Spider silk morphology for responsive materials

2013 ◽  
Vol 1498 ◽  
pp. 197-202
Author(s):  
Juan Guan ◽  
David Porter ◽  
Fritz Vollrath
Keyword(s):  
Shape Memory ◽  
Spider Silk ◽  
Morphological Changes ◽  
Synthetic Polymers ◽  
Structural Components ◽  
Oriented Polymers ◽  
Primary Amino Acid Sequence ◽  
Responsive Materials ◽  
Primary Amino ◽  
Spider Silks

ABSTRACTThis study reveals that an “old” mechanism for shape memory in oriented polymers is in fact just one separate contribution for “supercontraction” in Nephila spider major ampulate silks. When Nephila spider silks are in contact with liquid water, they “super”-contract up to 28% of the original stretched length. However, we discovered that under glass transition conditions these silks only relax with a maximum shrinkage of 13%, and this phenomenon is defined as Tg-contraction. Structural components permanent order (PO), permanent disorder (PD), meta order (MO) and meta disorder (MD) were proposed from the primary amino-acid sequence of the silk protein to explain morphological changes in the two contraction phenomena: MD contributes 13% of the full supercontraction and contributes to Tg-contraction; whereas MO (the proline-containing motifs) contributes the rest for the full super-contraction and does not contribute to Tg-contraction. The morphology in Nephila spider silk structure suggests two separate mechanisms to generate the shape memory effect in synthetic polymers.

scholarly journals Shape memory polymer network with thermally distinct elasticity and plasticity

2016 ◽  
Vol 2 (1) ◽  
pp. e1501297 ◽  
Author(s):  
Qian Zhao ◽  
Weike Zou ◽  
Yingwu Luo ◽  
Tao Xie
Keyword(s):  
Shape Memory ◽  
Molecular Design ◽  
Shape Change ◽  
Shape Memory Polymer ◽  
Polymer Network ◽  
Stimuli Responsive ◽  
Responsive Materials ◽  
Device Applications ◽  
Temperature Ranges ◽  
Rational Molecular Design

Stimuli-responsive materials with sophisticated yet controllable shape-changing behaviors are highly desirable for real-world device applications. Among various shape-changing materials, the elastic nature of shape memory polymers allows fixation of temporary shapes that can recover on demand, whereas polymers with exchangeable bonds can undergo permanent shape change via plasticity. We integrate the elasticity and plasticity into a single polymer network. Rational molecular design allows these two opposite behaviors to be realized at different temperature ranges without any overlap. By exploring the cumulative nature of the plasticity, we demonstrate easy manipulation of highly complex shapes that is otherwise extremely challenging. The dynamic shape-changing behavior paves a new way for fabricating geometrically complex multifunctional devices.

Poly(amide–ether) Thermoplastic Elastomers Based on Monodisperse Aromatic Amide Hard Segments as Shape-Memory and Moisture-Responsive Materials

2018 ◽  
Vol 51 (23) ◽  
pp. 9430-9441 ◽  
Author(s):  
Yuji Shibasaki ◽  
Toshiki Mori ◽  
Atsuhiro Fujimori ◽  
Mitsutoshi Jikei ◽  
Hideo Sawada ◽  
...  
Keyword(s):  
Shape Memory ◽  
Thermoplastic Elastomers ◽  
Responsive Materials ◽  
Aromatic Amide ◽  
Hard Segments

scholarly journals Hierarchical spidroin micellar nanoparticles as the fundamental precursors of spider silks

2018 ◽  
Vol 115 (45) ◽  
pp. 11507-11512 ◽  
Author(s):  
Lucas R. Parent ◽  
David Onofrei ◽  
Dian Xu ◽  
Dillan Stengel ◽  
John D. Roehling ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Spider Silk ◽  
Fiber Spinning ◽  
Fiber Formation ◽  
Natural Material ◽  
Physical Form ◽  
Spinning Process ◽  
Black Widow Spiders ◽  
Spider Silks

Many natural silks produced by spiders and insects are unique materials in their exceptional toughness and tensile strength, while being lightweight and biodegradable–properties that are currently unparalleled in synthetic materials. Myriad approaches have been attempted to prepare artificial silks from recombinant spider silk spidroins but have each failed to achieve the advantageous properties of the natural material. This is because of an incomplete understanding of the in vivo spidroin-to-fiber spinning process and, particularly, because of a lack of knowledge of the true morphological nature of spidroin nanostructures in the precursor dope solution and the mechanisms by which these nanostructures transform into micrometer-scale silk fibers. Herein we determine the physical form of the natural spidroin precursor nanostructures stored within spider glands that seed the formation of their silks and reveal the fundamental structural transformations that occur during the initial stages of extrusion en route to fiber formation. Using a combination of solution phase diffusion NMR and cryogenic transmission electron microscopy (cryo-TEM), we reveal direct evidence that the concentrated spidroin proteins are stored in the silk glands of black widow spiders as complex, hierarchical nanoassemblies (∼300 nm diameter) that are composed of micellar subdomains, substructures that themselves are engaged in the initial nanoscale transformations that occur in response to shear. We find that the established micelle theory of silk fiber precursor storage is incomplete and that the first steps toward liquid crystalline organization during silk spinning involve the fibrillization of nanoscale hierarchical micelle subdomains.

scholarly journals Intracellular Retention of the Corticotrophin-releasing Hormone (CRH) Precursor Within COS-7 Cells

1998 ◽  
Vol 46 (10) ◽  
pp. 1193-1197 ◽  
Author(s):  
Marcelo J. Perone ◽  
Simon Windeatt ◽  
Ewan Morrison ◽  
Andy Shering ◽  
Peter Tomasec ◽  
...  
Keyword(s):  
Amino Acid ◽  
Golgi Apparatus ◽  
Amino Acid Sequence ◽  
Protein Secretion ◽  
Intracellular Trafficking ◽  
Secretory Pathway ◽  
Intracellular Localization ◽  
Primary Amino Acid Sequence ◽  
Releasing Hormone ◽  
Primary Amino

We investigated the intracellular localization of CRH in transiently transfected COS-7 cells expressing the full-length rat corticotropin-releasing hormone (CRH) precursor cDNA. CRH synthesized by transfected COS-7 cells is mainly stored intracellularly. In contrast, CHO-K1 cells expressing the same CRH precursor stored and released equal amounts of immunoreactive (IR)-CRH. Ultrastructural analysis revealed that CRH is stored in electron-dense aggregates in the RER of transiently transfected COS-7 cells and does not migrate into the Golgi apparatus. On the basis of the different intracellular localization, storage, and release of CRH in COS-7 and CHO-K1 cells, we hypothesize that the intracellular trafficking of CRH within the constitutive secretory pathway for protein secretion not only depends on its primary amino acid sequence but might also be influenced by intracellular conditions or factors.

Hierarchical fibers for water collection inspired by spider silk

Nanoscale ◽  
2019 ◽  
Vol 11 (33) ◽  
pp. 15448-15463 ◽  
Author(s):  
Wei Chen ◽  
Zhiguang Guo
Keyword(s):  
Spider Silk ◽  
Effective Strategy ◽  
Water Collection ◽  
Spider Silks

The “wet-rebuilt” process of spider silk is considered an effective strategy for water collection. In this review, we give an advanced perspective on the fabrication and water-collection mechanisms from natural spider silks to functional fibers.

Artificial spider silk is smart like natural one: having humidity-sensitive shape memory with superior recovery stress

2019 ◽  
Vol 3 (11) ◽  
pp. 2472-2482 ◽  
Author(s):  
Harun Venkatesan ◽  
Jianming Chen ◽  
Haiyang Liu ◽  
Yoonjung Kim ◽  
Sungsoo Na ◽  
...  
Keyword(s):  
Shape Memory ◽  
Spider Silk ◽  
Recovery Stress ◽  
Dragline Silk ◽  
Spider Dragline Silk ◽  
Shape Memory Behaviour

Inspired by supercontraction, the recombinant spider dragline silk displayed humidity-responsive shape memory behaviour with impressive recovery stress.

scholarly journals Tensegrity Modelling and the High Toughness of Spider Dragline Silk

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1510
Author(s):  
Fernando Fraternali ◽  
Nicola Stehling ◽  
Ada Amendola ◽  
Bryan Andres Tiban Anrango ◽  
Chris Holland ◽  
...  
Keyword(s):  
Spider Silk ◽  
Low Voltage ◽  
Microstructural Characterization ◽  
Hierarchical Organization ◽  
Air Plasma ◽  
Poisson Effect ◽  
Dragline Silk ◽  
Spider Dragline Silk ◽  
A Chain ◽  
Spider Silks

This work establishes a tensegrity model of spider dragline silk. Tensegrity systems are ubiquitous in nature, being able to capture the mechanics of biological shapes through simple and effective modes of deformation via extension and contraction. Guided by quantitative microstructural characterization via air plasma etching and low voltage scanning electron microscopy, we report that this model is able to capture experimentally observed phenomena such as the Poisson effect, tensile stress-strain response, and fibre toughness. This is achieved by accounting for spider silks’ hierarchical organization into microfibrils with radially variable properties. Each fibril is described as a chain of polypeptide tensegrity units formed by crystalline granules operating under compression, which are connected to each other by amorphous links acting under tension. Our results demonstrate, for the first time, that a radial variability in the ductility of tensegrity chains is responsible for high fibre toughness, a defining and desirable feature of spider silk. Based on this model, a discussion about the use of graded tensegrity structures for the optimal design of next-generation biomimetic fibres is presented.

scholarly journals Amino acid sequence and the cellular location of the Na+-dependent d-glucose symporters (SGLT1) in the ovine enterocyte and the parotid acinar cell

1995 ◽  
Vol 312 (1) ◽  
pp. 293-300 ◽  
Author(s):  
P S Tarpey ◽  
I S Wood ◽  
S P Shirazi-Beechey ◽  
R B Beechey
Keyword(s):  
Plasma Membrane ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Amino Acid Sequences ◽  
Primary Amino Acid Sequence ◽  
Parotid Acinar Cells ◽  
Parotid Acinar Cell ◽  
Primary Amino

The Na(+)-dependent D-glucose symporter has been shown to be located on the basolateral domain of the plasma membrane of ovine parotid acinar cells. This is in contrast to the apical location of this transporter in the ovine enterocyte. The amino acid sequences of these two proteins have been determined. They are identical. The results indicated that the signals responsible for the differential targeting of these two proteins to the apical and the basal domains of the plasma membrane are not contained within the primary amino acid sequence.

Morphological characteristic and assessment of changesin the main structural components of the histohematological barrier of the thyroid tissue in cases of the sudden cardiac death from alcoholic cardiomyopathy

2017 ◽  
Vol 8 (5) ◽  
pp. 30-34
Author(s):  
Olga V. Sokolova ◽  
Orazmurad D. Yagmurov ◽  
Ruslan A. Nasyrov
Keyword(s):  
Sudden Cardiac Death ◽  
Thyroid Gland ◽  
Cardiac Death ◽  
Morphological Changes ◽  
Cytotoxic Action ◽  
Structural Components ◽  
Alcoholic Cardiomyopathy ◽  
Endothelial Lining ◽  
Gland Tissue ◽  
Thyroid Gland Tissue

A retrospective analysis of acts of forensic medical autopsies from the archive of St. Petersburg GBUS BSME and a histological study of thyroid gland tissue in 188 cases (95 women and 93 men) were carried out with statistical processing of the obtained results for the purpose of studying and assessing the morphological changes in the main components of the histohematological barrier of thyroid gland tissue in cases of the sudden cardiac death from alcoholic cardiomyopathy. The decrease in the weight of the thyroid gland in the investigated cases and the revealed morphological signs, indicative of a decrease in the memory function of the thyroid gland were found and can be caused by the prolonged toxic effect of ethanol and its metabolites. Morphological changes in the endothelial lining of the vessels of the microcirculatory bed are caused both by the direct cytotoxic action of ethanol and its metabolites and by the action of mediators, the release of which occurs as a result of stimulation of the reactive cells, which leads to swelling, deformation and increased activity of endothelial cell membranes with the expansion of intercellular spaces and the development of increased permeability of the endothelial lining, which, in its turn, contributes to disruption of electrolyte transport and nutrients transport with changes trophism thyroid gland tissue, which is a substrate for the appearance of dystrophic and necrobiotic processes in main structural components of the histogematogenous barrier of the thyroid gland. The revealed morphological changes in thyroid gland tissue in cases of death from alcoholic cardiomyopathy have a non-specific nature and should be considered in conjunction with other visceral manifestations that are a reflection of alcohol intoxication during the chronic alcoholism.

scholarly journals Investigating the transverse optical structure of spider silk micro-fibers using quantitative optical microscopy

Nanophotonics ◽  
2017 ◽  
Vol 6 (1) ◽  
pp. 341-348 ◽  
Author(s):  
Douglas J. Little ◽  
Deb M. Kane
Keyword(s):  
Refractive Index ◽  
Electromagnetic Scattering ◽  
Spider Silk ◽  
Transverse Optical ◽  
Graded Index ◽  
Argiope Keyserlingi ◽  
Wavelength Scale ◽  
Index Contrast ◽  
Spider Silks ◽  
Optical Structure

AbstractThe transverse optical structure of two orb-weaver (family Araneidae) spider dragline silks was investigated using a variant of the inverse-scattering technique. Immersing the silks in a closely refractive index-matched liquid, the minimum achievable image contrast was greater than expected for an optically homogeneous silk, given what is currently known about the optical absorption of these silks. This “excess contrast” indicated the presence of transverse optical structure within the spider silk. Applying electromagnetic scattering theory to a transparent double cylinder, the minimum achievable irradiance contrast for the Plebs eburnus and Argiope keyserlingi dragline silks was determined to be consistent with step index refractive index contrasts of 1−4×10−4 and 6–7×10−4, respectively, supposing outer-layer thicknesses consistent with previous TEM studies (50 nm and 100 nm, respectively). The possibility of graded index refractive index contrasts within the spider silks is also discussed. This is the strongest evidence, to date, that there is a refractive index contrast associated with the layered morphology of spider silks and/or variation of proportion of nanocrystalline components within the spider silk structure. The method is more generally applicable to optical micro-fibers, including those with refractive index variations on a sub-wavelength scale.

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