Dendrimeric Sulfanyl Porphyrazines: Synthesis, Physico-Chemical Characterization, and Biological Activity for Potential Applications in Photodynamic Therapy

Photodynamic Therapy: A Novel Approach for Head and Neck Cancer Treatment with Focusing on Oral Cavity

Oral cancers, specifically oral squamous cell carcinoma (OSCC), pose a significant global health challenge, with high incidence and mortality rates. Conventional treatments such as surgery, radiotherapy, and chemotherapy have limited effectiveness and can result in adverse reactions. However, as an alternative, photodynamic therapy (PDT) has emerged as a promising option for treating oral cancers. PDT involves using photosensitizing agents in conjunction with specific light to target and destroy cancer cells selectively. The photosensitizers accumulate in the cancer cells and generate reactive oxygen species (ROS) upon exposure to the activating light, leading to cellular damage and ultimately cell death. PDT offers several advantages, including its non-invasive nature, absence of known long-term side effects when administered correctly, and cost-effectiveness. It can be employed as a primary treatment for early-stage oral cancers or in combination with other therapies for more advanced cases. Nonetheless, it is important to note that PDT is most effective for superficial or localized cancers and may not be suitable for larger or deeply infiltrating tumors. Light sensitivity and temporary side effects may occur but can be managed with appropriate care. Ongoing research endeavors aim to expand the applications of PDT and develop novel photosensitizers to further enhance its efficacy in oral cancer treatment. This review aims to evaluate the effectiveness of PDT in treating oral cancers by analyzing a combination of preclinical and clinical studies.

Zinc(II) Sulfanyltribenzoporphyrazines with Bulky Peripheral Substituents—Synthesis, Photophysical Characterization, and Potential Photocytotoxicity

The study’s aim was to synthesize new unsymmetrical sulfanyl zinc(II) porphyrazines and subject them to physicochemical and electrochemical characterization and also an initial acute toxicity assessment. The procedure was initiated from a commercially available dimercaptomaleonitrile disodium salt and o-phthalonitrile using Linstead’s macrocyclization reaction conditions, which led to magnesium(II) tribenzoporphyrazine with 4-(3,5-dibutoxycarbonylphenoxy)butylthio substituents. The obtained macrocycle was demetallated with trifluoroacetic acid and subsequently remetallated with zinc(II) acetate toward the zinc(II) porphyrazine derivative. The zinc(II) tribenzoporphyrazine with 4-(3,5-dibutoxycarbonylphenoxy)butylthio substituents was then subjected to the reduction reaction with LiAlH4, yielding zinc(II) tribenzoporphyrazine with 4-[3,5-di(hydroxymethyl)phenoxy]butylthio substituents. The new zinc(II) tribenzoporphyrazines were characterized by UV-Vis spectroscopy, various NMR techniques (1HNMR, 13CNMR, 1H-1H COSY, 1H-13C HSQC, and 1H-13C HMBC), and mass spectrometry. In the UV-Vis spectra, both macrocycles revealed characteristic Soret and Q-bands, whose positions were dependent on the solvent used for the measurements. Zinc(II) tribenzoporphyrazines were studied using electrochemical and photochemical methods, including the singlet oxygen generation assessment. Both zinc(II) porphyrazines revealed high singlet oxygen generation quantum yield values of up to 0.59 in DMSO, which indicates their potential photosensitizing potential for photodynamic therapy. In addition, new derivatives were subjected to a Microtox® bioluminescence assay.

Multi-Functional Liposome: A Powerful Theranostic Nano-Platform Enhancing Photodynamic Therapy

Although photodynamic therapy (PDT) has promising advantages in almost non-invasion, low drug resistance, and low dark toxicity, it still suffers from limitations in the lipophilic nature of most photosensitizers (PSs), short half-life of PS in plasma, poor tissue penetration, and low tumor specificity. To overcome these limitations and enhance PDT, liposomes, as excellent multi-functional nano-carriers for drug delivery, have been extensively studied in multi-functional theranostics, including liposomal PS, targeted drug delivery, controllable drug release, image-guided therapy, and combined therapy. This review provides researchers with a useful reference in liposome-based drug delivery.

Nipagin-Functionalized Porphyrazine and Phthalocyanine-Synthesis, Physicochemical Characterization and Toxicity Study after Deposition on Titanium Dioxide Nanoparticles P25

Aza-porphyrinoids exhibit distinct spectral properties in UV-Vis, and they are studied in applications such as photosensitizers in medicine and catalysts in technology. The use of appropriate peripheral substituents allows the modulation of their physicochemical properties. Phthalocyanine and sulfanyl porphyrazine octa-substituted with 4-(butoxycarbonyl)phenyloxy moieties were synthesized and characterized using UV-Vis and NMR spectroscopy, as well as mass spectrometry. A comparison of porphyrazine with phthalocyanine aza-porphyrinoids revealed that phthalocyanine macrocycle exhibits higher singlet oxygen generation quantum yields, reaching the value of 0.29 in DMF. After both macrocycles had been deposited on titanium dioxide nanoparticles P25, the cytotoxicities and photocytotoxicities of the prepared materials were studied using a Microtox® acute toxicity test. The highest cytotoxicity occurred after irradiation with a red light for the material composed of phthalocyanine deposited on titania nanoparticles.

Sulfanyl Porphyrazines with Morpholinylethyl Periphery-Synthesis, Electrochemistry, and Photocatalytic Studies after Deposition on Titanium(IV) Oxide P25 Nanoparticles

The syntheses, spectral UV–Vis, NMR, and electrochemical as well as photocatalytic properties of novel magnesium(II) and zinc(II) symmetrical sulfanyl porphyrazines with 2-(morpholin-4-yl)ethylsulfanyl peripheral substituents are presented. Both porphyrazine derivatives were synthesized in cyclotetramerization reactions and subsequently embedded on the surface of commercially available P25 titanium(IV) oxide nanoparticles. The obtained macrocyclic compounds were broadly characterized by ESI MS spectrometry, 1D and 2D NMR techniques, UV–Vis spectroscopy, and subjected to electrochemical studies. Both hybrid materials, consisting of porphyrazine derivatives embedded on the titanium(IV) oxide nanoparticles’ surface, were characterized in terms of particle size and distribution. Next, they were subjected to photocatalytic studies with 1,3-diphenylisobenzofuran, a known singlet oxygen quencher. The applicability of the obtained hybrid material consisting of titanium(IV) oxide P25 nanoparticles and magnesium(II) porphyrazine derivative was assessed in photocatalytic studies with selected active pharmaceutical ingredients, such as diclofenac sodium salt and ibuprofen.

Photosensitizing potential of tailored magnetite hybrid nanoparticles functionalized with levan and zinc (II) phthalocyanine

Phototherapies, including photodynamic therapy (PDT), have been widely used in the treatment of various diseases, especially for cancer. However, there is still a lack of effective, safe photosensitizers that would be well tolerated by patients. The combination of several methods (like phototherapy and hyperthermia) constitutes a modern therapeutic approach, which demands new materials based on components that are non-toxic without irradiation. Therefore, this study presents the synthesis and properties of novel, advanced nanomaterials in which the advantage features of the magnetic nanoparticles and photoactive compounds were combined. The primary purpose of this work was the synthesis of magnetic nanoparticles coated with biocompatible and antitumor polysaccharide - levan, previously unknown from scientific literature, and the deposition of potent photosensitizer - zinc(II) phthalocyanine on their surface. In order to better characterize the nature of the coating covering the magnetic core, the atomic force microscope analysis, a contact angle measurement, and the mechanical properties of pure levan and its blend with zinc(II) phthalocyanine films were investigated. This magnetic nanomaterial revealed the ability to generate singlet oxygen upon exposure to light. Finally, preliminary toxicity of obtained nanoparticles was tested using the Microtox® test - with and without irradiation.

Photodynamic Activity of Tribenzoporphyrazines with Bulky Periphery against Wound Bacteria

Magnesium(II) tribenzoporphyrazines with phenoxybutylsulfanyl substituents were evaluated as photosensitizers in terms of their optical properties against wound bacteria. In the UV-vis spectra of analyzed tribenzoporphyrazines, typical absorption ranges were found. However, the emission properties were very weak, with fluorescence quantum yields in the range of only 0.002–0.051. What is important, they revealed moderate abilities to form singlet oxygen with the quantum yields up to 0.27. Under irradiation, the macrocycles decomposed via photobleaching mechanism with the quantum yields up to 8.64 × 10⁻⁵. The photokilling potential of tribenzoporphyrazines was assessed against Streptococcus pyogenes, Staphylococcus epidermidis, as well as various strains of Staphylococcus aureus, including methicillin-sensitive and-resistant bacteria. Both evaluated photosensitizers revealed high photodynamic potential against studied bacteria (>3 logs). S.aureus growth was reduced by over 5.9 log, methicillin-resistant S. aureus by 5.1 log, S.epidermidis by over 5.7 log, and S. pyogenes by over 4.7 log.

S-seco-porphyrazine as a new member of the seco-porphyrazine family - Synthesis, characterization and photocytotoxicity against cancer cells

An important subgroup within the porphyrazine (Pz) family constitutes seco-porphyrazines, in the chemical structure of which one pyrrole unit is opened in the oxidative process. So far, there are only limited data on N-seco- and C-seco-Pzs. Here, the synthesis of a novel member of the Pzs seco-family, represented by an S-seco-tribenzoporphyrazine analogue, 22,23-bis(4-(3,5-dibutoxycarbonylphenoxy)butylsulfanyl)tribenzo[b,g,l]-22,23-dioxo-22,23-seco-porphyrazinato magnesium(II), is reported, with moderate 34% yield. The new derivative was characterized using NMR spectroscopy, UV-Vis spectroscopy, and mass spectrometry. In the photochemical study performed following the indirect chemical method with 1,3-diphenylisobenzofuran, S-seco-Pz revealed a high singlet oxygen quantum yield of 0.27 in DMF. Potential photocytotoxicity of S-seco-Pz was assessed in vitro on three cancer cell lines - two oral squamous cell carcinoma cell lines derived from the tongue (CAL 27, HSC-3) and human cervical epithelial adenocarcinoma cells (HeLa). In the biological study, the macrocycle was tested in its free form and after loading into liposomes. It is worth noting that S-seco-Pz was found to be non-toxic in the dark, with cell viability levels over 80%. The photocytotoxic IC₅₀ values for free S-seco-Pz were 0.61, 0.18, and 4.1 µM for CAL 27, HSC-3 and HeLa cells, respectively. Four different liposomal compositions were analyzed, and the cationic liposomes revealed the highest photokilling efficacy, with the IC₅₀ values for CAL 27, HSC-3, and HeLa cells at 0.24, 0.25, and 0.31 µM, respectively. The results of the photocytotoxicity study indicate that the new S-seco-tribenzoporphyrazine can be considered as a potential photosensitizer in photodynamic therapy of cancer, along with the developed cationic liposomal nanocarrier.

Tribenzoporphyrazines with dendrimeric peripheral substituents and their promising photocytotoxic activity against Staphylococcus aureus

Infectious diseases constitute a serious problem for human health and life. Although many bacterial and fungal infections can be successfully cured by commonly used antibiotics, a new threat emerges in the form of microbial resistance. For this reason, researchers try to find not only new active pharmaceutical ingredients for conventional antibiotherapy but also try to develop new strategies of microbial inactivation. Photodynamic antimicrobial chemotherapy, which relies on reactive oxygen species generated in situ in the presence of a photosensitizer and with the light of an appropriate wavelength, is one of them. Porphyrazines have been considered as potential photosensitizers for anticancer and antimicrobial photodynamic therapy. In this study, three tribenzoporphyrazines with dendrimeric peripheral substituents were subjected to in vitro antimicrobial photocytotoxicity study. One magnesium(II) tribenzoporphyrazine with peripheral 3,5-bis(3,5-dimethoxybenzyloxy)benzylsulfanyl substituents was synthesized and subjected to physicochemical characterization using NMR, UV-Vis, and mass spectrometry techniques. In photochemical studies this molecule revealed moderate singlet oxygen generation ability (Φ_ΔDMF = 0.12, Φ_ΔDMSO = 0.13). The other two magnesium(II) tribenzoporphyrazines applied in the biological study were 4-[3,5-di(hydroxymethyl)phenoxy]butylsulfanyl-substituted tribenzoporphyrazine and 4-[3,5-bis(benzyloxy)benzyloxy]phenyl-substituted tribenzopyrazinoporphyrazine. For the assessment, three microbial strains were chosen: Gram-positive bacteria Staphylococcus aureus ATCC 25923, Gram-negative bacteria Escherichia coli ATCC 25922, and fungal strain Candida albicans ATCC 10231. Very high activity against Staphylococcus aureus at low 10^-6 M concentration was recorded for magnesium(II) tribenzoporphyrazines with peripheral 3,5-bis(3,5-dimethoxybenzyloxy)benzylsulfanyl and 4-[3,5-di(hydroxymethyl)phenoxy]butylsulfanyl substituents with calculated log reductions of 4.4 and 4.8, respectively. It is worth noting that magnesium(II) tribenzoporphyrazine with 4-[3,5-di(hydroxymethyl)phenoxy]butylsulfanyl substituents revealed also 3.2 log reduction in bacterial growth at the concentration 10^-7 M.

Porphyrinoids in photodynamic diagnosis and therapy of oral diseases

Photodynamic methods have found application not only in the treatment process as photodynamic therapy but also for the early detection of neoplastic lesions and tumors as photodynamic diagnosis. Early detection of the disease allows not only to avoid the patient’s lifetime risk but also significantly reduce the costs of anticancer therapy, which are increasing every year. There is a constant search for new and more effective photosensitizers which will provide safety in therapy while maintaining efficiency. This paper summarizes recent reports focused on the photodynamic diagnosis of oral cancers. Moreover, it shows methods of the photodynamic treatment of oral verrucous hyperplasia, erythroleukoplakia, and oral leukoplakia. The treatment of choice for these diseases is a surgical excision, which always leads to scar formation. Photodynamic therapy provides a new scar-less tool for the treatment.

Photodynamic inactivation of Enterococcus faecalis by non-peripherally substituted magnesium phthalocyanines entrapped in lipid vesicles

Photophysical properties and photodynamic antibacterial potential of magnesium phthalocyanines bearing 2-propoxy, benzyloxy, 3,5-bis(benzyloxy)benzyloxy substituents at non-peripheral positions were studied. The UV-Vis absorption spectra of researched phthalocyanine derivatives were found typical. Extension of peripheral substituent size from 2-propoxy to benzyloxy and finally 3,5-bis(benzyloxy)benzyloxy was accompanied by the rise of quantum yield of fluorescence up to 0.17 and 0.04 in DMF and DMSO, respectively. Similarly, the expansion of the phthalocyanine periphery from the 2-propoxy to benzyloxy and 3,5-bis(benzyloxy)benzyloxy groups resulted in a detectable increase of the singlet oxygen quantum yield values to 0.04, 0.12, 0.14 respectively, which was assessed following direct method of singlet oxygen phosphorescence measurement at 1270 nm. Studied phthalocyanines undergo photobleaching process with the quantum yields at the level of 10^-6 in DMSO and 10^-5 in DMF. The size of phthalocyanine impacted the process of liposomal formulation. Small liposome vesicles containing non-peripherally substituted phthalocyanines with 2-propoxy and benzyloxy substituents were obtained following extrusion method. The unification process of the liposomes loaded with 3,5-bis(benzyloxy)benzyloxy non-peripherally substituted phthalocyanines was not possible. In in vitro antimicrobial photodynamic inactivation study, log reduction values of bacterial (Enterococcus faecalis) growth at 3.61 and 2.99 were achieved for liposomal formulations containing phthalocyanines with 2-propoxy and benzyloxy substituents respectively, whereas phthalocyanine with 3,5-bis(benzyloxy)benzyloxy substituents was inactive. Phthalocyanine with 2-propoxy substituents exhibited relatively low toxicity in Vibrio fischeri bioluminescence test, whereas phthalocyanine with benzyloxy substituents revealed intense bioluminescence, which could be associated with hormesis phenomenon.

Liposomal formulations of magnesium sulfanyl tribenzoporphyrazines for the photodynamic therapy of cancer

Photodynamic therapy of cancer comprises the activation of photosensitizer molecules delivered to cancer cells, to generate reactive oxygen species that mediate cytotoxicity. In this study, previously synthesized dendritic magnesium tribenzoporphyrazines were incorporated into four types of liposomes containing either 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) or 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) as the zwitterionic lipids. The addition of either l-α-phosphatidyl-dl-glycerol (PG) or 1,2-dioleoyl-3-trimethylammoniumpropane (DOTAP) imparted a negative or positive charge, respectively. Novel formulations were tested in oral squamous cell carcinoma cell lines (CAL 27, HSC-3) as well as cervical adenocarcinoma cells (HeLa). Positively charged DOTAP:POPC liposomes were the most effective carriers for all tested tribenzoporphyrazines. Calculated IC₅₀ values for DOTAP:POPC liposomes indicated that the incorporation of tribenzoporphyrazines into these liposomes can improve photocytotoxicity up to 50-fold compared to the free forms of macrocycles. Oral cancer cells (CAL 27 and HSC-3) were more sensitive to liposomal photodynamic treatment than HeLa cells.

The chitosan - Porphyrazine hybrid materials and their photochemical properties

Three magnesium sulfanyl porphyrazines differing in the size of peripheral substituents (3,5-dimethoxybenzylsulfanyl, (3,5-dimethoxybenzyloxy)benzylsulfanyl, 3,5-bis[(3,5-bis[(3,5-dimethoxybenzyloxy)benzyloxy]benzylsulfanyl) were exposed to visible and ultraviolet radiation (UV A + B + C) in order to determine their photochemical properties. The course of photochemical reactions in dimethylformamide solutions and the ability of the systems to generate singlet oxygen were studied by UV-Vis spectroscopy, which additionally gave information on aggregation processes. The porphyrazines were found to be stable upon visible light irradiation conditions, but when exposed to high energy UV radiation, the efficient photodegradation of these macrocycles was observed. Therefore, these three magnesium sulfanyl porphyrazines were incorporated into chitosan matrix. The obtained thin films of chitosan doped with porphyrazines were subjected to polychromatic UV-radiation and studied by spectroscopic methods (UV-Vis, FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Application of chitosan as a polymer matrix for porphyrazines was found to be successful method that effectively stopped the unwelcome degradation of macrocycles, thus worth considering for their photoprotection. In addition, the surface properties of the hybrid material were determined by contact angle measurements and calculation of surface free energy. Intermolecular interactions between these novel porphyrazines and chitosan were detected. The mechanism of photochemical reactions occurring in studied systems has been discussed.

Multiwalled carbon nanotube/sulfanyl porphyrazine hybrids deposited on glassy carbon electrode — effect of nitro peripheral groups on electrochemical properties

We report on the synthesis, MS, UV-vis, NMR, HPLC and electrochemical characterization of magnesium sulfanyl porphyrazine with 2-[2-(4-nitrophenoxy)ethoxy]ethylsulfanyl substituents in the periphery. The electrochemical properties of novel macrocycle were studied by cyclic voltammetry and differential pulse voltammetry in non-aqueous electrolyte. The experimental data indicated the occurrence of clearly defined four redox couples corresponded to one-electron reactions of the [Formula: see text]-conjugated porphyrazine ring and substituents in the periphery. Multiwalled carbon nanotube/sulfanyl porphyrazine hybrids deposited on a glassy carbon electrode allowed for the evaluation of the effect of nitro peripheral groups on the electrochemical properties. The electrochemical behavior of immobilized nitro porphyrazine was consistent with the reduction mechanism for the various arylnitro compounds in aqueous media, with two processes characteristic of the redox transitions of the arylnitro group to the corresponding arylhydroxylamine and/or arylhydroxylamine–arylnitroso groups.