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1.
Chemistry ; 30(16): e202303766, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38233363

RESUMO

Intracellular Staphylococcus aureus (S. aureus), especially the methicillin resistant staphylococcus aureus (MRSA), are difficult to detect and eradicate due to the protection by the host cells. Antibacterial photodynamic therapy (aPDT) offers promise in treating intracellular bacteria, provided that selective damage to the bacteria ranther than host cells can be realized. According to the different nitroreductase (NTR) levels in mammalian cells and S. aureus, herein NTR-responsive photosensitizers (PSs) (T)CyI-NO2 were designed and synthesized. The emission and 1O2 generation of (T)CyI-NO2 are quenched by the 4-nitrobenzyl group, but can be specifically switched on by bacterial NTR. Therefore, selective imaging and photo-inactivation of intracellular S. aureus and MRSA were achieved. Our findings may pave the way for the development of more efficient and selective aPDT agents to combat intractable intracellular infections.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Fotoquimioterapia , Animais , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Staphylococcus aureus , Dióxido de Nitrogênio , Fotoquimioterapia/métodos , Antibacterianos/farmacologia , Mamíferos
2.
Int J Mol Sci ; 24(9)2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37175463

RESUMO

The ruthenium polypyridine complex [Ru(dppa)2(pytp)] (PF6)2 (termed as ZQX-1), where dppa = 4,7-diphenyl-1,10-phenanthroline and pytp = 4'-pyrene-2,2':6',2''-terpyridine, has been shown a high and selective cytotoxicity to hypoxic and cisplatin-resistant cancer cells either under irradiation with blue light or upon two-photon excitation. The IC50 values of ZQX-1 towards A549 cancer cells and HEK293 health cells are 0.16 ± 0.09 µM and >100 µM under irradiation at 420 nm, respectively. However, the mechanism of action of ZQX-1 remains unclear. In this work, using the quantitative proteomics method we identified 84 differentially expressed proteins (DEPs) with |fold-change| ≥ 1.2 in A549 cancer cells exposed to ZQX-1 under irradiation at 420 nm. Bioinformatics analysis of the DEPs revealed that photoactivated ZQX-1 generated reactive oxygen species (ROS) to activate oxidative phosphorylation signaling to overproduce ATP; it also released ROS and pyrene derivative to damage DNA and arrest A549 cells at S-phase, which synergistically led to oncotic necrosis and apoptosis of A549 cells to deplete excess ATP, evidenced by the elevated level of PRAP1 and cleaved capase-3. Moreover, the DNA damage inhibited the expression of DNA repair-related proteins, such as RBX1 and GPS1, enhancing photocytotoxicity of ZQX-1, which was reflected in the inhibition of integrin signaling and disruption of ribosome assembly. Importantly, the photoactivated ZQX-1 was shown to activate hypoxia-inducible factor 1A (HIF1A) survival signaling, implying that combining use of ZQX-1 with HIF1A signaling inhibitors may further promote the photocytotoxicity of the prodrug.


Assuntos
Antineoplásicos , Complexos de Coordenação , Rutênio , Humanos , Células A549 , Antineoplásicos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Fosforilação Oxidativa , Células HEK293 , Proteômica , Necrose , Apoptose , DNA/metabolismo , Trifosfato de Adenosina/metabolismo , Rutênio/farmacologia , Complexos de Coordenação/farmacologia
3.
Chemistry ; 28(6): e202103359, 2022 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-34890065

RESUMO

To realize clinical application of antibacterial photodynamic therapy (aPDT), one of the most arduous challenges is how to render aPDT agents high selectivity against bacterial pathogens. In light of the fact that amino group-containing lipids are rich on the outer surfaces of Gram-positive bacteria, we herein constructed an alkynyl-dangling ruthenium(II) polypyridine complex (Ru2) to preferentially label Staphylococcus aureus (S. aureus) and methicillin-resistant Staphylococcus aureus (MRSA) over mammalian cells via the amino-yne bio-orthogonal click reaction. Thanks to the strong singlet oxygen generation ability, Ru2 could photo-inactivate S. aureus and MRSA effectively and specifically. Phosphatidylethanolamine (PE) molecules also exist in mammalian cells but are not accessible for Ru2, leading to its poor binding/uptake and negligible cytotoxicity in the dark and upon irradiation towards mammalian cells as well as low hemolysis, all favorable for aPDT application.


Assuntos
Anti-Infecciosos , Staphylococcus aureus Resistente à Meticilina , Fotoquimioterapia , Animais , Antibacterianos/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Staphylococcus aureus
4.
Molecules ; 26(18)2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34577150

RESUMO

Photoactivated chemotherapy (PACT) is a novel cancer treatment method that has drawn increasing attention due to its high selectivity and low side effects by spatio-temporal control of irradiation. Compared with photodynamic therapy (PDT), oxygen-independent PACT is more suitable for treating hypoxic tumors. By finely tuning ligand structures and coordination configurations, many Ru(II) complexes can undergo photoinduced ligand dissociation, and the resulting Ru(II) aqua species and/or free ligands may have anticancer activity, showing their potential as PACT agents. In this mini-review, we summarized the progress in Ru(II)-based PACT agents, as well as challenges that researchers in this field still face.


Assuntos
Antineoplásicos , Complexos de Coordenação , Rutênio , Humanos , Fotoquimioterapia
5.
Chemistry ; 25(61): 13879-13884, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31468605

RESUMO

Ruthenium(II) polypyridyl complexes featuring peripheral quaternary ammonium structures were found to be able to selectively inactivate Gram-positive Staphylococcus aureus (S. aureus), including methicillin-resistant S. aureus (MRSA) upon visible light irradiation, but have low phototoxicity toward 293T cells, L02 cells and lack hemolysis toward rabbit red blood cells (RBC), exhibiting promising potential as a novel type of antimicrobial photodynamic therapy (aPDT) agents.

6.
Inorg Chem ; 56(4): 1865-1873, 2017 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-28128927

RESUMO

Ru(II)-complex-based DNA photocleavers have been extensively studied for their potential application in photodynamic therapy (PDT) and photodynamic antimicrobial chemotherapy (PACT). However, their MLCT absorption maxima are generally shorter than 600 nm, limiting PDT/PACT application severely. In this work, by incorporating a 5-chloro-8-oxyquinolate-based noninnocent ligand into a merocyanine scaffold Cl-7-IVQ, we obtained a new Ru complex of this ligand, [Ru(bpy)2(Cl-7-IVQ)]2+, which has intense absorption in the window 600-700 nm and enables an efficient •OH-mediated DNA photocleavage. This long-wavelength absorption band has a character of MLLCT transition from the hybrid Ru(dπ)-Cl-7-IVQ(π) orbital to the π*(Cl-7-IVQ) orbital and thus a contribution from the ππ* transition of the merocyanine framework, which endows the complex with a molar extinction coefficient as high as 1.73 × 104 M-1 cm-1 at 649 nm and allows for an efficient DNA photocleavage under an irradiation of low intensity. [Ru(bpy)2(Cl-7-IVQ)]2+ represents the first Ru(II)-complex-based DNA photocleaver that has an MLCT absorption maximum above 600 nm and can selectively inactivate E. coli bacterial cells over HeLa cells upon red light irradiation.


Assuntos
Complexos de Coordenação/farmacologia , DNA/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Rutênio/farmacologia , Absorção Fisiológica , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , DNA/química , Relação Dose-Resposta a Droga , Escherichia coli/citologia , Escherichia coli/metabolismo , Células HeLa , Humanos , Luz , Estrutura Molecular , Processos Fotoquímicos , Fotoquimioterapia , Teoria Quântica , Espécies Reativas de Oxigênio/metabolismo , Rutênio/química , Relação Estrutura-Atividade , Células Tumorais Cultivadas
7.
Inorg Chem ; 55(9): 4296-300, 2016 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-27101335

RESUMO

In this work, we demonstrate for the first time that [Ru(bpy)2(R-OQN)](+) complexes (bpy = 2,2'-bipyridine, R-OQN = 5-chloro-8-oxyquinolate or 5-bromo-8-oxyquinolate) are able to generate hydroxyl radicals and cleave DNA effectively upon visible light irradiation. The potent electron-donating ability of the R-OQN-based non-innocent ligands gives the complexes a high reducing capability, favoring the generation of superoxide anion radicals from which hydroxyl radicals may be generated. More interestingly, halogen substitution plays an important role. When the 5-Cl- or 5-Br-8-oxyquinolate ligand is replaced by 8-oxyquinolate or 5-CH3-8-oxyquinolate, the corresponding complexes lose their hydroxyl radical-generation and DNA photocleavage abilities. These findings open new applications for the non-innocent ligand-based Ru(II) complexes in the fields of biology and medicine, such as in photodynamic therapy (PDT).


Assuntos
Complexos de Coordenação/química , Clivagem do DNA/efeitos da radiação , DNA Super-Helicoidal/química , Rutênio/química , Acetonitrilas/química , Dimetil Sulfóxido/química , Radical Hidroxila/química , Ligantes , Luz , Espécies Reativas de Oxigênio/química
8.
Langmuir ; 30(48): 14573-80, 2014 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-25419964

RESUMO

Three new triarylmethane dyes (TAMs), MPCV, DPCV, and AEV, were synthesized and their photodynamic inactivation abilities against E. coli and human pulmonary carcinoma A549 cells were compared to two commercial TAMs, CV and EV. The enhanced hydrophilicity of MPCV and AEV decreases their cellular uptake to A549 cells dramatically. However, their binding affinity toward E. coli cells are comparable to that of CV and EV by virtue of the improved electrostatic attraction with highly negatively charged E. coli outer membranes. MPCV and AEV were also found to generate hydroxyl radicals more efficiently upon irradiation than CV and EV. Consequently, MPCV and AEV exhibited markedly improved photodynamic inactivation of E. coli cells but remarkably diminished photodynamic inactivation of A549 cells than CV and EV. The photodynamic inactivation ability of DPCV was much lower than that of CV due to its high propensity for bleaching in neutral aqueous solution. Our work demonstrates that the introduction of protonatable groups in a proper manner into the structures of TAMs may lead to selective binding and photodynamic inactivation toward bacterial cells over mammalian cells. This strategy may be extended to other types of photodynamic antimicrobial chemotherapy (PACT) agents to improve their clinical potential.


Assuntos
Metano/química , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Anti-Infecciosos/efeitos adversos , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Linhagem Celular , Escherichia coli/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Fármacos Fotossensibilizantes/efeitos adversos
9.
Dalton Trans ; 53(8): 3579-3588, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38314620

RESUMO

Photodynamic therapy (PDT) is promising for cancer treatment but still suffers from some limitations. For instance, PDT based on 1O2 generation (in a type-II mechanism) is heavily dependent on high oxygen concentrations and will be significantly depressed in hypoxic tumors. In addition, the residual photosensitizers after PDT treatment may cause severe side-effects under light irradiation. To solve these problems, herein a BODIPY (boron dipyrromethene)-modified Ru(II) complex [Ru(dip)2(tpy-BODIPY)]2+ (complex 1, dip = 4,7-diphenyl-1,10-phenanthroline, tpy = 2,2':6',2''-terpyridine) was designed and synthesized. Complex 1 exhibited both high singlet oxygen quantum yield (Φ = 0.7 in CH3CN) and excellent superoxide radical (O2˙-) generation, and thus demonstrated efficient PDT activity under both normoxic and hypoxic conditions. Moreover, complex 1 is photo-degradable in water, and greatly loses its ROS generation ability after PDT treatment. These novel properties of complex 1 make it promising for efficient PDT under both normoxic and hypoxic conditions with reduced side-effects.


Assuntos
Fotoquimioterapia , Fármacos Fotossensibilizantes , Fármacos Fotossensibilizantes/farmacologia , Compostos de Boro/farmacologia , Superóxidos
10.
Biomater Sci ; 12(12): 3154-3162, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38687170

RESUMO

The effectiveness of photodynamic therapy (PDT) has been greatly restricted by the hypoxic tumor microenvironment and the susceptible resistance of monotherapy. Although nanodrugs based on transition metal complexes capable of integrating PDT with photoactivated chemotherapy (PACT) have garnered tremendous attention as promising candidates for overcoming the above limitations, the therapeutic efficacy of these nanodrugs is still hampered by inadequate loading of active pharmaceutical ingredients (APIs) and the inherent ability of cancer cells to repair damaged DNA. Herein, we developed a photoactivated full-API nanodrug, Ru-T FAND, by one-step self-assembly of RuDPB and TH287. By virtue of its 100 wt% API content and favorable stability in water, the Ru-T FAND exhibited improved cellular uptake behavior and intracellular 1O2 generation. Attractively, the Ru-T FAND with triple anti-cancer modalities can photogenerate 1O2, photo-release DPB ligand and inhibit the repair of DNA damage, ultimately enhancing its phototherapeutic effect on cancer cells. Importantly, the uncaged DPB ligand from RuDPB emits red fluorescence, enabling real-time monitoring of the drug's absorption, distribution and efficacy. Collectively, the presented photoactivated Ru-T FANDs with multiple anti-cancer mechanisms will expand new horizons for the development of safe, efficient and synergistic tumor phototherapy strategies.


Assuntos
Antineoplásicos , Complexos de Coordenação , Dano ao DNA , Fotoquimioterapia , Humanos , Dano ao DNA/efeitos dos fármacos , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Antineoplásicos/farmacologia , Antineoplásicos/química , Monoéster Fosfórico Hidrolases/antagonistas & inibidores , Monoéster Fosfórico Hidrolases/metabolismo , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química , Linhagem Celular Tumoral , Nanopartículas/química , Rutênio/química , Rutênio/farmacologia , Elementos de Transição/química , Elementos de Transição/farmacologia , Enzimas Reparadoras do DNA/antagonistas & inibidores , Enzimas Reparadoras do DNA/metabolismo
11.
Chemphyschem ; 14(5): 1003-8, 2013 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-23401023

RESUMO

Nanoscaled coordination polymers based on biologically prevalent ions have potential applications in drug delivery and biomedical imaging. Herein, coordination polymer nanoparticles of anionic porphyrins, including meso-tetra(4-carboxyphenyl)-porphyrin (H2 TCPP(4-)) and meso-tetra(4-sulfonatophenyl)-porphyrin (H2 TPPS(4-)), and alkaline or alkaline earth metal cations, such as K(+) and Ca(2+), were constructed in aqueous solution in the presence of cucurbit[7]uril (CB7) or cucurbit[8]uril (CB8). UV/Vis absorption and fluorescence spectroscopy, dynamic light scattering (DLS), scanning electron spectroscopy (SEM), and atomic force microscopy (AFM) were applied to explore the assembly and particle formation of porphyrin anions and metal cations mediated by CBn. The particle size depends on the kinds of CBn and metal cations and their concentrations. The uptake of H2 TPPS(4-) particles by tumor cells (A549 cells) was found to be more efficient than H2 TPPS(4-) at 37 °C, showing the application potential of such assembled particles in biology and medicine.

12.
ChemMedChem ; 18(9): e202300065, 2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-36751034

RESUMO

Drug-resistant bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), pose a serious threat to human life. Therefore, there is urgent need to develop antibiotics with new chemical structures and antibacterial mechanisms, especially those that elicit little drug resistance after long-term use. Herein we synthesized three novel ruthenium complexes (Ru1-Ru3) containing the enaminone structures for the first time. At a concentration of 5 µM, Ru1-Ru3 can lead to a CFU reduction of about 5 log units towards S. aureus and MRSA. Interestingly, Ru3 displayed rapid bactericidal effects and could decrease the CFU numbers of both pathogens by 5 log units within 40 min. The control compounds (Ru4 and Ru5) without the enaminone structures displayed very poor antibacterial activity under the same conditions. Moreover, S. aureus did not show apparent drug resistance towards Ru3 after 20 passages incubation with a sublethal concentration. These results highlight the critical role of enaminone structures for antibacterial applications.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Humanos , Staphylococcus aureus , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/química , Esterilização , Resistência a Medicamentos
13.
Chemphyschem ; 13(11): 2739-47, 2012 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-22619214

RESUMO

Two new NIR-absorbing BODIPY dyes, each bearing two pyridinium groups, are synthesized and their DNA-binding affinities and DNA photocleavage abilities examined in depth. While one BODIPY dye photocleaves DNA mainly through singlet oxygen, the other photocleaves DNA through both singlet oxygen and hydroxyl radical. To the best of our knowledge, this is the first example of a hydroxyl radical being involved in the photodynamic behavior of BODIPY-type dyes. EPR experiments confirm the ability of these and several related BODIPYs to generate superoxide anion radical and hydroxyl radical. This finding may shed light on the mechanism of BODIPY-based photodynamic therapy (PDT) and open a new avenue for development of more efficient BODIPY-type PDT agents.


Assuntos
Compostos de Boro/química , DNA/química , Radical Hidroxila/química , Fármacos Fotossensibilizantes/química , Oxigênio Singlete/química , Cátions/química , Espectroscopia de Ressonância de Spin Eletrônica , Corantes Fluorescentes/química , Luz , Fotólise
14.
Photochem Photobiol Sci ; 11(4): 715-23, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22327540

RESUMO

Two 5,10,15,20-tetraphenylporphyrins with one phenyl group anchored to a rhodanine-terminated side chain, RhD-TPP and RhDCOOH-TPP, were designed and synthesized, and their protein photocleavage activities were investigated using bovine serum albumin (BSA) as a model protein. Both porphyrins exhibit similar absorption spectra, fluorescence spectra, fluorescence quantum yields, and singlet oxygen ((1)O(2)) quantum yields in organic solvents due to their structure similarity. They also show similar binding affinities and binding sites toward BSA. However, RhD-TPP is nearly inactive in protein photocleavage while RhDCOOH-TPP can lead to distinct photocleavage of BSA under the same experimental conditions. Such a difference may be attributed to the different binding modes of the two porphyrin derivatives toward BSA, though the apparent binding affinities and the binding sites are similar, and consequently a great difference in the (1)O(2) quantum yields of the two porphyrins bound on BSA. The presence of the COOH group in RhDCOOH is proposed to play an important role, leading to less hydrophobic character and additional interactions towards BSA.


Assuntos
Porfirinas/química , Rodanina/análogos & derivados , Rodanina/química , Animais , Bovinos , Cinética , Fotólise , Ligação Proteica , Teoria Quântica , Oxigênio Singlete/química , Oxigênio Singlete/metabolismo , Espectrometria de Fluorescência
15.
Inorg Chem ; 51(11): 6376-84, 2012 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-22591116

RESUMO

Two dirhodium(II) complexes, [Rh(II)(2)(µ-O(2)CCH(3))(2)(bpy)(2)](O(2)CCH(3))(2) (Rh(2)bpy(2); bpy = 2,2'-bipyridine) and [Rh(II)(2)(µ-O(2)CCH(3))(2)(phen)(2)](O(2)CCH(3))(2) (Rh(2)phen(2); phen = 1,10-phenanthroline) were synthesized, and their photocatalytic H(2) production activities were studied in multicomponent systems, containing [Ir(III)(ppy)(2)(dtbbpy)](+) (ppy = 2-phenylpyridine, dtbbpy = 4,4'-di-tert-butyl-2,2'-bipyridine) as the photosensitizer (PS) and triethylamine as the sacrificial reductant (SR). There is a more than 6-fold increase in the photocatalytic activity from Rh(2)bpy(2) to Rh(2)phen(2) just using phen in place of bpy. A turnover number as high as 2622 was obtained after 50 h of irradiation of a system containing 16.7 µM Rh(2)phen(2), 50 µM PS, and 0.6 M SR. The electrochemical, luminescence quenching, and transient absorption experiments demonstrate that Rh(I)Rh(I) is the true catalyst for the proton reduction. The real-time absorption spectra confirm that a new Rh-based species formed upon irradiation of the Rh(2)phen(2)-based multicomponent system, which exhibits an absorption centered at ∼575 nm. This 575-nm intermediate may account for the much higher H(2) evolution efficiency of Rh(2)phen(2). Our work highlights the importance of N-based chelate ligands and opens a new avenue for pursuing more efficient Rh(II)(2)-based complexes in photocatalytic H(2) production application.

16.
Dalton Trans ; 51(8): 3225-3233, 2022 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-35119445

RESUMO

Chemodynamic therapy (CDT) is novel and promising for cancer treatment, however, the potential systematic toxicity of the used nanoparticles is still a big concern. In this work the biocompatible hypocrellin A-Fe(III) nanoparticles (HA-Fe(III) NPs) were synthesized and studied. The CDT effect of HA-Fe(III) NPs in the dark is negligible but can be photo-activated upon red light irradiation, which is meaningful to realize precise CDT treatment by selective light irradiation. Moreover, HA-Fe(III) NPs can also generate O2˙-, which may be converted into H2O2 to further enhance the CDT effect. As a result, HA-Fe(III) NPs had little cytotoxicity in the dark at the concentration up to 200 µg ml-1, but exhibited efficient CDT activity upon red light irradiation under both normoxic and hypoxic conditions. The in vivo results also showed that HA-Fe(III) NPs can efficiently inhibit tumor growth upon 628 nm light irradiation.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Ferro/química , Nanopartículas Metálicas/química , Perileno/análogos & derivados , Fenol/química , Quinonas/química , Nanomedicina Teranóstica , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Humanos , Perileno/química , Processos Fotoquímicos
17.
Chemphyschem ; 12(16): 2933-40, 2011 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-21919182

RESUMO

To track nuclear dynamic processes by fluorescence imaging, nuclear stains should be highly fluorescent, resistant to photobleaching, and inert to nuclear processes. The nuclear stains of the Hoechst family, such as Hoechst 34580, show bright fluorescence only on groove binding to DNA, and therefore may interfere with visualization of nuclear dynamic processes induced by other stimuli. We study host-guest interactions between Hoechst 34580 and Cucurbit[7]uril (CB7) in aqueous solutions. The formation of CB7-Hoechst 34580 inclusion complexes with stoichiometry of 2:1 in water and 1:1 in phosphate-buffered saline (PBS) solution (pH 7.0) is confirmed by (1)H NMR, absorption spectra, fluorescence spectra, MALDI-TOF MS, and molecular modeling. Compared to Hoechst 34580, the inclusion complex exhibits redshifted absorption, intensified fluorescence, improved photostability, weakened DNA binding affinity, comparable ability to penetrate cell nuclei, and better nuclear-staining capability, and thus a new avenue for the application of cucurbituril in fluorescence imaging is opened.


Assuntos
Benzimidazóis/química , Hidrocarbonetos Aromáticos com Pontes/química , Núcleo Celular , Corantes Fluorescentes/química , Imidazóis/química , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Espectrometria de Fluorescência/métodos , Sítios de Ligação , Linhagem Celular Tumoral , Núcleo Celular/química , Núcleo Celular/ultraestrutura , Dicroísmo Circular , DNA/química , Interações Medicamentosas , Humanos , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular , Soluções , Termodinâmica , Imagem com Lapso de Tempo
18.
Photochem Photobiol Sci ; 10(6): 887-90, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21445436

RESUMO

[Ru(II)(bpy)(2)(dppn)](2+) (bpy = 2,2'-bipyridine, dppn = 4,5,9,16-tetraazadibenzo[a,c]naphthacene) was found to be able to photoinactivate Gram-negative Escherichia coli efficiently, showing the potential of transition-metal complexes as photosensitizers in the field of photodynamic antimicrobial chemotherapy (PACT).


Assuntos
Anti-Infecciosos/química , Complexos de Coordenação/química , Escherichia coli/efeitos dos fármacos , Fármacos Fotossensibilizantes/química , Rutênio/química , 2,2'-Dipiridil/química , Anti-Infecciosos/farmacologia , Complexos de Coordenação/farmacologia , Escherichia coli/efeitos da radiação , Luz , Fármacos Fotossensibilizantes/farmacologia
19.
RSC Adv ; 11(39): 24359-24365, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-35479006

RESUMO

Three new isomeric cobalt complexes of TPA (tris(2-pyridylmethyl)amine) based on methoxy substitution at the ortho, meta and para positions, respectively, were constructed and their photocatalytic proton reduction efficiencies were compared. It was found that there are good linear correlations with the Hammett constants of the substituents for the computed Co-N bond lengths, redox potentials of CoII/I and CoI/0 events, and the photocatalytic activities of the complexes. The ortho-substituted Co complex distinguished itself from the others remarkably in all these comparisons, demonstrating the presence of a steric effect besides the electronic effect. For other examined complexes, a stronger electron-donating substituent may lead to a higher hydrogen evolution efficiency, suggesting that the formation of a Co(iii) hydride intermediate is the rate-limiting step.

20.
Dalton Trans ; 50(31): 10845-10852, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34296720

RESUMO

Phototherapy for cancer treatment has received much attention in recent years, and compounds with multiple anticancer mechanisms upon irradiation are particularly appealing. In this work, a nitro-anthraquinone group was attached to a biq (2,2'-biquinoline) ligand based Ru(ii) complex, endowing the resultant Ru1 compound with multiple anticancer mechanisms upon 600 nm light irradiation. Ru1 can undergo biq ligand photodissociation, showing its potential as a photoactivated chemotherapy (PACT) agent. Moreover, a Ru(iii) centre and an anthraquinone anion centre may be generated upon irradiation, which can further oxidize NADH/NADPH and generate O2˙-, successfully eliciting photoredox catalysis and photodynamic therapy (PDT). Compared to the control complex Ru2 without the nitroanthraquinone group, Ru1 exhibited much enhanced photocytotoxicity towards a series of cancer cell lines and 3D multicellular spheroids upon red light irradiation.


Assuntos
Fotoquimioterapia , Fármacos Fotossensibilizantes , Complexos de Coordenação , Luz , Fototerapia , Rutênio
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