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  • 101.
    Tang, Zheng
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Tress, Wolfgang
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Bao, Qinye
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, The Institute of Technology.
    Jafari, Mohammad Javad
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Bergqvist, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Andersson, Mats R.
    Polymer Technology, Department of Chemical and Biological Engineering, Chalmers University of Technology, Göteborg, Sweden.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Universal modification of poor cathodes into good ones by a polymer interlayer for high performance reversed organic solar cells2014Manuscript (preprint) (Other academic)
    Abstract [en]

    In organic bulk-heterojunction solar cells, energy losses at the active layer/electrode interface are often observed. Modification of these interfaces with organic interlayers optimizes charge carrier injection and extraction and thus improves device performance. In this work, the effects of cathode modification by a conjugated polymer interlayer PFPA1 on the performance of reversed organic solar cells (substrate/cathode/active layer/transparent anode) based on different active material systems and different substrate electrodes are systematically investigated. A reduction of the work function irrespective of the substrate cathode used is observed upon the deposition of the PFPA1 interlayer; further related to an improved built-in electric field and open-circuit voltage. The amphiphilic character of the PFPA1 interlayer alters the surface energy of the substrate cathode, leading to the formation of a better active layer morphology aiding efficient exciton dissociation and photocurrent extraction in the modified solar cells. Hence, internal quantum efficiency is found significantly higher than that of their unmodified counterparts, while optically, the modified and unmodified solar cells are identical. Moreover, the deep HOMO of the PFPA1 interlayer improves the selectivity for all investigated substrate cathodes, thus enhancing the fill factor. We demonstrate a possibility of improving photovoltaic performance of reversed solar cells via a simple and universal interface modification and provide the basic guidelines for development and characterization of interface materials for organic solar cells in general.

  • 102.
    Tilbury, Maura A.
    et al.
    Natl Univ Ireland Galway, Ireland; Natl Univ Ireland Galway, Ireland.
    McCarthy, Sean
    Natl Univ Ireland Galway, Ireland.
    Domagalska, Magdalena
    Natl Univ Ireland Galway, Ireland.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Power, Anne Marie
    Natl Univ Ireland Galway, Ireland.
    Wall, J. Gerard
    Natl Univ Ireland Galway, Ireland; Natl Univ Ireland Galway, Ireland.
    The expression and characterization of recombinant cp19k barnacle cement protein from Pollicipes pollicipes2019In: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 374, no 1784, article id 20190205Article in journal (Refereed)
    Abstract [en]

    Adhesive proteins of barnacle cement have potential as environmentally friendly adhesives owing to their ability to adhere to various substrates in aqueous environments. By understanding the taxonomic breath of barnacles with different lifestyles, we may uncover commonalities in adhesives produced by these specialized organisms. The 19 kDa cement protein (cp19k) of the stalked barnacle Pollicipes pollicipes was expressed in Escherichia coli BL21 to investigate its adhesive properties. Initial expression of hexahistidine-tagged protein (rPpolcp19k-his) yielded low levels of insoluble protein. Co-overproduction of E. coli molecular chaperones GroEL-GroES and trigger factor (TF) increased soluble protein yields, although TF co-purified with the target protein (TF-rPpolcp19k-his). Surface coat analysis revealed high levels of adsorption of the TF-rPpolcp19k-his complex and of purified E. coli TF on both hydrophobic and hydrophilic surfaces, while low levels of adsorption were observed for rPpolcp19k-his. Tag-free rPpolcp19k protein also exhibited low adsorption compared to fibrinogen and Cell-Tak controls on hydrophobic, neutral hydrophilic and charged self-assembled monolayers under surface plasmon resonance assay conditions designed to mimic the barnacle cement gland or seawater. Because rPpolcp19k protein displays low adhesive capability, this protein is suggested to confer the ability to self-assemble into a plaque within the barnacle cement complex. This article is part of the theme issue Transdisciplinary approaches to the study of adhesion and adhesives in biological systems.

  • 103.
    Ullah Khan, Zia
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Bubnova, Olga
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering. Optoelectronics Group, Cavendish Laboratory, University of Cambridge, Cambridge, UK.
    Jafari, Mohammad Javad
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Brooke, Robert
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Science and Technology, Physics and Electronics. University of South Australia, Mawson Institute, Mawson Lakes 5095, Australia.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Gabrielsson, Roger
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Evans, Drew R.
    University of South Australia, Mawson Institute, Australia.
    Andreasen, Jens W.
    Technical University of Denmark, Department of Energy Conversion and Storage, Roskilde, Denmark.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Acido-basic control of the thermoelectric properties of poly(3,4-ethylenedioxythiophene)tosylate (PEDOT-Tos) thin films2015In: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 3, p. 10616-10623Article in journal (Refereed)
    Abstract [en]

    PEDOT-Tos is one of the conducting polymers that displays the most promising thermoelectric properties. Until now, it has been utterly difficult to control all the synthesis parameters and the morphology governing the thermoelectric properties. To improve our understanding of this material, we study the variation in the thermoelectric properties by a simple acido-basic treatment. The emphasis of this study is to elucidate the chemical changes induced by acid (HCl) or base (NaOH) treatment in PEDOT-Tos thin films using various spectroscopic and structural techniques. We could identify changes in the nanoscale morphology due to anion exchange between tosylate and Cl- or OH-. But, we identified that changing the pH leads to a tuning of the oxidation level of the polymer, which can explain the changes in thermoelectric properties. Hence, a simple acid-base treatment allows finding the optimum for the power factor in PEDOT-Tos thin films.

  • 104.
    Utterström, Johanna
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics.
    One Bead One Compound Screening for Cyclic Peptide Binding Partners2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In recent years a significant research focus has been on the development of biomimicking three-dimensional substrates for cell culturing. Hydrogels mimicking the extracellular matrix is a well-suited scaffold for this purpose and there are many different ways these can be cross-linked to retain their shape. The group of Molecular Materials at IFM, Linköping University, is focusing on the development of physical hydrogels hybridized through peptide-peptide interactions but all peptides used for this today are created using rational design and on top of this very large, making them time-consuming and expensive to fabricate. The aim of this project was to evaluate if One Bead One Compound (OBOC) libraries could be used as an alternative to rational design in the finding of cyclic peptide binding partners used in the hybridization of hydrogels. The results were not very promising though since only seven peptides passed all screening steps and of these only two could be sequenced. Of these two, only one was water soluble enough to enable binding interactions analysis but was then found to be a false hit. Nevertheless, it should be noticed that only a fraction of all possible combinations was screened and the results cannot exclude OBOC libraries as an approach in the quest of finding new cyclic peptide binding partners.

  • 105.
    Valiokas, Ramunas
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Malysheva, L.
    Bogolyubov Institute for Theoretical Physics.
    Onipko, A.
    Bogolyubov Institute for Theoretical Physics.
    Lee, Hung-Hsun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Ruzele, Z.
    Institute of Physics, Lithuania.
    Svedhem, S.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Svensson, S.C.T.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Gelius, U.
    Uppsala University.
    Liedberg, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics. Linköping University, The Institute of Technology.
    On the quality and structural characteristics of oligo(ethylene glycol) assemblies on gold: An experimental and theoretical study2009In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, Vol. 172, no 1-3, p. 9-20Article in journal (Refereed)
    Abstract [en]

    This paper presents results of several years of experimental and theoretical work on a library of oligo(ethylene glycol)-containing self-assembled monolayers (OEG SAMs) on gold. The library consists of 15 different thiol compounds, which all contain alkyl and OEG portions of different length, as well as amide moieties forming a stabilizing lateral hydrogen bonding network. We have investigated the quality, conformation, orientation, defect structure and infrared (IR) signatures of these OEG SAMs prepared by spontaneous adsorption from dilute solutions. It is shown that solution concentration and incubation time are important factors to obtain high quality SAMs, in particular for those containing long OEG chains. Further on, the thiol compounds should contain a sufficiently long alkyl spacer to provide in plane van der Waals interactions strong enough to govern the formation of a densely packed alkylthiolate overlayer on the Au(1 1 1) surface. Such a highly ordered alkyl support, which is additionally stabilized by the lateral hydrogen bonds, enables us to vary the length of the terminal OEG portion from 1 to at least 12, without affecting the integrity and conformational characteristics of the supporting (alkyl) part of the SAM. Also, we discuss the importance of appropriate modeling tools to advance the understanding of IR signatures of the OEG SAMs. Finally, we demonstrate the generality of our "modular approach" by analyzing the structure of OEG SAMs formed by compounds extended with an additional terminal amide and an alkyl tail. Thus, the SAMs discussed herein provide an attractive platform for construction of advanced nanoarchitectures on surfaces, not only limited to biomaterials and fouling applications.

  • 106.
    Vater, Svenja M.
    et al.
    Heidelberg University, Germany; Karlsruhe Institute Technology, Germany.
    Finlay, John
    University of Birmingham, England.
    Callow, Maureen E.
    University of Birmingham, England.
    Callow, James A.
    University of Birmingham, England.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Liedberg, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering. Nanyang Technology University, Singapore.
    Grunze, Michael
    Karlsruhe Institute Technology, Germany.
    Rosenhahn, Axel
    Heidelberg University, Germany; Karlsruhe Institute Technology, Germany; Ruhr University of Bochum, Germany.
    Holographic microscopy provides new insights into the settlement of zoospores of the green alga Ulva linza on cationic oligopeptide surfaces2015In: Biofouling (Print), ISSN 0892-7014, E-ISSN 1029-2454, Vol. 31, no 2, p. 229-239Article in journal (Refereed)
    Abstract [en]

    Interaction of zoospores of Ulva linza with cationic, arginine-rich oligopeptide self-assembled monolayers (SAMs) is characterized by rapid settlement. Some spores settle (ie permanently attach) in a normal manner involving the secretion of a permanent adhesive, retraction of the flagella and cell wall formation, whilst others undergo pseudosettlement whereby motile spores are trapped (attached) on the SAM surface without undergoing the normal metamorphosis into a settled spore. Holographic microscopy was used to record videos of swimming zoospores in the vicinity of surfaces with different cationic oligopeptide concentrations to provide time-resolved insights into processes associated with attachment of spores. The data reveal that spore attachment rate increases with increasing cationic peptide content. Accordingly, the decrease in swimming activity in the volume of seawater above the surface accelerated with increasing surface charge. Three-dimensional trajectories of individual swimming spores showed a hit and stick motion pattern, exclusively observed for the arginine-rich peptide SAMs, whereby spores were immediately trapped upon contact with the surface.

  • 107.
    Vignoni, Mariana
    et al.
    University of Ottawa, Canada.
    de Alwis Weerasekera, Hasitha
    University of Ottawa, Canada .
    Simpson, Madeline J.
    University of Ottawa, Canada .
    Phopase, Jaywant
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology.
    Mah, Thien-Fah
    University of Ottawa, Canada .
    Griffith, May
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Health Sciences.
    Alarcon, Emilio I.
    University of Ottawa, Canada .
    Scaiano, Juan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Health Sciences.
    LL37 peptide@silver nanoparticles: combining the best of the two worlds for skin infection control2014In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 6, no 11, p. 5725-5728Article in journal (Refereed)
    Abstract [en]

    Capping silver nanoparticles with LL37 peptide eradicates the anti-proliferative effect of silver on primary skin cells, but retains the bactericidal properties of silver nanoparticles with activities comparable to silver nitrate or silver sulfadiazine. In addition, LL37 capped silver nanoparticles have anti-biofilm formation activity.

  • 108.
    Villamil Giraldo, Ana M.
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Health Sciences.
    Appelqvist, Hanna
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, The Institute of Technology.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Lysosomotropic agents: impact on lysosomal membrane permeabilization and cell death2014In: Biochemical Society Transactions, ISSN 0300-5127, E-ISSN 1470-8752, Vol. 42, p. 1460-1464Article in journal (Refereed)
    Abstract [en]

    Lysosomes are acidic organelles essential for degradation, signalling and cell homoeostasis. In addition, they play a key role in cell death. Permeabilization of the lysosomal membrane and release of hydrolytic enzymes to the cytosol accompanies apoptosis signalling in several systems. The regulatory mechanism of lysosomal stability is, however, poorly understood. Lipophilic or amphiphilic compounds with a basic moiety will become protonated and trapped within lysosomes, and such lysosomotropic behaviour is also found in many pharmacological drugs. The natural sphingolipid sphingosine exhibits lysosomotropic detergent ability and is an endogenous candidate for controlling lysosomal membrane permeabilization. The lysosomotropic properties of certain detergents might be of use in lysosome-targeting anticancer drugs and drug delivery system in the future. The present review summarizes the current knowledge on the targeting and permeabilizing properties of lysosomotropic detergents from a cellular and physicochemical perspective.

  • 109.
    Villamil Giraldo, Ana Maria
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Fyrner, Timmy
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Physics, Chemistry and Biology, Chemistry.
    Wennmalm, Stefan
    Royal Institute Technology, Sweden.
    Parikh, Atul N.
    University of Calif Davis, CA 95616 USA; University of Calif Davis, CA 95616 USA.
    Öllinger, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Spontaneous Vesiculation and pH-Induced Disassembly of a Lysosomotropic Detergent: Impacts on Lysosomotropism and Lysosomal Delivery2016In: LANGMUIR, ISSN 0743-7463, Vol. 32, no 50, p. 13566-13575Article in journal (Refereed)
    Abstract [en]

    Lysosomotropic detergents (LDs) selectively rupture lysosomal membranes through mechanisms that have yet to be characterized. A consensus view, currently, holds that LDs, which are weakly basic, diffuse across cellular membranes as monomers in an uncharged state, and via protonation in the acidic lysosomal compartment, they become trapped, accumulate, and subsequently solubilize the membrane and induce lysosomal membrane permeabilization. Here we demonstrate that the lysosomotropic detergent O-methyl-serine dodecylamide hydrochloride (MSDH) spontaneously assembles into vesicles at, and above, cytosolic pH, and that the vesicles disassemble as the pH reaches 6.4 or lower. The aggregation commences at concentrations below the range of those used in cell studies. Assembly and disassembly of the vesicles was studied via dynamic light scattering, zeta potential measurements, cryo-TEM, and fluorescence correlation spectroscopy and was found to be reversible via control of the pH. Aggregation of MSDH into closed vesicles under cytosolic conditions is at variance with the commonly held view of LD behavior, and we propose that endocytotic pathways should be considered as possible routes of LD entry into lysosomes. We further demonstrate that MSDH vesicles can be loaded with fluorophores via a solution transition from low to high pH, for subsequent release when the pH is lowered again. The ability to encapsulate molecular cargo into MSDH vesicles together with its ability to disaggregate at low pH and to permeabilize the lysosomal membrane presents an intriguing possibility to use MSDH as a delivery system.

  • 110.
    Wang, Suhao
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Fazzi, Daniele
    Univ Cologne, Germany.
    Puttisong, Yuttapoom
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Jafari, Mohammad Javad
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Chen, Zhihua
    Flexterra Corp, IL 60077 USA.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Andreasen, Jens W.
    Tech Univ Denmark, Denmark.
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Facchetti, Antonio
    Flexterra Corp, IL 60077 USA; Northwestern Univ, IL 60208 USA; Northwestern Univ, IL 60208 USA.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Effect of Backbone Regiochemistry on Conductivity, Charge Density, and Polaron Structure of n-Doped Donor-Acceptor Polymers2019In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 31, no 9, p. 3395-3406Article in journal (Refereed)
    Abstract [en]

    We investigated the influence of backbone regiochemistry on the conductivity, charge density, and polaron structure in the widely studied n-doped donor-acceptor polymer poly[N,N-bis(2-octyldodecyl)-1,4,5,8-naphthalenediimide-2,6-diyl]-alt-5,5-(2,2-bithiophene) [P-(NDI2OD-T2)]. In contrast to classic semicrystalline polymers such as poly(3-hexylthiophene) (P3HT), the regioirregular (RI) structure of the naphthalenediimide (NDI)-bithiophene (T2) backbone does not alter the intramolecular steric demand of the chain versus the regioregular (RR) polymer, yielding RI-P(NDI2OD-T2) with similar energetics and optical features as its RR counterpart. By combining the electrical, UV-vis/infrared, X-ray diffraction, and electron paramagnetic resonance data and density functional theory calculations, we quantitatively characterized the conductivity, aggregation, crystallinity, and charge density, and simulated the polaron structures, molecular vibrations, and spin density distribution of RR-/RI-P(NDI2OD-T2). Importantly, we observed that RI-P(NDI2OD-T2) can be doped to a greater extent compared to its RR counterpart. This finding is remarkable and contrasts benchmark P3HT, allowing us to uniquely study the role of regiochemistry on the charge-transport properties of n-doped donor-acceptor polymers.

  • 111.
    Wang, Yi
    et al.
    Nanyang Technological University, Singapore.
    Liu, Xiaohu
    Nanyang Technological University, Singapore.
    Zhang, Jinling
    Nanyang Technological University, Singapore.
    Aili, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology. Nanyang Technological University, Singapore.
    Liedberg, Bo
    Nanyang Technological University, Singapore.
    Time-resolved botulinum neurotoxin A activity monitored using peptide-functionalized Au nanoparticle energy transfer sensors2014In: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 5, no 7, p. 2651-2656Article in journal (Refereed)
    Abstract [en]

    We report herein on the employment of synthetic peptide-functionalized gold nanoparticles (AuNPs) with various diameters as radiative quenchers for the time-resolved monitoring of botulinum A light chain (BoLcA) activity. The results demonstrate that larger AuNPs provide higher energy transfer efficiencies between the dye and the AuNPs, but poorer BoLcA activities for the proteolysis of peptides because of steric constraints. The initial turnover number for the BoLcA proteolysis of peptides on 18 nm AuNPs was retarded by a factor of 80 as compared with 1.4 nm AuNPs. A similar phenomenon has been observed for trypsin, however, with less hindrance on large AuNPs. Thus, the use of smaller 1.4 nm AuNPs in conjunction with robust synthetic peptides provides an attractive format for the time-resolved monitoring of protease activity and for BoLcA sensing at a highly competitive limit of detection (1 pM).

  • 112.
    Wang, Yuming
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Nanjing Tech Univ, Peoples R China.
    Jafari, Mohammad Javad
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Wang, Nana
    Nanjing Tech Univ, Peoples R China.
    Qian, Deping
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Moons, Ellen
    Karlstad Univ, Sweden.
    Wang, Jianpu
    Nanjing Tech Univ, Peoples R China.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Huang, Wei
    Nanjing Tech Univ, Peoples R China.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Light-induced degradation of fullerenes in organic solar cells: a case study on TQ1:PC71BM2018In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 6, no 25, p. 11884-11889Article in journal (Refereed)
    Abstract [en]

    The stability of organic solar cells (OSCs) is critical for practical applications of this emerging technology. Unfortunately, in spite of intensive investigations, the degradation mechanisms in OSCs have not been clearly understood yet. In this report, we employ a range of spectroscopic and transport measurements, coupled with drift-diffusion modelling, to investigate the light-induced degradation mechanisms of fullerene-based OSCs. We find that trap states formed in the fullerene phase under illumination play a critical role in the degradation of the open-circuit voltage (V-OC) in OSCs. Our results indicate that the degradation is intrinsic to the fullerenes in OSCs and that alternative acceptor materials are desired for the development of stable OSCs.

  • 113.
    Wibisono, Yusuf
    et al.
    University of Twente, Netherlands; Wetsus, Netherlands.
    Yandi, Wetra
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology.
    Golabi, Mohsen
    Nugraha, Roni
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics. Linköping University, The Institute of Technology.
    Cornelissen, Emile R.
    KWR Watercycle Research Institute, Netherlands.
    Kemperman, Antoine J. B.
    University of Twente, Netherlands.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology.
    Nijmeijer, Kitty
    University of Twente, Netherlands.
    Hydrogel-coated feed spacers in two-phase flow cleaning in spiral wound membrane elements: A novel platform for eco-friendly biofouling mitigation2015In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 71, p. 171-186Article in journal (Refereed)
    Abstract [en]

    Biofouling is still a major challenge in the application of nanofiltration and reverse osmosis membranes. Here we present a platform approach for environmentally friendly biofouling control using a combination of a hydrogel-coated feed spacer and two-phase flow cleaning. Neutral (polyHEMA-co-PEG(10)MA), cationic (polyDMAEMA) and anionic (polySPMA) hydrogels have been successfully grafted onto polypropylene (PP) feed spacers via plasma-mediated UV-polymerization. These coatings maintained their chemical stability after 7 days incubation in neutral (pH 7), acidic (pH 5) and basic (pH 9) environments. Anti-biofouling properties of these coatings were evaluated by Escherichia coli attachment assay and nanofiltration experiments at a TMP of 600 kPag using tap water with additional nutrients as feed and by using optical coherence tomography. Especially the anionic polySPMA-coated PP feed spacer shows reduced attachment of E. coli and biofouling in the spacer-filled narrow channels resulting in delayed biofilm growth. Employing this highly hydrophilic coating during removal of biofouling by two-phase flow cleaning also showed enhanced cleaning efficiency, feed channel pressure drop and flux recoveries. The strong hydrophilic nature and the presence of negative charge on polySPMA are most probably responsible for the improved antifouling behavior. A combination of polySPMA-coated PP feed spacers and two-phase flow cleaning therefore is promising and an environmentally friendly approach to control biofouling in NF/RO systems employing spiral-wound membrane modules.

  • 114.
    Wickham, Abeni
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Multifunctional Biomimetic Scaffolds Tailored for Cardiac Regeneration2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Nature has had millions of years to perfect the structural components of the human body, but has also produced the dysfunctions that result in the cancers and diseases, which ruin that perfection. Congenital heart defects, and myocardial infarction lead to scarring that remodels heart muscle, decreasing the contractility of the heart, with profound consequences for the host. Regenerative medicine is the study of strategies to return diseased body parts to their evolutionarily optimum structure.

    Nature has had millions of years to perfect the structural components of the human body, but has also produced the dysfunctions that result in the cancers and diseases, which ruin that perfection. Congenital heart defects, and myocardial infarction lead to scarring that remodels heart muscle, decreasing the contractility of the heart, with profound consequences for the host. Regenerative medicine is the study of strategies to return diseased body parts to their evolutionarily optimum structure. Cells alone cannot develop into functional tissue, as they require mechanical support and chemical signals from the extracellular matrix in order to play the correct role in the body. In order to imitate the process of tissue formation optimized by nature, scaffolds are developed as the architectural support for tissue regeneration. To mimic the elasticity and strength seen in the heart muscle is one of the major scientific conundrums of our time. The development of new multifunctional materials for scaffolds is an accepted solution for repairing failing heart muscle. In this thesis I accept the notion that endogenous cardiac cells can play a major role in addressing this problem, if we can attract them to the site of defect or injury and make them proliferate. I then proceed to show how improving on a commonly used synthetic polymer was used to develop two new biomaterials.

    Polycaprolactone (PCL) fibers and sheets were studied for their ability to adsorb proteins based on their surface energies. We found that although the wettability of the PCL might be similar to positive controls for cell attachment, the large differences in surface energies may account for the increased serum protein adsorption and limit cell adhesion. The effect of fiber morphology was then investigated with respect to proliferation of mesenchymal stem cells and cardiac progenitor cells. PCL was also mechanically enhanced with thiophene conjugated single walled carbon nanotubes (T-CNT); where small concentrations of the T-CNT allowed for a 2.5 fold increase in the percentage of elongation, while retaining the proliferation profile of the cardiac progenitor cells. Although PCL is a well-known implant material, the ability to attract and adhere cardiac cells was limited. Therefore we sought to develop new biomaterials with fiber morphologies similar to the muscle fiber of the heart, but with surface energies similar to positive controls for cell attachment. Poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-diyl] (TQ1) was then explored as a ribbon fiber and compared to collagen with embryonic cardiac cells, in vitro, and then implanted into rats for in vivo long term evaluations. The cardiac cells had a preferential adhesion to the TQ1 fibers, and in vivo, the fibers attracted more blood vessels and regrew functional tissue compared to the collagen controls. TQ1 fibers had the added ability to emit light in the near infrared region, which would allow for consistent tracking of the material. Although this material offered the morphological preference for the cardiac cells, it does not degrade and nor did it offer electrical conductivity. The heart muscle is an electrically active muscle. The dead tissue that is formed in the ischemic area loses its ability to  transfer the electrical signals. Hence, I have then developed collagen fibrous materials with silver nanowires to help store and inject charges that would be generated during the contraction of the heart muscle. The silver nanowires served to help carry charges whilst providing resistance to bacterial growth on the material. The collagen/silver nanowires composites were mechanically apt for the culture of embryonic cardiac cells.

    List of papers
    1. Polycaprolactone–thiophene-conjugated carbon nanotube meshes as scaffolds for cardiac progenitor cells
    Open this publication in new window or tab >>Polycaprolactone–thiophene-conjugated carbon nanotube meshes as scaffolds for cardiac progenitor cells
    Show others...
    2014 (English)In: Journal of Biomedical Materials Research. Part B - Applied biomaterials, ISSN 1552-4973, E-ISSN 1552-4981, Vol. 102, no 7, p. 1553-1561Article in journal (Refereed) Published
    Abstract [en]

    The myocardium is unable to regenerate itself after infarct, resulting in scarring and thinning of the heart wall. Our objective was to develop a patch to buttress and bypass the scarred area, while allowing regeneration by incorporated cardiac stem/progenitor cells (CPCs). Polycaprolactone (PCL) was fabricated as both sheets by solvent casting, and fibrous meshes by electrospinning, as potential patches, to determine the role of topology in proliferation and phenotypic changes to the CPCs. Thiophene-conjugated carbon nanotubes (T-CNTs) were incorporated to enhance the mechanical strength. We showed that freshly isolated CPCs from murine hearts neither attached nor spread on the PCL sheets, both with and without T-CNT. As electrospun meshes, however, both PCL and PCL/T-CNT supported CPC adhesion, proliferation, and differentiation. The incorporation of T-CNT into PCL resulted in a significant increase in mechanical strength but no morphological changes to the meshes. In turn, proliferation, but not differentiation, of CPCs into cardiomyocytes was enhanced in T-CNT containing meshes. We have shown that changing the topology of PCL, a known hydrophobic material, dramatically altered its properties, in this case, allowing CPCs to survive and differentiate. With further development, PCL/T-CNT meshes or similar patches may become a viable strategy to aid restoration of the postmyocardial infarction myocardium.

    Place, publisher, year, edition, pages
    John Wiley & Sons, 2014
    Keywords
    topology, carbon nanotubes, polycaprolactone, cardiac progenitor cells, electrospun meshes
    National Category
    Clinical Medicine Basic Medicine Physical Sciences
    Identifiers
    urn:nbn:se:liu:diva-111488 (URN)10.1002/jbm.b.33136 (DOI)000342963000020 ()24664884 (PubMedID)
    Available from: 2014-10-19 Created: 2014-10-19 Last updated: 2018-01-11Bibliographically approved
    2. Influence of Polycaprolactone Scaffold Topography on Progenitor and Mesenchymal Cell Proliferation
    Open this publication in new window or tab >>Influence of Polycaprolactone Scaffold Topography on Progenitor and Mesenchymal Cell Proliferation
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Polycaprolactone (PCL) is a frequently used polymer for tissue engineering applications and has been suggested as a suitable scaffold for cardiac regeneration. PCL can be effectively procesed using electrospinning to form fibrous scaffolds with defined topographies. The topography, as well as the materials and suraface properties, signficanltly effect the performance and host response of the scaffold. We have investigated the effect of PCL scaffold topology on protein adsorption and how this translate to cell adhesion and proliferation. PCL sheets are relatively hydrophobic with a water contact angle of 72o. The surface energy of PCL (20 mJ m‐2) was obatined using the Good van OSS and Chaudhury (GvOC) method, and is in the range of many antifouling materials. Non-specific protein adsorption on PCL sheets was yet substantial (0.45 mg cm‐2) when exposed to serum. A lower protein surface concentration was seen on fibrous PCL scaffolds prepared by electrospinning, presumably as a consequence of the lower diffusion in the scaffold. Proliferation of mesenchymal stem cells and cardiac progenitor cells was significantly improved when cultured on PCL sheets pre-treated with serum, but significantly lower than for fibrous PCL scaffolds. For the latter, no significant effect of serum pretreatment was observed, indicating that for PCL, fibre dimensions and scaffold topography has a larger influence on cell adhesion and proliferation than a high surface concentration of adsorbed proteins.

    National Category
    Clinical Medicine Basic Medicine Physical Sciences
    Identifiers
    urn:nbn:se:liu:diva-120769 (URN)
    Available from: 2015-08-24 Created: 2015-08-24 Last updated: 2018-01-11Bibliographically approved
    3. Near-Infrared Emitting and Pro-Angiogenic Electrospun Conjugated Polymer Scaffold for Optical Biomaterial Tracking
    Open this publication in new window or tab >>Near-Infrared Emitting and Pro-Angiogenic Electrospun Conjugated Polymer Scaffold for Optical Biomaterial Tracking
    Show others...
    2015 (English)In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 25, no 27, p. 4274-4281Article in journal (Refereed) Published
    Abstract [en]

    Noninvasive tracking of biomaterials is vital for determining the fate and degradation of an implant in vivo, and to show its role in tissue regeneration. Current biomaterials have no inherent capacity to enable tracing but require labeling with, for example, fluorescent dyes, or nanoparticles. Here a novel biocompatible fully conjugated electrospun scaffold is described, based on a semiconducting luminescent polymer that can be visualized in situ after implantation using fluorescence imaging. The polymer, poly [2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt -thiophene-2,5-diyl] (TQ1), is electrospun to form a fibrous mat. The fibers display fluorescence emission in the near-infrared region with lifetimes in the sub-nanosecond range, optimal for in situ imaging. The material shows no cytotoxic behaviors for embryonic chicken cardiomyocytes and mouse myoblasts, and cells migrate onto the TQ1 fibers even in the presence of a collagen substrate. Subcutaneous implantations of the material in rats show incorporation of the TQ1 fibers within the tissue, with limited inflammation and a preponderance of small capillaries around the fibers. The fluorescent properties of the TQ1 fibers are fully retained for up to 90 d following implantation and they can be clearly visualized in tissue using fluorescence and lifetime imaging, thus making it both a pro-angiogenic and traceable biomaterial.

    Place, publisher, year, edition, pages
    Wiley: 12 months, 2015
    Keywords
    biomaterials, conjugated polymers, near-infrared, angiogenesis, electrospinning
    National Category
    Biomaterials Science Polymer Chemistry
    Identifiers
    urn:nbn:se:liu:diva-120449 (URN)10.1002/adfm.201500351 (DOI)000357996600011 ()
    Note

    Funding Agencies|Linkoping University; Swedish Foundation for Strategic Research; Swedish Research Council

    Available from: 2015-08-12 Created: 2015-08-11 Last updated: 2017-12-04
    4. Electroactive biomimetic collagen-silver nanowire composite scaffolds
    Open this publication in new window or tab >>Electroactive biomimetic collagen-silver nanowire composite scaffolds
    Show others...
    2016 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 8, no 29, p. 14146-14155Article in journal (Refereed) Published
    Abstract [en]

    Electroactive biomaterials are widely explored as bioelectrodes and as scaffolds for neural and cardiac regeneration. Most electrodes and conductive scaffolds for tissue regeneration are based on synthetic materials that have limited biocompatibility and often display large discrepancies in mechanical properties with the surrounding tissue causing problems during tissue integration and regeneration. This work shows the development of a biomimetic nanocomposite material prepared from self-assembled collagen fibrils and silver nanowires (AgNW). Despite consisting of mostly type I collagen fibrils, the homogeneously embedded AgNWs provide these materials with a charge storage capacity of about 2.3 mC cm(-2) and a charge injection capacity of 0.3 mC cm(-2), which is on par with bioelectrodes used in the clinic. The mechanical properties of the materials are similar to soft tissues with a dynamic elastic modulus within the lower kPa range. The nanocomposites also support proliferation of embryonic cardiomyocytes while inhibiting the growth of both Gram-negative Escherichia coli and Gram-positive Staphylococcus epidermidis. The developed collagen/AgNW composites thus represent a highly attractive bioelectrode and scaffold material for a wide range of biomedical applications.

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2016
    National Category
    Biomaterials Science
    Identifiers
    urn:nbn:se:liu:diva-131731 (URN)10.1039/c6nr02027e (DOI)000381815000038 ()27385421 (PubMedID)
    Note

    Funding Agencies|Linkoping University; Swedish Foundation for Strategic Research (SSF).

    The previous status of this article was Manuscript and the working title was Collagen-Silver Nanowire Composites as Electrically Activeand Antibacterial Scaffolds for Embryonic Cardiac Cell Proliferation,

    Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-30Bibliographically approved
  • 115.
    Wickham, Abeni
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Koppal, Sandeep
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Dånmark, Staffan
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Aili, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    de Muinck, Ebo
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Influence of Polycaprolactone Scaffold Topography on Progenitor and Mesenchymal Cell ProliferationManuscript (preprint) (Other academic)
    Abstract [en]

    Polycaprolactone (PCL) is a frequently used polymer for tissue engineering applications and has been suggested as a suitable scaffold for cardiac regeneration. PCL can be effectively procesed using electrospinning to form fibrous scaffolds with defined topographies. The topography, as well as the materials and suraface properties, signficanltly effect the performance and host response of the scaffold. We have investigated the effect of PCL scaffold topology on protein adsorption and how this translate to cell adhesion and proliferation. PCL sheets are relatively hydrophobic with a water contact angle of 72o. The surface energy of PCL (20 mJ m‐2) was obatined using the Good van OSS and Chaudhury (GvOC) method, and is in the range of many antifouling materials. Non-specific protein adsorption on PCL sheets was yet substantial (0.45 mg cm‐2) when exposed to serum. A lower protein surface concentration was seen on fibrous PCL scaffolds prepared by electrospinning, presumably as a consequence of the lower diffusion in the scaffold. Proliferation of mesenchymal stem cells and cardiac progenitor cells was significantly improved when cultured on PCL sheets pre-treated with serum, but significantly lower than for fibrous PCL scaffolds. For the latter, no significant effect of serum pretreatment was observed, indicating that for PCL, fibre dimensions and scaffold topography has a larger influence on cell adhesion and proliferation than a high surface concentration of adsorbed proteins.

  • 116.
    Wickham, Abeni M.
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology.
    Islam, Mohammad Mirazul
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Health Sciences. Karolinska Institutet, Stockholm, Sweden.
    Mondal, Debasish
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences. Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Phopase, Jaywant
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology.
    Sadhu, Veera
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Tamás, Éva
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Polisetti, Naresh
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Health Sciences.
    Richter-Dahlfors, Agneta
    Karolinska Institutet, Stockholm, Sweden.
    Liedberg, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology. Nanyang Technological University, Singapore.
    Griffith, May
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Health Sciences. Karolinska Institutet, Stockholm, Sweden.
    Polycaprolactone–thiophene-conjugated carbon nanotube meshes as scaffolds for cardiac progenitor cells2014In: Journal of Biomedical Materials Research. Part B - Applied biomaterials, ISSN 1552-4973, E-ISSN 1552-4981, Vol. 102, no 7, p. 1553-1561Article in journal (Refereed)
    Abstract [en]

    The myocardium is unable to regenerate itself after infarct, resulting in scarring and thinning of the heart wall. Our objective was to develop a patch to buttress and bypass the scarred area, while allowing regeneration by incorporated cardiac stem/progenitor cells (CPCs). Polycaprolactone (PCL) was fabricated as both sheets by solvent casting, and fibrous meshes by electrospinning, as potential patches, to determine the role of topology in proliferation and phenotypic changes to the CPCs. Thiophene-conjugated carbon nanotubes (T-CNTs) were incorporated to enhance the mechanical strength. We showed that freshly isolated CPCs from murine hearts neither attached nor spread on the PCL sheets, both with and without T-CNT. As electrospun meshes, however, both PCL and PCL/T-CNT supported CPC adhesion, proliferation, and differentiation. The incorporation of T-CNT into PCL resulted in a significant increase in mechanical strength but no morphological changes to the meshes. In turn, proliferation, but not differentiation, of CPCs into cardiomyocytes was enhanced in T-CNT containing meshes. We have shown that changing the topology of PCL, a known hydrophobic material, dramatically altered its properties, in this case, allowing CPCs to survive and differentiate. With further development, PCL/T-CNT meshes or similar patches may become a viable strategy to aid restoration of the postmyocardial infarction myocardium.

  • 117.
    Wickham, Abeni
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Sjölander, Daniel
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Bergström, Gunnar
    Linköping University, Department of Physics, Chemistry and Biology, Biotechnology. Linköping University, Faculty of Science & Engineering.
    Wang, Ergang
    Chalmers, Sweden.
    Rajendran, Vijayalakshmi
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Health Sciences.
    Hildesjö, Camilla
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Skoglund, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Nilsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Aili, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Near-Infrared Emitting and Pro-Angiogenic Electrospun Conjugated Polymer Scaffold for Optical Biomaterial Tracking2015In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 25, no 27, p. 4274-4281Article in journal (Refereed)
    Abstract [en]

    Noninvasive tracking of biomaterials is vital for determining the fate and degradation of an implant in vivo, and to show its role in tissue regeneration. Current biomaterials have no inherent capacity to enable tracing but require labeling with, for example, fluorescent dyes, or nanoparticles. Here a novel biocompatible fully conjugated electrospun scaffold is described, based on a semiconducting luminescent polymer that can be visualized in situ after implantation using fluorescence imaging. The polymer, poly [2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt -thiophene-2,5-diyl] (TQ1), is electrospun to form a fibrous mat. The fibers display fluorescence emission in the near-infrared region with lifetimes in the sub-nanosecond range, optimal for in situ imaging. The material shows no cytotoxic behaviors for embryonic chicken cardiomyocytes and mouse myoblasts, and cells migrate onto the TQ1 fibers even in the presence of a collagen substrate. Subcutaneous implantations of the material in rats show incorporation of the TQ1 fibers within the tissue, with limited inflammation and a preponderance of small capillaries around the fibers. The fluorescent properties of the TQ1 fibers are fully retained for up to 90 d following implantation and they can be clearly visualized in tissue using fluorescence and lifetime imaging, thus making it both a pro-angiogenic and traceable biomaterial.

  • 118.
    Wickham, Abeni
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Vagin, Mikhail
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Khalaf, Hazem
    University of Örebro, Sweden.
    Bertazzo, Sergio
    UCL, England.
    Hodder, Peter
    TA Instruments Ltd, England.
    Dånmark, Staffan
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Bengtsson, Torbjorn
    University of Örebro, Sweden.
    Altimiras, Jordi
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Aili, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Electroactive biomimetic collagen-silver nanowire composite scaffolds2016In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 8, no 29, p. 14146-14155Article in journal (Refereed)
    Abstract [en]

    Electroactive biomaterials are widely explored as bioelectrodes and as scaffolds for neural and cardiac regeneration. Most electrodes and conductive scaffolds for tissue regeneration are based on synthetic materials that have limited biocompatibility and often display large discrepancies in mechanical properties with the surrounding tissue causing problems during tissue integration and regeneration. This work shows the development of a biomimetic nanocomposite material prepared from self-assembled collagen fibrils and silver nanowires (AgNW). Despite consisting of mostly type I collagen fibrils, the homogeneously embedded AgNWs provide these materials with a charge storage capacity of about 2.3 mC cm(-2) and a charge injection capacity of 0.3 mC cm(-2), which is on par with bioelectrodes used in the clinic. The mechanical properties of the materials are similar to soft tissues with a dynamic elastic modulus within the lower kPa range. The nanocomposites also support proliferation of embryonic cardiomyocytes while inhibiting the growth of both Gram-negative Escherichia coli and Gram-positive Staphylococcus epidermidis. The developed collagen/AgNW composites thus represent a highly attractive bioelectrode and scaffold material for a wide range of biomedical applications.

  • 119.
    Wunderer, Julia
    et al.
    Univ Innsbruck, Austria.
    Lengerer, Birgit
    Univ Innsbruck, Austria; Univ Mons, Belgium.
    Pjeta, Robert
    Univ Innsbruck, Austria.
    Bertemes, Philip
    Univ Innsbruck, Austria.
    Kremser, Leopold
    Innsbruck Med Univ, Austria.
    Lindner, Herbert
    Innsbruck Med Univ, Austria.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Hess, Michael W.
    Innsbruck Med Univ, Austria.
    Stock, David
    Univ Innsbruck, Austria.
    Salvenmoser, Willi
    Univ Innsbruck, Austria.
    Ladurner, Peter
    Univ Innsbruck, Austria.
    A mechanism for temporary bioadhesion2019In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 116, no 10, p. 4297-4306Article in journal (Refereed)
    Abstract [en]

    The flatworm Macrostomum lignano features a duo-gland adhesive system that allows it to repeatedly attach to and release from substrates in seawater within a minute. However, little is known about the molecules involved in this temporary adhesion. In this study, we show that the attachment of M. lignano relies on the secretion of two large adhesive proteins, M. lignano adhesion protein 1 (Mlig-ap1) and Mlig-ap2. We revealed that both proteins are expressed in the adhesive gland cells and that their distribution within the adhesive footprints was spatially restricted. RNA interference knockdown experiments demonstrated the essential function of these two proteins in flatworm adhesion. Negatively charged modified sugars in the surrounding water inhibited flatworm attachment, while positively charged molecules impeded detachment. In addition, we found that M. lignano could not adhere to strongly hydrated surfaces. We propose an attachment-release model where Mlig-ap2 attaches to the substrate and Mlig-ap1 exhibits a cohesive function. A small negatively charged molecule is secreted that interferes with Mlig-ap1, inducing detachment. These findings are of relevance for fundamental adhesion science and efforts to mitigate biofouling. Further, this model of flatworm temporary adhesion may serve as the starting point for the development of synthetic reversible adhesion systems for medicinal and industrial applications.

  • 120.
    Yandi, Wetra
    et al.
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics.
    Mieszkin, Sophie
    University of Birmingham, England; Newcastle University, England.
    Callow, Maureen E.
    University of Birmingham, England.
    Callow, James A.
    University of Birmingham, England.
    Finlay, John A.
    University of Birmingham, England; Newcastle University, England.
    Liedberg, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering. Nanyang Technology University, Singapore.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Antialgal activity of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) brushes against the marine alga Ulva2017In: Biofouling (Print), ISSN 0892-7014, E-ISSN 1029-2454, Vol. 33, no 2, p. 169-183Article in journal (Refereed)
    Abstract [en]

    Marine biofouling has detrimental effects on the environment and economy, and current antifouling coatings research is aimed at environmentally benign, non-toxic materials. The possibility of using contact-active coatings is explored, by considering the antialgal activity of cationic poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) brushes. The antialgal activity was investigated via zoospore settlement and sporeling growth assays of the marine algae Ulva linza and U. lactuca. The assay results for PDMAEMA brushes were compared to those for anionic and neutral surfaces. It was found that only PDMAEMA could disrupt zoospores that come into contact with it, and that it also inhibits the subsequent growth of normally settled spores. Based on the spore membrane properties, and characterization of the PDMAEMA brushes over a wide pH range, it is hypothesized that the algicidal mechanisms are similar to the bactericidal mechanisms of cationic polymers, and that further development could lead to successful contact-active antialgal coatings.

  • 121.
    Yandi, Wetra
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Mieszkin, Sophie
    University of Birmingham, Birmingham, UK.
    di Fino, Alessio
    Newcastle University, Newcastle, UK.
    Martin-Tanchereau, Pierre
    International Paint Ltd, Gateshead, UK.
    Callow, Maureen E
    University of Birmingham, Birmingham, UK.
    Callow, James A.
    University of Birmingham, Birmingham, UK.
    Tyson, Lyndsey
    International Paint Ltd, Gateshead, UK.
    Clare, Anthony S.
    Newcastle University, Newcastle, UK.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Charged hydrophilic polymer brushes and their relevance for understanding marine biofouling2016In: Biofouling (Print), ISSN 0892-7014, E-ISSN 1029-2454, Vol. 32, no 6, p. 609-625Article in journal (Refereed)
    Abstract [en]

    The resistance of charged polymers to biofouling was investigated by subjecting cationic (PDMAEMA), anionic (PSPMA), neutral (PHEMA-co-PEG10MA), and zwitterionic (PSBMA) brushes to assays testing protein adsorption; attachment of the marine bacterium Cobetia marina; settlement and adhesion strength of zoospores of the green alga Ulva linza; settlement of barnacle (Balanus amphitrite and B. improvisus) cypris larvae; and field immersion tests. Several results go beyond the expected dependence on direct electrostatic attraction; PSPMA showed good resistance towards attachment of C. marina, low settlement and adhesion of U. linza zoospores, and significantly lower biofouling than on PHEMA-co-PEG10MA or PSBMA after a field test for one week. PDMAEMA showed potential as a contact-active anti-algal coating due to its capacity to damage attached spores. However, after field testing for eight weeks, there were no significant differences in biofouling coverage among the surfaces. While charged polymers are unsuitable as antifouling coatings in the natural environment, they provide valuable insights into fouling processes, and are relevant for studies due to charging of nominally neutral surfaces.

  • 122.
    Yandi, Wetra
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology.
    Mieszkin, Sophie
    School of Biosciences, University of Birmingham, Birmingham, United Kingdom.
    Martin-Tanchereau, Pierre
    International Paint Ltd, Newcastle, United Kingdom; Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom.
    Callow, Maureen E.
    School of Biosciences, University of Birmingham, Birmingham, United Kingdom.
    Callow, James A.
    School of Biosciences, University of Birmingham, Birmingham, United Kingdom.
    Tyson, Lyndsey
    International Paint Ltd, Newcastle, United Kingdom.
    Liedberg, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Hydration and chain entanglement determines the optimum thickness of poly(HEMA-co-PEG10MA) brushes for effective antifouling properties2015Conference paper (Other academic)
  • 123.
    Yandi, Wetra
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology.
    Mieszkin, Sophie
    University of Birmingham, England .
    Martin-Tanchereau, Pierre
    Int Paint Ltd, England Northumbria University, England .
    Callow, Maureen E.
    University of Birmingham, England .
    Callow, James A.
    University of Birmingham, England .
    Tyson, Lyndsey
    Int Paint Ltd, England .
    Liedberg, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology.
    Hydration and Chain Entanglement Determines the Optimum Thickness of Poly(HEMA-co-PEG(10)MA) Brushes for Effective Resistance to Settlement and Adhesion of Marine Fouling Organisms2014In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 6, no 14, p. 11448-11458Article in journal (Refereed)
    Abstract [en]

    Understanding how surface physicochemical properties influence the settlement and adhesion of marine fouling organisms is important for the development of effective and environmentally benign marine antifouling coatings. We demonstrate that the thickness of random poly(HEMA-co-PEG(10)DMA) copolymer brushes affect antifouling behavior. Films of thicknesses ranging from 50 to 1000 angstrom were prepared via surface-initiated atom-transfer radical polymerization and characterized using infrared spectroscopy, ellipsometry, atomic force microscopy and contact angle measurements. The fouling resistance of these films was investigated by protein adsorption, attachment of the marine bacterium Cobetia marina, settlement and strength of attachment tests of zoospores of the marine alga Ulva linza and static immersion field tests. These assays show that the polymer film thickness influenced the antifouling performance, in that there is an optimum thickness range, 200-400 angstrom (dry thickness), where fouling of all types, as well as algal spore adhesion, was lower. Field test results also showed lower fouling within the same thickness range after 2 weeks of immersion. Studies by quartz crystal microbalance with dissipation and underwater captive bubble contact angle measurements show a strong correlation between lower fouling and higher hydration, viscosity and surface energy of the poly(HEMA-co-PEG(10)MA) brushes at thicknesses around 200-400 angstrom. We hypothesize that the reduced antifouling performance is caused by a lower hydration capacity of the polymer for thinner films, and that entanglement and crowding in the film reduces the conformational freedom, hydration capacity and fouling resistance for thicker films.

  • 124.
    Yeung, Sing Yee
    et al.
    Malmo Univ, Sweden; Malmo Univ, Sweden.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Pan, Guoqing
    Malmö Univ, Sweden.
    Cicenaite, Judita
    Malmö Univ, Sweden.
    Cardenas, Marite
    Malmö Univ, Sweden.
    Arnebrant, Thomas
    Malmö Univ, Swedenn.
    Sellergren, Borje
    Malmö Univ, Sweden.
    Reversible Self-Assembled Monolayers (rSAMs) as Robust and Fluidic Lipid Bilayer Mimics2018In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 34, no 13, p. 4107-4115Article in journal (Refereed)
    Abstract [en]

    Lipid bilayers, forming the outer barrier of cells, display a wide array of proteins and carbohydrates for modulating interfacial biological interactions. Formed by the spontaneous self-assembly of lipid molecules, these bilayers feature liquid crystalline order, while retaining a high degree of lateral mobility. Studies of these dynamic phenomena have been hampered by the fragility and instability of corresponding biomimetic cell membrane models. Here, we present the construct of a series of oligoethylene glycol-terminated reversible self-assembled monolayers (rSAMs) featuring lipid-bilayer-like fluidity, while retaining air and protein stability and resistance. These robust and ordered layers were prepared by simply immersing a carboxylic acid terminated self-assembled monolayer into 5-50 mu M aqueous omega-(4-ethylene glycol-phenoxy)-alpha-(4-amidinophenoxy)decane solutions. It is anticipated that this new class of robust and fluidic two-dimensional biomimetic surfaces will impact the design of rugged cell surface mimics and high-performance biosensors.

  • 125.
    Zeng, Fan
    et al.
    Univ Innsbruck, Austria.
    Wunderer, Julia
    Univ Innsbruck, Austria.
    Salvenmoser, Willi
    Univ Innsbruck, Austria.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Rothbaecher, Ute
    Univ Innsbruck, Austria.
    Identifying adhesive components in a model tunicate2019In: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 374, no 1784, article id 20190197Article in journal (Refereed)
    Abstract [en]

    Tunicates populate a great variety of marine underwater substrates worldwide and represent a significant concern in marine shipping and aquaculture. Adhesives are secreted from the anterior papillae of their swimming larvae, which attach and metamorphose into permanently adhering, filter-feeding adults. We recently described the cellular composition of the sensory adhesive organ of the model tunicate Ciona intestinalis in great detail. Notably, the adhesive secretions of collocytes accumulate at the tip of the organ and contain glycoproteins. Here, we further explore the components of adhesive secretions and have screened for additional specificities that may influence adhesion or cohesion of the Ciona glue, including other carbohydrate moieties, catechols and substrate properties. We found a distinct set of sugar residues in the glue recognized by specific lectins with little overlap to other known marine adhesives. Surprisingly, we also detect catechol residues that likely originate from an adjacent cellular reservoir, the test cells. Furthermore, we provide information on substrate preferences where hydrophobicity outperforms charge in the attachment. Finally, we can influence the settlement process by the addition of hydrophilic heparin. The further analysis of tunicate adhesive strategies should provide a valuable knowledge source in designing physiological adhesives or green antifoulants. This article is part of the theme issue Transdisciplinary approaches to the study of adhesion and adhesives in biological systems.

  • 126.
    Zhang, Qian
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Jiao, Fei
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Braun, Slawomir
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Jafari, Mohammad Javad
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Ground-state charge transfer for NIR absorption with donor/acceptor molecules: interactions mediated via energetics and orbital symmetries2017In: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 5, no 2, p. 275-281Article in journal (Refereed)
    Abstract [en]

    The interactions between electron donors (D) and acceptors (A) of organic semiconducting molecules are of great interest to organic electronics, e.g. electrical doping of organic semiconductors (OSCs), photo-generation of charges in organic solar cells, and light-emitting/detecting devices based on OSCs. A blend of D/A OSC is typically characterized by weak van der Waals interactions or integer charge transfer (ICT) between neighboring D/A molecules. In between these two scenarios of physical blends and ICT complexes, orbital hybridization between adjacent D/A molecules serves as a third alternative, characterized by an in situ formation of a ground state complex featuring partial charge transfer between participating donor and acceptor molecules. In this work is presented a comprehensive experimental study on partial charge-transfer complex (CPX) formed via orbital hybridization. Thiophenes and phthalocyanines are used as electron donors, while acceptor molecules of different geometries and electron affinities are employed with the aim to clarify how orbital symmetry, energy level alignment and steric hindrance affect orbital hybridization and subsequent tuning of the optical band-gap into the near infrared (NIR) region.

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