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1.
J Photochem Photobiol B ; 200: 111654, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31671373

RESUMO

The Enterococcus faecalis is a microorganism that causes multiple forms of resistance to a wide range of drugs used clinically. aPDT is a technique in which a visible light activates photosensitizer (PS), resulting in generation of reactive oxygen species that kill bacteria unselectively via an oxidative burst. aPDT is an alternative to antibiotics with the advantage of not causing resistance. The search for an alternative treatment of infections caused by E. faecalis, without using antibiotics, is off great clinical importance. The aim of present investigation was to assess the efficacy of using 3.32 ηg/mL of 1,9-dimethylmethylene blue (DMMB) as photosensitizer associated with the use of either Laser (λ660 nm) or LED (λ632 ±â€¯2 nm) using different energy densities (6, 12 and 18 J/cm2) to kill E. faecalis in vitro. Under different experimental conditions, 14 study groups, in triplicate, were used to compare the efficacy of the aPDT carried out with either the laser or LED lights using different energy densities associated to DMMB. The most probable number method (MPN) was used for quantitative analysis. Photodynamic antimicrobial effectiveness was directly proportional to the energy density used, reaching at 18 J/cm2, 99.999998% reduction of the counts of E. faecalis using both light sources. The results of this study showed that the use of 3.32 ηg/mL of DMMB associated with the use 18 J/cm2 of LED light (λ632 ±â€¯2 nm) reduced >7-log counts of planktonic culture of E. faecalis.


Assuntos
Enterococcus faecalis/efeitos dos fármacos , Luz , Azul de Metileno/análogos & derivados , Fármacos Fotossensibilizantes/farmacologia , Animais , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/veterinária , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Azul de Metileno/química , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/uso terapêutico
2.
Chem Commun (Camb) ; 55(87): 13128-13131, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31616871

RESUMO

We report here a novel light-triggered nanosystem based on co-assembling nanoaggregates (NAs) of lipophilic photosensitizers and lipophilic prodrugs containing multiple thioethers. Upon laser irradiation, the oxidization of the multiple thioethers by photosensitizer-generated singlet oxygen could rapidly destroy the NA structure, resulting in faster drug release than those containing a single thioether.


Assuntos
Luz , Nanopartículas/química , Fármacos Fotossensibilizantes/química , Pró-Fármacos/química , Sulfetos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Humanos , Estrutura Molecular , Tamanho da Partícula , Fármacos Fotossensibilizantes/farmacologia , Pró-Fármacos/farmacologia , Oxigênio Singlete/química , Sulfetos/farmacologia , Propriedades de Superfície
4.
Chem Commun (Camb) ; 55(90): 13518-13521, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31608902

RESUMO

A distyryl boron dipyrromethene based photosensitiser substituted with 1,2,4,5-tetrazine and alkyne moieties was prepared. Through site-specific bioorthogonal reactions with the complementary functional tags anchored on the membrane of A431 human epidermoid carcinoma cells, this versatile photosensitiser exhibited enhanced cellular uptake and photocytotoxicity. The bioorthogonal ligation was also demonstrated in tumour-bearing nude mice.


Assuntos
Antineoplásicos/farmacologia , Compostos de Boro/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Porfobilinogênio/análogos & derivados , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Compostos de Boro/síntese química , Compostos de Boro/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Camundongos , Camundongos Nus , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Imagem Óptica , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/química , Porfobilinogênio/síntese química , Porfobilinogênio/química , Porfobilinogênio/farmacologia , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-Atividade
5.
J Photochem Photobiol B ; 200: 111646, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31655457

RESUMO

Antimicrobial Photodynamic Therapy (aPDT) is an alternative to conventional treatments of local infections such as the use of antibiotics, which may lead to the development of resistance. aPDT besides requiring the use of a photosensitiser also needs a light source do be carried out. In the search for efficient and low-cost procedure the use of multispectral polarized light (λ400-2000 nm) emerges as a possibility for the execution of aPDT. The use of a highly effective photosensitizer is also of great importance. 1,9-Dimethyl-Methylene Blue Zinc Chloride Double Salt - DMMB is a potent phenothiazine derivative that presents high photodynamic action due to its high lipophilicity as well as a greater quantum yield of Singlet oxygen and phototoxicity when compared to other Photosensitizers. The aim of this study was to assess, In Vitro, the efficacy of aPDT on Staphylococcus aureus (ATCC 25923) using different concentrations of DMMB associated to a Polarized light source (Bioptron®, 40 mW, ᴓ = 15.8 cm2) using different energy densities. Based on the IC50, 150 and 300 ng/mL of DMMB concentrations were chosen for this study. Twelve experimental groups were used: (Control, PLs, PSs and aPDTs). Serial dilutions (up to 10-8) of the bacterial inoculum were used and the DMMB was added using the two previously determined concentrations. After 5 min of preincubation the dilutions of the inoculum were illuminated by the polarized light source. Subsequently, 100 µL of each dilution, in triplicate, were inoculated into Petri dishes containing TSA medium and incubated in a bacteriological oven at 37 °C for 24-h and quantification of UFCs was done. The results showed significant exponential reduction (p < .0001) of 99.93% (150 ng/mL + LP 10 J/cm2) and 99.97% (300 ng/mL + LP 5 J/cm2) the CFU counts in comparison to non-illuminated control. The results of this study allow to conclude that aPDT carried out with 1,9-Dimethyl-Methylene Blue Zinc Chloride Double Salt-DMMB and a PL souce was efficacious on the reduction (99.97%), in vitro, of the bacterial counts of S. aureus.


Assuntos
Anti-Infecciosos/farmacologia , Cloretos/química , Azul de Metileno/análogos & derivados , Fármacos Fotossensibilizantes/química , Staphylococcus aureus/efeitos dos fármacos , Compostos de Zinco/química , Anti-Infecciosos/química , Luz , Azul de Metileno/química , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia
6.
Photochem Photobiol Sci ; 18(11): 2792-2803, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31626259

RESUMO

We report the first exocyclically metallated tetrapyridinoporphyrazine, [tetrakis-(trans-Pt(NH3)2Cl)-tetra(3,4-pyrido)porphyrazine-zinc(ii)](NO3)4 (4), synthesized in a multistep synthesis starting from 3,4-pyridinedicarbonitrile (1). The synthetic procedure involved a platination reaction of the intermediate tetra(3,4-pyrido)porphyrazine-zinc(ii) (2), whereby the zinc(ii) enhanced the solubility of the intermediate enabling the platination reaction. A similar approach to synthesize [tetrakis-(trans-Pt(NH3)2Cl)-tetra(3,4-pyrido)porphyrazine](NO3)4 (5) failed due to the unsuitable solubility properties of the intermediate tetra(3,4-pyrido)porphyrazine (3). The final product 4 and the intermediates were characterized, the photochemical and photophysical properties were determined and the photocytotoxicities were investigated. We demonstrate that the platinated tetra-pyridinoporphyrazine 4 is a potential photosensitizer for photodynamic therapy (PDT).


Assuntos
Fármacos Fotossensibilizantes/química , Porfirinas/química , Zinco/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Luz , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/síntese química , Porfirinas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Espectrometria de Fluorescência , Estereoisomerismo
7.
Chem Commun (Camb) ; 55(90): 13542-13545, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31647067
8.
Photochem Photobiol Sci ; 18(10): 2521-2530, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31482167

RESUMO

Sprouted seeds are gaining popularity worldwide due to their high nutritional value. At the same time, they are among the most highly contaminated fresh produce and have been recognized as the primary source of food-borne pathogens, such as E. coli O157 and harmful microfungi. The antifungal and antibacterial properties of chlorophyllin-based photosensitization in vitro together with successful application of this treatment for microbial control in wheat sprouts have been investigated. First, we examined the antimicrobial efficiency of chlorophyllin (Chl, 1.5 × 10-5-5 × 10-3 M) activated in vitro by visible light (405 nm, radiant exposure: 18 J cm-2) against the food-borne pathogen Escherichia coli and plant pathogen Fusarium oxysporum. Results revealed that this treatment (1.5 × 10-5 M Chl, incubation time 1 h, 405 nm, radiant exposure: 18 J cm-2) can reduce the E. coli population by 95%. Moreover, at higher chlorophyllin concentrations (5 × 10-4-5 × 10-3 M Chl), it is possible to delay the growth of F. oxysporum by 51-74%. The decontamination of wheat seeds by chlorophyllin-based photosensitization (5 × 10-4 M Chl, 405 nm, radiant exposure: 18 J cm-2) remarkably reduced the viability of surface-attached mesophilic bacteria (∼2.5log CFU g-1), E. coli (∼1.5log CFU g-1) and yeasts/fungi (∼1.5log CFU g-1). Moreover, SEM images confirmed that this treatment did not damage the grain surface microstructure. Most importantly, Chl-based photosensitization did not reduce the seed germination rate or seedling growth and had no impact on the visual qualities of sprouts. In conclusion, the chlorophyllin-based photosensitization treatment, being nonthermal, environmentally friendly and cost-effective, has huge potential for microbial control of highly contaminated germinated wheat sprouts and seeds used to produce sprouts, especially in organic farming.


Assuntos
Clorofilídios/farmacologia , Escherichia coli/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Fármacos Fotossensibilizantes/farmacologia , Triticum/microbiologia , Antibacterianos/química , Antibacterianos/farmacologia , Clorofilídios/química , Germinação , Luz , Fármacos Fotossensibilizantes/química , Sementes/crescimento & desenvolvimento , Sementes/microbiologia , Triticum/crescimento & desenvolvimento
9.
Photochem Photobiol Sci ; 18(11): 2707-2716, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31556891

RESUMO

In this study, the optimal parameters for the photodynamic inactivation (PDI) of Staphylococcus aureus in bacterial suspensions and in cheese were assessed using a water-soluble curcumin salt as the photosensitizer (PS). The in vitro study aimed at finding the optimal concentration and light dose to promote S. aureus photokilling. Four main groups were proposed: CONTROL (L-C-), LIGHT (L+C-), CUR (L-C+) and PDI (L+C+). A fixed light dose (LED, 450 ± 10 nm, 10 J cm-2) was applied using four different PS concentrations (0.75, 1.0, 1.5 and 3.0 mg mL-1). The dose also varied from 10-100 J cm-2 for a fixed concentration. High inactivation rates were observed for all light doses, with a maximum reduction of 7.58 log10 at 100 J cm-2 (p ≪ 0.05). Saturation of the PDI effect was observed after a 10 minute illumination time, as well as a slight decrease in the S. aureus population for increasing illumination times in the L+C- group. As an application, the concentration showing the best decontamination performance in vitro (0.75 mg mL-1) was applied to decontaminate cheese in loco. PDI in two types of coalho cheese, a rennet-coagulated cheese commonly consumed in Brazil, was investigated. The results showed no significant inactivation in unpasteurized cheese, but a 4.34 log10 reduction for t > 5 min in pasteurized specimens. In conclusion, the present PDI-catalyzed curcumin photosensitizer inactivated S. aureus at statistically significant levels in vitro, in pasteurized cheese, but not in unpasteurized specimens.


Assuntos
Queijo/microbiologia , Curcumina/farmacologia , Contaminação de Alimentos/prevenção & controle , Fármacos Fotossensibilizantes/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Luz
10.
Photochem Photobiol Sci ; 18(11): 2730-2739, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31560013

RESUMO

Photodynamic therapy (PDT) of bacterial strains presents an attractive potential alternative to antibiotic therapies in search of the solution for the chemoresistance problem. The efficacy of the treatment is dependent on the interaction of photochemically active substances called photosensitizers (PSs) with the bacterial cell wall or their intracellular accumulation. In addition to exogenous PSs, other molecules such as 5-aminolevulinic acid (5-ALA), a natural precursor of heme, are gaining interest. When provided exogenously to cells, 5-ALA uptake results in the overproduction of various photoactive porphyrins. The pattern of their intracellular accumulation and release to the surroundings depends on incubation conditions such as the applied 5-ALA concentration, cell density and incubation duration. The detection of endogenously synthesized porphyrins in samples of Salmonella enterica cells and supernatants was accomplished after 4 h and 20 h incubation periods by means of fluorescence spectroscopy. The relative proportions of different types of porphyrins were assessed by modeling the registered spectra with the fluorescence spectra of standard porphyrins. After the shorter incubation period, the dominant porphyrins in the supernatant medium were coproporphyrins. The longer incubation period shifted the relative proportion of intracellular porphyrins from protoporphyrin IX towards water-soluble porphyrins such as uroporphyrin I, which interfered with additional by-products. The time-dependent changes in compositions of both intracellular and extracellular porphyrins imply that 5-ALA-induced sensitization might have triggered a complex protective mechanism of bacterial cells. Thus, identification and evaluation of the relative amounts of porphyrins, which accumulate in bacterial cells and are extruded outside after different time periods, could provide access to valuable information, working towards more efficient applications of 5-ALA-based antibacterial PDT.


Assuntos
Ácido Aminolevulínico/química , Fármacos Fotossensibilizantes/química , Porfirinas/química , Salmonella enterica/química , Espectrometria de Fluorescência , Ácido Aminolevulínico/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/metabolismo , Salmonella enterica/efeitos dos fármacos
12.
Chem Commun (Camb) ; 55(72): 10792-10795, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31432816

RESUMO

Hypoxia, as an important feature in tumor sites, greatly hinders the performance of photosensitizers, thus affecting the efficacy of photodynamic therapy (PDT). Therefore, designing and preparing new photosensitizer with high photosensitivity under hypoxic condition presents a great challenge that urgently needs to be solved. In this work, a new nano-MOF material using Mn(ii) as the active center can catalytically decompose high concentrations of H2O2 in tumor cells to generate O2, thereby improving the PDT efficacy in hypoxic tumors. The Mn-MOF also produces 1O2 under light irradiation, which finally induces cancer cell apoptosis. This work offers a new strategy for the design and discovery of effective photosensitizers for PDT.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Manganês/farmacologia , Estruturas Metalorgânicas/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Hipóxia Tumoral/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Feminino , Peróxido de Hidrogênio/metabolismo , Manganês/química , Estruturas Metalorgânicas/química , Camundongos , Oxigênio/metabolismo , Tamanho da Partícula , Fármacos Fotossensibilizantes/química , Propriedades de Superfície
13.
Chemistry ; 25(55): 12801-12809, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31381210

RESUMO

Photodynamic therapy (PDT) is a promising cancer ablation method, but its efficiency is easily affected by several factors, such as the insufficient delivery of photosensitizers, low oxygen levels as well as long distance between singlet oxygen and intended organelles. A multifunctional nanohybrid, named MGAB, consisting of gelatin-coated manganese dioxide and albumin-coated gold nanoclusters, was designed to overcome these issues by improving chlorin e6 (Ce6) delivery and stimulating oxygen production in lysosomes. MGAB were quickly degraded in a high hydrogen peroxide, high protease activity, and low pH microenvironment, which is closely associated with tumor growth. The Ce6-loaded MGAB were picked up by tumor cells through endocytosis, degraded within the lysosomes, and released oxygen and photosensitizers. Upon near-infrared light irradiation, the close proximity of oxygen with photosensitizer within lysosomes enabled the production of cytotoxic singlet oxygen, resulting in more effective PDT.


Assuntos
Portadores de Fármacos/química , Endocitose/fisiologia , Lisossomos/química , Compostos de Manganês/química , Óxidos/química , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/química , Oxigênio Singlete/metabolismo , Humanos , Raios Infravermelhos , Oxigênio , Fármacos Fotossensibilizantes/farmacocinética , Porfirinas/metabolismo , Oxigênio Singlete/química
14.
Int J Nanomedicine ; 14: 5527-5540, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31413561

RESUMO

Background: Nonspecific tumor targeting, potential relapse and metastasis of tumor after treatment are the main barriers in clinical photodynamic therapy (PDT) for cancer, hence, inhibiting relapse and metastasis of tumor is significant issues in clinic. Purpose: In this work, chidamide as a histone deacetylases inhibitor (HADCi) was bound onto a pH-responsive block polymer folate polyethylene glycol-b-poly(aspartic acid) (PEG-b-PAsp) grafted folate (FA-PEG-b-PAsp) to obtain the block polymer folate polyethylene glycol-b-poly(asparaginyl-chidamide) (FA-PEG-b-PAsp-chidamide, FPPC) as multimodal tumor-targeting drug-delivery carrier to inhibiting tumor cell proliferation and tumor metastasis in mice. Methods: Model photosensitizer pyropheophorbide-a (Pha) was encapsulated by FPPC in PBS to form the polymer micelles Pha@FPPC [folate polyethylene glycol-b-poly(asparaginyl-chidamide) micelles encapsulating Pha]. Pha@FPPC was characterized by transmission electron microscope and dynamic light scattering; also, antitumor activity in vivo and in vitro were investigated by determination of cellular ROS level, detection of cell apoptosis and cell cycle arrest, PDT antitumor activity in vivo and histological analysis. Results: With favorable and stable sphere morphology under transmission electron microscope (TEM) (~93.0 nm), Pha@FPPC greatly enhanced the cellular uptake due to its folate-mediated effective endocytosis by mouse melanoma B16-F10 cells and the yield of ROS in tumor cells induced by PDT, and mainly caused necrocytosis and blocked cell growth cycle not only in G2 phase but also in G1/G0 phase after PDT. Pha@FPPC exhibited lower dark cytotoxicity in vitro and a better therapeutic index because of its higher dark cytotoxicity/photocytotoxicity ratio. Moreover, Pha@FPPC not only significantly inhibited the growth of implanted tumor and prolonged the survival time of melanoma-bearing mice due to both its folate-mediated tumor-targeting and selectively accumulation at tumor site by EPR (enhanced permeability and retention)effect as micelle nanoparticles but also remarkably prevented pulmonary metastasis of mice melanoma after PDT compared to free Pha, demonstrating its dual antitumor characteristics of PDT and HDACi. Conclusion: As a folate-mediated and acid-activated chidamide-grafted drug-delivery carrier, FPPC may have great potential to inhibit tumor metastasis in clinical photodynamic treatment for cancer because of its effective and multimodal tumor-targeting performance as photosensitizer vehicle.


Assuntos
Aminopiridinas/química , Benzamidas/química , Ácido Fólico/uso terapêutico , Micelas , Fotoquimioterapia , Fármacos Fotossensibilizantes/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Clorofila/análogos & derivados , Clorofila/farmacologia , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Endocitose/efeitos dos fármacos , Ácido Fólico/farmacologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/patologia , Camundongos Endogâmicos C57BL , Nanopartículas/química , Nanopartículas/ultraestrutura , Fármacos Fotossensibilizantes/farmacologia , Polietilenoglicóis/química , Espécies Reativas de Oxigênio/metabolismo
15.
Life Sci ; 233: 116710, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31369762

RESUMO

AIMS: The naturally occurring compound curcumin has been proposed for a number of pharmacological applications. In spite of the promising chemotherapeutic properties of the molecule, the use of curcumin has been largely limited by its chemical instability in water. In this work, we propose the use of water soluble proteins to overcome this issue in perspective applications to photodynamic therapy of tumors. MATERIALS AND METHODS: Curcumin was bound to bovine serum albumin and its photophysical properties was studied as well as its effect on cell viability after light exposure through MTT assay and confocal imaging. KEY FINDINGS: Bovine serum albumin binds curcumin with moderate affinity and solubilizes the hydrophobic compound preserving its photophysical properties for several hours. Cell viability assays demonstrate that when bound to serum albumin, curcumin is an effective photosensitizer for HeLa cells, with better performance than curcumin alone. Confocal fluorescence imaging reveals that when curcumin is delivered alone, it preferentially associates with mitochondria, whereas curcumin bound to bovine serum albumin is found in additional locations within the cell, a fact that may be related to the higher phototoxicity observed in this case. SIGNIFICANCE: The higher bioavailability of the photosensitizing compound curcumin when bound to serum albumin may be exploited to increase the efficiency of the drug in photodynamic therapy of tumors.


Assuntos
Apoproteínas/metabolismo , Apoptose/efeitos dos fármacos , Curcumina/farmacologia , Sistemas de Liberação de Medicamentos , Mioglobina/metabolismo , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Soroalbumina Bovina/metabolismo , Animais , Apoproteínas/química , Apoptose/efeitos da radiação , Bovinos , Sobrevivência Celular , Curcumina/química , Células HeLa , Cavalos , Humanos , Mioglobina/química , Fármacos Fotossensibilizantes/química , Soroalbumina Bovina/química
16.
Chem Commun (Camb) ; 55(73): 10972-10975, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31453611

RESUMO

Platinum-resistant cancer cells are sensitive to changes in the levels of reactive oxidative species (ROS). Herein, we design a biotin-modified Ru(ii) complex as a photosensitizer (denoted as Ru-Biotin). Ru-Biotin can selectively target cancer cells and produce vast amounts of singlet oxygen under two-photon excitation at 820 nm leading to cell apoptosis. Ru-Biotin is therefore an excellent candidate to overcome platinum resistance via two-photon photodynamic therapy.


Assuntos
Antineoplásicos/farmacologia , Biotina/análogos & derivados , Biotina/farmacologia , Complexos de Coordenação/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Rutênio/química , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/efeitos da radiação , Apoptose/efeitos dos fármacos , Biotina/síntese química , Biotina/efeitos da radiação , Caspase 3/metabolismo , Caspase 7/metabolismo , Linhagem Celular Tumoral , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Complexos de Coordenação/efeitos da radiação , Humanos , Raios Infravermelhos , Fotoquimioterapia/métodos , Fótons , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/efeitos da radiação , Oxigênio Singlete/metabolismo
17.
Chem Biodivers ; 16(10): e1900262, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31429182

RESUMO

The photodynamic activity of Neutral Red and the new monobrominated Neutral Red was studied in suspensions of Staphylococcus aureus. The effect of mannitol and sodium azide in the presence of 25 µm photosensitizer on lethal photosensitization were investigated. The results of the mechanistic evaluation of Neutral Red showed that both mannitol and sodium azide produced a completed protective effect after irradiation without significant differences between them. The evaluation of monobrominated Neutral Red also showed a protective effect of microorganisms with the addition of mannitol. Although sodium azide produced a protective effect of the photoinactivation, it was incomplete and less than that exhibited by mannitol. The results indicate that the starting reagent, Neutral Red, is a producer of radical species, acting through a type I mechanism, whereas the halogenated derivative of Neutral Red produced reactive oxygen species and a contribution of singlet molecular oxygen cannot be discarded in the photoinactivation of Staphylococcus aureus cells. These results, analyzed together with the previously evaluated properties of the dyes, allow us to explain the differences observed in the photoinactivation of Staphylococcus aureus mediated by both azine photosensitizers.


Assuntos
Antibacterianos/farmacologia , Vermelho Neutro/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Azida Sódica/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Vermelho Neutro/análogos & derivados , Vermelho Neutro/química , Processos Fotoquímicos , Fármacos Fotossensibilizantes/química , Azida Sódica/química
18.
Photochem Photobiol Sci ; 18(10): 2374-2380, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31380867

RESUMO

Mosquitoes are carriers of dangerous infectious disease pathogens all over the world. Owing to travelling and global warming, tropical disease-carrying species such as Aedes, Anopheles and Culex spread beyond tropical and subtropical zones, even to Europe. The aim of this study is to investigate the potential of photodynamic agents to combat mosquito larvae. Three different photosensitizers were tested on Chaoborus sp. larvae: TMPyP and TPPS as antimicrobial photosensitizers, and mTHPC as a PDT drug against eukaryotic animal and human cells. Chaoborus sp. is a commercially available harmless species developing translucent larvae similar to the larvae of Aedes, Anopheles and Culex. The uptake of photosensitizers by the larvae was tested by fluorescence microscopy. All tested photosensitizers were observed in the intestinal tract of the living larvae, and none of the photosensitizers was found in the larval tissues. In phototoxicity tests, mTHPC and TPPS did not have any effect on the larvae, while TMPyP killed the larvae efficiently. TPPS is an antimicrobial photosensitizer, mainly phototoxic to Gram-positive bacteria. TMPyP is well known as an efficient photosensitizer against Gram-negative bacteria like most species of the intestinal flora. From this result, we conclude that the photodynamic inactivation of the intestinal flora leads to the death of mosquito larvae. The feasibility of mosquito larvae control by photodynamic inactivation of their intestinal flora instead of the direct killing of the larvae is a promising alternative to other highly toxic insecticides. Compared to insecticides and other biochemical toxins, photosensitizers are not dark toxic. No resistance against photosensitizers is known so far. Thus, the dilution of the active substances by being distributed in the environment, which promotes the development of resistance in biocides of all kinds, does not pose danger. Thus, it reduces the potential side effects on environment and human health.


Assuntos
Aedes/efeitos dos fármacos , Fármacos Fotossensibilizantes/farmacologia , Aedes/crescimento & desenvolvimento , Animais , Intestinos/efeitos dos fármacos , Larva/efeitos dos fármacos , Controle de Mosquitos , Porfirinas/farmacologia
19.
Photochem Photobiol Sci ; 18(11): 2565-2612, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31397467

RESUMO

Photodynamic therapy (PDT) is a well-established treatment option in the treatment of certain cancerous and pre-cancerous lesions. Though best-known for its application in tumor therapy, historically the photodynamic effect was first demonstrated against bacteria at the beginning of the 20th century. Today, in light of spreading antibiotic resistance and the rise of new infections, this photodynamic inactivation (PDI) of microbes, such as bacteria, fungi, and viruses, is gaining considerable attention. This review focuses on the PDI of viruses as an alternative treatment in antiviral therapy, but also as a means of viral decontamination, covering mainly the literature of the last decade. The PDI of viruses shares the general action mechanism of photodynamic applications: the irradiation of a dye with light and the subsequent generation of reactive oxygen species (ROS) which are the effective phototoxic agents damaging virus targets by reacting with viral nucleic acids, lipids and proteins. Interestingly, a light-independent antiviral activity has also been found for some of these dyes. This review covers the compound classes employed in the PDI of viruses and their various areas of use. In the medical area, currently two fields stand out in which the PDI of viruses has found broader application: the purification of blood products and the treatment of human papilloma virus manifestations. However, the PDI of viruses has also found interest in such diverse areas as water and surface decontamination, and biosafety.


Assuntos
Luz , Fotoquimioterapia/tendências , Viroses/terapia , Vírus/efeitos da radiação , Humanos , Papillomaviridae/efeitos dos fármacos , Papillomaviridae/efeitos da radiação , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Viroses/tratamento farmacológico , Viroses/metabolismo , Vírus/efeitos dos fármacos , Vírus/metabolismo
20.
Photochem Photobiol Sci ; 18(10): 2381-2396, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31432864

RESUMO

The synthesis, photophysics, and photobiological activities of a series of novel neutral heteroleptic cyclometalated iridium(iii) complexes incorporating boron dipyrromethene (BODIPY) substituted N-heterocyclic carbene (NHC) ligands (Ir1-Ir5) are reported. The effect of the substitution position of BODIPY on the NHC ligands, either on C4 of the phenyl ring (Ir1-Ir3) or C5 of the benzimidazole unit (Ir4 and Ir5), and its linker type (single or triple bond) on the photophysical properties was studied. Ir1-Ir5 exhibited BODIPY-localized intense 1IL (intraligand transition)/1MLCT (metal-to-ligand charge transfer) absorption at 530-543 nm and 1,3IL/1,3CT (charge transfer) emission at 582-610 nm. The nanosecond transient absorption results revealed that the lowest triplet excited states of these complexes were the BODIPY-localized 3π,π* states. Complexes Ir4 and Ir5 exhibited blue-shifted 1IL absorption and 1,3IL/1,3CT emission bands compared to the corresponding absorption and emission bands in complexes Ir1 and Ir3. However, replacing the methyl substituents on N3 of benzimidazole in complexes Ir1 and Ir4 with oligoether substituents in Ir3 and Ir5, respectively, did not impact the energies of the low-energy absorption and emission bands in the corresponding complexes. Water-soluble complexes Ir3 and Ir5 have been explored as photosensitizers for in vitro photodynamic therapy (PDT) effects toward human SKMEL28 melanoma cells. Ir3 showed no dark cytotoxicity (EC50 > 300 µM) but good photocytotoxic activity (9.66 ± 0.28 µM), whereas Ir5 exhibited a higher dark cytotoxicity (20.2 ± 1.26 µM) and excellent photocytotoxicity (0.15 ± 0.01 µM). The phototherapeutic indices with visible light (400-700 nm) activation were >31 for Ir3 and 135 for Ir5. Ir3 and Ir5 displayed 1O2 quantum yields of 38% and 22% in CH3CN, respectively, upon 450 nm excitation. Ir5 was more effective at generating reactive oxygen species (ROS) in vitro. Ir5 was also active against Staphylococcus aureus upon visible light activation, with a phototherapeutic index of >15 and EC50 value of 6.67 µM. These photobiological activities demonstrated that these neutral Ir(iii) complexes are promising in vitro PDT reagents, and substitution at C5 on the benzimidazole group of the NHC ligand was superior to C4 substitution on the phenyl ring.


Assuntos
Compostos de Boro/química , Complexos de Coordenação/química , Irídio/química , Metano/análogos & derivados , Fármacos Fotossensibilizantes/síntese química , Anti-Infecciosos/síntese química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/farmacologia , Complexos de Coordenação/uso terapêutico , Humanos , Ligantes , Luz , Metano/química , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Teoria Quântica , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Nanomedicina Teranóstica
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