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Shi-Ying Li, Bo-Ru Xie, Hong Cheng, Chu-Xin Li, Ming-Kang Zhang, Wen-Xiu Qiu, Wen-Long Liu, Xiao-Shuang Wang, Xian-Zheng Zhang
In this report, a biomimetic theranostic oxygen (O2)-meter (cancer cell membrane@Pt(II) porphyrinic-metal organic framework, designated as mPPt) was constructed for cancer targeted and phosphorescence image-guided photodynamic therapy (PDT). mPPt presents high photosensitizers (PSs) loading and evitable self-quenching behaviors for favorable biological O2 sensing and PDT. Besides, endowed by the surface functionalization of cancer cell membrane, the homotypic targeting and immune escape abilities of mPPt could dramatically enhance its cancer targeting ability...
October 12, 2017: Biomaterials
Yu-Heng Wang, Michael L Pegis, James M Mayer, Shannon S Stahl
A series of mononuclear pseudo-macrocyclic cobalt complexes have been investigated as catalysts for O2 reduction. Each of these complexes, with CoIII/II reduction potentials that span nearly 400 mV, mediate highly selective two-electron reduction of O2 to H2O2 (93-99%) using decamethylferrocene (Fc*) as the reductant and acetic acid as the proton source. Kinetic studies reveal that the rate exhibits a first-order dependence on [Co] and [AcOH], but no dependence on [O2] or [Fc*]. A linear correlation is observed between log(TOF) vs...
October 17, 2017: Journal of the American Chemical Society
Luzia Guyer, Kathrin Salinger, Undine Krügel, Stefan Hörtensteiner
During leaf senescence and fruit ripening, chlorophyll is degraded in a multistep pathway into linear tetrapyrroles called phyllobilins. A key feature of chlorophyll breakdown is the removal of the hydrophobic phytol chain that renders phyllobilins water soluble, an important prerequisite for their ultimate storage in the vacuole of senescent cells. Chlorophyllases had been considered for more than a century to catalyze dephytylation in vivo; however, this was recently refuted. Instead, pheophytinase was discovered as a genuine in vivo phytol hydrolase...
September 23, 2017: Journal of Experimental Botany
Jia Tian, Lei Xu, Yudong Xue, Xiaoze Jiang, Weian Zhang
Drug resistance is a primary obstacle that seriously reduces therapy efficiency of most chemotherapeutic agents. To address this issue, the photochemical internalization (PCI) was employed to help the anticancer drug escape from lysosome and improve their translocation to the nucleus. Herein, a pH-sensitive porphyrin-based amphiphilic block copolymer (PEG113-b-PCL54-a-porphyrin) was synthesized, which was acted not only as a carrier for the delivery of DOX, but also as a photosensitizer for PCI.PEG113-b-PCL54-a-porphyrin as a drug carrier exhibited a higher drug loading capacity, entrapment efficiency and DOX release content...
October 16, 2017: Biomacromolecules
Marney L Doran, Jose M Knee, Nan Wang, Teresa Z Rzezniczak, Tony L Parkes, Liang Li, Thomas J S Merritt
Oxidative stress results in substantial biochemical and physiological perturbations in essentially all organisms. To determine the broad metabolic effects of oxidative stress, we have quantified the response in Drosophila melanogaster to both genetically and environmentally derived oxidative stress. Flies were challenged with loss of Superoxide dismutase activity or chronic or acute exposure to the oxidizing chemical paraquat. Metabolic changes were then quantified using a recently developed chemical isotope labelling (CIL) liquid chromatography - mass spectrometry (LC-MS) platform that targets the carboxylic acid and amine/phenol submetabolomes with high metabolic coverage...
October 11, 2017: Free Radical Biology & Medicine
Tatyana A Maryutina, Andrei R Timerbaev
Metals occurring in crude oil in a great variety of complexed forms are minor but important constituents as they affect the refining and production operations, as well as participate in geochemical processes. These roles of metals are thought to be related to their chemical state the knowledge of which requires performing speciation analysis. While exact metal speciation in crude oil still remains obscure, earnest efforts to decipher it based on using up-to-date hyphenated techniques have been attempted in the past decade...
October 23, 2017: Analytica Chimica Acta
Jack W Chidgey, Philip J Jackson, Mark J Dickman, C Neil Hunter
Facultative phototrophs such as Rhodobacter sphaeroides can switch between heterotrophic and photosynthetic growth. This transition is governed by oxygen tension and involves the large-scale production of bacteriochlorophyll, which shares a biosynthetic pathway with haem up to protoporphyrin IX. Here, the pathways diverge with the insertion of Fe(2+) or Mg(2+) into protoporphyrin by ferrochelatase or magnesium chelatase, respectively. Tight regulation of this branchpoint is essential, but the mechanisms for switching between respiratory and photosynthetic growth are poorly understood...
October 14, 2017: Molecular Microbiology
Maximilian Wolf, Carmen Villegas, Olga Trukhina, Juan Luis Delgado, Tomas Torres, Nazario Martín, Timothy Clark, Dirk M Guldi
We report the synthesis of a full-fledged family of covalent electron donor-acceptor1-acceptor2 conjugates and their charge-transfer characterization by means of advanced photophysical assays. Both Zn(II)Porphyrins and Zn(II)Phthalocyanines were linked to different electron-transport chains of pairs of electron accepting C60 and C70 fullerenes. In this way, a fine-tuned redox gradient is established to power a unidirectional, long-range charge transport from the excited-state electron donor via a transient C60•- towards C70•-...
October 13, 2017: Journal of the American Chemical Society
Changling Liu, Yanhui Li, Bo Gao, Yanwei Li, Qian Duan, Toyoji Kakuchi
A novel comb-shaped porphyrin end-functionalized poly(N-isopropylacrylamide)-b-poly[oligo (ethylene glycol methyl ether methacrylate)] (Por-PNIPAM-b-POEGMA) was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Due to the incorporation of hydrophilic POEGMA contents, the copolymer shows the lower critical solution temperatures (LCST) of 37-41.8°C higher than PNIPAM. Moreover, this copolymer showed efficient singlet oxygen under light irradiation at 650nm, and the productivity of singlet oxygen was 0...
January 1, 2018: Materials Science & Engineering. C, Materials for Biological Applications
S M Nizam Uddin, Yuki Nagao
Controllable synthesis of organic thin film materials on solid surfaces is a challenging issue in the research field of surface science as it is affected by several physical parameters. In this work, we demonstrated a solution-based molecular layer deposition (MLD) approach to prepare porphyrin-based covalent organic molecular networks on a 3-aminopropyl trimethoxysilane (APTMS) modified substrate surface using the urea coupling reaction between 1,4-phenylene diisocyanate (1,4-PDI) and 5,10,15,20-tetrakis-(4-aminophenyl) porphyrin (H2TAPP) at room temperature (22 ± 2 ºC)...
October 12, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Kaoru Ohta, Shunrou Tokonami, Kotaro Takahashi, Yuto Tamura, Hiroko Yamada, Keisuke Tominaga
To improve the power conversion efficiency of solar cells, it is important to understand the underlying relaxation mechanisms of photogenerated charge carriers in organic semiconductors. In this work, we studied the charge carrier dynamics of diketopyrrolopyrrole-linked tetrabenzoporphyrin thin films where the diketopyrrolopyrrole unit has two n-butyl groups, abbreviated as C4-DPP-BP. We used time-resolved terahertz (THz) spectroscopy to track charge carrier dynamics with excitations at 800 nm and 400 nm. Compared with tetrabenzoporphyrin (BP), the extension of π-electron delocalization to the diketopyrrolopyrrole peripherals leads to an increase in absorption in the near-infrared region...
October 12, 2017: Journal of Physical Chemistry. B
Junjun Liang, Xin Chen, Guangbing Deng, Zhifen Pan, Haili Zhang, Qiao Li, Kaijun Yang, Hai Long, Maoqun Yu
BACKGROUND: The harsh environment on the Qinghai-Tibetan Plateau gives Tibetan hulless barley (Hordeum vulgare var. nudum) great ability to resist adversities such as drought, salinity, and low temperature, and makes it a good subject for the analysis of drought tolerance mechanism. To elucidate the specific gene networks and pathways that contribute to its drought tolerance, and for identifying new candidate genes for breeding purposes, we performed a transcriptomic analysis using two accessions of Tibetan hulless barley, namely Z772 (drought-tolerant) and Z013 (drought-sensitive)...
October 11, 2017: BMC Genomics
Xiaoxia Feng, Jiacheng Liu
Four novel water-soluble Cu(II) derivatives based on the meso-10, 15, 20-Tris (N-methyl-X-pyridyl)-5-(4'-salicyloylhydrazone) metalloporphyrin ligands (X=4, M=Zn(1) Co(2); X=2, M=Zn(3), Co(4)), have been prepared and isolated. Various physicochemical techniques indicate that complex 2 interacts with calf thymus DNA stronger than the others through partial intercalation, suggesting that Co(II) has no axial ligands at porphyrin core plays a crucial role, interestingly, 2 exhibits higher DNA binding affinity compared to 4, which could be ascribed to the influences of peripheral electronic effect of porphyrin ring...
September 29, 2017: Journal of Inorganic Biochemistry
M Martínez-Carmona, D Lozano, A Baeza, M Colilla, M Vallet-Regí
A novel singlet-oxygen sensitive drug delivery nanocarrier able to release its cargo after exposure to visible (Vis) light from a common lamp is presented. This nanodevice is based on mesoporous silica nanoparticles (MSN) decorated with porphyrin-caps grafted via reactive oxygen species (ROS)-cleavable linkages. In the presence of Vis light porphyrin-nanocaps produce singlet oxygen molecules that break the sensitive-linker, which triggers pore uncapping and therefore allows the release of the entrapped cargo (topotecan, TOP)...
October 11, 2017: Nanoscale
Cui Ye, Min Qiang Wang, Hong Qun Luo, Nian Bing Li
MicroRNAs (miRNAs) quantification, especially for their low abundance, is vital for diseases diagnosis, prognosis, and therapy, while plentiful miRNA assays seek extreme signal amplification strategies and ignore the increased background signal. Herein we develop a distinctive label-free "off-on" configuration for photoelectrochemical (PEC) sensing platform fabrication, coupling with DNA four-way junction (4J) architecture as well as G-wire superstructure for signal amplification, and ultrathin copper phosphate nanosheets (CuPi NSs) coating Au nanoparticles (Au-CuPi NSs) serving as highly efficient photocathode substrate...
October 11, 2017: Analytical Chemistry
Jiefei Wang, Yong Zhong, Xiao Wang, Weitao Yang, Feng Bai, Bingbo Zhang, Leanne Alarid, Kaifu Bian, Hongyou Fan
Structurally controlled nanoparticles, such as core-shell nanocomposite particles by combining two or more compositions possess enhanced or new functionalities that benefited from synergistic coupling of the two components. Here we report new nanocomposite particles with self-assembled porphyrin arrays as the core surrounded by amorphous silica as the shell. Synthesis of such nanocomposite nanoparticles was conducted through a combined surfactant micelle confined self-assembly and silicate sol-gel process using optically active porphyrin as a functional building block...
October 11, 2017: Nano Letters
Kun Jia, Guangyu Wang, Lijiao Liang, Meng Wang, Huhu Wang, Xinglian Xu
Salmonella has emerged as a well-recognized food-borne pathogen, with many strains able to form biofilms and thus cause cross-contamination in food processing environments where acid-based disinfectants are widely encountered. In the present study, RNA sequencing was employed to establish complete transcriptome profiles of Salmonella Enteritidis in the forms of planktonic and biofilm-associated cells cultured in Tryptic Soytone Broth (TSB) and acidic TSB (aTSB). The gene expression patterns of S. Enteritidis significantly differed between biofilm-associated and planktonic cells cultivated under the same conditions...
2017: Frontiers in Microbiology
Barbara Pucelik, Robert Paczyński, Grzegorz Dubin, Mariette M Pereira, Luis G Arnaut, Janusz M Dąbrowski
The impact of substituents on the photochemical and biological properties of tetraphenylporphyrin-based photosensitizers for photodynamic therapy of cancer (PDT) as well as photodynamic inactivation of microorganisms (PDI) was examined. Spectroscopic and physicochemical properties were related with therapeutic efficacy in PDT of cancer and PDI of microbial cells in vitro. Less polar halogenated, sulfonamide porphyrins were most readily taken up by cells compared to hydrophilic and anionic porphyrins. The uptake and PDT of a hydrophilic porphyrin was significantly enhanced with incorporation in polymeric micelles (Pluronic L121)...
2017: PloS One
Peter W Zach, Stefan A Freunberger, Ingo Klimant, Sergey M Borisov
We report a family of Pt and Pd benzoporphyrin dyes with versatile photophysical properties and easy access from cheap and abundant chemicals. Attaching 4 or 8 alkylsulfone groups onto a meso-tetraphenyltetrabenzoporphyrin (TPTBP) macrocylcle renders the dyes highly soluble in organic solvents, photostable and electron-deficient with the redox potential raised up to 0.65 V versus the parent porphyrin. The new dyes intensively absorb in the blue (Soret band, 440-480 nm) and in the red (Q band, 620-650 nm) parts of the electromagnetic spectrum and show bright phosphorescence at room-temperature in the NIR with quantum yields up to 30% in solution...
October 10, 2017: ACS Applied Materials & Interfaces
Daisuke Nishizaki, Hideo Iwahashi
Heme and nonheme high-valent Fe(IV)═O can mediate reactions of olefin epoxidation, alkane hydroxylation, aromatic hydroxylation, S-oxidation, P-oxidation, N-dealkylation, alkylaromatic oxidation, and alcohol oxidation. Bromocycloheptane forms as a product in the reaction of high-valent Fe(IV)═O with cycloheptane, suggesting that a cycloheptyl radical reacts with CCl3Br. However, the cycloheptyl radical has not yet been directly detected. To directly detect the radical intermediate in the reaction of the high-valent Fe(IV)═O, we analyzed reaction mixtures containing chloroiron tetraphenylporphyrin, iodosylbenzene, ethanol, and α-(4-pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN) in 1,2-dichloroethane by an electron spin resonance (ESR) spin-trapping method...
October 10, 2017: Inorganic Chemistry
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