3 results for Agheli, H

  • Viscoelastic Modeling of highly hydrated laminin layers at homogeneous and nanostructured surfaces: Quantification of protein layer properties using QCM-D and SPR

    Malmstrom Pendred, Jenny; Agheli, H; Kingshott, P; Sutherland, DS (2007)

    Journal article
    The University of Auckland Library

    The adsorption of proteins at material surfaces is important in applications such as biomaterials, drug delivery, and diagnostics. The interaction of cells with artificial surfaces is mediated through adsorbed proteins, where the type of protein, amount, orientation, and conformation are of consequence for the cell response. Laminin, an important cell adhesive protein that is central in developmental biology, is studied by a combination of quartz crystal microbalance with dissipation (QCM-D) and surface plasmon resonance (SPR) to characterize the adsorption of laminin on surfaces of different surface chemistries. The combination of these two techniques allows for the determination of the thickness and effective density of the protein layer as well as the adsorbed mass and viscoelastic properties. We also evaluate the capacity of QCM-D to be used as a quantitative technique on a nanostructured surface, where protein is adsorbed specifically in a nanopattern exploiting PLL-g-PEG as a protein-resistant background. We show that laminin forms a highly hydrated protein layer with different characteristics depending on the underlying substrate. Using a combination of QCM-D and atomic force microscopy (AFM) data from nanostructured surfaces, we model laminin and antibody binding to nanometer-scale patches. A higher amount of laminin was found to adsorb in a thicker layer of a lower effective density in nanopatches compared to equivalent homogeneous surfaces. These results suggest that modeling of QCM-D data of soft viscoelastic layers arranged in nanopatterns may be applied where an independent measure of the "dry" mass is known.

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  • Narlostructured biointerfaces

    Agheli, H; Malmstrom Pendred, Jenny; Hanarp, P; Sutherland, DS (2006)

    Journal article
    The University of Auckland Library

    Colloidal lithography is used to create nanostructured interfaces suitable for studying and interacting with cellular biosystems. Large areas of patterned surface can be produced. We investigate the use of plasma etching for transfer of the pattern of individual colloidal particles into the substrates to create short-range ordered arrays of topographic and/or chemical nanostructures. Colloidal masks perform differently to traditional photoresist masks and local redeposition of material around the particle has significant impact on the resultant structures. The colloidal particles can be reshaped to allow the fabrication of flat-topped structures. Topographic and chemical nanostructures can be used to template the self assembly of macromolecules. The phase separation of thin films of PS-PMMA symmetric block copolymers above nanostructure sites is aligned at the surface nanostructure by topographic features. PLL-PEG assembly at alkanethiol-modified nanoscale chemical patterns of gold/silicon allows the production of nanoscale protein patterns. Patterns of ferritin 100 nm in diameter are demonstrated. (c) 2005 Published by Elsevier B.V.

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  • Large area protein nanopatterning for biological applications

    Agheli, H; Malmstrom Pendred, Jenny; Larsson, EM; Textor, M; Sutherland, DS (2006)

    Journal article
    The University of Auckland Library

    Large area nanopatterns of functional proteins are demonstrated. A new approach to analyze atomic force microscopy height histograms is used to quantify protein and antibody binding to nanoscale patches. Arrays of nanopatches, each containing less than 40 laminin molecules, are shown to be highly functional binding close to 1 monoclonal anti-laminin IgG (site by IKVAV sequence) or 3-4 polyclonal anti-laminin IgG's per surface bound laminin. Complementary quartz crystal microbalance measurements indicate higher functionality at nanopatches than on homogeneous surfaces.

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