Advanced Materials

Cover image for Vol. 21 Issue 4

January 26, 2009

Volume 21, Issue 4

Pages 379–494

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Report
    7. Communications
    8. Research News
    9. Index
    1. Nanostructured Materials: Microstructural and Biochemical Characterization of the Nanoporous Sucker Rings from Dosidicus gigas (Adv. Mater. 4/2009)

      Ali Miserez, James C. Weaver, Peter B. Pedersen, Todd Schneeberk, Roger T. Hanlon, David Kisailus and Henrik Birkedal

      Article first published online: 14 JAN 2009 | DOI: 10.1002/adma.200990009

      Thumbnail image of graphical abstract

      The cover image shows an SEM image of a squid tentacle, revealing the individual sucker rings. These toothed ringlike structures within the suckers provide additional gripping power during prey capture and handling. The background image depicts the nanoscale network of parallel tubular elements from which the rings are constructed. The structural, mechanical and biochemical properties of this wholly organic material is discussed in detail by David Kisailus, Henrik Birkedal, and co-workers on p. 401.

  2. Inside Front Cover

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Report
    7. Communications
    8. Research News
    9. Index
    1. Biological Materials: Mechanical Function of a Complex Three-Dimensional Suture Joining the Bony Elements in the Shell of the Red-Eared Slider Turtle (Adv. Mater. 4/2009)

      Stefanie Krauss, Efrat Monsonego-Ornan, Elazar Zelzer, Peter Fratzl and Ron Shahar

      Article first published online: 14 JAN 2009 | DOI: 10.1002/adma.200990010

      Thumbnail image of graphical abstract

      The shell of a turtle is required to be a shield that is stiff at high loads, but must provide sufficient flexibility for respiration and locomotion at smaller loads. On p. 407, Peter Fratzl and co-workers show that these seemingly contradictory requirements are met by a self-locking material, whereby stiff bony elements are connected by a much softer suture with a complex three-dimensional shape.

  3. Contents

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Report
    7. Communications
    8. Research News
    9. Index
  4. Editorial

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Report
    7. Communications
    8. Research News
    9. Index
    1. You have free access to this content
      Biological and Biomimetic Materials (pages 387–388)

      Joanna Aizenberg and Peter Fratzl

      Article first published online: 14 JAN 2009 | DOI: 10.1002/adma.200803699

  5. Progress Report

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Report
    7. Communications
    8. Research News
    9. Index
    1. Influence of Structural Principles on the Mechanics of a Biological Fiber-Based Composite Material with Hierarchical Organization: The Exoskeleton of the Lobster Homarus americanus (pages 391–400)

      Helge-Otto Fabritius, Christoph Sachs, Patricia Romano Triguero and Dierk Raabe

      Article first published online: 14 JAN 2009 | DOI: 10.1002/adma.200801219

      Thumbnail image of graphical abstract

      The exoskeleton of the arthropod Homarus americanus is a hierarchically organized nanocomposite material consisting of a chitin-fiber matrix associated with proteins and various amounts of nanoscopic biominerals. We show that the combination of two design principles in this material - twisted plywood and honeycomb - results in remarkable macroscopic mechanical properties, which are highly variable depending on factors like hydration and mineral content.

  6. Communications

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Report
    7. Communications
    8. Research News
    9. Index
    1. Microstructural and Biochemical Characterization of the Nanoporous Sucker Rings from Dosidicus gigas (pages 401–406)

      Ali Miserez, James C. Weaver, Peter B. Pedersen, Todd Schneeberk, Roger T. Hanlon, David Kisailus and Henrik Birkedal

      Article first published online: 7 JAN 2009 | DOI: 10.1002/adma.200801197

      Thumbnail image of graphical abstract

      The individual toothed sucker rings of squid tentacles (highlighted in blue) provide additional gripping power during prey capture and handling. These rings comprise a nanoscale network of parallel tubular elements, as shown in the background image. The structural, mechanical, and biochemical properties of this wholly organic material are discussed in detail.

    2. Mechanical Function of a Complex Three-Dimensional Suture Joining the Bony Elements in the Shell of the Red-Eared Slider Turtle (pages 407–412)

      Stefanie Krauss, Efrat Monsonego-Ornan, Elazar Zelzer, Peter Fratzl and Ron Shahar

      Article first published online: 16 DEC 2008 | DOI: 10.1002/adma.200801256

      Thumbnail image of graphical abstract

      The shell of turtles is a shield which needs to be stiff at high loads but should provide sufficient flexibility for respiration and locomotion at smaller loads. We show that this seemingly contradictory requirement is met by a self-locking material, whereby stiff bony elements are connected by a much softer suture with a complex three-dimensional shape.

    3. Design Strategy of Minipig Molars Using Electronic Speckle Pattern Interferometry: Comparison of Deformation under Load between the Tooth-Mandible Complex and the Isolated Tooth (pages 413–418)

      Netta Lev-Tov Chattah, Ron Shahar and Steve Weiner

      Article first published online: 30 SEP 2008 | DOI: 10.1002/adma.200801187

      Thumbnail image of graphical abstract

      Using electronic speckle pattern interferometry minipig molars were tested under load inside the bone socket and when embedded in a stiff polymer. It is demonstrated that the molar bends in the direction of the load in both configurations even at low loads. This shows that the intrinsic reaction of the tooth crown to load is complemented by the structures supporting the tooth.

    4. Size-Dependent Endocytosis of Nanoparticles (pages 419–424)

      Sulin Zhang, Ju Li, George Lykotrafitis, Gang Bao and Subra Suresh

      Article first published online: 18 NOV 2008 | DOI: 10.1002/adma.200801393

      Thumbnail image of graphical abstract

      The cellular uptake of nanoparticles by living cells is predicted to be strongly size-dependent, according the thermodynamic analysis, and an optimal particle radius of ∼ 25–30 nm at which the cellular uptake reaches a maximum of several thousand is shown to exist. The theoretical prediction provides valuable guidance for the rational design of nanoparticle-based drug-delivery systems.

    5. Enzyme Directed Templating of Artificial Bone Mineral (pages 425–430)

      Erik D. Spoerke, Shawn G. Anthony and Samuel I. Stupp

      Article first published online: 14 JAN 2009 | DOI: 10.1002/adma.200802242

      Thumbnail image of graphical abstract

      An artificial, in vitro biomineralization process that utilizes a nanofiber gel to as a substrate for biomimetic hydroxyapatite mineralization in three dimensions is presented. The system employs the natural enzyme alkaline phosphatase and a phosphorylated, anionic nanofiber gel matrix to template hydroxyapatite nanocrystals with size, shape, and crystallographic orientation resembling natural bone mineral.

    6. Facile Conjugation of Biomolecules onto Surfaces via Mussel Adhesive Protein Inspired Coatings (pages 431–434)

      Haeshin Lee, Junsung Rho and Phillip B. Messersmith

      Article first published online: 25 NOV 2008 | DOI: 10.1002/adma.200801222

      Thumbnail image of graphical abstract

      A new surface bioconjugation strategy is presented. A polydopamine surface coating provides chemical activation on material surfaces, is resistant to hydrolysis, and offers selectivity in coupling of biomolecules via nucleophilic groups through simple pH control. Control of orientation of immobilized biomolecules may be possible using terminally modified DNA or His-containing proteins.

    7. The Multiple Roles of Additives in CaCO3 Crystallization: A Quantitative Case Study (pages 435–439)

      Denis Gebauer, Helmut Cölfen, Andreas Verch and Markus Antonietti

      Article first published online: 23 DEC 2008 | DOI: 10.1002/adma.200801614

      Thumbnail image of graphical abstract

      To date, the knowledge of the multiple roles of additives in calcium carbonate crystallization results from empirical control of crystal growth. We present a crystallization assay generating controlled supersaturation, which allows the categorization of different modes of additive action. This facilitates a novel understanding of the action of crystallization additives.

    8. How Nature Modulates a Fiber's Mechanical Properties: Mechanically Distinct Fibers Drawn from Natural Mesogenic Block Copolymer Variants (pages 440–444)

      Matthew J. Harrington and J. Herbert Waite

      Article first published online: 18 NOV 2008 | DOI: 10.1002/adma.200801072

      Thumbnail image of graphical abstract

      Mussel byssal threads are functionally graded biological fibers adapted for tethering the soft tissue of the organism (∼1 MPa) to hard surfaces !(25 GPa) in the rocky seashore. A stiffness gradient mitigates contact deformation and is defined by an incrementally regulated distribution of two protein block copolymer variants with stiff and pliable domains, respectively.

    9. Shaped Films of Ionotropic Hydrogels Fabricated Using Templates of Patterned Paper (pages 445–450)

      Paul J. Bracher, Malancha Gupta and George M. Whitesides

      Article first published online: 18 NOV 2008 | DOI: 10.1002/adma.200801186

      Thumbnail image of graphical abstract

      Patterned paper wet with multivalent cations can template the production of films of ionotropic hydrogels in topologically complex shapes such as Möbius strips and interlocking rings (see figure). The films have lateral dimensions as low as 2mm, and range in thickness from 0.2 to 1.3mm. The films are magnetically responsive when cross-linked by Ho3+ or Gd3+.

    10. The Effect of NaF In Vitro on the Mechanical and Material Properties of Trabecular and Cortical Bone (pages 451–457)

      Philipp J. Thurner, Blake Erickson, Patricia Turner, Ralf Jungmann, Jason Lelujian, Alexander Proctor, James C. Weaver, Georg Schitter, Daniel E. Morse and Paul K. Hansma

      Article first published online: 25 NOV 2008 | DOI: 10.1002/adma.200801204

      Thumbnail image of graphical abstract

      High doses of sodium fluoride in bones lead to severe softening, by weakening interfacial properties between the inorganic minerals and the organic components, while leaving mineralization unchanged. This leads to reduction of microdamage and associated stress-whitening pointing to a change in failure mode. Accordingly, elastic modulus, failure stress, and indentation-distance increase are decreased, whereas failure strain is increased.

    11. Intracellular Distribution of Macrophage Targeting Ferritin–Iron Oxide Nanocomposite (pages 458–462)

      Masaki Uchida, Deborah A. Willits, Karin Muller, Ann F. Willis, Larissa Jackiw, Mark Jutila, Mark J. Young, Alexandra E. Porter and Trevor Douglas

      Article first published online: 18 NOV 2008 | DOI: 10.1002/adma.200801209

      Thumbnail image of graphical abstract

      Intracellular distribution of iron oxide nanoparticles incorporated within a ferritin mutant that displays genetically introduced cell-targeted peptides (RGD-4C) on its exterior surface are investigated using scanning transmission electron microscopy with a high-angle annular dark-field detector. The particles (indicated by arrows) internalized into macrophages much more effectively than those with noncell-targeted ferritin.

    12. Fabrication of Bioinspired Actuated Nanostructures with Arbitrary Geometry and Stiffness (pages 463–469)

      Boaz Pokroy, Alexander K. Epstein, Maria C. M. Persson-Gulda and Joanna Aizenberg

      Article first published online: 18 NOV 2008 | DOI: 10.1002/adma.200801432

      Thumbnail image of graphical abstract

      Bio-inspired, multifunctional, high-aspect-ratio nanostructured surfaces are fabricated in a variety of materials with controlled geometry and stiffness. A soft-lithography method that allows the one-to-one replication of nanostructures and renders it possible to produce arbitrary nanostructures with cross-sectional shapes, orientations, and 2D lattices that are different from the original master is presented. The actuation of the posts is demonstrated.

    13. Calcite Growth in Hydrogels: Assessing the Mechanism of Polymer-Network Incorporation into Single Crystals (pages 470–473)

      Hanying Li and Lara A. Estroff

      Article first published online: 18 NOV 2008 | DOI: 10.1002/adma.200801498

      Thumbnail image of graphical abstract

      Calcite crystals grown in agarose hydrogels incorporate the gel network while retaining their single-crystal nature. The amount of gel network that is incorporated is determined by two competing factors: crystallization pressure promotes the exclusion of the gel network, while faster growth rates favor its incorporation.

    14. Syntheses of Porous Self-Supporting Metal-Nanoparticle Assemblies with 3D Morphologies Inherited from Biosilica Templates (Diatom Frustules) (pages 474–478)

      Zhihao Bao, Eric M. Ernst, Sehoon Yoo and Kenneth H. Sandhage

      Article first published online: 15 DEC 2008 | DOI: 10.1002/adma.200801499

      Thumbnail image of graphical abstract

      Porous 3D metal-nanoparticle assemblies with selectable morphologies are synthesized. Biosilica templates (diatom frustules) are first converted into silicon replicas via magnesiothermic reduction. Electroless metal deposition, followed by silicon dissolution, then yields metal-nanoparticle assemblies with the 3D template morphology (figure reveals a silver assembly; inset images reveal internal features after partial ion milling and EDX analysis).

    15. Hierarchical Gecko-Like Adhesives (pages 479–482)

      Christian Greiner, Eduard Arzt and Aránzazu del Campo

      Article first published online: 14 NOV 2008 | DOI: 10.1002/adma.200801548

      Thumbnail image of graphical abstract

      The role of hierarchy in gecko-like adhesive surfaces is presented. Experiments on two-level structured surfaces with micropillars of different dimensions demonstrate that hierarchy does not seem to positively influence adhesion of structured surfaces to planar substrates, but may be relevant when stiff materials or rough substrates come into play, where adaptability of the adhesive structure is required for successful contact.

    16. Hexagonal Surface Micropattern for Dry and Wet Friction (pages 483–486)

      Michael Varenberg and Stanislav N. Gorb

      Article first published online: 30 DEC 2008 | DOI: 10.1002/adma.200802734

      Thumbnail image of graphical abstract

      Hexagonal micropattern mimicking the attachment pads of bush crickets is reported to control dry and wet elastomer friction. This micropattern eliminates completely the stick–slip disturbances when in dry conditions, and prevents hydroplaning when in wet conditions, rendering the surface behavior stable and predictable.

  7. Research News

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Report
    7. Communications
    8. Research News
    9. Index
    1. Silk as a Biomimetic Ideal for Structural Polymers (pages 487–492)

      David Porter and Fritz Vollrath

      Article first published online: 7 JAN 2009 | DOI: 10.1002/adma.200801332

      Thumbnail image of graphical abstract

      Two factors are critical for understanding silks: the nanoscale semicrystalline folding structure, which gives high strength and toughness, and the degree of hydration of the disordered fraction, which modifies these material properties. The combination of these two factors allows for a massive range of mechanical properties. Understanding and controlling these two factors are the key to the functionality of protein elastomers.

  8. Index

    1. Top of page
    2. Cover Picture
    3. Inside Front Cover
    4. Contents
    5. Editorial
    6. Progress Report
    7. Communications
    8. Research News
    9. Index

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