Publications by authors named "Mariana B Spesia"

Cefadroxil is a widely used antibiotic with a low elimination efficiency in wastewater treatments plants, so it represents a contaminants of emerging concern that should be removed. The photosensitization process that involves natural pigments and visible sunlight can be offered as an environmentally friendly alternative to be considered for Cefadroxil degradation. In this investigation, we carried out a mechanistic and kinetic approach to Cefadroxil photodegradation sensitized by Riboflavin and Humic Acid, in individual and combined processes.

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The effect of photodynamic inactivation (PDI) sensitized by 5,10,15,20-tetra(4-N,N,N-trimethylammoniophenyl)porphyrin (TMAP) on different components of mono- and dual-species biofilms of Staphylococcus aureus and Escherichia coli was determined by different methods. First, the plate count technique showed that TMAP-PDI was more effective on S. aureus than E.

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To improve bacterial photodynamic inactivation (PDI), this work analyzes the photodynamic effect caused by the combination of photosensitizers (PSs) on two bacterial models and different growth mode. Simultaneous administration of PSs from different families, zinc(II) 2,9,16,23-tetrakis[4-(N-methylpyridyloxy)]phthalocyanine (ZnPPc), 5,10,15,20-tetra(4-N,N,N-trimethylammonium phenyl)porphyrin (TMAP), meso-tetrakis(9-ethyl-9-methyl-3-carbazoyl)chlorin (TEMCC) and 5,10,15,20-tetrakis[4-(3-N,N-dimethylaminopropoxy)phenyl] chlorin (TAPC) was investigated against Staphylococcus aureus and Escherichia coli, in planktonic form, biofilm and growth curve. Various PSs combinations showed greater inactivation compared to when used separately under the same conditions but at twice the concentration.

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Phthalocyanine derivatives have been proposed as photosensitizers for the treatment of several microbial infections. In this review, the progress in the structures of phthalocyanines was analyzed, considering that these compounds can easily functionalize and can form complexes with various metal ions. In this sense, different substituents were used to increase the interaction with the microorganisms, improving their photodynamic inactivation.

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The main causes of food spoilage come from the process of oxidation and the contamination by microorganisms. For the purpose of increasing food shelf-life the industries employ different techniques, being the addition of preservatives, one of the most used. The aim of this contribution was to investigate the potential antioxidant properties of tyrosol (4-hydroxyphenethyl alcohol, 4-OH) and tyrosol derived isomers (2-hydroxyphenethyl alcohol, 2-OH and 3-hydroxyphenethyl alcohol, 3-OH) against reactive oxygen species (ROS) and the antimicrobial effect on Staphylococcus aureus and Escherichia coli.

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Photodynamic inactivation (PDI) protocols using photoactive metallated porphyrin-doped conjugated polymer nanoparticles (CPNs) and blue light were developed to eliminate multidrug-resistant pathogens. CPNs-PDI protocols using varying particle concentrations and irradiation doses were tested against nine pathogenic bacterial strains including antibiotic-resistant bacteria of the ESKAPE (, , , , , and ) pathogens group. The bactericidal effect was achieved in methicillin-resistant () strains using low light doses (9.

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The development of convenient synthetic methods and improved materials for the production of high load-capacity and biocompatible drug delivery systems is a challenging task with important implications in health sciences. In this work, acrylamide/2-hydroxyethylmethacrylate and N-isopropylacrylamide/2-hydroxyethylmethacrylate hydrogels were synthesized by photopolymerization using energy-efficient green-LEDs. A functionalized silsesquioxane was used as both crosslinker and co-initiator for the photopolymerization.

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Objective: The goal of this work was to investigate the photodynamic activity of 5,10,15,20-tetrakis[4-(3-N,N-dimethylaminopropoxy)phenyl]chlorin (TAPC) and zinc(II) 2,9,16,23-tetrakis[4-(N-methylpyridyloxy)]phthalocyanine iodide (ZnPPc ) as photosensitizers to inactivate Staphylococcus aureus biofilms and prevent their formations in different culture media.

Methods: We incubated S aureus biofilms in different culture media: tryptic soy (TS), nutrient (N), Müeller Hinton (MH) broth, TS with glucose 2 and 5% (w/v) with 5 μM ZnPPc or TAPC and irradiated with visible light (350-800 nm). Photodynamic inactivation (PDI) was determined by count of colony forming units (CFU) and crystal violet method.

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The photodynamic action mechanism sensitized by a non-charged porphyrin-fullerene C dyad (TCP-C) and its tetracationic analogue (TCP-C ) was investigated in solution and in cells. The ability of both dyads to form a photoinduced charge-separated state was evidenced by the reduction of methyl viologen in ,-dimethylformamide (DMF). Moreover, the formation of superoxide anion radicals induced by these dyads was detected by the reduction of nitro blue tetrazolium.

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The photodynamic mechanism sensitized by N,N-dimethyl-2-[4-(3-N,N,N-trimethylammoniopropoxy)phenyl]fulleropyrrolidinium (DPC) was investigated in Staphylococcus aureus cells. Different experimental conditions were used to detect reactive oxygen species (ROS) in S. aureus cell suspensions.

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A novel 5,10,15,20-tetrakis[4-(3-N,N-dimethylaminopropoxy)phenyl]chlorin (TAPC) was synthesized by reduction of the corresponding porphyrin TAPP with p-toluenesulfonhydrazide, followed by selective oxidation with o-chloranil. Spectroscopic properties and the photodynamic activity of these photosensitizers were compared in N,N-dimethylformamide. An increase in the absorption band at 650nm was found for the chlorin derivative with respect to TAPP.

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A porphyrin-fullerene C60 dyad (TCP-C60) substituted by carbazoyl groups was used to obtain electrogenerated polymeric films on optically transparent indium tin oxide (ITO) electrodes. This approach produced stable and reproducible polymers, holding fullerene units. The properties of this film were compared with those formed by layers of TCP/TCP-C60 and TCP/ZnTCP.

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The effect of divalent cations, EDTA and chitosan (CS) on the uptake and photoinactivation of Escherichia coli produced by 5,10,15,20-tetrakis(4-N,N,N-trimethylammoniumphenyl)porphyrin (TMAP(4+)), 5,10-di(4-methylphenyl)-15,20-di(4-N,N,N-trimethylammoniumphenyl)porphyrin (MPAP(2+)) and 5,10,15,20-tetra(4-sulphonatophenyl)porphyrin (TPPS(4-)) were examined under different conditions. These porphyrins were rapidly bound to E. coli cells (<2.

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Trace amounts of the widely used β-lactam antibiotics (Atbs) in waste water may cause adverse effects on the ecosystems and contribute to the proliferation of antibiotic-resistant bacteria. On these grounds, kinetic and mechanistic aspects of photosensitized degradation of Ceftriaxone (Cft) and Cefotaxime (Ctx), have been studied in pure water by stationary and time-resolved techniques. Additionally, possible implications of these photoprocesses on the antimicrobial activity of the Atbs have also been investigated.

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A covalently linked porphyrin-fullerene C60 dyad 5 was synthesized by 1,3-dipolar cycloaddition using 5-(4-formylphenyl)-10,15,20-tris[3-(N-ethylcarbazoyl)]porphyrin, N-methylglycine and fullerene C60. Methylation of 5 was used to obtain a cationic dyad 6. Spectroscopic properties were compared in toluene, N,N-dimethylformamide (DMF) and toluene/sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/water reverse micelles.

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The photodynamic mechanism of action induced by N,N-dimethyl-2-(4'-N,N,N-trimethylaminophenyl)fulleropyrrolidinium iodide (DTC60(2+)) was investigated on Candida albicans and Escherichia coli cells. First, photogeneration of superoxide anion radical by DTC60(2+) in the presence of NADH was detected using nitro blue tetrazolium method in reverse micelles. In C.

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Photoinactivation of Streptococcus mitis induced by zinc(II) 2,9,16,23-tetrakis[2-(N,N,N-trimethylamino)ethoxy]phthalocyanine (ZnEPc(4+)) was studied under different experimental condition in order to obtain information about the photodynamic processes and the cellular damage. A 3 log decrease in S. mitis survival was found in cell suspensions (~2×10(8) cells/mL) incubated with 2 μM ZnEPc(4+) and irradiated for 30 min with visible light (54 J/cm(2)).

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Sinorhizobium meliloti is a symbiotic nitrogen-fixing bacterium that elicits nodule formation on roots of alfalfa plants. S. meliloti produces two exopolysaccharides (EPSs), termed EPS I and EPS II, that are both able to promote symbiosis.

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Novel unsymmetrically substituted Zn(II) phthalocyanine bearing an adamantylethoxy group (AZnPc) was synthesized by the ring expansion reaction of boron(III) subphthalocyanine chloride with an appropriated phthalonitrile derivative (APc). Also, APc was used to obtain a new Zn(II) phthalocyanine bearing four adamantylethoxy groups (A(4)ZnPc) by cyclotetramerization reaction. The spectroscopic and photodynamic properties of these photosensitizers were compared with those of a Zn(II) phthalocyanine substituted by four methoxy groups (M(4)ZnPc) in different media.

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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.

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Photodynamic inactivation (PDI) of Escherichia coli has been studied in cultures treated with zinc(II) 2,9,16,23-tetrakis[4-(N-methylpyridyloxy)]phthalocyanine (ZnPPc(+4)) to obtain insight about the mechanism of damage. This phthalocyanine is rapidly bound to cells, reaching a value of approximately 0.8 nmol/10(6) cells when the cultures were incubated with 2 microM sensitizer.

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The mechanistic aspects of Escherichia coli photodynamic inactivation (PDI) have been investigated in bacteria treated with 5,10,15-tris[4-(3-N,N,N-trimethylammoniumpropoxy)phenyl]-20-(4-trifluoromethylphenyl)porphyrin iodide (A3B3+) and visible light. The photosensitization activity of A3B3+ porphyrin was compared with that of 5,10,15,20-tetra(4-N,N,N-trimethylammonium phenyl)porphyrin p-tosylate (TMAP4+), which is an active tetracationic sensitizer to eradicate bacteria. The PDI damages on plasmid and genomic DNA were analyzed by electrophoresis.

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A novel N,N-dimethyl-2-(4'-N,N,N-trimethylaminophenyl)fulleropyrrolidinium iodide (DTC(60)(2+)) has been synthesized by 1,3-dipolar cycloaddition using 4-(N,N-dimethylamino) benzaldehyde, N-methylglycine and fullerene C(60). This approach produced an N-methyl-2-(4'-N,N-dimethylaminophenyl)fulleropyrrolidine with 38% yield. Exhaustive methylation of this fullerene derivative with methyl iodide yielded 95% of dicationic DTC(60)(2+).

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The photodynamic effect of novel cationic porphyrins, with different pattern of meso-substitution by 4-(3-N,N,N-trimethylammoniumpropoxy)phenyl (A) and 4-(trifluoromethyl)phenyl (B) groups, have been studied in both solution bearing photooxidizable substrates and in vitro on a typical Gram-negative bacterium Escherichia coli. In these sensitizers, the cationic groups are separated from the macrocycle ring by a propoxy spacer. Thus, the charges have a high mobility and a minimal influence on photophysical properties of the porphyrin.

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The photodynamic effect of meso-substituted cationic porphyrins, 5-[4-(trimethylammonium)phenyl]-10,15,20-tris(2,4,6-trimethoxyphenyl)porphyrin iodide 1, 5,10-di(4-methylphenyl)-15,20-di(4-trimethylammoniumphenyl)porphyrin iodide 2 and 5-(4-trifluorophenyl)-10,15,20-tris(4-trimethylammoniumphenyl)porphyrin iodide 3, have been investigated in both homogeneous medium bearing photooxidizable substrates and in vitro on a typical gram-negative bacterium Escherichia coli. Absorption and fluorescence spectroscopic studies were compared in N,N-dimethylformamide. Fluorescence quantum yields (varphiF) of 0.

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