flow and subsequently increasing oxygen supply in the tumor. Taken together, our current work demonstrated a nanoplatform for multimodal imaging guided targeted dual-therapy, which revealed a potential strategy for tumor treatment.

Simple and Selective HPLC-UV/Vis Bioanalytical Method to Determine Aluminum Phthalocyanine Chloride in Skin Permeation Studies.

Considering the feasibility of the aluminum phthalocyanine chloride (AlPcCl) application in the topical photodynamic therapy of cutaneous tumors and the lack of HPLC methods capable of supporting skin permeation experiments using this compound, the aim of this study was to obtain a simple and selective chromatographic method for AlPcCl determination in skin matrices. A HPLC-UV/Vis method was developed using a normal-phase column operating at 30°C, an isocratic mobile phase of methanol : phosphoric acid (0.01 M) at 1.5 mL/min, and detection at 670 nm. The method exhibited (i) selectivity against various contaminants found in the different skin layers, (ii) high drug extraction capacity from the hair follicle (>70%) and remaining skin (>80%), and (iii) low limits of detection and of quantification (0.03 and 0.09 μg/mL, resp.). The method was also linear in the range from 0.1 to 5.0 µg/mL (r = 0.9994) and demonstrated robustness with regard to experimental chromatographic parameters according to a factorial design. Lastly, the developed method was successfully tested in in vitro skin permeation studies of AlPcCl, proving its effectiveness in the development of pharmaceutical delivery systems containing this drug for topical photodynamic therapy of skin cancers.

Solvent Effect, Photochemical and Photophysical Properties of Phthalocyanines with Different Metallic Nuclei

Photophysical and photochemical properties of lithium phthalocyanine ( 1 ), gallium(III) phthalocyanine chloride ( 2 ), titanium(IV) phthalocyanine dichloride ( 3 ) and iron(II) phthalocyanine ( 4 ) were investigated in dimethyl sulfoxide (DMSO), tetrahydrofuran (THF) and DMSO-THF mixtures. The influence of the central metal on these properties was analyzed according to solvent type, axial ligands and their paramagnetic and diamagnetic effect. Fluorescence lifetimes were recorded using a time correlated single photon counting setup (TCSPC) technique. In order to demonstrate the generation of reactive oxygen species under light irradiation, the indirect method (applying 1,3-diphenylisobenzofuran (DPBF) as chemical suppressor) and the direct method (analyzing the phosphorescence decay curves of singlete oxygen at 1270 nm) were employed. Compounds 1 , 2 and 3 showed a monomeric behavior in all media while compound 4 presented low aggregation in DMSO, but a very pronounced aggregation behavior in THF. Steady-state fluorescence anisotropy was compared with emission spectra and complex 4 presented values beyond the expected limits. DOI: http://dx.doi.org/10.17807/orbital.v9i5.1047