scholarly journals Vacancy-enhanced generation of singlet oxygen for photodynamic therapy

2019 ◽  
Vol 10 (8) ◽  
pp. 2336-2341 ◽  
Author(s):  
Shanyue Guan ◽  
Li Wang ◽  
Si-Min Xu ◽  
Di Yang ◽  
Geoffrey I. N. Waterhouse ◽  
...  

Oxygen vacancy introduced defects in the band gap of BiOBr–H allow facile electron transfer from a photo-excited ruthenium complex to the semiconductor, thereby increasing ROS yields and PDT efficiency.

2009 ◽  
Vol 85 (3) ◽  
pp. 705-713 ◽  
Author(s):  
Daniela Silva Maranho ◽  
Renata Galvão de Lima ◽  
Fernando Lucas Primo ◽  
Roberto Santana da Silva ◽  
Antonio Claudio Tedesco

2009 ◽  
Vol 13 (01) ◽  
pp. 99-106 ◽  
Author(s):  
Noemí Rubio ◽  
Víctor Martínez-Junza ◽  
Jordi Estruga ◽  
José I. Borrell ◽  
Margarita Mora ◽  
...  

Biosubstrate-sensitizer binding is one of the factors that enhances the type-I mechanism over the type-II in the whole photodynamic process. 2,7,12,17-Tetraphenylporphycene (TPPo), a second-generation photosensitizer, is a hydrophobic compound with good photophysical properties for photodynamic therapy applications that has proved its ability for the photoinactivation of different cell lines. Nevertheless, little is known about its mechanism of action. This paper focuses on the study of the interaction/binding of TPPo with different model biomolecules that may favor the type-I mechanism in the overall photodynamic process, including nucleosides, proteins, and phospholipids. Compared with more hydrophilic photosensitizers, it is concluded that TPPo is more likely to undergo type-II (singlet oxygen) than type-I (electron transfer) photodynamic processes in biological environments.


2020 ◽  
Author(s):  
busenur Aslanoglu ◽  
Ilya Yakavets ◽  
Vladimir Zorin ◽  
Henri-Pierre Lassalle ◽  
Francesca Ingrosso ◽  
...  

Computational tools have been used to study the photophysical and photochemical features of photosensitizers in photodynamic therapy (PDT) –a minimally invasive, less aggressive alternative for cancer treatment. PDT is mainly based by the activation of molecular oxygen through the action of a photoexcited sensitizer (photosensitizer). Temoporfin, widely known as mTHPC, is a second-generation photosensitizer, which produces the cytotoxic singlet oxygen when irradiated with visible light and hence destroys tumor cells. However, the bioavailability of the mostly hydrophobic photosensitizer, and hence its incorporation into the cells, is fundamental to achieve the desired effect on malignant tissues by PDT. In this study, we focus on the optical properties of the temoporfin chromophore in different environments –in <i>vacuo</i>, in solution, encapsulated in drug delivery agents, namely cyclodextrin, and interacting with a lipid bilayer.


2021 ◽  
Author(s):  
Esra Tanrıverdi Eçik ◽  
Onur BULUT ◽  
Hasan Hüseyin Kazan ◽  
Elif Şenkuytu ◽  
Bunyemin Cosut

Photodynamic therapy (PDT) is a promising strategy in cancer treatment with its relatively lower side effect profile. Undoubtedly, the key component of PDT is the photosensitizers with a high ability...


Author(s):  
Anja Busemann ◽  
Ingrid Flaspohler ◽  
Xue-Quan Zhou ◽  
Claudia Schmidt ◽  
Sina K. Goetzfried ◽  
...  

AbstractThe known ruthenium complex [Ru(tpy)(bpy)(Hmte)](PF6)2 ([1](PF6)2, where tpy = 2,2’:6’,2″-terpyridine, bpy = 2,2’-bipyridine, Hmte = 2-(methylthio)ethanol) is photosubstitutionally active but non-toxic to cancer cells even upon light irradiation. In this work, the two analogs complexes [Ru(tpy)(NN)(Hmte)](PF6)2, where NN = 3,3'-biisoquinoline (i-biq, [2](PF6)2) and di(isoquinolin-3-yl)amine (i-Hdiqa, [3](PF6)2), were synthesized and their photochemistry and phototoxicity evaluated to assess their suitability as photoactivated chemotherapy (PACT) agents. The increase of the aromatic surface of [2](PF6)2 and [3](PF6)2, compared to [1](PF6)2, leads to higher lipophilicity and higher cellular uptake for the former complexes. Such improved uptake is directly correlated to the cytotoxicity of these compounds in the dark: while [2](PF6)2 and [3](PF6)2 showed low EC50 values in human cancer cells, [1](PF6)2 is not cytotoxic due to poor cellular uptake. While stable in the dark, all complexes substituted the protecting thioether ligand upon light irradiation (520 nm), with the highest photosubstitution quantum yield found for [3](PF6)2 (Φ[3] = 0.070). Compounds [2](PF6)2 and [3](PF6)2 were found both more cytotoxic after light activation than in the dark, with a photo index of 4. Considering the very low singlet oxygen quantum yields of these compounds, and the lack of cytotoxicity of the photoreleased Hmte thioether ligand, it can be concluded that the toxicity observed after light activation is due to the photoreleased aqua complexes [Ru(tpy)(NN)(OH2)]2+, and thus that [2](PF6)2 and [3](PF6)2 are promising PACT candidates. Graphic abstract


RSC Advances ◽  
2021 ◽  
Vol 11 (25) ◽  
pp. 15323-15331
Author(s):  
Yao Xu ◽  
Xiang Wang ◽  
Kang Song ◽  
Jun Du ◽  
Jinliang Liu ◽  
...  

Three new iridium complexes were synthesized and fabricated with BSA to form nano-photosensitizers, which can catalyze oxygen to produce singlet oxygen to achieve photodynamic therapy of tumor cells.


2021 ◽  
Author(s):  
Nan Zheng ◽  
Xiahui Li ◽  
Shangwei Huangfu ◽  
Kangkai Xia ◽  
Ruofei Yue ◽  
...  

A linear poly-porphyrin with high Mw and conjugated by PEG and acetazolamide was developed with enhanced singlet oxygen quantum yield, improved photo-toxicity and excellent in vivo photodynamic therapy.


2018 ◽  
Vol 08 (04) ◽  
pp. 024-027
Author(s):  
Shiny Inasu ◽  
Biju Thomas

AbstractA novel noninvasive photochemical approach for infection control, namely photodynamic therapy, has received much attention in the treatment of oral diseases which requires three nontoxic ingredients namely visible harmless light, a photosensitizer and oxygen are involved in this therapy. It is based on the principle that a photosensitizer binds to the target cells which when activated by light of a suitable wavelength results in the production of singlet oxygen and other very reactive agents that are extremely toxic to certain cells and bacteria. This article highlights the application of photo-dynamic therapy in management of periodontal disease and its current status.


Author(s):  
Jiaxin Shen ◽  
Dandan Chen ◽  
Ye Liu ◽  
Guoyang Gao ◽  
Zhihe Liu ◽  
...  

Photodynamic therapy (PDT) is a promising method for cancer therapy and also may initiate unexpected damages to normal cells and tissues. Herein, we developed a near-infrared (NIR) light-activatable nanophotosensitizer, which...


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