Photodynamic Antimicrobial Activity Research Articles

The Implications of Ortho-, Meta- and Para- Directors on the In-Vitro Photodynamic Antimicrobial Chemotherapy Activity of Cationic Pyridyl-Dihydrothiazole Phthalocyanines

The Implications of Ortho-, Meta- and Para- Directors on the In-Vitro Photodynamic Antimicrobial Chemotherapy Activity of Cationic Pyridyl-Dihydrothiazole Phthalocyanines

The study on biological activities of silver nanoparticles produced via green synthesis method using Salvia officinalis and Thymus vulgaris.

In the present study, Ag nanoparticles (AgNPs) were synthesized from Salvia officinalis and Thymus vulgaris, known as phytotherapy plants. The obtained silver nanoparticles were characterized using SEM, XRD, FTIR, and UV/Vis spectra. The antioxidant capacities of Salvia officinalis-mediated AgNP (SO-AgNP) and Thymus vulgaris-mediated AgNP (TV-AgNP) were analyzed in vitro using 1,1-diphenyl-2-picrylhydrazyl and iron chelating activity assays. DPPH activities were 83.74% and 57.17% for SO-AgNP and TV-AgNP at concentration 200 mg/L, respectively. Both green synthesized AgNPs exhibited good iron chelating activity. In addition, the DNA cleavage activities of SO-AgNPs and TV-AgNP were investigated with agarose gel electrophoresis technique. SO-AgNPs and TV-AgNP showed single-strand DNA cleavage activity. AgNPs showed that the SO-AgNP and TV-AgNp were effective against bacteria and fungi, and antimicrobic activities were assessed as minimal inhibition concentration (MIC). Remarkably, green synthesized AgNPs showed highly effective cell viability and biofilm inhibition effect. AgNPs also demonstrated slightly antimicrobial photodynamic activity after LED irradiation.

Discovery of Meso-(meta-Pyridinium) BODIPY Photosensitizers: In Vitro and In Vivo Evaluations for Antimicrobial Photodynamic Therapy.

Antimicrobial photodynamic therapy (aPDT) has emerged as a novel and promising approach for the treatment of pathogenic microorganism infections. The efficacy of aPDT depends greatly on the behavior of the photosensitizer. Herein, we report the design, preparation, antimicrobial photodynamic activities, as well as structure-activity relationships of a series of photosensitizers modified at the meso position of a 1,3,5,7-tetramethyl BODIPY scaffold with various pyridinyl and pyridinium moieties. The photodynamic antimicrobial activities of all photosensitizers have been tested against Staphylococcus aureus, Escherichia coli, Candida albicans, and Methicillin-resistant S. aureus (MRSA). The methyl meso-(meta-pyridinium) BODIPY photosensitizer (3c) possessed the highest phototoxicity against these pathogens at minimal inhibitory concentrations (MIC) ranging from 0.63 to 1.25 μM with a light dose of 81 J/cm2. Furthermore, 3c exhibited an impressive antimicrobial efficacy in S. aureus-infected mice wounds. Taken together, these findings suggest that 3c is a promising candidate as the antimicrobial photosensitizer for combating pathogenic microorganism infections.

Photodynamic antimicrobial activity of magnesium(II) porphyrazine with bulky peripheral sulfanyl substituents

Magnesium(II) porphyrazine bearing bulky sulfanyl substituents was evaluated as a photosensitizer (PS) for photodynamic antimicrobial chemotherapy (PACT). In the photostability study, the studied porphyrazine under light irradiation decomposed via photobleaching process with quantum yields up to 1.05 ⋅ 10−5. Singlet oxygen quantum yields for the PS were determined by indirect method with chemical singlet oxygen trap (1,3-diphenylisobenzofuran, DPBF) and reference (unsubstituted zinc(II) phthalocyanine). Liposomes containing porphyrazine derivative were obtained with thin-film hydration method and their size was measured with NanoSight LM10 (Malvern). Biological activity evaluation was performed with the agar plate method. The photocytotoxicity of sulfanyl porphyrazine against various wound bacteria (Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, and Streptococcus pyogenes) was studied. The highest reduction value in bacterial growth exceeding 4 log was observed for S. epidermidis. Equally high reduction values of 3.4 log and 4.2 log at 10 and 100 µM, respectively, were observed against S. pyogenes. The novel sulfanyl porphyrazine can be considered as a potential PS in further antimicrobial photodynamic therapy related studies.

Assessment of invitro Cytotoxic, iNOS, Antioxidant and Photodynamic Antimicrobial Activities of Water-soluble Sulfonated Phthalocyanines.

In recent years, much effort has been devoted to the development of effective anticancer agents. In this manner, the utilization of water-soluble sulfonated phthalocyanines is crucial for many cancer cell lines. In this study, phthalonitrile and metallophthalocyanine compounds linked by benzenesulfonic acid groups have been prepared. Antimicrobial behaviors of those compounds were investigated by performing disk diffusion and photodynamic assays on gram-positive and negative bacteria. Indium phthalocyanine (InClPc) (3) showed inhibition activity against B. cereus, B. subtilis and S. aureus with disk diffusion assay. Also, gallium and indium phthalocyanines (2 and 3) exhibited inhibitory activity on both gram-positive and -negative microorganisms after light activation. Increasing the inhibitor concentration and light exposure time increased the inhibition activity for both molecules. GaClPc (2) demonstrated the maximum reducing power capacity among studied compounds, and CoPc (4) showed even better DPPH radical scavenging ability than the standard molecule Trolox at 2000 µg mL-1 concentration. The dose-dependent effect of compounds on cytotoxicity was studied against cancer cells PANC-1, MDA-MB-231, HepG2, A549, HeLa, CaCo-2 and non-tumorigenic cells HEK-293. All compounds showed no significant cytotoxic effect on any cell line up to the highest treated concentration at 50 µg mL-1 . However, all phthalocyanines had significant nitric oxide inhibition activity, and only in copper phthalocyanine (CuPc) (5), the MTT IC50 value was reached on LPS-activated RAW 264.7 macrophage cells. The lowest inducible nitric oxide synthase (iNOS) IC50 values were defined as 6 ± 1 μg mL-1 and 7 ± 0.5 μg mL-1 for CuPc (5) and InClPc (3), respectively.

Photophysicochemical and Biological Properties of New Phthalocyanines Bearing 4-(trifluoromethoxy)phenoxy and 2-(4-methylthiazol-5-yl)ethoxy Groups on Peripheral Positions.

As thiazoles and fluorinated groups are well known as active species of hybrid pharmaceutical agents, this study aimed to evaluate the synergic effect of these groups on the biological features of phthalocyanines for the first time in the hope of discovering efficient pharmaceutical agents. Therefore, a new phthalonitrile derivative namely 4-(2-(4-methylthiazol-5-yl)ethoxy)-5-(4-(trifluoromethoxy)phenoxy)phthalonitrile (1) and its metal-free (2)/metal phthalocyanines (3-5) were prepared and characterized using various spectroscopic techniques. Solubility of new phthalocyanines (2-5) was examined in a series of polar and nonpolar solvents. Additionally, sono/photochemical methods were applied to examine the photophysical and sono/photochemical properties of new zinc phthalocyanine to measure its potential as a probable material for sono/photodynamic therapies. The antioxidant activities of compounds (1-5) were evaluated using the DPPH scavenging activity method and the highest radical scavenging activity was obtained 92.13% (200 mg L-1 ) for manganese phthalocyanine. All the phthalocyanines demonstrated high DNA nuclease activity, as well. The antimicrobial activities of compounds (1-5) were investigated using disk diffusion and microdilution methods. The phthalocyanines exhibited effective microbial cell inhibition activity against Escherichia coli (E.coli). Antimicrobial photodynamic therapy activity was investigated against E.coli by LED irradiation. Compounds (2-5) acted as photosynthesizers. Also, they displayed significant biofilm inhibition activity against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa).

Indium phthalocyanines: Comparative photophysicochemical properties and photodynamic antimicrobial activities against Staphylococcus aureus and Escherichia coli

In this study, the photodynamic antimicrobial activities of a series of new tetra-substituted indium phthalocyanine (InPc) complexes are assessed. An aldehyde substituted complex (2) was initially prepared, which was converted through a condensatioreaction to an imine-pyrrolidine substituted complex (3), which in turn was quaternized to form a tetracationic species (4). Favorable photophysicochemical properties were obtained by incorporating a heavy In(III) ion into the central cavity. Aggregation studies revealed that 2–4 remain non-aggregated in DMSO at concentration below 25 µM. The photodeactivation of S.aureus and E.coli was studied. Log reduction values > 9.0 were obtained for cationic InPc 4 after 30 min of incubation and exposure to light for 75 min.

Antimicrobial Photodynamic Activity of Hydrophilic Riboflavin Derivatives

Antimicrobial Photodynamic Activity of Hydrophilic Riboflavin Derivatives

Synthesis, photophysical properties and photodynamic antimicrobial activity of meso 5,10,15,20-tetra(pyren-1-yl)porphyrin and its indium(III) complex

In this study, free-base meso 5,10,15,20-tetra(pyren-1-yl)porphyrin (H2TPyP) and its corresponding indium(III) complex (InClTPyP) were synthesized and characterized on the basis of mass spectrometry, 1H NMR spectroscopy and elemental analysis. InClTPyP was obtained in good yield by treating the free base H2TPyP with indium(III) chloride. Purification of these compounds was achieved through column chromatography using different solvent systems. Metallation of the free base to form a metallo-porphyrin afforded improved photophysical properties. There was a bathochromic shift in wavelength of absorption from the parent free base H2TPyP ([Formula: see text] = 431 nm) to metallated indium(III) complex ([Formula: see text] = 443 nm). The fluorescence quantum yield in H2TPyP was higher ([Formula: see text] = 0.131) than in InClTPyP ([Formula: see text] = 0.017) due to efficient intersystem crossing to the triplet manifold in the metallated porphyrin. Upon illumination, both H2TPyP and InClTPyP show effective dose dependent antimicrobial activity against Staphylococcus aureus with photoinactivation IC[Formula: see text] values of 27.89 and 16.67 [Formula: see text]M, respectively.

Photodynamic antimicrobial activity of benzimidazole substituted phthalocyanine when conjugated to Nitrogen Doped Graphene Quantum Dots against Staphylococcus aureus

In this study, peripherally benzimidazole unit substituted ZnPc (1) and its conjugation to nitrogen doped graphene quantum dot (NGQD) as potential phthalocyanine support via π-π stacking have been presented and fully characterized. The bottom-up solution-based synthesized NGQDs was conjugated non-covalently to zinc phthalocyanine to form NGQDs-Pc nanoconjugates. The photophysical and photochemical properties of both such as absorption, fluorescence, fluorescence life time, singlet oxygen quantum yields, triplet state quantum yields and exited state lifetimes were investigated in solutions. We observed a decrease in the fluorescence quantum yields with a corresponding increase in the triplet quantum yield and singlet oxygen quantum yield of the nanoconjugates in comparison to the phthalocyanine complex alone. Photodynamic antimicrobial chemotherapy activities (PACT) of ZnPc alone and its nanoconjugate were determined towards Staphylococcus aureus.

Insights on the polypyrrole based nanoformulations for photodynamic therapy

This review is written to endow updated information on polypyrrole based photosensitizers for the treatment of deadly diseases such as cancer and microbial infection. Tetrapyrrolic macromolecules such as porphyrins and phthalocyanines hold unique photophysical properties which make them very useful compounds for various biomedical applications. Besides their properties, they also have some limitations such as low water solubility, bioavailability, biocompatibility and lack of specificity, etc. Researchers are trying to overcome these limitations by incorporating photosensitizers into the different types of nanoparticles and improve the quality of photodynamic therapy. We have contributed to this field by synthesizing and developing polypyrrolic photosensitizer based nanoparticles for potential applications in antimicrobial and anticancer photodynamic activity. Throughout this review, newly synthesized and existing PSs conjugated/encapsulated/doped/incorporated with nanoparticles are emphasized, which are essential for current and future research themes. Also in this review, we briefly summarized the research work carried over the past few years by considering the porphyrin based photosensitizers as alternative therapeutic entities for the treatment of microbial infections, cancers, and many other diseases.

Biofilm‐Sensitive Photodynamic Nanoparticles for Enhanced Penetration and Antibacterial Efficiency

AbstractEfficient antimicrobials are urgently needed for the treatment of bacterial biofilms due to their resistance to traditional drugs. Photodynamic therapy (PDT) is a new strategy that has been used to combat bacteria and biofilms. Cationic photosensitizers, particularly cationic photodynamic nanoagents, are usually chosen to enhance photodynamic antimicrobial activity. However, positively charged nanoparticles (NPs) are beneficial to cellular internalization, which causes increased cell cytotoxicity. Herein, a pH‐sensitive photodynamic nanosystem is designed. Rose Bengal (RB) polydopamine (PDA) NPs are decorated in a layer‐by‐layer fashion with polymyxin B (PMB) and gluconic acid (GA) to generate functionally adaptive NPs (RB@PMB@GA NPs). RB@PMB@GA NPs remain negative at physiological pH and exhibit good biocompatibility. When RB@PMB@GA NPs are exposed to an acidic infectious environment, the surface charge of the NPs is, in turn, positively charged as a result of pH‐sensitive electrostatic interactions. This surface charge conversion allows the RB@PMB@GA to effectively bind to the surfaces of bacteria and enhance photoinactivation efficiency against gram‐negative bacteria. Most importantly, RB@PMB@GA NPs exhibit good biofilm penetration and eradication under acidic conditions. Furthermore, RB@PMB@GA NPs efficiently eliminate biofilm infections in vivo. This study provides a promising strategy for safely treating biofilm‐associated infections in vivo.

Promising photodynamic antimicrobial activity of polyimine substituted zinc phthalocyanine and its polycationic derivative when conjugated to nitrogen, sulfur, co-doped graphene quantum dots against Staphylococcus aureus

Antimicrobial resistance is a most important problem facing the treatment of infectious diseases. Antimicrobial photodynamic therapy is an alternative treatment strategy, considered to be cost-effective and feasible. For this purpose, octa-imine substituted ZnPc (3) have been prepared and conjugated to nitrogen, sulfur co-doped graphene quantum dots (N,S-GQDs) through π-π stacking. The photophysical and photochemical properties of Pc alone and and Pc-conjugated to the GQD nanomaterial such as absorption, fluorescence, fluorescence life time, singlet oxygen quantum yields, triplet state quantum yields and exited state lifetimes were investigated in solutions before in vitro cell studies. The PACT activity of prepared structures was investigated against Gram-positive (Staphylococcus aureus). Our results suggest that the in the case of conjugation of zinc Pc to N,S-GQDs, photodynamic inactivation increased with the 100 % reduction percentage

Photochemical properties and promising activity against staphylococci of sulfanyl porphyrazines with dendrimeric moieties

Magnesium(II) porphyrazines bearing dendrimeric 3,5-dimethoxybenzylthio, 3,5-bis(3,5-dimethoxybenzyloxy)benzylthio, 3,5-bis[(3,5-bis((3,5-dimethoxybenzyloxy)-benzyloxy]benzylthio groups were studied as photosensitizers against bacteria typically found in wounds. They revealed intensive absorbance in the UV–Vis spectra. Singlet oxygen quantum yields of sulfanyl porphyrazines were low and appeared in the range between 0.01 and 0.05. In the photodegradation study, all macrocycles decomposed under light irradiation with the photodecomposition quantum yields up to 1.90 ∙ 10-5. For the antimicrobial photodynamic activity studies, sulfanyl porphyrazines were loaded into liposome carriers. Significant photodynamic activities of macrocycles against Staphylococcus aureus with 4.6 log and Staphylococcus epidermidis with 3.5 log were observed.

Preparation of a Porphyrin Metal-Organic Framework with Desirable Photodynamic Antimicrobial Activity for Sustainable Plant Disease Management.

Considering the severity of plant pathogen resistance toward commonly used agricultural microbicides, as well as the potential threats of agrichemicals to the eco-environment, there is a pressing need for antimicrobial approaches that are capable of inactivating pathogens efficiently without the risk of inducing resistances and harm. In this work, a porphyrin metal-organic framework (MOF) nanocomposite was constructed by incorporating 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin tetra(p-toluenesulfonate) (TMPyP) as a photosensitizer (PS) in the cage of a variant MOF (HKUST-1) to efficiently produce singlet oxygen (1O2) to inactivate plant pathogens under light irradiation. The results showed that the prepared PS@MOF had a loading rate of PS about 12% (w/w) and excellent and broad-spectrum photodynamic antimicrobial activity in vitro against three plant pathogenic fungi and two pathogenic bacteria. Moreover, PS@MOF showed outstanding control efficacy against Sclerotinia sclerotiorum on cucumber in the pot experiment. Allium cepa chromosome aberration assays and safety evaluation on cucumber and Chinese cabbage indicated that PS@MOF had no genotoxicity and was safe to plants. Thus, porphyrin MOF demonstrated a great potential as an alternative and efficient new microbicide for sustainable plant disease management.

Enhanced Photodynamic inactivation of Staphylococcus Aureus with Schiff base substituted Zinc phthalocyanines through conjugation to silver nanoparticles

We present the preparation of Schiff base substituted neutral phthalocyanines derived from aldehyde-substituted phthalocyanine which are conjugated to silver nanoparticles through covalent-like strong interactions. The photophysicochemical properties of the nanoconjugates and the Pcs alone were studied comparatively. The photodynamic antimicrobial chemotherapy (PACT) activities. of prepared photosensitizers was investigated against Gram-positive bacterium (Staphylococcus aureus). Unlike Pcs alone, conjugated phthalocyanines to silver nanoparticles showed excellent photodynamic antimicrobial activity with the 100% reduction percentage upon illumination.

Evaluation of antimicrobial photodynamic activities of 5-aminolevulinic acid derivatives.

Antibiotic resistance is increasing day by day, thereby increase the chances of more infections by resistant bacteria. In this situation, antimicrobial photodynamic therapy (aPDT) is gaining more attraction. To evaluate the antimicrobial effect of ALA derivatives using photodynamic therapy. In this study, we evaluated the aPDT effect of different derivatives of 5-ALA. In vivo and in vitro studies were performed to measure the antimicrobial activity. Different light doses and different concentrations of drugs were used to test anti-bacterial effect of drugs as well as to detect any physiological changes in animal model after the treatment. In vivo studies revealed that ALA-methyl ester, ALA-hexyl ester, and ALA-13A are potent photosensitizers. In vitro studies involved wound healing rate, body weight, and dietary intake were evaluated, and results showed that ALA, ALA-methyl ester, ALA-hexyl ester, and ALA-13A had good anti-bacterial effects, fast healing rate, and no effect on other physical parameters. Photodynamic therapy is increasingly used to treat different types of skin infections caused by bacterial strains. Our studies revealed that ALA-methyl ester, ALA-hexyl ester, and ALA-13A are promising photosensitizers for photodynamic therapy to inhibit the growth of resistant bacterial strains.

Antimicrobial photodynamic activity of hydrophilic riboflavin derivatives

Antimicrobial photodynamic activity of hydrophilic riboflavin derivatives

Study of Photophysico-chemical and Antimicrobial Photodynamic Properties of Visible Light Active Azometal(II) Complexes

The Co(II) and Mn(II) complexes with octahedral geometries of the type [Co(L)2(H2O)2] and [Mn(L)2(H2O)2] were synthesized and characterized by elemental analysis, FT-IR, UV-visible spectra, powered XRD and photoluminescence. Both metal(II) complexes were prepared with 4-[(Z)-(8-hydroxyquinolin-5-yl)diazenyl]-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one. The complexes were evaluated for in vitro antimicrobial photodynamic activity against Gram-positive, Gram-negative bacteria and fungi. The cell inhibition rate was found to be 80-96%. in vitro Cytotoxic studies were performed for the synthesized complexes against human melanoma (A-375) and human primary glioblastoma (U-87) cell lines by MTT assay where Co(II) complex showed potential inhibitory efficiency with IC50 value of 115 μg/mL when compared to Mn(II) complex.

Photoinduced Antimicrobial Activity of Curcumin-Containing Coatings: Molecular Interaction, Stability and Potential Application in Food Decontamination.

Polyvinyl acetate (PVAc) and curcumin (Cu) were utilized for preparing new protecting PVAc–Cux (x = 1, 5 and 10) coatings exerting antimicrobial photodynamic activity upon white light irradiation. Toward Salmonella typhimurium or Staphylococcus aureus, the killing efficiency represented the dependence on the Cu concentration and irradiation intensity. Toward S. aureus, the killing efficiency of PVAc–Cu10 coating reached 93% at an energy density of 72 J/cm2. With the change in storage time of coating, the results implied significant stability of photosterilization efficiency within 60 days. Compared with the control experiment, lower total viable counts (TVCs) and total volatile basic nitrogen (TVB-N) values in fresh meat packaged by PVDC films with PVAc–Cu10 coatings during storage at 4 °C demonstrated the practicability of the PVAc–Cux coatings in decontaminating fresh pork. PVAc packed curcumin tightly within polymer chains, thus preventing tautomerization or, more probably, conformational transition, which is advantageous for improving photostability and emission lifetime.