Imidazole-modified porphyrin as a pH-responsive sensitizer for cancer photodynamic therapy

Zhu, Xianchun; Lu, Wentong; Zhang, Yazhou; Reed, Aisha; Newton, Brandon; Fan, Zhen; Yu, Hongtao; Ray, Paresh Chandra; Gao, Rong

doi:10.1039/c1cc13328d

Cited by 55 publications

(30 citation statements)

References 26 publications

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“…QDots are small semiconductor NPs that possess several exciting features such as high photostability, narrow and tunable emission spectra and high brightness [17]. Owing to these properties, QDots have shown great potential for many biomedical applications, including cell labeling applications [18][19][20][21], long-term tracking of (single) molecules [22], in vivo imaging [23,24] and photodynamic therapy [25,26]. However, despite their excellent photophysical properties, their toxicity, in particular due to the release of Cd 2+ ions [27,28], remains an issue of debate [29,30].…”

Section: Introductionmentioning

confidence: 99%

The effect of nanoparticle degradation on poly(methacrylic acid)-coated quantum dot toxicity: The importance of particle functionality assessment in toxicology

et al. 2014

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Colloidal semiconductor nanoparticles (quantum dots) have attracted a lot of interest in technological and biomedical research, given their potent fluorescent properties. However, the use of heavy metal-containing nanoparticles remains an issue of debate. The possible toxic effects of quantum dots remain a hot research topic and several questions such as possible intracellular degradation of quantum dots and the effect thereof on both cell viability and particle functionality remain unresolved. In the present work, poly(methacrylic acid)-coated CdSe/ZnS quantum dots were synthesized and characterized, after which their effects on cultured cells were evaluated using a multiparametric setup. The data reveal that the quantum dots are taken up through endocytosis and when exposed to the low pH of the endosomal structures, they partially degrade and release cadmium ions, which lowers their fluorescence intensity and augments particle toxicity. Using the multiparametric method, the quantum dots were evaluated at nontoxic doses in terms of their ability to visualize labeled cells for longer time periods. The data revealed that comparing different particles in terms of their applied dose is challenging, likely due to difficulties in obtaining accurate nanoparticles concentrations, but evaluating particle toxicity in terms of their biological functionality enables an easy and straightforward comparison.

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Section: Introductionmentioning

confidence: 99%

The effect of nanoparticle degradation on poly(methacrylic acid)-coated quantum dot toxicity: The importance of particle functionality assessment in toxicology

et al. 2014

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“…For high‐tumor‐specific damage and imaging, low pH‐induced activation is key. An imidazole‐modified porphyrin as a low‐pH‐activatable porphyrin has been reported . This system is extremely interesting; however, the ratio of the photosensitization efficiency in the ON state to that in the OFF state is not sufficiently high.…”

Section: Introductionmentioning

confidence: 99%

Improvement of the ON/OFF Switching Performance of a pH‐Activatable Porphyrin Derivative by the Introduction of Phosphorus(V)

et al. 2019

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An activatable photosensitizer for singlet oxygen is of significance due to its potential application in tumor‐specific photodynamic therapy and diagnosis. In this study, a pH‐activatable system that enables the specific photosensitization of singlet oxygen at a low pH value was developed based on the complexation of a porphyrin‐aniline conjugate with phosphorus(V). As a result of complexation with phosphorus, the water solubility of the porphyrin‐aniline conjugate was improved 100‐fold. Furthermore, this complexation strongly suppressed the singlet‐oxygen‐generating activity of the porphyrin photosensitizer under basic conditions, and the quantum yield of the singlet oxygen photosensitization markedly increased under acidic conditions. Based on these improvements, an extremely high ON/OFF switching ratio of the quantum yield was obtained (>400‐fold).

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“…Our recent work showed that imidazole-modified porphyrin, 5,10,15,20-tetrakis(N-(2-(1H-imidazol-4-yl)ethyl)benzamide)porphyrin, produced twice as many 1 O 2 molecules at pH 5.0 than at pH 7.4, whereas 1 O 2 quenching rate was reduced by a factor of 2.5 for a pH change from 7.4 to 5.0. 20 Imidazole moieties were employed as a pH-sensitive trigger for controllable 1 O 2 release. Wang, Zhang and co-workers prepared a pH-responsive nanoparticle-5 based platform for controllable 1 O 2 production where both hydrophobic porphyrin and pH-indicator bromocresol purple (BCP) were encapsulated in organically modified silica nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

Enhanced photodynamic selectivity of nano-silica-attached porphyrins against breast cancer cells

Fan

et al. 2012

J. Mater. Chem.

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The synthesis and characterization of bare silica (4 nm in diameter) nanoparticle-attached meso-tetra(N-methyl-4-pyridyl)porphine (SiO2-TMPyP, 6 nm in diameter) are described for pH-controllable photosensitization. Distinguished from organosilanes, SiO2 nanoparticles were functionalized as a potential quencher of triplet TMPyP and/or singlet oxygen (1O2) at alkaline pH, thereby turning off sensitizer photoactivity. In weak acidic solutions, TMPyP was released from SiO2 surface for efficient production of 1O2. By monitoring 1O2 luminescence at 1270 nm, quantum yields of 1O2 production were found to be pH-dependent, dropping from ~ 0.45 in a pH range of 3–6 to 0.08 at pH 8–9, which is consistent with pH-dependent adsorption behavior of TMPyP on SiO2 surface. These features make bare SiO2-attached cationic porphyrin a promising candidate for use in PDT for cancer treatment in which efficient 1O2 production at acidic pH and sensitizer deactivation at physiological pH are desirable. The enhanced therapeutic selectivity was confirmed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tests and trypan blue exclusion tests of cell viability in breast cancer cell lines. Bimolecular quenching rate constants of 1O2 by free TMPyP, SiO2 and SiO2-TMPyP nanoparticles were also determined.

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Imidazole-modified porphyrin as a pH-responsive sensitizer for cancer photodynamic therapy

Abstract: 5,10,15,20-Tetrakis(N-(2-(1H-imidazol-4-yl)ethyl)benzamide)porphyrin produced twice as many singlet oxygen ((1)O(2)) molecules at pH 5.0 (quantum yield 0.53 ± 0.01) than at pH 7.4, whereas the (1)O(2) quenching rate was reduced by a factor of 2.5 for a pH change from 7.4 to 5.0.

Cited by 55 publications

References 26 publications

The effect of nanoparticle degradation on poly(methacrylic acid)-coated quantum dot toxicity: The importance of particle functionality assessment in toxicology

The effect of nanoparticle degradation on poly(methacrylic acid)-coated quantum dot toxicity: The importance of particle functionality assessment in toxicology

Improvement of the ON/OFF Switching Performance of a pH‐Activatable Porphyrin Derivative by the Introduction of Phosphorus(V)

Enhanced photodynamic selectivity of nano-silica-attached porphyrins against breast cancer cells

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