Shahgaldian, Patrick

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Shahgaldian
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Patrick
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Shahgaldian, Patrick

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2015 - 201916
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Enddatum: 2019 × Institut: Institut für Chemie und Bioanalytik ×

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Gerade angezeigt 1 - 10 von 16
  • Vorschaubild nicht verfügbar
    Publikation
    Hydrophobicity-responsive engineered mesoporous silica nanoparticles: application in the delivery of essential nutrients to bacteria combating oil spills
    (Royal Society of Chemistry, 06/2019) Corvini, Nora; Corvini, Philippe; Shahgaldian, Patrick; El Idrissi, Mohamed; Dimitriadou, Eleni [in: Chemical Communications]
    Facile chemical modification of mesoporous silica particles allows the production of gated reservoir systems capable of hydrophobicity-triggered release. Applied to the delivery of nutrients specifically to an oil phase, the systems developed have been shown to reliably assist the bacterial degradation of hydrocarbons. The gated system developed, made of C18 hydrocarbon chains, is demonstrated to be in a closed collapsed state in an aqueous environment, yet opens up through solvation by lipophilic alkanes and releases its content on contact with the oil phase.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    Decoding the ocean's microbiological secrets for marine enzyme biodiscovery
    (Oxford University Press, 2019) Ferrer, Manuela; Shahgaldian, Patrick [in: FEMS Microbiology Letters]
    A global census of marine microbial life has been underway over the past several decades. During this period, there have been scientific breakthroughs in estimating microbial diversity and understanding microbial functioning and ecology. It is estimated that the ocean, covering 71% of the earth's surface with its estimated volume of about 2 × 1018 m3 and an average depth of 3800 m, hosts the largest population of microbes on Earth. More than 2 million eukaryotic and prokaryotic species are thought to thrive both in the ocean and on its surface. Prokaryotic cell abundances can reach densities of up to 1012 cells per millilitre, exceeding eukaryotic densities of around 106 cells per millilitre of seawater. Besides their large numbers and abundance, marine microbial assemblages and their organic catalysts (enzymes) have a largely underestimated value for their use in the development of industrial products and processes. In this perspective article, we identified critical gaps in knowledge and technology to fast-track this development. We provided a general overview of the presumptive microbial assemblages in oceans, and an estimation of what is known and the enzymes that have been currently retrieved. We also discussed recent advances made in this area by the collaborative European Horizon 2020 project 'INMARE'.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    A Two‐Dimensional Polymer Synthesized at the Air/Water Interface
    (Wiley, 06/2018) Müller, Vivian; Hinaut, Antoine; Moradi, Mina; Jung, Thomas A.; Shahgaldian, Patrick; Möhwald, Helmuth; Hofer, Greogor; Kröger, Martin; King, Benjamin T.; Meyer, Ernst; Glatzel, Thilo; Schlüter, Dieter A.; Baljozovic, Milos [in: Angewandte Chemie]
    A trifunctional, partially fluorinated anthracene‐substituted triptycene monomer was spread at an air/water interface into a monolayer, which was transformed into a long‐range‐ordered 2D polymer by irradiation with a standard UV lamp. The polymer was analyzed by Brewster angle microscopy, scanning tunneling microscopy measurements, and non‐contact atomic force microscopy, which confirmed the generation of a network structure with lattice parameters that are virtually identical to a structural model network based on X‐ray diffractometry of a closely related 2D polymer. The nc‐AFM images highlight the long‐range order over areas of at least 300×300 nm2. As required for a 2D polymer, the pore sizes are monodisperse, except for the regions where the network is somewhat stretched because it spans over protrusions. Together with a previous report on the nature of the cross‐links in this network, the structural information provided herein leaves no doubt that a 2D polymer has been synthesized under ambient conditions at an air/water interface.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    Surface Immobilization and Shielding of a Transaminase Enzyme for the Stereoselective Synthesis of Pharmaceutically Relevant Building Blocks
    (Schweizerische Chemische Gesellschaft, 05/2018) Alami, Ayoub Talbi; Richina, Frederica; Hernandez, Maria; Dudal, Yves; Shahgaldian, Patrick [in: Chimia]
    Transaminases are enzymes capable of stereoselective reductive amination; they are of great interest in the production of chiral building blocks. However, the use of this class of enzymes in industrial processes is often hindered by their limited stability under operational conditions. Herein, we demonstrate that a transaminase enzyme from Aspergillus terreus can be immobilized at the surface of silica nanoparticles and protected in an organosilica shell of controlled thickness. The so-protected enzyme displays a high biocatalytic activity, and additionally provides the possibility to be retained in a reactor system for continuous operation and to be recycled.
    01A - Beitrag in wissenschaftlicher Zeitschrift
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    Publikation
    Two-dimensional calix[4]arene-based metal-organic coordination networks of tunable crystallinity
    (Wiley, 13.11.2017) Moradi, Mina; Tulli, Ludovico; Nowakowski, Jan; Jung, Thomas A; Shahgaldian, Patrick; Baljozovic, Milos [in: Angewandte Chemie: International Edition]
    A flexible and versatile method to fabricate two-dimensional metal–organic coordination networks (MOCNs) by bottom-up self-assembly is described. 2D crystalline layers were formed at the air–water interface, coordinated by ions from the liquid phase, and transferred onto a solid substrate with their crystallinity preserved. By using an inherently three-dimensional amphiphile, namely 25,26,27,28-tetrapropoxycalix[4]arene-5,11,17,23-tetracarboxylic acid, and a copper metal node, large and monocrystalline dendritic MOCN domains were formed. The method described allows for the fabrication of monolayers of tunable crystallinity on liquid and solid substrates. It can be applied to a large range of differently functionalized organic building blocks, also beyond macrocycles, which can be interconnected by diverse metal nodes.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    Cyclodextrin-based polymeric materials for the specific recovery of polyphenolic compounds through supramolecular host-guest interactions
    (Springer, 06/2017) El Idrissi, Mohamed; Molina Bacca, Aurora E.; Frascari, Dario; Corvini, Philippe; Shahgaldian, Patrick [in: Journal of Inclusion Phenomena and Macrocyclic Chemistry]
    While the specific recovery of valuable chemicals from waste streams represents an environmentally-friendly and potentially economically-relevant alternative to synthetic chemical productions, it remains a largely unmet challenge. This is partially explained by the complexity of designing sorption materials able to target one specific compound and able to function in complex matrices. In this work, a series of cyclodextrin-based polymers (CDPs) were designed to selectively extract phenolic compounds from a complex organic matrix that is olive oil mill wastewater (OMW). In order to endow these polymers with selective adsorption properties, several monomers and cross-linkers were screened and selected. The adsorption properties of the CDPs produced were first tested with selected phenolic compounds commonly found in OMW, namely syringic acid, p-coumaric acid, tyrosol and caffeic acid. The selected CDPs were subsequently tested for their ability to adsorb phenolic compounds directly from OMW, which is known to possess a high and complex organic content. It was demonstrated through high-performance liquid chromatography-mass spectroscopy analyses that efficient removal of phenolic compounds from OMW could be achieved but also that two compounds, namely tyrosol and hydroxytyrosol, could be selectively extracted from OMW.
    01A - Beitrag in wissenschaftlicher Zeitschrift
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    Publikation
    Enzyme Armoring by an Organosilica Layer: Synthesis and Characterization of Hybrid Organic/Inorganic Nanobiocatalysts
    (Academic Press, 02/2017) Correro, Maria Rita; Sykora, Sabine; Corvini, Philippe; Shahgaldian, Patrick [in: Methods in Enzymology]
    The availability of highly stable and reusable enzymes is one of the main challenges in bio-based industrial processes. Enzyme immobilization and encapsulation represent promising strategies to reach this goal. In this chapter, the synthetic strategy to produce hybrid organic/inorganic nanobiocatalysts (NBC) is reported. This strategy is based on the sequential immobilization of an enzyme on the surface of silica nanoparticles followed by the growth, at the surface of the nanoparticles, of a shielding layer which serves as an armor to protect the enzyme against denaturation/degradation. This armor is produced through a thickness-controlled organosilane poly-condensation onto the nanoparticle surface around the enzyme to form a protective organosilica layer. The armored nanobiocatalysts present enhanced catalytic activity and improved stability against heat, pH, chaotropic agents, proteases, and ultrasound. The method is versatile in that it can be successfully adapted to a number of different enzymes.
    01A - Beitrag in wissenschaftlicher Zeitschrift
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    Publikation
    A Biocatalytic Nanomaterial for the Label-Free Detection of Virus-Like Particles
    (Wiley, 2017) Sykora, Sabine; Correro, Maria Rita; Moridi, Negar; Belliot, Gaël; Pothier, Pierre; Dudal, Yves; Corvini, Philippe; Shahgaldian, Patrick [in: ChemBioChem]
    The design of nanomaterials that are capable of specific and sensitive biomolecular recognition is an on-going challenge in the chemical and biochemical sciences. A number of sophisticated artificial systems have been designed to specifically recognize a variety of targets. However, methods based on natural biomolecular detection systems using antibodies are often superior. Besides greater affinity and selectivity, antibodies can be easily coupled to enzymatic systems that act as signal amplifiers, thus permitting impressively low detection limits. The possibility to translate this concept to artificial recognition systems remains limited due to design incompatibilities. Here we describe the synthesis of a synthetic nanomaterial capable of specific biomolecular detection by using an internal biocatalytic colorimetric detection and amplification system. The design of this nanomaterial relies on the ability to accurately grow hybrid protein-organosilica layers at the surface of silica nanoparticles. The method allows for label-free detection and quantification of targets at picomolar concentrations.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    Template-free hierarchical self-assembly of a pyrene derivative into supramolecular nanorods
    (Payame Noor University, 2017) El Idrissi, Mohamed; Teat, Simon J.; Corvini, Philippe; Paterson, Martin J.; Dalgarno, Scott J.; Shahgaldian, Patrick [in: Chemical Communications]
    The accurate molecular design of organic building blocks is of great importance for the creation of large supramolecular entities with precise dimensional organisation. Herein we report on the design of a new pyrene derivative that yields, through a hierarchical self-assembly process and in the absence of template, stable and well defined nanorods. X-ray diffraction studies allowed elucidation of the three dimensional packing of this pyrene derivative within the self-assembled nanorods.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild nicht verfügbar
    Publikation
    Supramolecular enzyme engineering in complex nanometer-thin biomimetic organosilica layers
    (Royal Society of Chemistry, 09/2016) Correro, Maria Rita; Takacs, Michael; Sykora, Sabine; Corvini, Philippe; Shahgaldian, Patrick [in: RSC Advances]
    The use of enzymes in industrial processes is often hampered by their limited stability under operational conditions. As enzymes' function and stability are directly correlated to their three-​dimensional structure, numerous methods aiming at the preservation of this structure have been developed. While stabilization can be achieved using solid scaffolds for encapsulating the enzyme, it often results in loss of enzymic activity owing to a lack of conformational mobility of the biocatalyst. With the idea of mimicking protein-​protein interactions to create a network of weak force interactions between the surface of an immobilized enzyme and a synthetic protective layer, we have developed a chem. strategy allowing the use of complex mixts. of building blocks mimicking the lateral chain of natural amino acids. After crosslinking a model enzyme at the surface of silica nanoparticles, incubation with eight different organosilane mixts. allowed growing protective organosilica layers of controlled thicknesses. The nanoparticles produced were characterized by SEM and their biocatalytic activity was measured under a series of operational stress conditions. Our results clearly demonstrated that increasing the complexity and biomimetic nature of the protection layer allowed for relevant improvement of the protection effect. Indeed, when compared with the basic formulation, selected complex formulations allowed for an improvement of up to 100​% when treated at 50 °C for 60 min or in the presence of a denaturing detergent (SDS)​.
    01A - Beitrag in wissenschaftlicher Zeitschrift