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1.
Int J Nanomedicine ; 15: 8075-8095, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33116519

RESUMO

Purpose: Sonodynamic therapy (SDT) is a new therapeutic modality for the noninvasive cancer treatment based on the association of ultrasound and sonosensitizer drugs. Topical SDT requires the development of delivery systems to properly transport the sonosensitizer, such as zinc phthalocyanine (ZnPc), to the skin. In addition, the delivery system itself can participate in sonodynamic events and influence the therapeutic response. This study aimed to develop ZnPc-loaded micelle to evaluate its potential as a topical delivery system and as a cavitational agent for low-frequency ultrasound (LFU) application with the dual purpose of promoting ZnPc skin penetration and generating reactive oxygen species (ROS) for SDT. Methods: ZnPc-loaded micelles were developed by the thin-film hydration method and optimized using the Quality by Design approach. Micelles' influence on LFU-induced cavitation activity was measured by potassium iodide dosimeter and aluminum foil pits experiments. In vitro skin penetration of ZnPc was assessed after pretreatment of the skin with LFU and simultaneous LFU treatment using ZnPc-loaded micelles as coupling media followed by 6 h of passive permeation of ZnPc-loaded micelles. The singlet oxygen generation by LFU irradiation of the micelles was evaluated using two different hydrophilic probes. The lipid peroxidation of the skin was estimated using the malondialdehyde assay after skin treatment with simultaneous LFU using ZnPc-loaded micelles. The viability of the B16F10 melanoma cell line was evaluated using resazurin after treatment with different concentrations of ZnPc-loaded micelles irradiated or not with LFU. Results: The micelles increased the solubility of ZnPc and augmented the LFU-induced cavitation activity in two times compared to water. After 6 h ZnPc-loaded micelles skin permeation, simultaneous LFU treatment increased the amount of ZnPc in the dermis by more than 40 times, when compared to non-LFU-mediated treatment, and by almost 5 times, when compared to LFU pretreatment protocol. The LFU irradiation of micelles induced the generation of singlet oxygen, and the lipoperoxidation of the skin treated with the simultaneous LFU was enhanced in three times in comparison to the non-LFU-treated skin. A significant reduction in cell viability following treatment with ZnPc-loaded micelles and LFU was observed compared to blank micelles and non-LFU-treated control groups. Conclusion: LFU-irradiated mice can be a potential approach to skin cancer treatment by combining the functions of increasing drug penetration and ROS generation required for SDT.


Assuntos
Indóis/farmacologia , Micelas , Compostos Organometálicos/farmacologia , Ultrassom , Alumínio/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Humanos , Melanoma/tratamento farmacológico , Melanoma/patologia , Melanoma Experimental/patologia , Fosfatidiletanolaminas/química , Fármacos Fotossensibilizantes/farmacologia , Polietilenoglicóis/química , Iodeto de Potássio/química , Oxigênio Singlete/química , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/patologia , Suínos
2.
Chemosphere ; 261: 127747, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32721695

RESUMO

To develop a metal-free biochar with high and inherent catalytic activity towards refractory and highly toxic contaminants in advanced oxidation processes, it is necessary to explore its reaction pathways and responsible catalytic sites. Herein, a metal-free biochar derived from corn cob (CCBC) was prepared and used for reaction pathway analysis during peroxydisulfate (PDS) activation. The pyrolysis temperature played an important role for regulating the biochar structure and properties, and CCBC obtained at 800 °C showed the best adsorption capacity and catalytic activity towards five typical organic pollutants, including 2, 4-dichlorophenol, Tetracycline hydrochloride, Ciprofloxacin, Methyl orange and Rhodamine B, due to its richer pore and defect structure. Further treatment of pharmaceutical wastewater demonstrated the good efficiency and potential of this metal-free catalyst for practical application. Radical (58% contribution) and non-radical (42% contribution) pathways were both found in CCBC/PDS system. More importantly, further redox experiments manifested that the carbon framework (defects, sp2-hybrid carbon, etc.) only made a contribution to the free radical pathway, while the ketone group (CO) of CCBC was proved to be mainly responsible for the non-radical pathway, namely the generation of singlet oxygen (1O2).


Assuntos
Carvão Vegetal/química , Sulfatos/química , Purificação da Água/métodos , Adsorção , Carbono/química , Domínio Catalítico , Compostos Orgânicos/isolamento & purificação , Oxirredução , Pirólise , Oxigênio Singlete/química , Águas Residuárias/química , Poluentes Químicos da Água/isolamento & purificação
3.
Nat Commun ; 11(1): 3262, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32591538

RESUMO

The use of photodynamic therapy (PDT) against cancer has received increasing attention over recent years. However, the application of the currently approved photosensitizers (PSs) is limited by their poor aqueous solubility, aggregation, photobleaching and slow clearance from the body. To overcome these limitations, there is a need for the development of new classes of PSs with ruthenium(II) polypyridine complexes currently gaining momentum. However, these compounds generally lack significant absorption in the biological spectral window, limiting their application to treat deep-seated or large tumors. To overcome this drawback, ruthenium(II) polypyridine complexes designed in silico with (E,E')-4,4'-bisstyryl-2,2'-bipyridine ligands show impressive 1- and 2-Photon absorption up to a magnitude higher than the ones published so far. While nontoxic in the dark, these compounds are phototoxic in various 2D monolayer cells, 3D multicellular tumor spheroids and are able to eradicate a multiresistant tumor inside a mouse model upon clinically relevant 1-Photon and 2-Photon excitation.


Assuntos
Complexos de Coordenação/uso terapêutico , Desenho de Fármacos , Fotoquimioterapia , Fótons , Rutênio/química , Animais , Proliferação de Células , Sobrevivência Celular , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Feminino , Células HeLa , Humanos , Camundongos Nus , Oxigênio Singlete/química , Análise Espectral , Esferoides Celulares/patologia
4.
Chemosphere ; 258: 127308, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32535450

RESUMO

Singlet oxygen (1O2) is well known to be formed through energy transfer from excited state organic matters to O2, playing an important role in the transformations of contaminants. However, the contribution of small oxidated aromatic compounds (OACs) to the production of 1O2 in surface water is unclear. In this study, 28 OACs were selected to investigate the correlations between their photochemical production abilities of 1O2 and molecular structures. Our results showed that the steady-state concentrations and quantum yields of 1O2 (Φ1O2) generated by OACs were in the range of 7.0 × 10-14-1.4 × 10-12 M and 2.2 × 10-4-4.7 × 10-2, respectively, indicating that the photochemical production abilities of 1O2 by OACs varied greatly with types and positions of functional groups on the molecule. More importantly, the observed photochemical production of 1O2 was most notable in cases of molecules containing -OCH3 group and benzoquinone. A good quantitative structure-property relationship model was established between 1O2 producing ability, energy of the lowest unoccupied molecular orbitals (ELUMO) and the most positive net charge of hydrogen atoms (qH+) of OACs. In addition, the role of 1O2 produced by 2, 6-dimethoxy-1, 4-benzoquinone, the OAC with the highest Φ1O2, in the photodegradation of organic contaminants was validated by the enhanced degradation of atorvastatin under simulated sunlight, suggesting that OACs ubiquitously existed in surface water may greatly affect the fate and ecological risks of organic contaminants.


Assuntos
Oxigênio Singlete/química , Poluentes Químicos da Água/química , Estrutura Molecular , Compostos Orgânicos , Oxirredução , Fotólise , Luz Solar , Água , Poluentes Químicos da Água/análise
5.
Chemosphere ; 258: 127378, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32554023

RESUMO

Light driven degradation is very promising for pollutants remediation. In the present work, photochemical reaction of tetrabromobisphenol A (TBBPA) under LED white light (λ > 400 nm) irradiation system was investigated to figure out the TBBPA photochemical degradation pathways and isotope fractionation patterns associated with transformation mechanisms. Results indicated that photochemical degradation of TBBPA would happen only with addition to humic acid in air bubbling but not in N2 bubbling. For photochemical reaction of TBBPA, singlet oxygen (1O2) was found to be important reactive oxygen species for the photochemical degradation of TBBPA. 2,6-Dibromo-4-(propan-2-ylidene)cyclohexa-2,5-dienone and two isopropyl phenol derivatives were identified as the photochemical degradation intermediates by 1O2. 2,6-Dibromo-4-(1-methoxy-ethyl)-phenol was determined as an intermediate via oxidative skeletal rearrangement, reduction and O-methylation. Hydrolysis product hydroxyl-tribromobisphenol A was also observed in the reductive debromination process. In addition, to deeply explore the mechanism, carbon and bromine isotope analysis were performed using gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) and gas chromatography-multicollector inductively coupled plasma mass spectrometry (GC/MC/ICPMS) during the photochemical degradation of TBBPA. The results showed that photochemical degradation could not result in statistically significant isotope fractionation, indicated that the bond cleavage of C-C and C-Br were not the rate controlling process. Stable isotope of carbon being not fractionated will be useful for distinguishing the pathways of TBBPA and tracing TBBPA fate in water systems. This work sheds light on photochemical degradation mechanisms of brominated organic contaminants.


Assuntos
Recuperação e Remediação Ambiental/métodos , Fotólise , Bifenil Polibromatos/análise , Poluentes Químicos da Água/análise , Substâncias Húmicas/análise , Radical Hidroxila/química , Isótopos , Modelos Teóricos , Oxirredução , Bifenil Polibromatos/efeitos da radiação , Oxigênio Singlete/química , Poluentes Químicos da Água/efeitos da radiação
6.
Phys Chem Chem Phys ; 22(21): 12228-12238, 2020 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-32432253

RESUMO

Light activated photosensitizers generate reactive oxygen species (ROS) that interfere with cellular components and can induce cell death, e.g., in photodynamic therapy (PDT). The effect of cellular components and especially proteins on the photochemistry and photophysics of the sensitizers is a key aspect in drug design and the correlating cellular response with the generation of specific ROS species. Here, we show the complex range of effects of binding of photosensitizer to a multidrug resistance protein, produced by bacteria, on the formers reactivity. We show that recruitment of drug like molecules by LmrR (Lactococcal multidrug resistance Regulator) modifies their photophysical properties and their capacity to induce oxidative stress especially in 1O2 generation, including rose bengal (RB), protoporphyrin IX (PpIX), bodipy, eosin Y (EY), riboflavin (RBF), and rhodamine 6G (Rh6G). The range of neutral and charged dyes with different exited redox potentials, are broadly representative of the dyes used in PDT.


Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Proteínas de Bactérias/metabolismo , Fármacos Fotossensibilizantes/química , Subfamília B de Transportador de Cassetes de Ligação de ATP/química , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Sítios de Ligação , Corantes/metabolismo , Corantes/efeitos da radiação , Lactococcus/química , Luz , Mutação , Fármacos Fotossensibilizantes/metabolismo , Fármacos Fotossensibilizantes/efeitos da radiação , Ligação Proteica , Oxigênio Singlete/química
7.
Chemistry ; 26(34): 7583-7588, 2020 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-32428322

RESUMO

Co single-atom catalysts (SACs) with good aqueous solubility and abundant labelling functional groups were prepared in Co/Fe bimetallic metal-organic frameworks by a facile solvothermal method without high-temperature calcination. In contrast to traditional chemiluminescence (CL) catalysts, Co SACs accelerated decomposition of H2 O2 to produce a large amount of singlet oxygen (1 O2 ) rather than superoxide (O2 .- ) and hydroxyl radical (OH. ). They were found to dramatically enhance the CL emission of the luminol-H2 O2 reaction by 1349 times, and, therefore, were employed as very sensitive signal probes for conducting CL immunoassay of cardiac troponin I. The detection limit of the target analyte was as low as 3.3 pg mL-1 . It is the first time that employment of SACs for boosting CL reactions has been validated. The Co SACs can also be employed to trace other biorecognition events with high sensitivity.


Assuntos
Radical Hidroxila/química , Luminol/química , Oxigênio Singlete/química , Catálise , Limite de Detecção , Luminescência , Medições Luminescentes/métodos , Estruturas Metalorgânicas , Superóxidos
8.
Chem Commun (Camb) ; 56(40): 5425-5428, 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32292970

RESUMO

A photoactivatable fluorogenic tetrazine-rhodaphenothiazine probe was synthesized and studied in light-assisted, bioorthogonal labeling schemes. Experimental results revealed that the bioorthogonally conjugated probe efficiently sensitizes 1O2 generation upon illumination with green or orange light and undergoes self-oxidation leading to an intensely fluorescent sulfoxide product. An added value of the present probe is that it is also suitable for STED super-resolution microscopy using a 660 nm depletion laser.


Assuntos
Corantes Fluorescentes/química , Fenotiazinas/química , Fármacos Fotossensibilizantes/química , Rodaminas/química , Animais , Células COS , Chlorocebus aethiops , Corantes Fluorescentes/efeitos da radiação , Lasers , Luz , Microscopia Confocal/instrumentação , Microscopia Confocal/métodos , Oxirredução/efeitos da radiação , Fenotiazinas/efeitos da radiação , Fármacos Fotossensibilizantes/efeitos da radiação , Rodaminas/efeitos da radiação , Oxigênio Singlete/química
9.
Ecotoxicol Environ Saf ; 197: 110644, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32325330

RESUMO

Fludioxonil has been proven valuable as a broad-spectrum fungicide. However, there are concerns about its risk posed to non-target organisms in aquatic environments. In this paper, the mechanism, photoproducts transformation and eco-toxicity of fludioxonil during •OH/1O2-initiated process were systematically studied using quantum chemistry and computational toxicology. The results indicate that the two favorable pathways of •OH/1O2-initiated reactions are both occurred in pyrrole ring. It can conclude that the rate constants of •OH and 1O2 are 1.23 × 1010 and 3.69 × 107 M-1 s-1 at 298K, respectively, which results in half-lives of <2 days in surface waters under sunlit near-surface conditions. Based on toxicity assessments, these photoproducts showed a decreased aquatic toxicity but the majority products are still toxic. This study gives more insight into the chemical transformation mechanism of fludioxonil in aquatic environments.


Assuntos
Dioxóis/análise , Radical Hidroxila/química , Fotólise , Pirróis/análise , Oxigênio Singlete/química , Poluentes Químicos da Água/análise , Reação de Cicloadição , Dioxóis/química , Dioxóis/efeitos da radiação , Ecotoxicologia , Cinética , Pirróis/química , Pirróis/efeitos da radiação , Poluentes Químicos da Água/química , Poluentes Químicos da Água/efeitos da radiação
10.
J Agric Food Chem ; 68(9): 2747-2756, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32028770

RESUMO

The induction period (IP) of ethyl linoleate stressed at 60 °C was monitored via the formation of hydroperoxides. The addition of lycopene (1% w/w) increased the IP from 7.0 to 10.0 h to prove the strong antioxidative potential in contrast to ß-carotene with pro-oxidative effects (IP: 6.0 h), both showing strong scavenging activity under fast degradation. When peroxidation was induced by singlet oxygen, both carotenoids effectively inhibited the formation of hydroperoxides, with quenching activity only observed at low singlet oxygen concentrations, while scavenging still dominated. Thus, carotenoids did not interact with the introduced singlet oxygen but rather with the radical intermediates of fat oxidation. These experiments were then transferred to lecithin-based micelles more related to biological systems, where singlet oxygen was generated in the outer aqueous phase. Lycopene and ß-carotene delayed or inhibited lipid peroxidation depending on concentration. In this setup, ß-carotene showed exclusively quenching activity, while lycopene was additionally degraded to about 70%.


Assuntos
Ácidos Linoleicos/química , Licopeno/química , beta Caroteno/química , Antioxidantes/química , Antioxidantes/farmacologia , Cinética , Lecitinas/química , Ácidos Linoleicos/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Modelos Químicos , Oxirredução , Oxigênio Singlete/química
11.
Nanoscale ; 12(9): 5332-5340, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32090217

RESUMO

Bicontinuous nanospheres (BCNs) are underutilized self-assembled nanostructures capable of simultaneous delivery of both hydrophilic and hydrophobic payloads. Here, we demonstrate that BCNs assembled from poly(ethylene glycol)-block-poly(propylene sulfide) (PEG-b-PPS), an oxidation-sensitive copolymer, are stably retained within cell lysosomes following endocytosis, resisting degradation and payload release for days until externally triggered. The oxygen scavenging properties and enhanced stability of the bicontinuous PEG-b-PPS nanoarchitecture significantly protected cells from typically cytotoxic application of pro-apoptotic photo-oxidizer pheophorbide A and chemotherapeutic camptothecin. The photo-oxidation triggered transition from a bicontinuous to micellar morphology overcame this stability, allowing on-demand cytosolic delivery of camptothecin for enhanced control over off-on cytotoxicity. These results indicate that inducible transitions in the nanostructure morphology can influence intracellular stability and toxicity of self-assembled nanotherapeutics.


Assuntos
Citosol/metabolismo , Luz , Micelas , Nanoestruturas/química , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Camptotecina/química , Camptotecina/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Clorofila/análogos & derivados , Clorofila/química , Clorofila/farmacologia , Portadores de Fármacos/química , Endocitose , Lisossomos/metabolismo , Camundongos , Oxirredução , Polietilenoglicóis/química , Células RAW 264.7 , Oxigênio Singlete/química , Oxigênio Singlete/metabolismo , Sulfetos/química
12.
J Photochem Photobiol B ; 205: 111820, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32065959

RESUMO

Recent studies focus on usage of blue light of λ = 450 nm in combination with photosensitizers to treat surface skin disorders, including cancers. In search of convenient therapeutic factor we studied riboflavin analogue 3-methyl-tetraacetylriboflavin (3MeTARF) as potential sensitizer. Riboflavin (Rfl) itself, non -toxic in the darkness, upon absorption of UVA and blue light, may act as photosensitizer. However, Rfl efficiency is limited due to its susceptibility to photodecomposition. Riboflavin's acetylated analogue, 3MeTARF, bears substituents in ribose chain, which inhibit intramolecular processes leading to degradation. Upon excitation, this compound, reveals higher photochemical resistance, remaining a good singlet oxygen generator. Thus, being more stable as the sensitizer, might be much more efficient in photodynamic processes. The objective of undertaken study was to elucidate mechanisms of 3MeTARF photoreactivity under the irradiation with blue light in comparison to its mater compound, riboflavin. We approached this goal by using spectroscopic methods, like direct singlet oxygen phosphorescence detection at 1270 nm, EPR spin trapping and oximetry. Additionally, we tested both riboflavin and 3MeTARF phototoxicity against melanoma cells (WM115) and we studied mechanism of photodynamic cell death, as well. Moreover, 3MeTARF induces apoptosis in melanoma cells at ten times lower concentration than riboflavin itself. Our studies confirmed that 3MeTARF remains stable upon blue light activation and is more efficient photosensitizer than Rfl.


Assuntos
Radiossensibilizantes , Riboflavina , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Dermatite Fototóxica , Humanos , Peróxido de Hidrogênio/metabolismo , Luz , Radiossensibilizantes/química , Radiossensibilizantes/efeitos da radiação , Radiossensibilizantes/toxicidade , Riboflavina/análogos & derivados , Riboflavina/química , Riboflavina/efeitos da radiação , Riboflavina/toxicidade , Oxigênio Singlete/química
13.
Nat Commun ; 11(1): 357, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31953423

RESUMO

Hypoxia of solid tumor compromises the therapeutic outcome of photodynamic therapy (PDT) that relies on localized O2 molecules to produce highly cytotoxic singlet oxygen (1O2) species. Herein, we present a safe and versatile self-assembled PDT nanoagent, i.e., OxgeMCC-r single-atom enzyme (SAE), consisting of single-atom ruthenium as the active catalytic site anchored in a metal-organic framework Mn3[Co(CN)6]2 with encapsulated chlorin e6 (Ce6), which serves as a catalase-like nanozyme for oxygen generation. Coordination-driven self-assembly of organic linkers and metal ions in the presence of a biocompatible polymer generates a nanoscale network that adaptively encapsulates Ce6. The resulted OxgeMCC-r SAE possesses well-defined morphology, uniform size distribution and high loading capacity. When conducting the in situ O2 generation through the reaction between endogenous H2O2 and single-atom Ru species of OxgeMCC-r SAE, the hypoxia in tumor microenvironment is relieved. Our study demonstrates a promising self-assembled nanozyme with highly efficient single-atom catalytic sites for cancer treatment.


Assuntos
Nanopartículas/química , Fotoquimioterapia/métodos , Porfirinas/química , Oxigênio Singlete/química , Oxigênio Singlete/farmacologia , Animais , Apoptose/efeitos dos fármacos , Materiais Biocompatíveis , Catalase/química , Catalase/uso terapêutico , Linhagem Celular Tumoral , Células HEK293 , Células HeLa , Humanos , Peróxido de Hidrogênio/farmacologia , Camundongos , Nanopartículas/uso terapêutico , Nanotecnologia , Neoplasias/tratamento farmacológico , Fármacos Fotossensibilizantes/farmacologia , Polímeros/farmacologia , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/farmacologia , Hipóxia Tumoral/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos
14.
Molecules ; 25(2)2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31936003

RESUMO

: A series of free base and Zn(II) phthalocyanines featuring fluorenyl antennae linked by methoxy or oxo bridges to the phthalocyanine core (Pc) were synthesized and characterized. Selected linear and nonlinear (two-photon absorption) optical properties of these new compounds were subsequently studied. As previously observed for related porphyrin dendrimers bearing 2-fluorenyl peripheral dendrons, an efficient energy transfer occurs from the peripheral antennae to the central phthalocyanine core following excitation in the fluorenyl-based π-π* absorption band of these chromophores. Once excited, these compounds relax to the ground state, mostly by emitting intense red light or by undergoing intersystem crossing. As a result, the tetrafunctionalized Zn(II) phthalocyanines are fluorescent, but can also efficiently photosensitize molecular oxygen in tetrahydrofurane (THF), forming singlet oxygen with nearly comparable yields to bare Zn(II) phthalocyanine (ZnPc). In comparison with the latter complex, the positive role of the fluorenyl-containing antennae on one- and two-photon brightness (2PA) is presently demonstrated when appended in peripheral (ß) position to the phthalocyanine core. Furthermore, when compared to known porphyrin analogues, the interest in replacing the porphyrin by a phthalocyanine as the central core to obtain more fluorescent two-photon oxygen photosensitizers is clearly established. As such, this contribution paves the way for the future development of innovative biphotonic photosensitizers usable in theranostics.


Assuntos
Fluorenos/química , Indóis/química , Fármacos Fotossensibilizantes/química , Oxigênio Singlete/química , Transferência de Energia , Fluorenos/síntese química , Indóis/síntese química , Luz , Luminescência , Modelos Moleculares , Estrutura Molecular , Compostos Organometálicos/síntese química , Compostos Organometálicos/química , Fótons , Porfirinas/química , Oxigênio Singlete/isolamento & purificação , Análise Espectral
15.
Chemosphere ; 247: 125872, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31931308

RESUMO

Reactivity of the singlet oxygen (SO), which is assumed to be one of the important oxidizers in natural waters, towards to a set of persistent herbicides, was measured for the first time using time resolved luminescence technique. It was observed that rate constants of SO reactions with the majority of studied herbicides are less than 106 M-1s-1 allowing to conclude about negligible participation of SO in oxidation of the compounds in natural waters.


Assuntos
Herbicidas/química , Oxigênio Singlete/química , Poluentes Químicos da Água/química , Cinética , Oxirredução , Oxigênio , Soluções
16.
J Photochem Photobiol B ; 204: 111802, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31981990

RESUMO

Suitable properties as well as eco-friendly synthesis of photoluminescent Au nanoclusters (NCs) make them promising compounds for biomedical diagnostics and visualization applications. However, the potential photochemical activity of such agents on cancerous cells is largely unknown. The nanoclusters (BSA-Au NCs) were synthetized in the presence of BSA (an average hydrodynamic diameter was about 9.4 nm, while the size of the metal cluster was <1.3 nm according to atomic force microscopy measurements) and possessed a broad photoluminescence band at 680 nm in buffered (pH 7.2) aqueous medium. The photochemical activity was studied by adding two fluorescent probes (dihydrorhodamine or Singlet Oxygen Sensor Green) for detection of reactive oxygen species in samples irradiated at 405 nm to minimize direct excitation of the probes. The photoluminescence measurements evidenced the capability of BSA-Au NCs to generate reactive oxygen species upon light exposure, while the observed sensitivity of the photoluminescence properties might be used to indicate photooxidative processes in the medium. The viability test performed on breast cancer cells after incubation with BSA-Au NCs and subsequent irradiation revealed notable difference in induced phototoxicity between two cell lines, which was not the case after the corresponding treatment using the photosensitizer chlorin e6.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Espécies Reativas de Oxigênio/metabolismo , Soroalbumina Bovina/química , Oxigênio Singlete/metabolismo , Animais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Bovinos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Feminino , Corantes Fluorescentes/química , Humanos , Lasers Semicondutores , Nanopartículas Metálicas/uso terapêutico , Nanopartículas Metálicas/toxicidade , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Espécies Reativas de Oxigênio/química , Oxigênio Singlete/química , Espectrometria de Fluorescência
17.
J Phys Chem Lett ; 11(4): 1228-1238, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31990196

RESUMO

Sonodynamic therapy eliminates cancer cells with reactive oxygen species (ROS) triggered by ultrasound whose energy is spatiotemporally controllable, is safe to human tissues and organs, and penetrates deeply through tissues. Its application, however, is hindered by the scarcity of sonodynamic sensitizers. We herein demonstrate piezoelectric materials as a new source of sonodynamic sensitizers, using few-layer black phosphorus (BP) nanosheet as a model. BP nanosheet exhibited ultrasound-excited cytotoxicity to cancer cells via ROS generation, thereby suppressing tumor growth and metastasis without causing off-target toxicity in tumor-bearing mouse models. The ultrasonic wave introduces mechanical strain to the BP nanosheet, leading to piezoelectric polarization which shifts the conduction band of BP more negative than O2/·O2- while its valence band more positive than H2O/·OH, thereby accelerating the ROS production. This work identifies a new mechanism for discovering sonodynamic sensitizers and suggests BP nanosheet as an excellent sensitizer for tumor sonodynamic therapy.


Assuntos
Nanoestruturas/química , Fósforo/química , Ondas Ultrassônicas , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Camundongos , Nanoestruturas/toxicidade , Neoplasias/patologia , Neoplasias/radioterapia , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/metabolismo , Oxigênio Singlete/química , Oxigênio Singlete/metabolismo , Transplante Heterólogo , Ultrassonografia
18.
Inorg Chem ; 59(4): 2426-2433, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-31977196

RESUMO

The development of new photoactive metal complexes that can trigger oxidative damages to the genetic material is of great interest. In the present paper, we describe the detailed study of a highly photo-oxidant iridium(III) complex that triggers photoinduced electron transfer (PET) with purine DNA bases. The PET has been studied by luminescence and laser flash photolysis experiments. From plasmid DNA agarose gel electrophoresis experiments, we demonstrated the high ability of the iridium complex to induce strand breaks upon light irradiation. Reactive oxygen species (ROS)-specific scavengers and stabilizers were employed to identify that the photocleavage process, the results of which infer singlet oxygen and hydrogen peroxide as the predominant species. To the best of our knowledge, the present work represents one of the few study for highly photo-oxidant bis-cyclometalated iridium(III) complex toward DNA.


Assuntos
Complexos de Coordenação/química , DNA/química , Complexos de Coordenação/efeitos da radiação , Quebras de DNA/efeitos dos fármacos , Peróxido de Hidrogênio/química , Irídio/química , Irídio/efeitos da radiação , Luz , Oxirredução , Oxigênio Singlete/química
19.
Molecules ; 25(1)2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31947934

RESUMO

We have previously demonstrated that singlet oxygen photosensitization abilities of Zn(II) phthalocyanines (Zn(II)Pcs) are enhanced through α-functionalization with bulky fluorinated substituents (i.e., bis(trifluoromethyl)phenyl units) at facing positions of ABAB Zn(II)Pcs, where A and B refer to differently functionalized isoindoles. In this work, we have prepared the Zn(II)Pc ABAB 1 endowed with hydrophilic triethylene glycol monomethyl ether (i.e., at the A isoindoles) to provide solubility in aqueous media, together with its A3B and A4 counterparts, and compared their ability to behave as photosensitizers for photodynamic therapy. All photophysical data, aggregation studies and preliminary in vitro biological assays in cell cultures of SCC-13 (squamous cell carcinoma) and HeLa (cervical cancer cells), have proved ABAB 1 as the best photosensitizer of the series.


Assuntos
Indóis/química , Indóis/uso terapêutico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/uso terapêutico , Linhagem Celular Tumoral , Células HeLa , Humanos , Interações Hidrofóbicas e Hidrofílicas , Polietilenoglicóis/química , Oxigênio Singlete/química , Solubilidade
20.
J Oleo Sci ; 69(1): 7-22, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31902897

RESUMO

Recently, singlet-oxygen (1O2) quenching and aroxyl-radical (ArO·) scavenging rates (kQ and kS, respectively) of eight vegetable oils were measured in the ethanol/chloroform/D2O solution. Furthermore, the kQ and kS values and concentrations of four tocopherols and four tocotrienols contained in the vegetable oils were measured. In this study, the concentrations of nine fatty acids (including stearic, oleic, linoleic, and linolenic acids) comprising the above-mentioned eight vegetable oils were determined by gas chromatography. The kQ and kS values for ethyl stearate, ethyl oleate, ethyl linoleate, methyl linolenate, and glyceryl trioleate in the ethanol/chloroform/D2O solution were measured by UV-vis spectrophotometry. Based on the results obtained for the above-mentioned fatty acid esters, the kQ and kS values were estimated for nine fatty acids. Furthermore, comparisons of kQ values observed for the vegetable oils with the sum of the product {∑kQAO-i [AO-i]} of the kQAO-i values obtained for each antioxidant-i (AO-i) and the concentrations ([AO-i]) of AO-i (i.e., four tocopherols (& four tocotrienols) and nine fatty acids) contained in vegetable oils were performed. Based on the results, a detailed comparison of the contributions of the tocopherols (and tocotrienols) and the fatty acids to the 1O2-quenching rate constants (kQ) was performed. This indicated that both the tocopherols (and tocotrienols) and the fatty acids contribute to the 1O2- quenching. A similar comparison was conducted for the ArO· -scavenging rate constants (kS). The results suggested that only the tocopherols (and tocotrienols) contained in the oils contributed to the ArO· -scavenging, with negligible contribution from the fatty acids.


Assuntos
Ácidos Graxos/química , Depuradores de Radicais Livres , Óleos Vegetais/química , Oxigênio Singlete/química , Vitamina E/química
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