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Spin-wave based technologies that use collective oscillation of electrons termed magnons have been proposed for future computing landscapes due to their low energy consumption and high data transfer speeds. Magnonic crystals, materials with magnetic properties periodically varied in space, are central to such technologies. However, they are currently limited by the lithography techniques used for the magnetic patterning. To address this issue, bottom-up self-assembly using polymer templates to order magnetic cargo is presented. In this work, block copolymer micelles are used as templates to direct the organization of polyoxometalate (POM) molecules into organized assemblies. The structural organization of these assemblies is evaluated using microscopy and scattering techniques. The organized POM assemblies are demonstrated to modulate spin-waves excited in permalloy thin films. This work demonstrates the first use of a bottom-up approach to realize the fabrication of a magnonic assembly at the nanoscale. It further paves the way to achieve magnon-mediated self-assembled computing architectures.
Sesha Manuguri; Nadine J. van der Heijden; Seong J. Nam; Badri Narayanan Narasimhan; Bohang Wei; Marco A. Cabero Z.; Haiming Yu; Simon Granville; Duncan J. McGillivray; Penelope J. Brothers; David E. Williams; Jenny Malmström. Polymer Micelle Directed Magnetic Cargo Assemblies Towards Spin‐wave Manipulation. Advanced Materials Interfaces 2021, 8, 2100455 .
AMA StyleSesha Manuguri, Nadine J. van der Heijden, Seong J. Nam, Badri Narayanan Narasimhan, Bohang Wei, Marco A. Cabero Z., Haiming Yu, Simon Granville, Duncan J. McGillivray, Penelope J. Brothers, David E. Williams, Jenny Malmström. Polymer Micelle Directed Magnetic Cargo Assemblies Towards Spin‐wave Manipulation. Advanced Materials Interfaces. 2021; 8 (15):2100455.
Chicago/Turabian StyleSesha Manuguri; Nadine J. van der Heijden; Seong J. Nam; Badri Narayanan Narasimhan; Bohang Wei; Marco A. Cabero Z.; Haiming Yu; Simon Granville; Duncan J. McGillivray; Penelope J. Brothers; David E. Williams; Jenny Malmström. 2021. "Polymer Micelle Directed Magnetic Cargo Assemblies Towards Spin‐wave Manipulation." Advanced Materials Interfaces 8, no. 15: 2100455.
The extracellular matrix provides complex biophysical cues to cells which respond to these signals with signalling cascades that determine various cellular processes including fate. Many material systems have been explored to mimic the mechanical properties of the extracellular matrix to determine the cell responses to mechanical cues. While stiffness has emerged as an important regulator of cell behaviour, recently, other mechanical properties such as strain stiffening and viscoelasticity have also emerged as potent regulators. This review explores the substrates used for studying mechanotransduction and strategies adopted to impart more complex mechanical cues including spatiotemporal control of mechanical properties. In addition, practical considerations for designing hydrogels for cell culture are discussed and the response of cells to viscoelastic cues in particular is discussed in depth. Recent mechanotransduction studies of combinations of mechanical and other cues are finally reviewed. It is anticipated that such multi-physical cues will further the understanding of mechanotransduction involved in complex processes such as migration and mechanical memory and provide a framework in controlling cell behaviour.
Badri Narayanan Narasimhan; Matthew S Horrocks; Jenny Malmström. Hydrogels with Tunable Physical Cues and their Emerging Roles in Studies of Cellular Mechanotransduction. Advanced NanoBiomed Research 2021, 2100059 .
AMA StyleBadri Narayanan Narasimhan, Matthew S Horrocks, Jenny Malmström. Hydrogels with Tunable Physical Cues and their Emerging Roles in Studies of Cellular Mechanotransduction. Advanced NanoBiomed Research. 2021; ():2100059.
Chicago/Turabian StyleBadri Narayanan Narasimhan; Matthew S Horrocks; Jenny Malmström. 2021. "Hydrogels with Tunable Physical Cues and their Emerging Roles in Studies of Cellular Mechanotransduction." Advanced NanoBiomed Research , no. : 2100059.
The conducting polymer, polypyrrole (PPy), has been widely studied as electrochemical actuators due to their electrochemical stability, fast actuation and high strains. However, conducting polymers films are rigid and brittle, which limit their applications. Conducting polymer hydrogel composites take advantage of hydrogels’ elastic properties and extend their use to biological applications, implants and flexible sensor applications. We systematically investigated the out-of-plane actuation of poly(N-isopropylacrylamide) (pNIPAM) hydrogel by utilising the redox properties of a PPy film. We assess the PPy film growth with different sized dopants and find that PPy-dodecylbenzene sulfonate (DBS) films exhibited the largest strain (∼20 %) with a cation-driven actuation. We show that the Young's Modulus of the composite hydrogel was ∼10 kPa, which remained constant regardless of the redox state of PPy. Furthermore, we show that the PPy-DBS film grown in the pNIPAM hydrogel exhibits more than x2 the actuation of the PPy-DBS film alone by electrochemical switching of the redox state. This system has potential applications for soft actuators, controlling ion flux, drug delivery or applying electrical stimuli for cell culture studies.
Matthew S. Ting; Badri Narayanan Narasimhan; Jadranka Travas-Sejdic; Jenny Malmström. Soft conducting polymer polypyrrole actuation based on poly(N-isopropylacrylamide) hydrogels. Sensors and Actuators B: Chemical 2021, 343, 130167 .
AMA StyleMatthew S. Ting, Badri Narayanan Narasimhan, Jadranka Travas-Sejdic, Jenny Malmström. Soft conducting polymer polypyrrole actuation based on poly(N-isopropylacrylamide) hydrogels. Sensors and Actuators B: Chemical. 2021; 343 ():130167.
Chicago/Turabian StyleMatthew S. Ting; Badri Narayanan Narasimhan; Jadranka Travas-Sejdic; Jenny Malmström. 2021. "Soft conducting polymer polypyrrole actuation based on poly(N-isopropylacrylamide) hydrogels." Sensors and Actuators B: Chemical 343, no. : 130167.
Stainless steel is used in a large variety of food and medical applications, where it is susceptible to adsorption of proteins and other materials on its surface, ultimately leading to biofouling. Here, we report the synthesis of a copolymer bearing both poly(ethylene glycol) (PEG)-antifouling and phosphate-containing monomers, abbreviated as poly(PEGMA-co-MEP), to be used as an easily applied nano-coating for a stainless steel substrate. Highly tenacious films could be easily deposited by dipping the stainless steel substrate into a dilute aqueous solution of the polymer for a few minutes, which then resisted rinsing over many days. This simple attachment method, which does not need solvents, annealing, or adhesion promoters, looks to be very easy transferable into commercial applications. From quartz crystal microbalance with dissipation experiments, the films were found only about one polymer layer thick. A variety of proteins and skim milk were tested against the poly(PEGMA-co-MEP)-coated surfaces, which showed almost a 100% reduction in binding affinity. In addition, fluorescence microscopy results showed that PEG phosphate and phosphonate-coated surfaces exhibited strong inhibition of bacterial adhesion for both Escherichia coli and Bacillus cereus over several days. Other PEG polymers containing carboxylic acids as anchoring groups were also tested and gave a somewhat worse performance.
Farzana Kousar; Jenny Malmström; Simon Swift; Jacqueline Ross; Janesha Perera; Stephen C. Moratti. Protein-Resistant Behavior of Poly(ethylene glycol)-Containing Polymers with Phosphonate/Phosphate Units on Stainless Steel Surfaces. ACS Applied Polymer Materials 2021, 3, 2785 -2801.
AMA StyleFarzana Kousar, Jenny Malmström, Simon Swift, Jacqueline Ross, Janesha Perera, Stephen C. Moratti. Protein-Resistant Behavior of Poly(ethylene glycol)-Containing Polymers with Phosphonate/Phosphate Units on Stainless Steel Surfaces. ACS Applied Polymer Materials. 2021; 3 (5):2785-2801.
Chicago/Turabian StyleFarzana Kousar; Jenny Malmström; Simon Swift; Jacqueline Ross; Janesha Perera; Stephen C. Moratti. 2021. "Protein-Resistant Behavior of Poly(ethylene glycol)-Containing Polymers with Phosphonate/Phosphate Units on Stainless Steel Surfaces." ACS Applied Polymer Materials 3, no. 5: 2785-2801.
Dissipating hydrogels made with poly(tannic acid) exhibit superior and stable mechanical properties suitable for load bearing and cell culture applications.
Badri Narayanan Narasimhan; Gerrit Sjoerd Deijs; Sesha Manuguri; Matthew Sheng Hao Ting; M. A. K. Williams; Jenny Malmström. A comparative study of tough hydrogen bonding dissipating hydrogels made with different network structures. Nanoscale Advances 2021, 3, 2934 -2947.
AMA StyleBadri Narayanan Narasimhan, Gerrit Sjoerd Deijs, Sesha Manuguri, Matthew Sheng Hao Ting, M. A. K. Williams, Jenny Malmström. A comparative study of tough hydrogen bonding dissipating hydrogels made with different network structures. Nanoscale Advances. 2021; 3 (10):2934-2947.
Chicago/Turabian StyleBadri Narayanan Narasimhan; Gerrit Sjoerd Deijs; Sesha Manuguri; Matthew Sheng Hao Ting; M. A. K. Williams; Jenny Malmström. 2021. "A comparative study of tough hydrogen bonding dissipating hydrogels made with different network structures." Nanoscale Advances 3, no. 10: 2934-2947.
Nanoscale control over pore surface properties is a challenging objective for nanopore research and could enable advanced bioanalytical applications, along with enhanced precision and accuracy of existing measurement processes. This work reports a one-pot strategy for the functionalization of thermoplastic polyurethane (TPU) tunable nanopores with polymer brushes. These elastomeric pores are used for tunable resistive pulse sensing (TRPS), which can detect and analyze a broad range of microparticle and nanoparticle species in aqueous electrolytes. Grafting is achieved using the recently developed Graftfast method, via the chemical reduction of diazonium salts. The study focuses on Graftfast of negatively charged poly(acrylic acid) (PAA) brushes. The method is further exemplified through the grafting of neutral brushes with a view to utilizing their possible antifouling properties: zwitterionic poly(sulfobetaine), 2-hydroxyethyl methacrylate, and poly(ethylene glycol) methyl ethermethacrylate. The successful TPU functionalization was characterized using Fourier transform infrared spectroscopy, contact angle measurements, and X-ray photoelectron spectroscopy. For PAA-grafted pores, the TRPS configuration was used for studies of ionic current rectification, streaming potential, and resistive pulse durations for 500-nm-diameter carboxylated polystyrene spheres. Results were consistent with increased negative surface charge on the pore walls, confirming successful pore functionalization.
Anupama Rao Gulur Srinivas; Rafiq Hilali; Mona Damavandi; Jenny Malmstrom; David Barker; Eva Weatherall; Geoff Willmott; Jadranka Travas-Sejdic. Polymer Brush Functionalization of Polyurethane Tunable Nanopores for Resistive Pulse Sensing. ACS Applied Polymer Materials 2020, 3, 279 -289.
AMA StyleAnupama Rao Gulur Srinivas, Rafiq Hilali, Mona Damavandi, Jenny Malmstrom, David Barker, Eva Weatherall, Geoff Willmott, Jadranka Travas-Sejdic. Polymer Brush Functionalization of Polyurethane Tunable Nanopores for Resistive Pulse Sensing. ACS Applied Polymer Materials. 2020; 3 (1):279-289.
Chicago/Turabian StyleAnupama Rao Gulur Srinivas; Rafiq Hilali; Mona Damavandi; Jenny Malmstrom; David Barker; Eva Weatherall; Geoff Willmott; Jadranka Travas-Sejdic. 2020. "Polymer Brush Functionalization of Polyurethane Tunable Nanopores for Resistive Pulse Sensing." ACS Applied Polymer Materials 3, no. 1: 279-289.
Accurate mechanical characterization of adherent cells and their substrates is important for understanding the influence of mechanical properties on cells themselves. Recent mechanobiology studies outline the importance of mechanical parameters, such as stress relaxation and strain stiffening on the behavior of cells. Numerous techniques exist for probing mechanical properties and it is vital to understand the benefits of each technique and how they relate to each other. This mini review aims to guide the reader through the toolbox of mechanical characterization techniques by presenting well-established and emerging methods currently used to assess mechanical properties of substrates and cells.
Badri Narayanan Narasimhan; Matthew S. Ting; Tarek Kollmetz; Matthew S. Horrocks; Anaïs E. Chalard; Jenny Malmström. Mechanical Characterization for Cellular Mechanobiology: Current Trends and Future Prospects. Frontiers in Bioengineering and Biotechnology 2020, 8, 1 .
AMA StyleBadri Narayanan Narasimhan, Matthew S. Ting, Tarek Kollmetz, Matthew S. Horrocks, Anaïs E. Chalard, Jenny Malmström. Mechanical Characterization for Cellular Mechanobiology: Current Trends and Future Prospects. Frontiers in Bioengineering and Biotechnology. 2020; 8 ():1.
Chicago/Turabian StyleBadri Narayanan Narasimhan; Matthew S. Ting; Tarek Kollmetz; Matthew S. Horrocks; Anaïs E. Chalard; Jenny Malmström. 2020. "Mechanical Characterization for Cellular Mechanobiology: Current Trends and Future Prospects." Frontiers in Bioengineering and Biotechnology 8, no. : 1.
The co-assembly of peptides and proteins in poly(styrene-block-ethylene oxide) (PS-b-PEO) thin films has proven to be a promising method to fabricate polymer-biomolecule functional materials. Contrary to the covalent immobilization of biomolecules on surfaces, co-assembly presents the opportunity to arrange cargo within thin films, which can be released upon exposure to an aqueous environment. The use of a mixed solvent system ensures the solubilization of hydrophobic polymer as well as the solubilization and protection of the biomolecule cargo. However, to produce largely defect-free films of PS-b-PEO from a solvent mixture containing water is challenging due to the narrow range of solvent miscibility and polymer/protein solubility. This work explores the limits of using a benzene/methanol/water solvent mixture for the production of thin PS-b-PEO films and provides a template for the fabrication optimization of block copolymer thin films in different complex solvent systems. The film quality is analyzed using optical microscopy and atomic force microscopy and correlated to the solvent composition. By adjusting the solvent composition to 80/18.8/1.2 vol % benzene/methanol/water, it was possible to reliably fabricate thin films with less than 1% macroscopic defect surface coverage. Using the optimized solvent composition, we also demonstrate the fabrication of ordered PS-b-PEO films containing lysozyme. Furthermore, we show the release of lysozyme into aqueous media, which highlights the potential use of such films for drug delivery applications.
Tarek Kollmetz; Isabela Monteiro A; Juliet A. Gerrard; Jenny Malmström. Polystyrene-block-poly(ethylene oxide) Thin Films Fabricated from a Solvent Mixture for the Co-Assembly of Polymers and Proteins. ACS Omega 2020, 5, 26365 -26373.
AMA StyleTarek Kollmetz, Isabela Monteiro A, Juliet A. Gerrard, Jenny Malmström. Polystyrene-block-poly(ethylene oxide) Thin Films Fabricated from a Solvent Mixture for the Co-Assembly of Polymers and Proteins. ACS Omega. 2020; 5 (41):26365-26373.
Chicago/Turabian StyleTarek Kollmetz; Isabela Monteiro A; Juliet A. Gerrard; Jenny Malmström. 2020. "Polystyrene-block-poly(ethylene oxide) Thin Films Fabricated from a Solvent Mixture for the Co-Assembly of Polymers and Proteins." ACS Omega 5, no. 41: 26365-26373.
Evidence is presented that the polysaccharide rhamnogalacturonan I (RGI) can be biosynthesised in remarkably organised branched configurations, in surprisingly long versions, and can self-assemble into a plethora of structures. AFM imaging has been applied to study the outer mucilage obtained from wild type (WT) and mutant (bxl1-3 and cesa5-1) Arabidopsis thaliana seeds. For WT mucilage, ordered, multi-chain structures of the polysaccharide RGI were observed, with a helical twist visible in favourable circumstances. Molecular dynamics (MD) simulations demonstrated the stability of several possible multi-chain complexes, and the possibility of twisted fibril formation. For bxl1-3 seeds the imaged polymers clearly showed the presence of sidechains. These were surprisingly regular and well organised with an average length of ~ 100 nm and a spacing of ~ 50 nm. The heights of the sidechains imaged were suggestive of single polysaccharide chains, while the backbone was on average four times this height and showed regular height variations along its length consistent with models of multi-chain fibrils examined in MD. Finally, in mucilage extracts from cesa5-1 seeds, a minor population of chains in excess of 30 m long was observed.
Martin A. K. Williams; Valérie Cornuault; Amir Irani; V. Vaughan Symonds; Jenny Malmstrom; Yiran An; Ian M. Sims; Susan M. Carnachan; Christine Salle; Helen M. North. Polysaccharide Structures in the Outer Mucilage of Arabidopsis Seeds Visualized by AFM. Biomacromolecules 2020, 21, 1450 -1459.
AMA StyleMartin A. K. Williams, Valérie Cornuault, Amir Irani, V. Vaughan Symonds, Jenny Malmstrom, Yiran An, Ian M. Sims, Susan M. Carnachan, Christine Salle, Helen M. North. Polysaccharide Structures in the Outer Mucilage of Arabidopsis Seeds Visualized by AFM. Biomacromolecules. 2020; 21 (4):1450-1459.
Chicago/Turabian StyleMartin A. K. Williams; Valérie Cornuault; Amir Irani; V. Vaughan Symonds; Jenny Malmstrom; Yiran An; Ian M. Sims; Susan M. Carnachan; Christine Salle; Helen M. North. 2020. "Polysaccharide Structures in the Outer Mucilage of Arabidopsis Seeds Visualized by AFM." Biomacromolecules 21, no. 4: 1450-1459.
Polystyrene-block-polyethylene oxide (PS-b-PEO) coated surfaces have been explored as cell culture substrates in the past decade. However, their cytocompatibility has not been extensively assessed. In this study, the in vitro cytocompatibility of PS-b-PEO was investigated. Cellular morphology, metabolic activity, and viability were evaluated at 1, 3, and 5 days after cell seeding. Viability was greater than 90% throughout the 5 days culture, with abundant cell spreading evident by the formation of prominent F-actin stress fibres. The cytocompatibility study was complemented by the analysis of adsorption of a range of extracellular matrix proteins on PS-b-PEO thin films by quartz crystal microbalance with dissipation. Protein adsorption tests revealed that there was no significant difference in protein adhesion between surfaces with a PEO domain coverage of ≈28%, compared to the homogeneous polystyrene control. The findings demonstrate that PS-b-PEO thin films are cytocompatible and are a favourable surface coating for cell culture studies.
Isabela Monteiro A.; Tarek Kollmetz; David S. Musson; Sue R. McGlashan; Jenny Malmström. Polystyrene-block-polyethylene oxide thin films: In vitro cytocompatibility and protein adsorption testing. Biointerphases 2020, 15, 011003 .
AMA StyleIsabela Monteiro A., Tarek Kollmetz, David S. Musson, Sue R. McGlashan, Jenny Malmström. Polystyrene-block-polyethylene oxide thin films: In vitro cytocompatibility and protein adsorption testing. Biointerphases. 2020; 15 (1):011003.
Chicago/Turabian StyleIsabela Monteiro A.; Tarek Kollmetz; David S. Musson; Sue R. McGlashan; Jenny Malmström. 2020. "Polystyrene-block-polyethylene oxide thin films: In vitro cytocompatibility and protein adsorption testing." Biointerphases 15, no. 1: 011003.
Atomic force microscopy (AFM) enables imaging of surface-deposited proteins and protein structures under physiological conditions, which is a benefit compared to ultra-high vacuum techniques such as electron microscopy. AFM also has the potential to provide more information from the phase in tapping mode or from functional AFM modes. The sample preparation, probe selection, and imaging conditions are crucial for successful imaging of proteins. Here we give a detailed account of the steps toward imaging of soft samples in both air and liquid along with the basic theory underpinning these details.
Yiran An; Sesha Sarathchandra Manuguri; Jenny Malmström. Atomic Force Microscopy of Proteins. Methods in Molecular Biology 2019, 2073, 247 -285.
AMA StyleYiran An, Sesha Sarathchandra Manuguri, Jenny Malmström. Atomic Force Microscopy of Proteins. Methods in Molecular Biology. 2019; 2073 ():247-285.
Chicago/Turabian StyleYiran An; Sesha Sarathchandra Manuguri; Jenny Malmström. 2019. "Atomic Force Microscopy of Proteins." Methods in Molecular Biology 2073, no. : 247-285.
Electrochemical water splitting is a sustainable, environmentally friendly method of hydrogen generation for green energy. However, the ideal electrocatalyst, platinum, is limited by cost and scarcity. Thus, new approaches are needed to minimise the amount of platinum required for efficient hydrogen production, while retaining its electrocatalytic activity. In this work, we report the development of a novel electrocatalyst based on platinum nanoparticles (PtNPs) deposited on conducting poly(3,4-ethylenedioxythiophene) (PEDOT), grafted with poly(acrylic acid) (PAA) chains. The presence of PAA controls the PtNP size and prevents aggregation during electrodeposition. The composite materials demonstrated enhanced electrocatalytic activity for the hydrogen evolution reaction (HER) in acid, with onset potentials as low as -84 mV vs RHE and exchange current densities up to 161 µA cm-2.Thus, these composite electrodes show promise as a straightforward, cost-effective alternative to conventional platinum HER catalysts. Furthermore, this novel fabrication approach shows great potential for the development of future electrocatalysts, providing an infinitely tailorable substrate for nanoparticle deposition thanks to the versatility of grafted conducting polymer films.
Alissa J. Hackett; Jenny Malmstrom; Jadranka Travas-Sejdic. Grafting Poly(acrylic acid) from PEDOT To Control the Deposition and Growth of Platinum Nanoparticles for Enhanced Electrocatalytic Hydrogen Evolution. ACS Applied Energy Materials 2019, 2, 1436 -1444.
AMA StyleAlissa J. Hackett, Jenny Malmstrom, Jadranka Travas-Sejdic. Grafting Poly(acrylic acid) from PEDOT To Control the Deposition and Growth of Platinum Nanoparticles for Enhanced Electrocatalytic Hydrogen Evolution. ACS Applied Energy Materials. 2019; 2 (2):1436-1444.
Chicago/Turabian StyleAlissa J. Hackett; Jenny Malmstrom; Jadranka Travas-Sejdic. 2019. "Grafting Poly(acrylic acid) from PEDOT To Control the Deposition and Growth of Platinum Nanoparticles for Enhanced Electrocatalytic Hydrogen Evolution." ACS Applied Energy Materials 2, no. 2: 1436-1444.
Isabela Monteiro A.; Tarek Kollmetz; Jenny Malmström. Engineered systems to study the synergistic signaling between integrin-mediated mechanotransduction and growth factors (Review). Biointerphases 2018, 13, 06D302 .
AMA StyleIsabela Monteiro A., Tarek Kollmetz, Jenny Malmström. Engineered systems to study the synergistic signaling between integrin-mediated mechanotransduction and growth factors (Review). Biointerphases. 2018; 13 (6):06D302.
Chicago/Turabian StyleIsabela Monteiro A.; Tarek Kollmetz; Jenny Malmström. 2018. "Engineered systems to study the synergistic signaling between integrin-mediated mechanotransduction and growth factors (Review)." Biointerphases 13, no. 6: 06D302.
The photophysical and ion‐sensing properties of densely grafted conjugated polymer poly‐p‐phenylenevinylene‐g‐poly(2‐(methacryloyloxy)ethyl)trimethylammonium chloride (PPV‐g‐PMETAC) are presented herein. The grafted polymer exhibits excellent iodide‐sensing which is easily observed using fluorescence spectroscopy. The iodide detection limit for PPV‐g‐PMETAC was found to be 10 nM and was independent of temperature and pH <12. The change in fluorescence of PPV‐g‐PMETAC, upon exposure to iodide, was attributed to polymer aggregation due to changes in the morphology of the grafted PMETAC side chains, which was observed using atomic force microscopic and dynamic light scattering studies. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018
Mona Damavandi; Lisa I. Pilkington; Jenny Malmström; Kathryn A. Whitehead; Jadranka Travas-Sejdic; David Barker. Poly-p -phenylenevinylene-g -poly(2-(methacryloyloxy)Ethyl)trimethylammonium chloride (PPV-g-PMETAC): A fluorescent, water-soluble, selective anion sensor. Journal of Polymer Science Part A: Polymer Chemistry 2018, 56, 1997 -2003.
AMA StyleMona Damavandi, Lisa I. Pilkington, Jenny Malmström, Kathryn A. Whitehead, Jadranka Travas-Sejdic, David Barker. Poly-p -phenylenevinylene-g -poly(2-(methacryloyloxy)Ethyl)trimethylammonium chloride (PPV-g-PMETAC): A fluorescent, water-soluble, selective anion sensor. Journal of Polymer Science Part A: Polymer Chemistry. 2018; 56 (17):1997-2003.
Chicago/Turabian StyleMona Damavandi; Lisa I. Pilkington; Jenny Malmström; Kathryn A. Whitehead; Jadranka Travas-Sejdic; David Barker. 2018. "Poly-p -phenylenevinylene-g -poly(2-(methacryloyloxy)Ethyl)trimethylammonium chloride (PPV-g-PMETAC): A fluorescent, water-soluble, selective anion sensor." Journal of Polymer Science Part A: Polymer Chemistry 56, no. 17: 1997-2003.
The ability of proteins to form hierarchical structures through self-assembly provides an opportunity to synthesize and organize nanoparticles. Ordered nanoparticle assemblies are a subject of wide interest due to the potential to harness their emergent functions. In this work, the toroidal shaped form of the protein peroxiredoxin, which has a pore size of 7 nm, was used to organize iron oxyhydroxide nanoparticles. Iron in the form of Fe2+ was sequestered into the central cavity of the toroid ring using metal binding sites engineered there, then hydrolysed to form iron oxyhydroxide particles bound into the protein pore. By precise manipulation of the pH, the mineralized toroids were organized into stacks confining one dimensional nanoparticle assemblies. We report the formation and the procedures leading to the formation of such nanostructures, and their characterization by chromatography and microscopy. Electrostatic force microscopy clearly revealed the formation of iron containing nanorods, as a result of the self-assembly of the iron-loaded protein. This research augurs well for the use of peroxiredoxin as a template to form nanowires and structures for electronic and magnetic applications.
Sesha Sarathchandra Manuguri; Kyle Webster; N. Amy Yewdall; Yiran An; Hari Venugopal; Vaibhav Bhugra; Adrian Turner; Laura Joy Domigan; Juliet A. Gerrard; David Edward Williams; Jenny Malmström. Assembly of Protein Stacks With in Situ Synthesized Nanoparticle Cargo. Nano Letters 2018, 18, 5138 -5145.
AMA StyleSesha Sarathchandra Manuguri, Kyle Webster, N. Amy Yewdall, Yiran An, Hari Venugopal, Vaibhav Bhugra, Adrian Turner, Laura Joy Domigan, Juliet A. Gerrard, David Edward Williams, Jenny Malmström. Assembly of Protein Stacks With in Situ Synthesized Nanoparticle Cargo. Nano Letters. 2018; 18 (8):5138-5145.
Chicago/Turabian StyleSesha Sarathchandra Manuguri; Kyle Webster; N. Amy Yewdall; Yiran An; Hari Venugopal; Vaibhav Bhugra; Adrian Turner; Laura Joy Domigan; Juliet A. Gerrard; David Edward Williams; Jenny Malmström. 2018. "Assembly of Protein Stacks With in Situ Synthesized Nanoparticle Cargo." Nano Letters 18, no. 8: 5138-5145.
Conjugated polymers (CPs) are conductive in their doped state and display unique optoelectronic behavior. The interface between biological and man‐made materials is central in biomedical applications such as biosensing, tissue engineering, and implantable devices. This chapter focuses on the emerging field of modification of CPs with polymer brushes for biointerface applications. It discusses the synthetic approaches to CP‐containing graft copolymers, with particular reference to copolymer chemistries of interest for biointerfaces applications. Biosensing plays an increasingly important role in a wide range of fields, including health care, environmental monitoring, food quality monitoring, and biosecurity, where biosensors are used to detect genetic abnormalities, pathogens, viruses, toxins, and biological markers of diseases. The grafted polymeric side chains can be chosen to offer functionalities for adding further functional moieties; for example, adding a specific cell binding motif to a conductive and antifouling surface for tissue engineering applications.
Alissa Hackett; Lisa T. Strover; Paul Baek; Jenny Malmström; Jadranka Travas-Sejdic. Polymer-Grafted Conjugated Polymers as Functional Biointerfaces. Conjugated Polymers for Biological and Biomedical Applications 2018, 359 -401.
AMA StyleAlissa Hackett, Lisa T. Strover, Paul Baek, Jenny Malmström, Jadranka Travas-Sejdic. Polymer-Grafted Conjugated Polymers as Functional Biointerfaces. Conjugated Polymers for Biological and Biomedical Applications. 2018; ():359-401.
Chicago/Turabian StyleAlissa Hackett; Lisa T. Strover; Paul Baek; Jenny Malmström; Jadranka Travas-Sejdic. 2018. "Polymer-Grafted Conjugated Polymers as Functional Biointerfaces." Conjugated Polymers for Biological and Biomedical Applications , no. : 359-401.
A siloxane surface-anchored quaternary ammonium salt (AQAS: Biosafe HM4100 in this study) has been chemisorbed onto a quartz substrate. The aim of this study is to elucidate, using Atomic Force Microscopy (AFM) and X-Ray Photoelectron Spectroscopy (XPS), the structure of the chemisorbed AQAS layers. The AQAS biocide includes a C18 alkyl chain previously invoked in lysis potency. The AQAS coverage appears in zones on the surface which include a first layer (c.2.6nm) and multi-layering which were explored using AFM. The X-ray Photoelectron Spectroscopy (XPS) data exhibited two N1s signals at about 402 and 399eV, with only the former exhibiting angular dependence. This signal at 402eV was assigned to the first anchored layer with perpendicular orientation determined by the AQAS anchoring to the surface. In preliminary AFM studies of bacteria on these AQAS surfaces, perturbations on the Staphylococcus aureus cells, and the degradation of Escherichia coli cells, suggest lysis potency.
Rachel T. Mathew; Ralph P. Cooney; Jenny Malmström; Colin S. Doyle. Atomic Force Microscopy and Angular-Dependent X-ray Photoelectron Spectroscopy Studies of Anchored Quaternary Ammonium Salt Biocides on Quartz Surfaces. Langmuir 2018, 34, 4750 -4761.
AMA StyleRachel T. Mathew, Ralph P. Cooney, Jenny Malmström, Colin S. Doyle. Atomic Force Microscopy and Angular-Dependent X-ray Photoelectron Spectroscopy Studies of Anchored Quaternary Ammonium Salt Biocides on Quartz Surfaces. Langmuir. 2018; 34 (16):4750-4761.
Chicago/Turabian StyleRachel T. Mathew; Ralph P. Cooney; Jenny Malmström; Colin S. Doyle. 2018. "Atomic Force Microscopy and Angular-Dependent X-ray Photoelectron Spectroscopy Studies of Anchored Quaternary Ammonium Salt Biocides on Quartz Surfaces." Langmuir 34, no. 16: 4750-4761.
A highly selective, label-free sensor for the non-Hodgkin lymphoma gene, with an aM detection limit, utilizing electrochemical impedance spectroscopy (EIS) is presented. The sensor consists of a conducting electrospun fibre mat, surface-grafted with poly(acrylic acid) (PAA) brushes and a conducting polymer sensing element with covalently attached oligonucleotide probes. The sensor was fabricated from electrospun NBR rubber, embedded with poly(3,4-ethylenedioxythiophene) (PEDOT), followed by grafting poly(acrylic acid) brushes and then electrochemically polymerizing a conducting polymer monomer with ssDNA probe sequence pre-attached. The resulting non-Hodgkin lymphoma gene sensor showed a detection limit of 1aM (1 × 10mol/L), more than 400 folds lower compared to a thin-film analogue. The sensor presented extraordinary selectivity, with only 1%, 2.7% and 4.6% of the signal recorded for the fully non-complimentary, T-A and G-C base mismatch oligonucleotide sequences, respectively. We suggest that such greatly enhanced selectivity is due to the presence of negatively charged carboxylic acid moieties from PAA grafts that electrostatically repel the non-complementary and mismatch DNA sequences, overcoming the non-specific binding.
Thomas E. Kerr-Phillips; Nihan Aydemir; Eddie Wai Chi Chan; David Barker; Jenny Malmström; Cedric Plesse; Jadranka Travas-Sejdic. Conducting electrospun fibres with polyanionic grafts as highly selective, label-free, electrochemical biosensor with a low detection limit for non-Hodgkin lymphoma gene. Biosensors and Bioelectronics 2018, 100, 549 -555.
AMA StyleThomas E. Kerr-Phillips, Nihan Aydemir, Eddie Wai Chi Chan, David Barker, Jenny Malmström, Cedric Plesse, Jadranka Travas-Sejdic. Conducting electrospun fibres with polyanionic grafts as highly selective, label-free, electrochemical biosensor with a low detection limit for non-Hodgkin lymphoma gene. Biosensors and Bioelectronics. 2018; 100 ():549-555.
Chicago/Turabian StyleThomas E. Kerr-Phillips; Nihan Aydemir; Eddie Wai Chi Chan; David Barker; Jenny Malmström; Cedric Plesse; Jadranka Travas-Sejdic. 2018. "Conducting electrospun fibres with polyanionic grafts as highly selective, label-free, electrochemical biosensor with a low detection limit for non-Hodgkin lymphoma gene." Biosensors and Bioelectronics 100, no. : 549-555.
Non-specific protein adsorption is detrimental to the performance of many biomedical devices. Polystyrene is a commonly used material in devices and thin films. Simple reliable surface modification of polystyrene to render it protein resistant is desired in particular for device fabrication and orthogonal functionalisation schemes. This report details modifications carried out on a polystyrene surface to prevent protein adsorption. The trialed surfaces included Pluronic F127 and PLL-g-PEG, adsorbed on polystyrene, using a polydopamine-assisted approach. Quartz crystal microbalance with dissipation (QCM-D) results showed only short-term anti-fouling success of the polystyrene surface modified with F127, and the subsequent failure of the polydopamine intermediary layer in improving its stability. In stark contrast, QCM-D analysis proved the success of the polydopamine assisted PLL-g-PEG coating in preventing bovine serum albumin adsorption. This modified surface is equally as protein-rejecting after 24 h in buffer, and thus a promising simple coating for long term protein rejection of polystyrene.
Marcelle Hecker; Matthew Sheng Hao Ting; Jenny Malmström. Simple Coatings to Render Polystyrene Protein Resistant. Coatings 2018, 8, 55 .
AMA StyleMarcelle Hecker, Matthew Sheng Hao Ting, Jenny Malmström. Simple Coatings to Render Polystyrene Protein Resistant. Coatings. 2018; 8 (2):55.
Chicago/Turabian StyleMarcelle Hecker; Matthew Sheng Hao Ting; Jenny Malmström. 2018. "Simple Coatings to Render Polystyrene Protein Resistant." Coatings 8, no. 2: 55.
Recent research has highlighted the exciting possibilities enabled by the use of protein structures as nanocomponents to form functional nanodevices. To this end, control over protein-protein and protein-surface interactions is essential. In this study, the authors probe the interaction of human peroxiredoxin 3 with gold surfaces, a protein that has been previously identified as having potential use in nanotechnology. Analytical ultracentrifugation and transmission electron microscopy revealed the pH mediated assembly of protein toroids into tubular structures across a small pH range. Quartz crystal microbalance with dissipation measurements showed differences in absorbed protein mass when pH is switched from pH 8.0 to 7.2, in line with the formation of supramolecular structures observed in solution studies. Scanning tunneling microscopy under ambient conditions showed that these protein tubes form on surfaces in a concentration dependent manner, with a tendency for protein adsorption and supramolecular assembly at the edges of Au(111) terraces. Finally, self-assembled monolayer modification of Au surfaces was explored as a means to control the adsorption and orientation of pH triggered protein structures.
Laura J. Domigan; Helen Ashmead; Simone DiMartino; Jenny Malmstrom; F. Grant Pearce; Matthew Blunt; David E. Williams; Juliet A. Gerrard. Formation of supramolecular protein structures on gold surfaces. Biointerphases 2017, 12, 04E405 .
AMA StyleLaura J. Domigan, Helen Ashmead, Simone DiMartino, Jenny Malmstrom, F. Grant Pearce, Matthew Blunt, David E. Williams, Juliet A. Gerrard. Formation of supramolecular protein structures on gold surfaces. Biointerphases. 2017; 12 (4):04E405.
Chicago/Turabian StyleLaura J. Domigan; Helen Ashmead; Simone DiMartino; Jenny Malmstrom; F. Grant Pearce; Matthew Blunt; David E. Williams; Juliet A. Gerrard. 2017. "Formation of supramolecular protein structures on gold surfaces." Biointerphases 12, no. 4: 04E405.