Junying Wang

Rational Design of Molecular Fluorophores for Biological Imaging in the NIR‐II Window

A new design for second near-infrared window (NIR-II) molecular fluorophores based on a shielding unit-donor-acceptor-donor-shielding unit (S-D-A-D-S) structure is reported. With 3,4-ethylenedioxy thiophene as the donor and fluorene as the shielding unit, the best performance fluorophores IR-FE and IR-FEP exhibit an emission quantum yield of 31% in toluene and 2.0% in water, respectively, representing the brightest organic dyes in NIR-II region reported so far.

Highly Catalytic Nanodots with Renal Clearance for Radiation Protection

Ionizing radiation (gamma and X-ray) is widely used in industry and medicine, but it can also pose a significant hazardous effect on health and induce cancer, physical deformity, and even death, due to DNA damage and invasion of free radicals. There is therefore an urgent unmet demand in designing highly efficient radioprotectants with synergetic integration of effective renal clearance and low toxicity. In this study, we designed ultrasmall (sub-5 nm) highly catalytically active and cysteine-protected MoS2 dots as radioprotectants and investigated their application in protection against ionizing radiation. In vivo preclinical studies showed that the surviving fraction of MoS2-treated mice can appreciably increase to up to 79% when they were exposed to high-energy ionizing radiation. Furthermore, MoS2 dots can contribute in cleaning up the accumulated free radicals within the body, repairing DNA damage, and recovering all vital chemical and biochemical indicators, suggesting their unique role as free radical scavengers. MoS2 dots showed rapid and efficient urinary excretion with more than 80% injected dose eliminated from the body after 24 h due to their ultrasmall hydrodynamic size and did not cause any noticeable toxic responses up to 30 days.

Photocatalytic Oxidation Desulfurization of Diesel Oil Using Ti-containing Zeolite

Abstract Photocatalytic oxidation of dibenzothiophene with hydrogen peroxide using Ti-containing zeolite (TS-1) as photocatalyst at ultraviolet lamp irradiation has been studied. The effect of the amount of photocatalyst and hydrogen peroxide concentration were investigated in detail. Optimal photocatalyst amount and hydrogen peroxide concentration were obtained at amounts of near 0.1 g/10 mL and 3 mL/10 mL, respectively. The oxidation proceeds in the oil phase and most of the oxidation products transfer to water phase, resulting in the successive removal of the dibenzothiophene from the n-octane phase without additional extraction by solvent. Kinetics parameters of the photocatalytic oxidation of DBT were measured and calculated. The result shows the kinetics of photocatalytic oxidation of DBT is first-order. The activity of photocatalyst was not obviously decreased after reuse ×5. Using this photocatalytic oxidation system can effectively reduce the sulfur content in diesel oil. The resulting oil contained less than 100 μg/g sulfur, and this corresponds to 90% removal.

A bright organic NIR-II nanofluorophore for three-dimensional imaging into biological tissues

Fluorescence imaging of biological systems in the second near-infrared (NIR-II, 1000–1700 nm) window has shown promise of high spatial resolution, low background, and deep tissue penetration owing to low autofluorescence and suppressed scattering of long wavelength photons. Here we develop a bright organic nanofluorophore (named p-FE) for high-performance biological imaging in the NIR-II window. The bright NIR-II >1100 nm fluorescence emission from p-FE affords non-invasive in vivo tracking of blood flow in mouse brain vessels. Excitingly, p-FE enables one-photon based, three-dimensional (3D) confocal imaging of vasculatures in fixed mouse brain tissue with a layer-by-layer imaging depth up to ~1.3 mm and sub-10 µm high spatial resolution. We also perform in vivo two-color fluorescence imaging in the NIR-II window by utilizing p-FE as a vasculature imaging agent emitting between 1100 and 1300 nm and single-walled carbon nanotubes (CNTs) emitting above 1500 nm to highlight tumors in mice.Imaging in the second near-infrared window has attracted attention due to superior penetration depth and low signal interference. Here, the authors describe a new organic nano fluorophore with high quantum yield and demonstrate its use for in vivo imaging.

Catalytic topological insulator Bi2Se3 nanoparticles for in vivo protection against ionizing radiation

Bi2Se3 nanoparticles (NPs) have attracted wide interests in biological and medical applications. Layer-like Bi2Se3 with high active surface area is promising for free radical scavenging. Here, we extended the medical applications of Bi2Se3 NPs further to in vivo protection against ionizing radiation based on their superior antioxidant activities and electrocatalytic properties. It was found that Bi2Se3 NPs can significantly increase the surviving fraction of mice after exposure of high-energy radiation of gamma ray. Additionally, the Bi2Se3 NPs can help to recover radiation-lowered red blood cell counts, white blood cell counts and platelet levels. Further investigations revealed that Bi2Se3 NPs behaved as functional free radical scavengers and significantly decreased the level of methylenedioxyamphetamine. In vivo toxicity studies showed that Bi2Se3 NPs did not cause significant side effects in panels of blood chemistry, clinical biochemistry and pathology.

Original ArticleCatalytic topological insulator Bi2Se3 nanoparticles for in vivo protection against ionizing radiation

Bi2Se3 nanoparticles (NPs) have attracted wide interests in biological and medical applications. Layer-like Bi2Se3 with high active surface area is promising for free radical scavenging. Here, we extended the medical applications of Bi2Se3 NPs further to in vivo protection against ionizing radiation based on their superior antioxidant activities and electrocatalytic properties. It was found that Bi2Se3 NPs can significantly increase the surviving fraction of mice after exposure of high-energy radiation of gamma ray. Additionally, the Bi2Se3 NPs can help to recover radiation-lowered red blood cell counts, white blood cell counts and platelet levels. Further investigations revealed that Bi2Se3 NPs behaved as functional free radical scavengers and significantly decreased the level of methylenedioxyamphetamine. In vivo toxicity studies showed that Bi2Se3 NPs did not cause significant side effects in panels of blood chemistry, clinical biochemistry and pathology.

Hollow PtPdRh Nanocubes with Enhanced Catalytic Activities for In Vivo Clearance of Radiation-Induced ROS via Surface-Mediated Bond Breaking

Catalytic nanomaterials can be used extrinsically to combat diseases associated with a surplus of reactive oxygen species (ROS). Rational design of surface morphologies and appropriate doping can substantially improve the catalytic performances. In this work, a class of hollow polyvinyl pyrrolidone-protected PtPdRh nanocubes with enhanced catalytic activities for in vivo free radical scavenging is proposed. Compared with Pt and PtPd counterparts, ternary PtPdRh nanocubes show remarkable catalytic properties of decomposing H2 O2 via enhanced oxygen reduction reactions. Density functional theory calculation indicates that the bond of superoxide anions breaks for the energetically favorable status of oxygen atoms on the surface of PtPdRh. Viability of cells and survival rate of animal models under exposure of high-energy γ radiation are considerably enhanced by 94% and 50% respectively after treatment of PtPdRh nanocubes. The mechanistic investigations on superoxide dismutase (SOD) activity, malondialdehyde amount, and DNA damage repair demonstrate that hollow PtPdRh nanocubes act as catalase, peroxidase, and SOD analogs to efficiently scavenge ROS.

Highly efficient catalytic scavenging of oxygen free radicals with graphene-encapsulated metal nanoshields

Normal levels of oxygen free radicals play an important role in cellular signal transduction, redox homeostasis, regulatory pathways, and metabolic processes. However, radiolysis of water induced by high-energy radiation can produce excessive amounts of exogenous oxygen free radicals, which cause severe oxidative damages to all cellular components, disrupt cellular structures and signaling pathways, and eventually lead to death. Herein, we show that hybrid nanoshields based on single-layer graphene encapsulating metal nanoparticles exhibit high catalytic activity in scavenging oxygen superoxide(·

Ultrasmall Pt Clusters Reducing Radiation-Induced Injuries via Scavenging Free Radicals

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