Reactive Oxygen Species Yield Research Articles

Synergy of Surface Phosphates and Oxygen Vacancies Enables Efficient Photocatalytic Methane Conversion at Room Temperature.

Room-temperature photocatalytic conversion of CH4 into liquid oxygenates with O2/H2O provides an appealing route for sustainable chemical industry, which, however, suffers from poor efficiency due to the undesired carrier kinetics and low yield of reactive oxygen species of the currently available photocatalysts. Here, we report an effective surface engineering strategy where concurrent constructions of oxygen vacancies and phosphate sites on TiO2 nanosheets address the above challenge. The surface oxygen vacancies and phosphates are respective acceptors of photogenerated electrons and holes for promoted separation and migration of charge carriers. Moreover, in addition to the facilitated activation of O2 to •OH by electrons at oxygen vacancies, the surface phosphates also facilely adsorb H2O via hydrogen bonds and thus effectively transfer holes to H2O for enhanced •OH production, thereby boosting CH4 conversion. As a result, compared with TiO2 sheets with only oxygen vacancies, a 2.8 times improvement in liquid oxygenate production with near-unity selectivity is achieved by virtue of the synergy of surface oxygen vacancies and phosphate sites, together with an unprecedent quantum efficiency of 19.8% under 365 nm irradiation.

Confining manganese-based peroxymonosulfate activation in carbon nanotube membrane for phenol degradation: Combined effect of oxygen vacancy defects and nanoconfinement

In this study, an open ends carbon nanotube (OCNT) membrane, which confined fine-tuned oxygen vacancy defects (Odef) modified MnOx inside OCNT (MnOx-in-OCNT), was developed for enhancing peroxymonosulfate (PMS) activation towards phenol (PE) removal. The MnOx-in-OCNT membrane filtration coupled with PMS activation process (MFPA process) achieved outstanding removal (100%) of PE at a high permeate flux of 585.0 L m2 h−1 bar−1 (residence time of only 8.8 s). The unit degradation rate (2 min running time) and mass transfer rate of MnOx-in-OCNT were 2.0 and 8.4 times higher than that of CCNT (closed caps CNT) membrane with surface-loaded MnOx (MnOx-out-CCNT) MFPA process, and its catalytic performance was much superior to MnOx-in-OCNT powder reactions and MnOx-in-OCNT membrane batch reactions. The PMS activation mechanism experienced an obvious enhancement yield of reactive oxygen species (ROS) from MnOx-out-CCNT to MnOx-in-OCNT MFPA process. The enhanced PMS activation and boosted ROS yield of MnOx-in-OCNT was mainly attributed to the co-effect of the fine-tuned Odef and nanoconfinement. The contact frequency between PMS, pollutant and Odef was greatly enhanced via nanoconfinement effect, leading to the enhanced yield of SO4•− and •OH. Meanwhile, the O2 was enriched and reacts with enhanced Odef under nanoconfined-space to produce O2•− and 1O2. Then, the co-enhanced ROS (SO4•−, •OH, 1O2 and O2•−) displayed wide applicability for phenolic pollutants removal owing to their presence of –OH. Finally, the possible degradation pathway of PE was deduced by DFT calculations and HPLC analysis.

Ozone-Initiated Yield of Reactive Oxygen Species in a Model Indoor Surface Film

Recent evidence suggests that products of indoor ozone chemistry contribute to cardiovascular pathophysiology. A hypothetical exposure pathway is the formation of reactive oxygen species (ROS) on indoor surfaces, and subsequent partitioning of ROS to respirable particulate matter (PM). For this pathway to be relevant, the ozone-initiated surface yield of ROS should be large enough to contribute substantially to total ROS intake by PM. Here, we exposed a model indoor surface film comprising a mixture of skin and cooking oil lipids to ozone and measured the yield of condensed-phase ROS using a colorimetric method sensitive primarily to hydroperoxides and calibrated with hydrogen peroxide. Approximately 46% of the ozone that was consumed in the reaction formed ROS on a molar basis. Approximately half of the ROS formed is persistent for at least several hours on the surface. ROS continued to form in the absence of ozone, suggesting that a mechanism other than ozonation continues to oxidize the lipids, such as autoxidation. The yields observed here are well above that necessary to contribute to the ROS airborne concentrations observed in field studies.

2D Piezoelectric BiVO4 Artificial Nanozyme with Adjustable Vanadium Vacancy for Ultrasound Enhanced Piezoelectric/Sonodynamic Therapy.

Increasing the yield of reactive oxygen species (ROS) to enhance oxidative stress in cells is an eternal goal in cancer therapy. In this study, BiVO4 artificial nanozyme is developed with adjustable vanadium vacancy for ultrasound (US) enhanced piezoelectric/sonodynamic therapy. Under US excitation, the vanadium vacancy-rich BiVO4 nanosheets (abbreviated Vv -r BiVO4 NSs) facilitate the generation of a large number of electrons to improve the ROS yield. Meanwhile, the mechanical strain imposed by US irradiation makes the Vv -r BiVO4 NSs display a typical piezoelectric response, which tilts the conduction band to be more negative and the valance band more positive than the redox potentials of O2 /O2 •- and H2 O/·OH, boosting the efficiency of ROS generation. Both density functional theory calculations and experiments confirm that the introduction of cationic vacancy can improve the sonodynamic effect. As expected, Vv -r BiVO4 NSs have better peroxidase enzyme catalytic and glutathione depletion activities, resulting in increased intracellular oxidative stress. This triple amplification strategy of oxidative stress induced by US substantially inhibits the growth of cancer cells. The work may open an avenue to achieve a synergetic therapy by introducing cationic vacancy, broadening the biomedical use of piezoelectric materials.

Kinetics and mechanism of enhanced norfloxacin degradation by Fe3O4@La-BiFeO3 based on weak magnetization and efficient charge separation

Improving the yield of reactive oxygen species and inhibiting the recombination of photogenerated e- and h+ have been reliable strategies to accelerate the rate-limiting step for nano photocatalytic materials. A novel magnetic Fe3O4@La-BiFeO3 composite with variable molar ratios was successfully synthesized via a facile hydrothermal method for the photo-Fenton-like degradation of norfloxacin (NOR) under visible light irradiation. The comprehensive characterization of the crystal phase purity, morphological structure and elemental composition of the catalyst confirmed the formation of a heterojunction structure between Fe3O4 and La-BiFeO3. The effects of the composite molar ratio, initial pH, catalyst addition, and H2O2 concentration on the degradation efficiency were investigated. 20% Fe3O4@La-BiFeO3 showed the best catalytic activity with 93.8% removal of NOR after 60 min of reaction and the pseudo-first-order rate constant was 0.05952 min−1, attributed to the synergistic interaction of the photocatalytic and Fenton-like processes. The excellent stability and recyclability of the catalyst ensured the catalytic reactions continued to occur efficiently. The appropriate amount of Fe3O4 reduced the band gap of the catalyst, and the introduction of a weak magnetic field accelerated the transfer of electrons between interfaces, effectively restrained the recombination of photogenerated e-/h+ and directly enhanced the yield of ·OH and O2·-. This work not only realized the preparation of a heterogeneous photo-Fenton-like catalyst with high application potential for the degradation of antibiotics, but also provided new prospects for designing efficient catalysts on the basis of theoretical guidance.

3D variable Co species carbon foam enhanced reactive oxygen species generation and ensured long-term stability for water purification

Cobalt (Co) and oxides are the most common catalysts for activating peroxymonosulfate (PMS). However, practical applications of Co-based PMS-advanced oxidation processes are difficult to realize the degradation of the targeted pollutants due to poor yield of reactive oxygen species (ROS) and inaccessible active sites. Here, we designed 3D oxygen vacancy-rich (Vo-rich) variable Co species@carbon foam (CoxOy@CF) via coupling solvent-free and pyrolysis strategies for degrading tetracycline by PMS activation. The kinetic rate of optimized (Co@CoO) CoxOy@CF-1.0 (1.0 presented the molar ratio of Co2+ and 2-methylimidazole) enhanced by an order of magnitude compared to that of ZIFs derivatives (ZIFs-500) (0.073 vs 0.155 min−1) due to the special structure. The flow-through unit maintained over 90% removal within 12 h, which was far better than that of ZIFs-500/PMS system. We used electrochemical analysis, quenching experiment, in-situ FTIR and Raman spectra to further investigate the possible mechanism of the 3D CoxOy@CF-1.0/PMS system. 3D CoxOy@CF-1.0 stimulated the production of the metastable catalyst-PMS* complex obtained O2− as intermediates accompanied by the redox cycling of Co2+/Co3+, which created the dominant ROS (more 1O2) in the presence of Vo, which was completely different for ZIFs-500/PMS with coordinated and dominant radical and non-radical pathways. This study could large-scale generate variable cobalt-based catalysts for enhanced ROS generation, leading the new insight for boosting practical applications.

Assembling CoAl-layered metal oxide into the gravity-driven catalytic membrane for Fenton-like catalytic degradation of pharmaceuticals and personal care products

Application of peroxymonosulfate (PMS)-based Fenton-like heterogeneous catalysis in water treatment remains scarce due to mass transfer limitation and poor yield of reactive oxygen species (ROS). Herein, assembling reactive CoAl-layered metal oxide (LMO) into the gravity-driven catalytic membrane was carried out to overcome the inherent limitations. Indeed, compared to the conventional batch reactor (less than 35% removal), the LMO membrane/PMS system achieved effective degradation (94.17%) of the probe chemical ranitidine along with several other selected pharmaceuticals and personal care products (PPCP, >80%). This, as predicted by density functional theory calculations, could be attributed to remarkable activation of PMS by the exposed (001) surfaces and (100) edges of CoAl-LMO, spontaneously generating ROS for PPCP degradation. Electron charge density difference analysis estimated efficient charge accumulation and depletion between PMS and LMO, implying strong interaction and charge transfer in the LMO membrane/PMS system. Notably, ROS quenching experiments and electron paramagnetic resonance spectroscopy confirmed the theoretical findings, which showed that PPCP degradation in the LMO membrane/PMS system is caused by both the radicals (SO4•− + •OH = 51.97%) and nonradicals (1O2 = 20.58%) pathways. The LMO membrane achieved long-term stable performance (>90% removal), and the analysis of the used membrane suggested an increase in the relative distribution of oxygen vacancies or ≡Co–OH species, which is favourable for PMS activation. Overall, this study offers a simple strategy for efficient removal of several PPCPs, which could be applied sustainably in water treatment.

Engineering of plasmonic metal-semiconductor yolk-shell nanostructures for multi-intensified photodynamic- and immuno- therapy against drug resistant bacteria

Photodynamic therapy (PDT) as well as immunotherapy are effective therapies to combat the systemic infection. Nevertheless, the development of the treatments are restrained by the lack of efficient photosensitizers (PS) and the genetic diversity of the bacteria. Here, we report Ag doped Au-CdS1−ySey yolk-shell nanostructures (AYSs) which exhibit excellent near-infrared (NIR) light induced PDT and immunotherapy performance. The tailored plasmonic Au nanorods (NRs) are able to gather the NIR light, offering the basis for PDT. Moreover, high yield of reactive oxygen species (ROS) is achieved through the following creativity: i) enhanced light trapping ability by the microcavity, ii) smooth injection process of hot electrons (HEs) by the suitable band gap alignment, iii) inhibiting the combination of electric charges by the doped Ag with appropriate concentration. Therefore, the AYSs exhibit more 30 times of ROS production as well as lower 64 times of MIC than the conventional core-shell nanostructures. Notably, repeated enhanced antibacterial PDT are carried out to obtain versatile antigens from various dead bacteria to awaken the immune cells adequately and boost immune response with the help of Selenium (Se) which is distributed in the shell. As a result, the systemic drug resistant bacterial infection is cured successfully.

Constructing a novel CuS/Cu2S Z-scheme heterojunction for highly-efficiency NIR light-driven antibacterial activity

Constructing a Z-scheme photocatalytic system offers great advantages for boosting photocatalytic performance due to its effective charge carrier transfer and strong redox capability. Herein, Cu2S/CuS nanosheets heterojunction were prepared by a facile one-pot solvothermal method. CuS/Cu2S Z-scheme heterojunction realized rapid bacteria-killing under near-infrared (NIR) irradiation. The optimized CuS/Cu2S (CuS/Cu2S-1) achieved 99 % antibacterial efficiency against Escherichia coli (E. coli) within 10 min NIR irradiation. Owing to the optimization of CuS/Cu2S-1 Z-scheme heterojunction, the efficient interfacial charge separation was realized, thereby resulting in a high yield of reactive oxygen species. Moreover, the heterojunction exhibited locally a higher temperature under NIR irradiation, favorable for eradicating bacteria. In addition, radical scavenging tests and ESR spectra results showed that ⋅O2–, ⋅OH and 1O2 were main active species responsible for sterilization. Under the synergy of photocatalytic and photothermal effects, the membrane structure of bacteria was severely damaged in CuS/Cu2S-1 system. This study not only offers a reliable approach for photothermocatalytic inactivation, but also affords the bases for the development of Z-scheme heterojunction aimed at designing highly efficient photocatalysts.

Achieving Fast Charge Separation by Ferroelectric Ultrasonic Interfacial Engineering for Rapid Sonotherapy of Bacteria-Infected Osteomyelitis.

Bacteria-infected osteomyelitis is life-threatening without effective therapeutic methods clinically. Here, a rapid and effective therapeutic strategy to treat osteomyelitis through ferroelectric polarization interfacial engineering of BiFeO3 /MXene (Ti3 C2 ) triggered by ultrasound (US) is reported. Under US, the ferroelectric polarization induces the formation of thepiezoelectric field. US cavitation effectinduced sonoluminescence stimulates BiFeO3 /Ti3 C2 to produce photogenerated carriers. With synergistic action ofthepolarization electric field and Schottky junction, BiFeO3 /Ti3 C2 accelerates the separation of electrons and holes and simultaneously inhibits the backflow of electrons, thus improving the utilization of polarized charges and photogenerated charges and consequently enhancing the yield of reactive oxygen species under US. As a result, 99.87 ± 0.05% of Staphylococcus aureus are efficiently killed in 20min with the assistance of ultrasonic heating. The theory of ferroelectric ultrasonic interfacial engineering is proposed, which brings new insight for developing ferroelectric ultrasonic responsive materials used for the diagnosis and therapy of deep tissue infection and other acoustoelectric devices.

Naphthalene degradation dominated by homogeneous reaction in Fenton-like process catalyzed by pyrite: Mechanism and application

Fe-containing natural minerals, such as pyrite, have been conducted an extensive study in Fenton-like processes, however, answers for the role of homogeneous and heterogeneous reactions and their application potentials need to be theoretically demonstrated. In this study, the performance and mechanism of Fenton-like process catalyzed by pyrite were investigated by surface characterizations and degradation experiments using naphthalene as a target contaminant. First, the major role of homogeneous reaction in the naphthalene degradation in H2O2/pyrite system was confirmed by iron determination and iron quenching tests, where 2,2′-bipyridine was used as the iron quencher. Second, it was clarified that sulfur species including polysulfides, elemental sulfur, and thiosulfate facilitated the Iron redox cycle and the yield of reactive oxygen species, thus enhanced the degradation of naphthalene. Moreover, compared with sulfidated nanoscale zero valent iron and ferrous sulfide, pyrite exhibited superiority in naphthalene degradation due to higher reaction stoichiometry efficiency (0.31) and lower running cost (77 RMB (kg naphthalene)−1). Finally, pyrite showed excellent performance for various pollutants removal and in multiple water environments. This work provides the underlying mechanisms of H2O2/pyrite process and a solid step forward to pyrite application in the remediation of naphthalene contaminated water.

Identifying the evolution of primary oxidation mechanisms and pollutant degradation routes in the electro-cocatalytic Fenton-like systems

Herein, electro-catalysis (EC) as the electron donor to accelerate the continuable Fe(III)/Fe(II) cycles in different inorganic peroxides (i.e., peroxymonosulfate (PMS), peroxydisulfate (PDS) and hydrogen peroxide (HP)) activation systems were established. These electro-cocatalytic Fenton-like systems exhibited an excellent degradation efficiency of sulfamethoxazole (SMX). A series of analytical and characterization methods including quenching experiments, probe experiments, and electron paramagnetic resonance spectrometry (EPR) were implemented to systematically sort out the source and yield of reactive oxygen species (ROS). A wide kind of ROS including hydroxyl radical (•OH), singlet oxygen (1O2), and sulfate radical (SO4•−), which contributed 38%, 37%, and 24% were produced in EC/Fe(III)/PMS system, respectively. •OH was the dominant ROS in both EC/Fe(III)/PDS and EC/Fe(III)/HP processes. According to the analysis of SMX degradation routes and biotoxicity, abundant degradation pathways were identified in EC/Fe(III)/PMS process and lower environmental impact was achieved in EC/Fe(III)/HP process. The diversiform ROS of EC/Fe(III)/PMS system makes it exhibit greater environmental adaptability in complex water matrixes and excellent low-energy consumption performance in many organic pollutants degradation. Continuous flow treatment experiments proved that the three systems have great sustainability and practical application prospect. This work provides a strong basis for constructing suitable systems to achieve different treatment requirements.

Rapid Ferroelectric-Photoexcited Bacteria-Killing of Bi4Ti3O12/Ti3C2T x Nanofiber Membranes.

The online version contains supplementary material available at 10.1007/s42765-022-00234-8.

Photodynamic Therapy and Antibacterial Activities of a Novel Synthesized Quaternary Zn-Cu-In-S/ZnS QDs- mTHPP Porphyrin Conjugate.

Photodynamic therapy (PDT) is a non-invasive treatment modality that destroys abnormally growing cells or microorganisms. Porphyrins are used as photosensitizers in PDT; however, their clinical application has been limited by their poor water solubility, resulting in aggregation and low quantum yields of reactive oxygen species (ROS). To overcome these limitations and improve PDT efficacy, we herein report the conjugation of ZnCuInS/ZnS (ZCIS/ZnS) quantum dots (QDs) to 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin (mTHPP). The optimal conditions for QDs porphyrin conjugation formation were systematically evaluated. This study further assessed the PDT efficacy and antibacterial potency of the synthesized ZCIS/ZnS-mTHPP conjugates. The PDT efficacy of the QDs, mTHPP, and conjugate was evaluated against the murine metastatic melanoma (B16 F10 Nex2) cell line. This was performed with and without LED irradiation. The conjugate exhibited the highest reduction in cell viability following LED irradiation (72%) compared to the bare QDs (19%) and mTHPP (1%). Antimicrobial studies conducted on E. coli showed that the conjugation exhibits a higher antibacterial effect than the bare QDs, even without light. The results suggest that conjugate is a promising class of materials for anti-cancer and antimicrobial PDT.

Smart Fe3O4@ZnO Core-Shell Nanophotosensitizers Potential for Combined Chemo and Photodynamic Skin Cancer Therapy Controlled by UVA Radiation.

PurposePhotodynamic therapy (PDT) is a non-invasive therapeutic modality that is used for several types of cancer and involves three essential elements (light, photosensitizer (PS), and oxygen). However, clinical PS is limited by the low yield of reactive oxygen species (ROS) and a long retention time. Therefore, developing a low-cost PS that can significantly increase ROS yield in a short time is of utmost importance.MethodsIn this study, brusatol (Bru) was loaded on the surface of ultraviolet A (UVA)-responsive zinc oxide (ZnO)-coated magnetic nanoparticles (Fe3O4@ZnO-Bru). The PS was well characterized by transmission electron microscopy (TEM), Fourier Transform infrared spectroscopy (FTIR), a superconducting quantum interference device, and dynamic light scattering (DLS). 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and Hoechst staining were used to determine the inhibitory effect of Fe3O4@ZnO-Bru on squamous cell carcinoma cells (SCC) with or without UVA radiation. Intracellular ROS levels and expression of the Nrf2 signaling pathway were also determined.ResultsFTIR showed that Bru was successfully loaded on Fe3O4@ZnO. Fe3O4@ZnO-Bru was superparamagnetic, and the zeta potential was 8.86 ± 0.77 mV. The Bru release behavior was controlled by UVA. Fe3O4@ZnO-Bru with UVA irradiation induced an increase of 48% ROS productivity compared to Fe3O4@ZnO-Bru without UVA irradiation, resulting in a strong inhibitory effect on SCC. Furthermore, Fe3O4@ZnO-Bru nanocomposites (Fe3O4@ZnO-Bru NCs) had nearly no toxic effect on healthy cells without UVA radiation. The released Bru could significantly inhibit the Nrf2 signaling pathway to reduce the activity of scavenging excess ROS in SCC.ConclusionIn this study, Fe3O4@ZnO-Bru was successfully synthesized. PDT was combined with photochemotherapy, which exhibited a higher inhibitory effect on SCC. It can be inferred that Fe3O4@ZnO-Bru holds great potential for skin SCC therapy.

Macrophage-Targeted Sonodynamic/Photothermal Synergistic Therapy for Preventing Atherosclerotic Plaque Progression Using CuS/TiO2 Heterostructured Nanosheets.

Sonodynamic therapy (SDT) and photothermal therapy (PTT) are two effective strategies for the treatment of atherosclerotic plaques. However, the low yield of reactive oxygen species (ROS) of conventional organic sonosensitizers and the low biosafety of hyperthermia limit the therapeutic efficacy of SDT and PTT. Herein, we report copper sulfide/titanium oxide heterostructure nanosheets modified with hyaluronic acid (HA) and PEG (HA-HNSs) for low-intensity sonodynamic and mild-photothermal synergistic therapy for early atherosclerotic plaques. CuS/TiO2 heterostructure nanosheets (HNSs) show high electron-hole separation efficiency and superior sonodynamic performance, because it has high surface energy crystal facets as well as a narrow band. Moreover, HNSs exhibit intense absorbance in the NIR-II region, which endows the nanosheets with excellent photothermal performance. With a further modification of HA, HA-HNSs can selectively target intraplaque proinflammatory macrophages through CD44-HA interaction. Because SDT reduces the expression of heat shock protein 90 and PTT facilitates the sonocatalytic process, the combination of SDT and PTT based on HA-HNSs could synergistically induce proinflammatory macrophage apoptosis. More importantly, the synergistic therapy prevents the progression of early atherosclerotic plaque by removing lesional macrophages and mitigating inflammation. Taken together, this work provides a macrophage-targeting sonodynamic/photothermal synergistic therapy, which is an effective translational clinical intervention for early atherosclerotic plaques.

Two-Dimensional MXene-Originated In Situ Nanosonosensitizer Generation for Augmented and Synergistic Sonodynamic Tumor Nanotherapy.

Despite the merits of high tissue-penetrating depth, no ionizing radiation, and low cost, sonodynamic therapy (SDT) still suffers from a low quantum yield of reactive oxygen species (ROS), limited delivery efficiency, and potential toxicity of sonosensitizers. Different from the direct delivery of sonosensitizers into tumor tissue for SDT, this work reports the fabrication of two-dimensional (2D) nanosonosensitizers/nanocatalysts (Ti3C2/CuO2@BSA) for the in situ generation of nanosonosensitizers by responding to the tumor microenvironment, achieving the high-performance and synergistic sonodynamic/chemodynamic tumor therapy. CuO2 nanoparticle integration on 2D Ti3C2 MXene achieved in situ H2O2 generation in an acidic tumor microenvironment for oxidizing Ti3C2 to produce TiO2 nanosonosensitizers, accompanied by the enhanced separation of electrons (e-) and holes (h+) by the carbon matrix after oxidation, further augmenting the SDT efficacy. Ultrasound irradiation during the sonodynamic process also enhanced the Cu-initiated Fenton-like reaction to produce more ROS for synergizing the sonodynamic tumor therapy. The experimental results confirm and demonstrate the synergistic therapeutic effects of chemodynamic and sonodynamic nanotherapy both in vitro and in vivo. The antitumor mechanisms of synergistic chemodynamic and sonodynamic therapies are associated with the upregulation of oxidative phosphorylation, ROS generation, and apoptosis as demonstrated by RNA sequencing. This work thus provides a distinct paradigm of 2D MXene-originated in situ nanosonosensitizer generation for augmented and synergistic sonodynamic tumor nanotherapy.

Plasma characteristics of atmospheric pinhole discharge in water

Solution-phase synthesis needs rapid generation of high-density reactive species to initiate the chemical reaction. Here we report a novelty method to efficiently produce reactive species (including ∙H, ∙OH, ∙O, H2O2 and O3) by atmospheric pinhole discharge in water. The plasma is initiated in bubbles generated by Joule heat on both sides of the pinhole leading to the increase of contact volume between the plasma and the liquid. The discharge type is similar to arc discharge, which can continuously act with liquids. The energy yield of reactive oxygen species in water can be attained to 1.5 g/kWh without the addition of O2. In addition, the in-liquid pinhole discharge can be maintained at a relatively high solution conductivity over 1000 μS/cm.

Magnetic-targeted capacitive heterostructure of polypyrrole for hypoxia-tolerant synergistic photodynamic/photothermal therapy under near infrared excitation

Dual/Multi-modal photonanomedicines with the maximized antitumor efficacy has attracted extensive concerning. In this contribution, through photovoltaic engineering of photothermal conjugated polymer, a facile magnetic-targeted capacitive heterostructure of polypyrrole (upconversion nanoparticles (UCNPs)@SiO2-Fe3O4 @polypyrrole (USFP)), capable of photodynamic therapy (PDT) and photothermal therapy (PTT) upon near infrared (NIR) excitation is purposefully developed. Owing to the optimized regulation of photoreaction pathway via photoinduced capacitance effect, the yield of reactive oxygen species (ROS) including 1O2 in polypyrrole can be significantly promoted. Notably, the external layers (porous silica and polypyrrole) of USFP allow the encounter and subsequent Fenton reaction between Fe3O4 and H2O2 in tumor site, thereby further enhancing the photodynamic effect via an effective O2 supply. Upon intravenous injection into tumor-bearing mice, USFP can accumulate in tumors through a magnetic guidance, ablation experiments in vitro and in vivo confirmed the enhanced synergistic therapeutic effect and desirable biocompatibility of USFP.

Photoacoustic Effect of Near-Infrared Absorbing Organic Molecules via Click Chemistry.

Near-infrared dyes were developed to be contrast agents due to their ability to improve the productivity of photoacoustic (PA) imaging and photothermal therapy (PTT) treatments. During the article, we described in detail the PA and PT effects of a category of organic molecules. F4-TCNQ could potentially cause a red-shift in the peak PA intensity. The results show that the PTT intensity of the near-infrared dyes with phenyl groups were higher than near-infrared dyes with thiophene groups. We also investigated the photodynamic treatment effect of C1b to demonstrate that these dyes are highly desirable in biochemistry. The high photoacoustic intensity of the organic molecules and the good yield of reactive oxygen species could indicate that these dyes have good potential for a wide range of imaging applications. Finally, we embedded the dye (C1b) in a liposomal hydrophobic phospholipid bilayer (C1b⊂L) to facilitate the application of hydrophobic dyes in biomedical applications, which can be absorbed by cells with good compatible and high stability for the imaging of cellular PA.