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Differential photothermal and photodynamic performance behaviors of gold nanorods, nanoshells and nanocages under identical energy conditions
摘要： Various gold (Au) nanostructures have shown promising near infrared (NIR) light-activated phototherapeutic effects; however, their reported photothermal or photodynamic performance behavior is usually inconsistent or even conflicted, dramatically limiting the improvement of phototherapeutic Au nanostructures. The potential reason for this uncertainty is mainly because the photoactivities of Au nanostructures are not evaluated under identical energy conditions. Herein, three Au nanostructures, Au nanorods (NRs), nanoshells (NSs), and nanocages (NCs), were prepared to provide the same localized surface plasmon resonance (LSPR) peaks at 808 nm. All these Au nanostructures (at the same optical density) could fully exert their photoactivities under the identical and optimal energy condition of 808 nm laser irradiation. It was found that these Au nanostructures could induce similar levels of temperature elevation but different levels of reactive oxygen species (ROS) production, where Au NCs exhibited the highest ROS production, followed by Au NSs and NRs. In vitro and in vivo phototherapeutic assessments further supported that Au NCs could cause the most severe cell death and tumor growth regression. This means that the identical incident energy has different contribution to photothermal and photodynamic performance of Au nanostructures, and the corner angle structures of Au NCs compared with NSs and NCs could more efficiently convert the photon energy into photodynamic property. Taken all together, Au NCs hold great potential for phototherapy due to their efficient energy utilization capability.
关键词： reactive oxygen species,photodynamic therapy,gold nanostructures,photothermal therapy,cancer treatment
更新于2025-11-21 11:08:12
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Triplet-State Photochemistry of Dissolved Organic Matter: Triplet-State Energy Distribution and Surface Electric Charge Conditions
摘要： Excited triplet states of chromophoric dissolved organic matter (3CDOM*) are highly reactive species in sunlit surface waters and play a critical role in reactive oxygen species (ROS) formation and pollutant attenuation. In the present study, a series of chemical probes, including sorbic acid, sorbic alcohol, sorbic amine, trimethylphenol, and furfuryl alcohol, were employed to quantitatively determine 3CDOM* and 1O2 in various organic matters. Using a high concentration of sorbic alcohol as high-energy triplet states quencher, 3CDOM* can be first distinguished as high-energy triplet states (>250 kJ mol?1) and low-energy triplet states (<250 kJ mol?1). The terrestrial-origin natural organic matter (NOM) was found to mainly consist of low-energy triplet states, while high-energy triplet states were predominant in autochthonous-origin NOM and effluent/wastewater organic matter (EfOM/WWOM). The 1O2 quantum yields and electron transfer quantum yield coefficients (f TMP) generated from low-energy triplet states remained constant in all tested organic matters. External phenolic compound showed quenching effects on triplet-state formation and tended to have a higher quenching efficiency for aromatic ketone triplet states, which are the main high-energy triplet states. In comparison with terrestrial-origin NOM, autochthonous-origin NOM and EfOM/WWOM presented lower reaction rate constants for sorbic amines and higher reaction rate constants for sorbic acid, and these differences are likely due to dissimilar surface electric charge conditions. Understanding the triplet-state photochemistry of CDOM is essential for providing useful insights into their photochemical effects in aquatic systems.
关键词： surface charge,triplet-state photochemistry,energy distribution,dissolved organic matter,reactive oxygen species,chemical probes
更新于2025-11-19 16:56:35
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One-step Aqueous Synthesis of Zn-based Quantum Dots as Potential Generators of Reactive Oxygen Species
摘要： The actual incorporation of dopant species into the ZnS Quantum Dots (QDs) host lattice will induce structural defects evidenced by a red shift in the corresponding exciton. The doping should create new intermediate energetic levels between the valence and conduction bands of the ZnS and affect the electron-hole recombination. These trap states would favour the energy transfer processes involved with the generation of cytotoxic radicals, so-called Reactive Oxygen Species, opening the possibility to apply these nanomaterials in cancer research. Any synthesis approach should consider the direct formation of the QDs in biocompatible medium. Accordingly, the present work addresses the microwave-assisted aqueous synthesis of pure and doped ZnS QDs. As-synthesized quantum dots were fully characterized on a structural, morphological and optical viewpoint. UV-Vis analyzes evidenced the excitonic peaks at approximately 310 nm, 314 nm and 315 nm for ZnS, Cu-ZnS and Mn-ZnS, respectively, Cu/Zn and Mn/Zn molar ratio was 0.05%. This indicates the actual incorporation of the dopant species into the host lattice. In addition, the Photoluminescence spectrum of non-doped ZnS nanoparticles showed a high emission peak that was red shifted when Mn2+ or Cu2+ were added during the synthesis process. The main emission peak of non-doped ZnS, Cu-doped ZnS and Mn-doped ZnS were observed at 438 nm, 487 nm and 521 nm, respectively. Forthcoming work will address the capacity of pure and Cu-, Mn-ZnS quantum dots to generate cytotoxic Reactive Oxygen Species for cancer treatment applications.
关键词： Cancer research,ZnS Quantum Dots,Doping,Microwave-assisted synthesis,Reactive Oxygen Species
更新于2025-11-19 16:46:39
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The role of the reactive oxygen species and the influence of KBiO3 synthesis method in the photodegradation of methylene blue and ciprofloxacin
摘要： KBiO3 was synthesized by three methods: chemical substitution, hydrothermal and sonochemical. All reaction products were analyzed by X-ray powder diffraction and reveal that KBiO3 presents a cubic structure. The morphology of each sample was analyzed with scanning electron microscopy (SEM), and the micrographs show particles with cube-like (chemical substitution), spheres-like (sonochemical) and flakes-like (hydrothermal) shape. HR-TEM technique was used to confirm the crystal structure and to determine the particle size of the samples, also it was used to corroborate the morphology. The photocatalytic activity of KBiO3 was evaluated on the reactions of the degradation of methylene blue (MB) and Ciprofloxacin (CPFX). An almost 100% discoloration of MB was reached at 120 min with KBiO3 obtained by the sonochemical method and a 67% degradation of CPFX was obtained by KBiO3 synthesized by the hydrothermal method. These results were associated with the catalyst morphology and organic adsorption on the surface of the catalyst. With the aim for a further understanding of the photocatalytic degradation of MB and CPFX, scavengers such as benzoquinone, isopropanol, and catalase were added to the photocatalytic reaction in order to identify the reactive oxygen species (ROS) involved. It has been found that hydrogen peroxide (H2O2) was the primary oxidizing species for the degradation of MB; meanwhile in the case of the oxidation of CPFX occurred by the presence of the superoxide radical (O2?·).
关键词： Photocatalysis,Organic pollutants,Reactive oxygen species,Scavengers,KBiO3
更新于2025-09-23 15:23:52
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Oxidative stress generated by irradiation of a zinc(II) phthalocyanine induces a dual apoptotic and necrotic response in melanoma cells
摘要： Melanoma is an aggressive form of skin carcinoma, highly resistant to traditional therapies. Photodynamic therapy (PDT) is a non-invasive therapeutic procedure that can exert a selective cytotoxic activity toward malignant cells. In this work we evaluated the effect of a cationic zinc(II) phthalocyanine (Pc13) as photosensitizer on a panel of melanoma cells. Incubation with Pc13 and irradiation induced a concentration and light dose-dependent phototoxicity. In order to study the mechanism underlying Pc13-related cell death and to compare the effect of different doses of PDT, the most sensitive melanoma B16F0 cells were employed. By confocal imaging we showed that Pc13 targeted lysosomes and mitochondria. After irradiation, a marked increase in intracellular reactive oxygen species was observed and a complete protection from Pc13 phototoxicity was reached in the presence of the antioxidant trolox. Acridine orange/ethidium bromide staining showed morphological changes indicative of both apoptosis and necrosis. Biochemical hallmarks of apoptosis, including a significant decrease in the expression levels of Bcl-2, Bcl-xL and Bid and mitochondrial membrane permeabilization, were observed at short times post irradiation. The consequent release of cytochrome c to cytosol and caspase-3 activation led to PARP-1 cleavage and DNA fragmentation. Simultaneously, a dose dependent increase of lactate dehydrogenase in the extracellular compartment of treated cells revealed plasma membrane damage characteristic of necrosis. Taken together, these results indicate that a dual apoptotic and necrotic response is triggered by Pc13 PDT-induced oxidative stress, suggesting that combined mechanisms of cell death could result in a potent alternative for melanoma treatment.
关键词： Necrosis,Mitochondrial membrane permeabilization,Apoptosis,Reactive oxygen species,Photodynamic therapy,Cationic phthalocyanine
更新于2025-09-23 15:23:52
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Partially etched Bi2O2CO3 by metal chloride for enhanced reactive oxygen species generation: A tale of two strategies
摘要： Light-mediated reactive oxygen species generation with water and oxygen is generally regarded as a mild and efficient way for organic pollutants removal. However, it is highly difficult but desirable to construct a photochemical system with increased reactive oxygen species production. Herein, by using Bi2O2CO3 as a prototype, we devise a simple metal chloride-involved etching method to achieve better light absorption and charge carriers separation in a wide-band-gap semiconductor, thus giving rise to improved molecular oxygen activation. The improved photoinduced reactive oxygen species production is further verified by excellent photocatalytic degradation ability of RhB, TC and BPA under visible and ultraviolet light illumination. In addition, the metal chloride-induced strategies—heterojunction formation and cation doping—significantly affect the dynamics and transfer of carriers, which are advantageous to manipulate one-/two-electron pathway for producing reactive oxygen species.
关键词： Metal chloride,Photocatalytic,Bi2O2CO3,Reactive oxygen species,Heterojunction
更新于2025-09-23 15:23:52
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Hypocrellin A-based photodynamic action induces apoptosis in A549 cells through ROS-mediated mitochondrial signaling pathway
摘要： Over recent decades, many studies have reported that hypocrellin A (HA) can eliminate cancer cells with proper irradiation in several cancer cell lines. However, the precise molecular mechanism underlying its anticancer effect has not been fully defined. HA-mediated cytotoxicity and apoptosis in human lung adenocarcinoma A549 cells were evaluated after photodynamic therapy (PDT). A temporal quantitative proteomics approach by isobaric tag for relative and absolute quantitation (iTRAQ) 2D liquid chromatography with tandem mass spectrometric (LC–MS/MS) was introduced to help clarify molecular cytotoxic mechanisms and identify candidate targets of HA-induced apoptotic cell death. Specific caspase inhibitors were used to further elucidate the molecular pathway underlying apoptosis in PDT-treated A549 cells. Finally, down-stream apoptosis-related protein was evaluated. Apoptosis induced by HA was associated with cell shrinkage, externalization of cell membrane phosphatidylserine, DNA fragmentation, and mitochondrial disruption, which were preceded by increased intracellular reactive oxygen species (ROS) generations. Further studies showed that PDT treatment with 0.08 μmol/L HA resulted in mitochondrial disruption, pronounced release of cytochrome c, and activation of caspase-3, -9, and -7. Together, HA may be a possible therapeutic agent directed toward mitochondria and a promising photodynamic anticancer candidate for further evaluation.
关键词： iTRAQ,Hypocrellin A,Proteomic,Reactive oxygen species,LC–MS/MS,Photodynamic therapy
更新于2025-09-23 15:23:52
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CeO2/TiO2 nanostructures enhance adsorption and photocatalytic degradation of organic compounds in aqueous suspension
摘要： Mixed oxide interfaces are critical in the delivery of active components in photocatalytic processes. Cerium doped TiO2 photocatalysts were prepared using a hydrothermal route to manipulate the morphology of the photocatalyst and improve the interaction between CeO2 and TiO2 nanoparticles. These changes were compared with the photocatalytic activity and adsorption capacity of the solids. The photocatalysts were used to degrade polyvinylpyrrolidone (PVP) and methylene blue (MB) as test compounds. A low photodegradation rate of PVP (0.0001 min?1 and 0.0005 min?1 under visible and UV light, respectively) was observed using Ce-doped photocatalysts, with no adsorption. The high adsorption capacity of MB (34.46 mg g?1) proved that the local morphology of the nanostructured CeO2/TiO2 photocatalysts is more important than the amount of CeO2 in the sample, and the main role of the CeO2 on mixed photocatalysts is to improve thermal stability during the synthesis. XRD, XPS, BET surface area, UV–vis and TEM techniques confirmed this conclusion. The rate of degradation of MB by the Ce-doped photocatalyst decreased dramatically when using the singlet oxygen scavenger L-Histidine (0.0214 min?1 to 0.0001 min?1), indicating a photocatalysis sensitized by the dye, under visible and UV light.
关键词： Cerium,Photosensitization,Reactive oxygen species,Adsorption,Morphology
更新于2025-09-23 15:23:52
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Carteolol hydrochloride reduces visible light-induced retinal damage in?vivo and BSO/glutamate-induced oxidative stress in?vitro
摘要： The purpose of this study was to determine whether carteolol eye drops, a b-adrenoceptor antagonist used as an intraocular hypotensive agent, has protective effects against the light-induced oxidative stress in retina. Dark-adapted pigmented rats were pre-treated with topical carteolol ophthalmic solution or saline and then exposed to visible light. The effects on electroretinogram (ERG), morphology, oxidative stress, and expression of mRNAs in the retinas were determined. The L-buthionine-(S,R)-sulfoximine (BSO)/glutamate-induced oxidative stress in 661 W cells, a murine photoreceptor cell line, was evaluated by cell death assays, production of reactive oxygen species (ROS), and activation of caspase. In vivo studies showed that exposure to light caused a decrease in the amplitudes of ERGs and the outer nuclear layer (ONL) thickness and an increase of the 8-hydroxy-20-deoxyguanosine (8-OHdG)-positive cells in the ONL. These changes were significantly reduced by pre-treatment with carteolol. Carteolol also significantly up-regulated the mRNA levels of thioredoxin 1 and glutathione peroxidase 1 compared to saline-treated group. Moreover, carteolol and timolol, another b-adrenoceptor antagonist, significantly inhibited BSO/glutamate-induced cell death and reduced caspase-3/7 activity and ROS production in vitro. Therefore, carteolol could protect retina from light-induced damage with multiple effects such as enhancing the antioxidative potential and decreasing the intracellular ROS production.
关键词： Antioxidative potential,Oxidative stress,Carteolol hydrochloride,Light-induced retinal damage,Reactive oxygen species
更新于2025-09-23 15:23:52
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Photodynamic therapy versus systemic antibiotic for the treatment of periodontitis in a rat model
摘要： Backgroup: To compare the therapeutic effect of photodynamic therapy (PDT) with Toluidine blue O hydrogel versus systemic antibiotic (SA) in treating periodontitis on rats. Methods: Thirty-two Wistar rats were divided into 4 groups and treated differently: Negative Control (NC) group, normal rats; Positive Control (PC) group, rats with periodontitis; SA group, rats with periodontitis treated with systemic antibiotic; PDT group, rats with periodontitis treated with PDT. After treatment, Gingival sulcus bacterial load was measured by counting the colony forming units per milliliter (CFU ml-1). The tooth and periodontal tissues were histologically processed to analyze histological and immunohistochemical profile. Gingival samples were obtained to quantify interleukyn-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) levels. Results: Gingival sulcus bacteria load is significantly lower in PDT group compared to the SA group. The histological analysis showed that some extremely effective repair signs of periodontal tissue were presented in PDT group, such as no periodontal pocket, no bone resorption, few inflammatory cells, massive fibroblasts and collagen fibers. Several effective repair signs of periodontal tissue were also observed in SA group, such as shallow periodontal pocket, small amount of inflammatory cells, substantial fibroblasts and collagen fibers. There were lower COX-2, MMP-8 and RANK immunolabeling, higher OPG immunolabeling in PDT group compared with SA group. The IL-1β and TNF-α levels in PDT group were lower than those in NC group, but higher than those in SA group. Conclusions: PDT was effective to treat experimental periodontitis and was superior to systemic metronidazole as a treatment for periodontitis.
关键词： Cytokine(s),Reactive oxygen species (ROS),Antimicrobial(s),Periodontitis
更新于2025-09-23 15:23:52