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Enhancing magnetic resonance/photoluminescence imaging-guided photodynamic therapy by multiple pathways
摘要： Mitochondria, which are a major source of adenosine triphosphate (ATP) and apoptosis regulators, are the key organelles that promote tumor cell proliferation, and their dysfunction affects tumor cell behavior. Additionally, mitochondria have been shown to play a central role in the biosynthesis of protoporphyrin IX (PpIX), which is a widely used photosensitizer that has been used for tumor detection, monitoring and photodynamic therapy. Nevertheless, photosensitizers administrated exogenously are often restricted by limited bioavailability. δ-Aminolevulinic acid (δ-ALA) is a naturally occurring delta amino acid that can be converted in situ to PpIX via the heme biosynthetic pathway in mitochondria. Because δ-ALA is the precursor for PpIX, δ-ALA-based photodynamic therapy (PDT) shows promise in treating cancer. However, the accumulation of δ-ALA within endosomal system limits the production of PpIX and eventually impedes its effectiveness. Theranostic nanoparticles (NPs) capable of endosomal escape are expected to optimize the endogenous biosynthetic yield. In this study, δ-ALA was improved with triphenylphosphonium cation (TPP+), a high net position cation in endosomal escape and as a mitochondria-targeting ligand, and was further modified with bovine serum albumin stabilized manganese dioxide (MnO2). The tumor microenvironment (TME) responsive MnO2 in this system can elevate oxygen content to relieve hypoxia. Both enhanced photosensitizer yield and elevated oxygen contributing to the final therapeutic effect. Moreover, the enhancement of magnetic resonance imaging (MRI) (r1=5.410 s-1mM-1) stemming from the degradation of MnO2 by the TME could serve as a guide prior to treatment for accurate location, while in situ hysteretic photoluminescence imaging derived from PpIX can be utilize as a supervisor for the biomedical prognosis evaluation. This systematic design could broaden application and highlight the considerable therapeutic promise of PDT.
关键词： dual-imaging nanoplatform,mitochondria,endogenously biosynthetic photosensitizer
更新于2025-11-21 11:08:12
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Improvement of the ON/OFF Switching Performance of a pH-Activatable Porphyrin Derivative by the Introduction of Phosphorus(V)
摘要： An activatable photosensitizer for singlet oxygen is of significance due to its potential applications for high 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 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 by 100 times. 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 times).
关键词： pH activatable photosensitizer,ON/OFF switching,singlet oxygen,aniline,phosphorous porphyrin,protonation,fluorescence,acid
更新于2025-09-23 15:23:52
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High Photosensitized Singlet Oxygen Generating Zinc and Chloroindium Phthalocyanines Bearing (4-isopropylbenzyl)oxy Groups as Potential Agents for Photophysicochemical Applications
摘要： In this study, novel phthalonitrile derivatives (1 and 2) and their peripherally and non-peripherally tetra (4-isopropylbenzyl)oxy-substituted zinc and chloroindium phthalocyanine complexes (3-6) have been prepared for the first time. The synthesized phthalonitrile derivatives and phthalocyanine complexes were characterized spectroscopically. Not only the chloroindium phthalocyanines but also zinc phthalocyanines are essentially free from aggregation in THF at the studied micromolar concentration. The purpose is to compare the effects of two types of substitution on the phthalocyanines to be used as sensitizers in photodynamic therapy (PDT). Photophysical and photochemical properties of all phthalocyanines are investigated and the results showed that the peripheral phthalocyanines more effectively photooxidize DPBF through singlet oxygen. The photochemical results showed that both ZnPc (3 and 5) and InPc (4 and 6) can be used as sensitizers in PDT because of their very high singlet oxygen quantum yields (range from 0.80 to 0.97).
关键词： Singlet Oxygen,Photosensitizer,Phthalocyanines,Photodynamic Therapy
更新于2025-09-23 15:23:52
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Photosensitizing single-site metal?organic framework enabling visible-light-driven CO2 reduction for syngas production
摘要： Photocatalytic CO2 reduction into syngas (CO and H2) is one of sustainable strategies for recycling CO2 into value-added products. Herein, a simple and effective two-step self-assembly process was developed to functionalize phosphorescent metal-organic framework (MOF) with single site catalyst. The resulting (Co/Ru)n-UiO-67(bpydc) supplied molecular platform to enable fast multielectron injection from photosensitizers (PSs) to Co-catalyst, leading to the first MOF-based composite photocatalyst for efficient syngas production with a yield of 13600 μmol·g?1 (H2 : CO = 2 : 1) in 16 h, 29.2-fold higher than that of its homogeneous counterpart. The H2/CO ratios can be well controlled by carefully adjusting the molar ratio of PS/catalyst in the MOF platform and the water content in the photocatalytic system. This work provides a prospective strategy for recycling CO2 into H2-rich syngas by merging PSs and single-site catalysts into a MOF platform.
关键词： Metal-organic framework,CO2 reduction,photosensitizer,photocatalyst,syngas
更新于2025-09-23 15:23:52
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Doubly N-Confused Calix[6]phyrin Bis-Organopalladium Complexes: Photostable Triplet Sensitizers for Singlet Oxygen Generation
摘要： Triplet photosensitizers that generate singlet oxygen efficiently are attractive for applications such as photodynamic therapy (PDT). Extending the absorption band to a near-infrared (NIR) region (700 nm~) with reasonable photostability is one of the major demands in the rational design of such sensitizers. We herein prepared a series of mono- and bis-palladium complexes (1-Pd-H2, 2-Pd-H2, 1-Pd-Pd, and 2-Pd-Pd) based on modified calix[6]phyrins as photosensitizers for singlet oxygen generation. These palladium complexes showed intense absorption profiles in the visible-to-NIR region (500–750 nm) depending on the number of central metals. Upon photoirradiation in the presence of 1,5-dihydroxynaphthalene (DHN) as a substrate for reactive oxygen species, the bis-palladium complexes generated singlet oxygen with high efficiency and excellent photostability. Singlet oxygen generation was confirmed from the characteristic spectral feature of the spin trapped complex in the EPR spectrum and the intact 1O2 emission at 1270 nm.
关键词： Photostability,Palladium N-confused calix[6]phyrin,Triplet Photosensitizer,Singlet oxygen
更新于2025-09-23 15:23:52
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[Methods in Molecular Biology] Autophagy Volume 1880 (Methods and Protocols) || Triggering Mitophagy with Photosensitizers
摘要： One can utilize light illumination to stimulate mitochondrial reactive oxygen species production through the use of mitochondria-specific photosensitizers. By proper tuning of the light dosage, the methodology permits probing of a multitude of mitochondrial damage responses, including mitophagy. This light-controllable trick offers unique opportunities for the investigation of mitophagy—one can spatiotemporally define mitochondrial damage, alter the number of impaired mitochondria, as well as modulate the severity of the mitochondrial injury. This light-activated mitophagy can be adapted not only to single-cell imaging techniques but also to cell population-based biochemical assays.
关键词： Mitophagy,Photosensitizer,Autophagy,MitoTracker Deep Red
更新于2025-09-23 15:22:29
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Photoluminescence of Seven-Coordinate Zirconium and Hafnium Complexes with 2,2’-Pyridylpyrrolide Ligands
摘要： Luminescent seven-coordinated zirconium and hafnium complexes bearing three mono-anionic 2,2′-pyridylpyrrolide ligands and one chloride were synthesized. Solid state structures and the dynamic behaviours in solution were probed by X-ray crystallography and variable temperature 1H NMR experiments, respectively. Absorption spectroscopy and time-dependent density functional theory (TD-DFT) calculations supported a hybrid of ligand-to-metal charge transfer (LMCT)/ligand-to-ligand charge transfer (LLCT) for the visible light absorption band. The complexes (MePMPMe)3MCl (M = Zr, Hf, MePMPMe = 3,5-dimethyl-2-(2-pyridyl)pyrrolide) are emissive in solution at room temperature upon irradiation with visible light due to a combination of phosphorescence and fluorescence characterized by excited state lifetimes in the μs and low to sub-ns time-scale, respectively. Electrochemical experiments revealed that the zirconium complex possesses a reversible redox event under highly reducing condition (– 2.29 V vs Fc+/0).
关键词： Seven-coordinated,Group IV,Earth abundant,LMCT,Photosensitizer
更新于2025-09-23 15:22:29
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Graphene role in improved solar photocatalytic performance of TiO2-RGO nanocomposite
摘要： TiO2-RGO (TG) nanocomposite applied as photocatalysts have been synthesized via a facile low-temperature wet chemistry process, during which the reduction of graphene oxide (RGO) and the growth of titanium dioxide (TiO2) nanoparticles on the RGO nanosheets are achieved simultaneously. RGO role in TG nanocomposites as photocatalysts were analyzed in methylene blue photocatalytic degradation under UV and solar irradiation. The TG nanocomposites were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy and transmission electron microscopy. The photocatalytic efficiency of the TG-30 sample under UV and TG-45 solar irradiation was ～7 and ～5 times that of pristine TiO2, respectively. The enhancement of the photocatalytic activity with UV irradiation in TG was attributed to the high separation efficiency of photoinduced electron–hole pairs, while the enhancement of photocatalytic activity with solar irradiation in the TG was attributed to RGO role, acted as a photosensitizer and a charges separator, simultaneously.
关键词： semiconductors,Solar photocatalysis,photosensitizer,composite materials,charger separator,recombination and trapping
更新于2025-09-23 15:22:29
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Encapsulation of zinc phthalocyanine into bovine serum albumin aggregates
摘要： Artificial hybridization of molecules with proteins is beneficial for biomedical applications. Herein, we describe a novel method for encapsulation of zinc phthalocyanine (ZnPc) aggregates into bovine serum albumin (BSA) aggregates, but not monomeric BSA. This property is potentially useful for not only photodynamic or photothermal therapy but also development of a novel delivery system for hydrophobic drug molecules.
关键词： Gel-filtration chromatography,Photosensitizer,Aggregation,Bovine serum albumin,Phthalocyanine,Photodynamic therapy
更新于2025-09-23 15:22:29
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Study on Five Porphyrin-Based Photosensitizers for Singlet Oxygen Generation
摘要： Five porphyrin derivatives were synthesized and characterized in order to be utilized as photosensitizers for singlet oxygen generation. UV-Vis absorption properties of porphyrins were experimentally and theoretically discussed. The results indicated that the increase in π-conjugation of porphyrin core can lower the S1-T1 energy gap and is favorable for efficient energy transfer. The singlet oxygen generation ability of porphyrins was measured and compared under both simulated sunlight and yellow light. As for the results using simulated sunlight, EBHPP and CEBHPP exhibited best and similar performance because they bear strong near-IR absorption and S1-T1 interactions. However, under yellow light conditions CEBHPP has better ability for singlet oxygen generation because of strong absorbance from 650–750 nm. The DNA photocleavage measurements were performed to evaluate the biological activity of the porphyrin derivatives. The photocleavage activities were in the order of TPP < TPP-NO2 < BHPP < EBHPP < CEBHPP, and the possible reasons were discussed. This work is useful for the design of more efficient photosensitizers.
关键词： Photosensitizer,Porphyrin,Singlet oxygen,UV-Vis absorption,Photodynamic therapy
更新于2025-09-23 15:22:29