80 research outputs found

    Potent PBS/Polysorbate-Soluble Transplatin-Derived Porphyrin-Based Photosensitizers for Photodynamic Therapy

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    In this study, we addressed an important drawback of our previously reported tetraplatinated (metallo)porphyrin-based photosensitizers (PSs) for photodynamic therapy (PDT), namely, the poor solubility in aqueous media. We aimed to create tetraplatinated porphyrin-based PSs that are soluble in aqueous media modified with polysorbate (Tween) and do not need to be pre-dissolved in organic solvents. A structural optimization of the previously reported PSs resulted in the synthesis of an extremely potent novel porphyrin-based PS. The novel PS displays effective phototoxicity upon light irradiation against multicellular tumor spheroids and has a phototoxic index (PI) of 6030 in HeLa cells. This PI value is, to the best of our knowledge, the highest value reported for any porphyrin so far

    Quantification of Pollen Viability in Lantana camara By Digital Holographic Microscopy

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    Pollen grains represent the male gametes of seed plants and their viability is critical for efficient sexual reproduction in the plant life cycle. Pollen analysis is used in diverse research thematics to address a range of botanical, ecological and geological questions. More recently it has been recognized that pollen may also be a vector for transgene escape from genetically modified crops, and the importance of pollen viability in invasion biology has also been emphasized. In this work, we analyse and report an efficient visual method for assessing the viability of pollen using digital holographic microscopy (DHM). We test this method on pollen grains of the invasive Lantana camara, a well known plant invader known to most of the tropical world. We image pollen grains and show that the quantitative phase information provided by the DHM technique can be readily related to the chromatin content of the individual cells and thereby to pollen viability. Our results offer a new technique for pollen viability assessment that does not require staining, and can be applied to a number of emerging areas in plant science.Comment: 13 pages, 5 figure

    Image-based robot assisted bicompartmental knee arthroplasty versus total knee arthroplasty

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    Objective: To evaluate the short-term clinical outcomes of image-based robot-assisted bicruciate retaining bicompartmental knee arthroplasty and compare it to robot-assisted total knee arthroplasty in the Indian population. Methods: Between December 2018 and November 2019, five patients (six knees) underwent robot-assisted bicompartmental knee arthroplasty (BCKA). These patients were demographically matched with five patients (six knees) who underwent robot-assisted total knee arthroplasty (TKA) during the same period. Clinical outcomes of these twelve knees were assessed in the form of knee society score (KSS) score, Oxford knee score (OKS), and forgotten joint score (FJS) after a minimum follow-up period of 25 months. The data between the two cohorts were compared and analyzed. Results: Scores obtained from both cohorts were subjected to statistical analysis. SPSS software was utilized and the Mann Whitney U-test was utilized to compare the two groups. There was no statistically significant difference found between the two groups in terms of functional outcome. Conclusion: Image-based robot-assisted BCKA is a bone stock preserving and more physiological procedure which can be a promising alternative to patients presenting with isolated arthritis of only two compartments of the knee. Although long-term, larger trials are warranted to establish it as an alternative, our pilot study shows an equally favorable outcome as TKA, making it an exciting new avenue in the field of arthroplasty

    Low-Dose Near-Infrared Light-Activated Mitochondria-Targeting Photosensitizers for PDT Cancer Therapy

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    Phthalocyanines (Pcs) are promising candidates for photodynamic therapy (PDT) due to their absorption in the phototherapeutic window. However, the highly aromatic Pc core leads to undesired aggregation and decreased reactive oxygen species (ROS) production. Therefore, short PEG chain functionalized A3B type asymmetric Pc photosensitizers (PSs) were designed in order to decrease aggregation and increase the aqueous solubility. Here we report the synthesis, characterization, optical properties, cellular localization, and cytotoxicity of three novel Pc-based agents (LC31, MLC31, and DMLC31Pt). The stepwise functionalization of the peripheral moieties has a strong effect on the distribution coefficient (logP), cellular uptake, and localization, as well as photocytotoxicity. Additional experiments have revealed that the presence of the malonic ester moiety in the reported agent series is indispensable in order to induce photocytotoxicity. The best-performing agent, MLC31, showed mitochondrial targeting and an impressive phototoxic index (p.i.) of 748 in the cisplatin-resistant A2780/CP70 cell line, after a low-dose irradiation of 6.95 J/cm2. This is the result of a high photocytotoxicity (IC50 = 157 nM) upon irradiation with near-infrared (NIR) light, and virtually no toxicity in the dark (IC50 = 117 μM). Photocytotoxicity was subsequently determined under hypoxic conditions. Additionally, a preliminarily pathway investigation of the mitochondrial membrane potential (MMP) disruption and induction of apoptosis by MLC31 was carried out. Our results underline how agent design involving both hydrophilic and lipophilic peripheral groups may serve as an effective way to improve the PDT efficiency of highly aromatic PSs for NIR light-mediated cancer therapy

    The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

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    The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

    DAF-16/FOXO and EGL-27/GATA promote developmental growth in response to persistent somatic DNA damage

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    Genome maintenance defects cause complex disease phenotypes characterized by developmental failure, cancer susceptibility and premature ageing. It remains poorly understood how DNA damage responses function during organismal development and maintain tissue functionality when DNA damage accumulates with ageing. Here we show that the FOXO transcription factor DAF-16 is activated in response to DNA damage during development, whereas the DNA damage responsiveness of DAF-16 declines with ageing. We find that in contrast to its established role in mediating starvation arrest, DAF-16 alleviates DNA-damage-induced developmental arrest and even in the absence of DNA repair promotes developmental growth and enhances somatic tissue functionality. We demonstrate that the GATA transcription factor EGL-27 co-regulates DAF-16 target genes in response to DNA damage and together with DAF-16 promotes developmental growth. We propose that EGL-27/GATA activity specifies DAF-16-mediated DNA damage responses to enable developmental progression and to prolong tissue functioning when DNA damage persists

    A C. elegans homolog for the UV-hypersensitivity syndrome disease gene UVSSA

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    The transcription-coupled repair pathway (TC-NER) plays a vital role in removing transcription-blocking DNA lesions, particularly UV-induced damage. Clinical symptoms of the two TC-NER-deficiency syndromes, Cockayne syndrome (CS) and UV-hypersensitivity syndrome (UVSS) are dissimilar and the underlying molecular mechanism causing this difference in disease pathology is not yet clearly understood. UV-stimulated scaffold protein A (UVSSA) has been identified recently as a new causal gene for UVSS. Here we describe a functional homolog of the human UVSSA gene in the nematode Caenorhabditis elegans, uvs-1 (UVSSA-like-1). Mutations in uvs-1 render the animals hypersensitive to UV-B irradiation and transcription-blocking lesion-inducing illudin-M, similar to mutations in TC-NER deficient mutants. Moreover, we demonstrate that TC-NER factors including UVS-1 are required for the survival of the adult animals after UV-treatment. (c) 2016 Elsevier B.V. All rights reserved

    A C. elegans homolog of the Cockayne syndrome complementation group A gene

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    Cockayne syndrome (CS) is a debilitating and complex disorder that results from inherited mutations in the CS complementation genes A and B, CSA and CSB. The links between the molecular functions of the CS genes and the complex pathophysiology of CS are as of yet poorly understood and are the subject of intense debate. While mouse models reflect the complexity of CS, studies on simpler genetic models might shed new light on the consequences of CS mutations. Here we describe a functional homolog of the human CSA gene in Caenorhabditis elegans. Similar to its human counterpart, mutations in the nematode csa-1 gene lead to developmental growth defects as a consequence of DNA lesions. (C) 2014 Elsevier B.V. All rights reserved

    Exocyclically metallated tetrapyridinoporphyrazine as a potential photosensitizer for photodynamic therapy

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    We report the first exocyclically metallated tetrapyridinoporphyrazine, [tetrakis-(trans-Pt(NH3)2Cl)-tetra(3,4-pyrido)porphyrazine-zinc(II)](NO3)4 (4), synthesized in a multistep synthesis starting from 3,4-pyridinedicarbonitrile (1). The synthetic procedure involved a platination reaction of the intermediate tetra(3,4-pyrido)porphyrazine-zinc(II) (2), whereby the zinc(II) enhanced the solubility of the intermediate enabling the platination reaction. A similar approach to synthesize [tetrakis-(trans-Pt(NH3)2Cl)-tetra(3,4-pyrido)porphyrazine](NO3)4 (5) failed due to the unsuitable solubility properties of the intermediate tetra(3,4-pyrido)porphyrazine (3). The final product 4 and the intermediates were characterized, the photochemical and photophysical properties were determined and the photocytotoxicities were investigated. We demonstrate that the platinated tetra-pyridinoporphyrazine 4 is a potential photosensitizer for photodynamic therapy (PDT)
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