Investigating the efficiency of novel metallo-phthalocyanine PDT-induced cell death in MCF-7 breast cancer cells

Ru(II) CONTAINING PHOTOSENSITIZERS FOR PHOTODYNAMIC THERAPY: A CRITIQUE ON REPORTING AND AN ATTEMPT TO COMPARE EFFICACY

Ruthenium(II)-based coordination complexes have emerged as photosensitizers (PSs) for photodynamic therapy (PDT) in oncology as well as antimicrobial indications and have great potential. Their modular architectures that integrate multiple ligands can be exploited to tune cellular uptake and subcellular targeting, solubility, light absorption, and other photophysical properties. A wide range of Ru(II) containing compounds have been reported as PSs for PDT or as photochemotherapy (PCT) agents. Many studies employ a common scaffold that is subject to systematic variation in one or two ligands to elucidate the impact of these modifications on the photophysical and photobiological performance. Studies that probe the excited state energies and dynamics within these molecules are of fundamental interest and are used to design next-generation systems. However, a comparison of the PDT efficacy between Ru(II) containing PSs and 1st or 2nd generation PSs, already in clinical use or preclinical/clinical studies, is rare. Even comparisons between Ru(II) containing molecular structures are difficult, given the wide range of excitation wavelengths, power densities, and cell lines utilized. Despite this gap, PDT dose metrics quantifying a PS's efficacy are available to perform qualitative comparisons. Such models are independent of excitation wavelength and are based on common outcome parameters, such as the photon density absorbed by the Ru(II) compound to cause 50% cell kill (LD50) based on the previously established threshold model. In this focused photophysical review, we identified all published studies on Ru(II) containing PSs since 2005 that reported the required photophysical, light treatment, and in vitro outcome data to permit the application of the Photodynamic Threshold Model to quantify their potential efficacy. The resulting LD50 values range from less than 1013 to above 1020 [hν cm-3], indicating a wide range in PDT efficacy and required optical energy density for ultimate clinical translation.

Evaluation of cell damage induced by irradiated Zinc-Phthalocyanine-gold dendrimeric nanoparticles in a breast cancer cell line

BACKGROUND

Cancer is a non-communicable disease that occurs following a mutation in the genes which control cell growth. Breast cancer is the most diagnosed cancer among South African women and a major cause of cancer-related deaths worldwide. Photodynamic therapy (PDT) is an alternative cancer therapy that uses photochemotherapeutic agents, known as photosensitizers. Drug-delivery nanoparticles are commonly used in nanomedicine to enhance drug-therapeutic efficiency. This study evaluated the photodynamic effects following treatment with 0.3 μM multiple particles delivery complex (MPDC) and irradiated with a laser fluence of 10 J/cm2 using a 680 nm diode laser in a breast cancer cell line (MCF-7).

METHODS

Cell damage was assessed by inverted light microscopy for cell morphology; the Apoptox-Glo triple assay was used for cell viability, caspase activity and identification of cytodamage markers; flow cytometric analysis for cell death pathways and mitochondrial membrane potential; the enzyme linked immunosorbent assay (ELISA) for cytochrome C release; and real-time reverse transcriptase polymerase chain reaction (RT-PCR) array for gene expression.

RESULTS

Laser activated-MPDC induced a significant change in morphology of PDT-treated cells, with the appearance of apoptotic like morphological features. An increase in cytotoxicity, caspase activity, cell depolarization and cytochrome C release were identified in PDT-treated cells. Finally, the upregulation of BAX, BCL-2, CASP-2 and ULK-1 genes was observed.

CONCLUSION

The MPDC yielded a successful and stable hybrid agent with potent photodynamic abilities.

Phototoxic effect of aluminium-chlorine and aluminium-hydroxide phthalocyanines on Leishmania (l.) amazonensis

This study investigated the activity of photosensitive phthalocyanines on promastigotes and amastigotes of Leishmania (L.) amazonensis. Aluminum phthalocyanine chloride (AlPcCl), Aluminum phthalocyanine hydroxide (AlPcOH) and zinc phthalocyanine (PcZn) were tested in the presence (matte red LED, potency of 2.5-2.3 μW for 30 min) and absence of light against L. amazonensis promastigotes and the parasite viability was evaluated after 24, 48 and 72 h. The amastigote forms were treated with AlPcCl and AlPcOH, following the same lighting protocols described for the promastigote forms, being evaluated after 24 h. Cytotoxicity to human erythrocytes and peritoneal macrophages was also evaluated. The results showed that AlPcCl and AlPcOH in the presence of light have antileishmania activity, with leishmanistatic effects on promastigotes and amastigotes of L. amazonensis, without causing cytotoxicity to peritoneal macrophages and erythrocytes. The concentrations that inhibited 50% of the promastigote forms after 24 h of light exposure were 0.21 ± 0.08 μM for AlPcCl and 0.23 ± 0.06 μM for AlPcOH. In 48 h and 72 h after the treatment, the IC₅₀ of AlPcCl was 0.13 ± 0.02 and 0.12 ± 0.03 μM and for AlPcOH was 0.14 ± 0.01 μM and 0.11 ± 0.01 μM, respectively. PcZn showed no activity on promastigotes of L. amazonensis. This study showed a substantial photodynamic activity of the phthalocyanines AlPcCl and AlPcOH against intracellular amastigotes forms of L. amazonensis after irradiation, presenting IC₅₀ values of 0.62 ± 0.06 μM and 0.92 ± 0.12 μM, respectively. These results support the possibility of using photodynamic therapy for the treatment of cutaneous leishmaniasis.

Photophysical and photochemical properties of novel peripherally triethyleneoxysulfanyl substituted monomeric and Si–Si bonded dimeric silicon phthalocyanines

Monomeric and Si–Si bonded dimeric silicon(IV) phthalocyanines bearing 4[Formula: see text],7[Formula: see text],10[Formula: see text]-trioxaundecylsulfanyl groups were synthesized. These novel phthalocyanine derivatives were characterized by general analysis methods such as FT-IR, MALDI-TOF or HRMS, 1H NMR and UV-vis electronic absorption. Their aggregation behaviors were described in dimethyl sulfoxide (DMSO). In addition, the photophysical and photochemical properties of these phthalocyanines were also investigated in DMSO to determine potential of these phthalocyanines to acts as photosensitizer for photodynamic therapy (PDT) of cancer. Their high singlet oxygen generation demonstrated their suitability for PDT applications. These peripherally 4[Formula: see text],7[Formula: see text],10[Formula: see text]-trioxaundecylsulfanyl substituted silicon(IV) phthalocyanines are promising Type II photosensitizers owing to their favorable singlet oxygen generation capability. In addition, their fluorescence quenching behavior by 1,4-benzoquinone were also studied in DMSO.

Novel type ketone-substituted metallophthalocyanines: synthesis, spectral, structural, computational and anticancer studies

This work reports on the synthesis and characterization of phthalocyanines (M = Cu(ii) (2), Zn(ii) (3) In(iii) (4) and Co(ii) (5)) peripherally tetra-substituted with 1-(4-hydroxyphenyl)propan-1-one.

Cyanines in photodynamic reaction assisted by reversible electroporation--in vitro study on human breast carcinoma cells

BACKGROUND

Ineffective drug delivery is a vast problem of anticancer therapies. The aim of this study was to investigate the possibility of enhancement of cyanines transport through the cell membrane by electroporation and to evaluate a photodynamic activity of these compounds.

METHODS

We evaluated in vitro the effectiveness of photodynamic reaction with cyanines on breast adenocarcinoma cells (MCF-7/WT) and normal Chinese hamster ovary cells (CHO) lacking voltage-dependent ion channels, alone and combined with electropermeabilization. Among six cyanines tested, two compounds could be indicated as good therapeutic candidates: IR-775 and IR-786. Cellular effects were assessed with MTT assay reporting cell mitochondrial activity and with SRB assay based on the measurement of cellular protein content. Cyanines localization was observed with confocal microscope.

RESULTS

Photodynamic reaction of MCF-7/WT cells with IR-775 and IR-786 did not result in cellular dysfunction. Electric field intensities and pulse duration, non-toxic for cells, significantly increased photocytotoxicity of the cyanines after electropermeabilization with IR-775 and IR-786. Much shorter exposure times were efficient for cyanines in photodynamic reaction assisted by electroporation (10 min instead of 24h).

CONCLUSIONS

Our results indicate that electroporation of cancerous cells in the presence of cyanine dyes could increase the uptake of the photosensitizer, which correlates with a higher cytotoxicity in the breast adenocarcinoma cell line. Electroporation may be an attractive delivery system for photosensitizers in photodynamic therapy, enabling application of new compounds and reduction of drug dose and exposure time.