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He W, Wang M, Mei G, Liu S, Khan AQ, Li C, Feng D, Su Z, Bao L, Wang G, Liu E, Zhu Y, Bai J, Zhu M, Zhou X, Liu Z. Establishing superfine nanofibrils for robust polyelectrolyte artificial spider silk and powerful artificial muscles. Nat Commun 2024; 15:3485. [PMID: 38664427 PMCID: PMC11045855 DOI: 10.1038/s41467-024-47796-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
Spider silk exhibits an excellent combination of high strength and toughness, which originates from the hierarchical self-assembled structure of spidroin during fiber spinning. In this work, superfine nanofibrils are established in polyelectrolyte artificial spider silk by optimizing the flexibility of polymer chains, which exhibits combination of breaking strength and toughness ranging from 1.83 GPa and 238 MJ m-3 to 0.53 GPa and 700 MJ m-3, respectively. This is achieved by introducing ions to control the dissociation of polymer chains and evaporation-induced self-assembly under external stress. In addition, the artificial spider silk possesses thermally-driven supercontraction ability. This work provides inspiration for the design of high-performance fiber materials.
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Grants
- This work was supported by the National Key Research and Development Program of China (Grants Nos. 2022YFB3807103, 2022YFA1203304, and 2019YFE0119600, Z.F.L.), the National Natural Science Foundation of China (grants 52350120, 52090034, 52225306, 51973093, and 51773094, Z.F.L.), Frontiers Science Center for Table Organic Matter, Nankai University (grant number 63181206. Z.F.L.), the Fundamental Research Funds for the Central Universities (grant 63171219. Z.F.L.), Lingyu Grant (2021-JCJQ-JJ-1064, Z.L.F.).
- the National Natural Science Foundation of China (grant 22371300, X.Z.)
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Affiliation(s)
- Wenqian He
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials, Tianjin Key Laboratory of Functional Polymer Materials, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Meilin Wang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials, Tianjin Key Laboratory of Functional Polymer Materials, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Guangkai Mei
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials, Tianjin Key Laboratory of Functional Polymer Materials, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Shiyong Liu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials, Tianjin Key Laboratory of Functional Polymer Materials, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Abdul Qadeer Khan
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials, Tianjin Key Laboratory of Functional Polymer Materials, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Chao Li
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials, Tianjin Key Laboratory of Functional Polymer Materials, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Danyang Feng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials, Tianjin Key Laboratory of Functional Polymer Materials, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Zihao Su
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials, Tianjin Key Laboratory of Functional Polymer Materials, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Lili Bao
- Department of Science, China Pharmaceutical University, Nanjing, 211198, China
| | - Ge Wang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials, Tianjin Key Laboratory of Functional Polymer Materials, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Enzhao Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular disease, Department of Cardiology, Tianjin Institute of Cardiology, The Second Hospital of Tianjin Medical University, Tianjin, 300211, China
| | - Yutian Zhu
- College of Materials, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 311121, China
| | - Jie Bai
- Chemical Engineering College, Inner Mongolia University of Technology, Hohhot, 010051, China
| | - Meifang Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China.
| | - Xiang Zhou
- Department of Science, China Pharmaceutical University, Nanjing, 211198, China.
| | - Zunfeng Liu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials, Tianjin Key Laboratory of Functional Polymer Materials, College of Chemistry, Nankai University, Tianjin, 300071, China.
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Wu SD, Chuang WT, Ho JC, Wu HC, Hsu SH. Self-Healing of Recombinant Spider Silk Gel and Coating. Polymers (Basel) 2023; 15:polym15081855. [PMID: 37112001 PMCID: PMC10141599 DOI: 10.3390/polym15081855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 04/08/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
Self-healing properties, originating from the natural healing process, are highly desirable for the fitness-enhancing functionality of biomimetic materials. Herein, we fabricated the biomimetic recombinant spider silk by genetic engineering, in which Escherichia coli (E. coli) was employed as a heterologous expression host. The self-assembled recombinant spider silk hydrogel was obtained through the dialysis process (purity > 85%). The recombinant spider silk hydrogel with a storage modulus of ~250 Pa demonstrated autonomous self-healing and high strain-sensitive properties (critical strain ~50%) at 25 °C. The in situ small-angle X-ray scattering (in situ SAXS) analyses revealed that the self-healing mechanism was associated with the stick-slip behavior of the β-sheet nanocrystals (each of ~2-4 nm) based on the slope variation (i.e., ~-0.4 at 100%/200% strains, and ~-0.9 at 1% strain) of SAXS curves in the high q-range. The self-healing phenomenon may occur through the rupture and reformation of the reversible hydrogen bonding within the β-sheet nanocrystals. Furthermore, the recombinant spider silk as a dry coating material demonstrated self-healing under humidity as well as cell affinity. The electrical conductivity of the dry silk coating was ~0.4 mS/m. Neural stem cells (NSCs) proliferated on the coated surface and showed a 2.3-fold number expansion after 3 days of culture. The biomimetic self-healing recombinant spider silk gel and thinly coated surface may have good potential in biomedical applications.
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Affiliation(s)
- Shin-Da Wu
- Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Wei-Tsung Chuang
- National Synchrotron Radiation Research Center (NSRRC), Hsinchu 30076, Taiwan
| | - Jo-Chen Ho
- Department of Biochemical Science and Technology, National Taiwan University, Taipei 10617, Taiwan
| | - Hsuan-Chen Wu
- Department of Biochemical Science and Technology, National Taiwan University, Taipei 10617, Taiwan
| | - Shan-Hui Hsu
- Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan
- Institute of Cellular and System Medicine, National Health Research Institutes, Miaoli 350, Taiwan
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Miserez A, Yu J, Mohammadi P. Protein-Based Biological Materials: Molecular Design and Artificial Production. Chem Rev 2023; 123:2049-2111. [PMID: 36692900 PMCID: PMC9999432 DOI: 10.1021/acs.chemrev.2c00621] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Polymeric materials produced from fossil fuels have been intimately linked to the development of industrial activities in the 20th century and, consequently, to the transformation of our way of living. While this has brought many benefits, the fabrication and disposal of these materials is bringing enormous sustainable challenges. Thus, materials that are produced in a more sustainable fashion and whose degradation products are harmless to the environment are urgently needed. Natural biopolymers─which can compete with and sometimes surpass the performance of synthetic polymers─provide a great source of inspiration. They are made of natural chemicals, under benign environmental conditions, and their degradation products are harmless. Before these materials can be synthetically replicated, it is essential to elucidate their chemical design and biofabrication. For protein-based materials, this means obtaining the complete sequences of the proteinaceous building blocks, a task that historically took decades of research. Thus, we start this review with a historical perspective on early efforts to obtain the primary sequences of load-bearing proteins, followed by the latest developments in sequencing and proteomic technologies that have greatly accelerated sequencing of extracellular proteins. Next, four main classes of protein materials are presented, namely fibrous materials, bioelastomers exhibiting high reversible deformability, hard bulk materials, and biological adhesives. In each class, we focus on the design at the primary and secondary structure levels and discuss their interplays with the mechanical response. We finally discuss earlier and the latest research to artificially produce protein-based materials using biotechnology and synthetic biology, including current developments by start-up companies to scale-up the production of proteinaceous materials in an economically viable manner.
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Affiliation(s)
- Ali Miserez
- Center for Sustainable Materials (SusMat), School of Materials Science and Engineering, Nanyang Technological University (NTU), Singapore637553.,School of Biological Sciences, NTU, Singapore637551
| | - Jing Yu
- Center for Sustainable Materials (SusMat), School of Materials Science and Engineering, Nanyang Technological University (NTU), Singapore637553.,Institute for Digital Molecular Analytics and Science (IDMxS), NTU, 50 Nanyang Avenue, Singapore637553
| | - Pezhman Mohammadi
- VTT Technical Research Centre of Finland Ltd., Espoo, UusimaaFI-02044, Finland
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4
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Mohtar JA, Shahimin MFM. Laboratory breeding and rearing of cellar spider, Crossopriza lyoni Blackwall. Dev Genes Evol 2022; 232:125-136. [PMID: 36190549 DOI: 10.1007/s00427-022-00697-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 09/20/2022] [Indexed: 01/30/2023]
Abstract
Spiders have emerged as one of the leading model organisms in many research fields due to their compelling biology. Often, scientific investigations involving the use of spiders face inevitable problems associated with the lack of specimens from laboratory stock, resulting in difficulties in yielding reproducible investigations for predictive research. Thus, several species of well-studied spiders, including Parasteatoda tepidariorum, have been successfully bred for such purposes. Crossopriza lyoni is a Haplogyne spider, globally distributed and widespread in human inhabitants, prompting interest in various studies over the last decades. Despite its scientific importance, no laboratory-bred C. lyoni has been documented. Therefore, we describe a successful captive breeding system of the species under controlled conditions to establish a laboratory stock culture. Methods for mating induction, egg collection and segregation, artificial embryo incubation, and colony husbandry are discussed. The technique presented is a simple and low-cost approach that is reliable for C. lyoni propagation in the laboratory over several generations.
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Affiliation(s)
- Johan Ariff Mohtar
- Faculty of Chemical Engineering Technology, Universiti Malaysia Perlis, 02100, Padang Besar, Perlis, Malaysia.
| | - Mohd Faidz Mohamad Shahimin
- Faculty of Chemical Engineering Technology, Universiti Malaysia Perlis, 02100, Padang Besar, Perlis, Malaysia
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Zhang Y, Zhang C, Wang R, Tan W, Gu Y, Yu X, Zhu L, Liu L. Development and challenges of smart actuators based on water-responsive materials. SOFT MATTER 2022; 18:5725-5741. [PMID: 35904079 DOI: 10.1039/d2sm00519k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Water-responsive (WR) materials, due to their controllable mechanical response to humidity without energy actuation, have attracted lots of attention to the development of smart actuators. WR material-based smart actuators can transform natural humidity to a required mechanical motion and have been widely used in various fields, such as soft robots, micro-generators, smart building materials, and textiles. In this paper, the development of smart actuators based on different WR materials has been reviewed systematically. First, the properties of different biological WR materials and the corresponding actuators are summarized, including plant materials, animal materials, and microorganism materials. Additionally, various synthetic WR materials and their related applications in smart actuators have also been introduced in detail, including hydrophilic polymers, graphene oxide, carbon nanotubes, and other synthetic materials. Finally, the challenges of the WR actuator are analyzed from the three perspectives of actuator design, control methods, and compatibility, and the potential solutions are also discussed. This paper may be useful for the development of not only soft actuators that are based on WR materials, but also smart materials applied to renewable energy.
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Affiliation(s)
- Yiwei Zhang
- School of Automation and Electrical Engineering, Shenyang Ligong University, Shenyang 110159, Liaoning, China.
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, China.
- Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang 110169, China
| | - Chuang Zhang
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, China.
- Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang 110169, China
| | - Ruiqian Wang
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, China.
- Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang 110169, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenjun Tan
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, China.
- Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang 110169, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanyu Gu
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, China.
- Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang 110169, China
- School of Mechanical Engineering and Automation, Northeastern University, Shenyang, 110819, China
| | - Xiaobin Yu
- School of Automation and Electrical Engineering, Shenyang Ligong University, Shenyang 110159, Liaoning, China.
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, China.
- Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang 110169, China
| | - Lizhong Zhu
- School of Automation and Electrical Engineering, Shenyang Ligong University, Shenyang 110159, Liaoning, China.
| | - Lianqing Liu
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, China.
- Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang 110169, China
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6
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Nygaard MS, Jul MS, Debrabant B, Madsen GI, Qvist N, Ellebæk MB. Remote ischemic postconditioning has a detrimental effect and remote ischemic preconditioning seems to have no effect on small intestinal anastomotic strength. Scand J Gastroenterol 2022; 57:768-774. [PMID: 35196954 DOI: 10.1080/00365521.2022.2041715] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND The effect of remote pre- and postconditioning on anastomotic healing has been sparsely studied. The aim of our study was to investigate whether remote ischemic conditioning (RIC) applied before and after the creation of a small bowel anastomosis had an effect on anastomotic healing on postoperative day five evaluated by a tensile strength test and histological analysis. MATERIALS AND METHODS Twenty-two female piglets were randomized into two groups. The intervention group (n = 12) received RIC on the forelimbs consisting of 15 min of ischemia followed by 30 min of reperfusion before the first end-to-end ileal anastomosis was created. The RIC procedure was repeated and the second and more distal anastomosis was performed. The control group (n = 10) had two similar anastomoses with similar time intervals but without RIC. On postoperative day five, the anastomoses were subjected to macroscopic evaluation, tensile strength test and histological examination. RESULTS Mean tensile strength when the first transmural rupture appeared (MATS-2) was significantly lower in the first anastomosis in the intervention group compared to the control group (11.4 N vs 14.7 N, p < .05). Similar result was found by the maximal strength (MATS-3) as defined by a drop in the load curve (12.3 N vs 15.9 N, p < .05). Histologically, a significantly higher necrosis score was found in the anastomosis in the intervention group (1.4 vs 0.8, p < .05). No other significant differences were found. CONCLUSIONS In conclusion, post-anastomotic remote ischemic conditioning had a detrimental effect and pre-anastomotic conditioning seems to have no effect on small intestinal anastomotic strength.
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Affiliation(s)
- Mathilde Skov Nygaard
- Research Unit for Surgery, Odense University Hospital, Odense, Denmark; University of Southern Denmark, Odense, Denmark
| | - Mie Strandby Jul
- Research Unit for Surgery, Odense University Hospital, Odense, Denmark; University of Southern Denmark, Odense, Denmark
| | - Birgit Debrabant
- Department of Public Health, Epidemiology, Biostatistics and Biodemography, University of Southern Denmark, Odense C, Denmark
| | - Gunvor Iben Madsen
- Research Unit for Pathology, Odense University Hospital, Odense, Denmark; University oif Southern Denmark, Odense, Denmark
| | - Niels Qvist
- Research Unit for Surgery, Odense University Hospital, Odense, Denmark; University of Southern Denmark, Odense, Denmark
| | - Mark Bremholm Ellebæk
- Research Unit for Surgery, Odense University Hospital, Odense, Denmark; University of Southern Denmark, Odense, Denmark
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7
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Cohen N, Eisenbach CD. Humidity-Driven Supercontraction and Twist in Spider Silk. PHYSICAL REVIEW LETTERS 2022; 128:098101. [PMID: 35302814 DOI: 10.1103/physrevlett.128.098101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 01/05/2022] [Accepted: 02/09/2022] [Indexed: 06/14/2023]
Abstract
Spider silk is a protein material that exhibits extraordinary and nontrivial properties such as the ability to soften, decrease in length (i.e., supercontract), and twist upon exposure to high humidity. These behaviors stem from a unique microstructure in combination with a transition from glassy to rubbery as a result of humidity-driven diffusion of water. In this Letter we propose four length scales that govern the mechanical response of the silk during this transition. In addition, we develop a model that describes the microstructural evolution of the spider silk thread and explains the response due to the diffusion of water molecules. The merit of the model is demonstrated through an excellent agreement to experimental findings. The insights from this Letter can be used as a microstructural design guide to enable the development of new materials with unique spiderlike properties.
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Affiliation(s)
- Noy Cohen
- Department of Materials Science and Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Claus D Eisenbach
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, USA and Institute for Polymer Chemistry, University of Stuttgart, D-70569 Stuttgart, Germany
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8
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Li J, Li S, Huang J, Khan AQ, An B, Zhou X, Liu Z, Zhu M. Spider Silk-Inspired Artificial Fibers. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2103965. [PMID: 34927397 PMCID: PMC8844500 DOI: 10.1002/advs.202103965] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 11/19/2021] [Indexed: 05/14/2023]
Abstract
Spider silk is a natural polymeric fiber with high tensile strength, toughness, and has distinct thermal, optical, and biocompatible properties. The mechanical properties of spider silk are ascribed to its hierarchical structure, including primary and secondary structures of the spidroins (spider silk proteins), the nanofibril, the "core-shell", and the "nano-fishnet" structures. In addition, spider silk also exhibits remarkable properties regarding humidity/water response, water collection, light transmission, thermal conductance, and shape-memory effect. This motivates researchers to prepare artificial functional fibers mimicking spider silk. In this review, the authors summarize the study of the structure and properties of natural spider silk, and the biomimetic preparation of artificial fibers from different types of molecules and polymers by taking some examples of artificial fibers exhibiting these interesting properties. In conclusion, biomimetic studies have yielded several noteworthy findings in artificial fibers with different functions, and this review aims to provide indications for biomimetic studies of functional fibers that approach and exceed the properties of natural spider silk.
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Affiliation(s)
- Jiatian Li
- State Key Laboratory of Medicinal Chemical BiologyCollege of Pharmacy and College of ChemistryKey Laboratory of Functional Polymer MaterialsFrontiers Science Center for New Organic MatterNankai UniversityTianjin300071China
| | - Sitong Li
- State Key Laboratory of Medicinal Chemical BiologyCollege of Pharmacy and College of ChemistryKey Laboratory of Functional Polymer MaterialsFrontiers Science Center for New Organic MatterNankai UniversityTianjin300071China
| | - Jiayi Huang
- State Key Laboratory of Medicinal Chemical BiologyCollege of Pharmacy and College of ChemistryKey Laboratory of Functional Polymer MaterialsFrontiers Science Center for New Organic MatterNankai UniversityTianjin300071China
| | - Abdul Qadeer Khan
- State Key Laboratory of Medicinal Chemical BiologyCollege of Pharmacy and College of ChemistryKey Laboratory of Functional Polymer MaterialsFrontiers Science Center for New Organic MatterNankai UniversityTianjin300071China
| | - Baigang An
- School of Chemical EngineeringUniversity of Science and Technology LiaoningAnshan114051China
| | - Xiang Zhou
- Department of ScienceChina Pharmaceutical UniversityNanjing211198China
| | - Zunfeng Liu
- State Key Laboratory of Medicinal Chemical BiologyCollege of Pharmacy and College of ChemistryKey Laboratory of Functional Polymer MaterialsFrontiers Science Center for New Organic MatterNankai UniversityTianjin300071China
- School of Chemical EngineeringUniversity of Science and Technology LiaoningAnshan114051China
| | - Meifang Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai201620China
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9
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Gould J. Hauling up a hefty meal: Long‐Jawed spider (Araneae, Tetragnathidae) uses silk lines to transport large prey vertically through the air in the absence of a web. Ethology 2021. [DOI: 10.1111/eth.13137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- John Gould
- School of Environmental and Life Sciences University of Newcastle Callaghan NSW Australia
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10
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Cohen N, Levin M, Eisenbach CD. On the Origin of Supercontraction in Spider Silk. Biomacromolecules 2021; 22:993-1000. [PMID: 33481568 DOI: 10.1021/acs.biomac.0c01747] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Spider silk is a protein material that exhibits extraordinary and nontrivial properties such as the ability to soften and decrease its length by up to ∼60% upon exposure to high humidity. This process is commonly called supercontraction and is the result of a transition from a highly oriented glassy phase to a disoriented rubbery phase. In this work, we derive a microscopically motivated and energy-based model that captures the underlying mechanisms that give rise to supercontraction. We propose that the increase in relative humidity and the consequent wetting of a spider silk have two main consequences: (1) the dissociation of hydrogen bonds and (2) the swelling of the fiber. From a mechanical viewpoint, the first consequence leads to the formation of rubbery domains. This process is associated with an entropic gain and a loss of orientation of chains in the silk network, which motivates the contraction of the spider silk. The swelling of the fiber is accompanied by the extension of chains in order to accommodate the influx of water molecules. Supercontraction occurs when the first consequence is more dominant than the second. The model presented in this work allows us to qualitatively track the transition of the chains from glassy to rubbery states and determine the increase in entropy, the loss of orientation, and the swelling as the relative humidity increases. We also derive explicit expressions for the stiffness and the mechanical response of a spider silk under given relative humidity conditions. To illustrate the merit of this model, we show that the model is capable of capturing several experimental findings. The insights from this work can be used as a microstructural design guide to enable the development of new materials with unique spider-like properties.
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Affiliation(s)
- Noy Cohen
- Department of Materials Science and Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Michal Levin
- Department of Materials Science and Engineering, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Claus D Eisenbach
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, United States.,Institute for Polymer Chemistry, University of Stuttgart, D-70569 Stuttgart, Germany
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11
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Belbéoch C, Lejeune J, Vroman P, Salaün F. Silkworm and spider silk electrospinning: a review. ENVIRONMENTAL CHEMISTRY LETTERS 2021; 19:1737-1763. [PMID: 33424525 PMCID: PMC7779161 DOI: 10.1007/s10311-020-01147-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/18/2020] [Indexed: 05/27/2023]
Abstract
Issues of fossil fuel and plastic pollution are shifting public demand toward biopolymer-based textiles. For instance, silk, which has been traditionally used during at least 5 milleniums in China, is re-emerging in research and industry with the development of high-tech spinning methods. Various arthropods, e.g. insects and arachnids, produce silky proteinic fiber of unique properties such as resistance, elasticity, stickiness and toughness, that show huge potential for biomaterial applications. Compared to synthetic analogs, silk presents advantages of low density, degradability and versatility. Electrospinning allows the creation of nonwoven mats whose pore size and structure show unprecedented characteristics at the nanometric scale, versus classical weaving methods or modern techniques such as melt blowing. Electrospinning has recently allowed to produce silk scaffolds, with applications in regenerative medicine, drug delivery, depollution and filtration. Here we review silk production by the spinning apparatus of the silkworm Bombyx mori and the spiders Aranea diadematus and Nephila Clavipes. We present the biotechnological procedures to get silk proteins, and the preparation of a spinning dope for electrospinning. We discuss silk's mechanical properties in mats obtained from pure polymer dope and multi-composites. This review highlights the similarity between two very different yarn spinning techniques: biological and electrospinning processes.
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Affiliation(s)
- Clémence Belbéoch
- ENSAIT: Ecole Nationale Superieure des Arts et Industries Textiles, Roubaix, France
| | - Joseph Lejeune
- ENSAIT: Ecole Nationale Superieure des Arts et Industries Textiles, Roubaix, France
| | - Philippe Vroman
- ENSAIT: Ecole Nationale Superieure des Arts et Industries Textiles, Roubaix, France
| | - Fabien Salaün
- ENSAIT: Ecole Nationale Superieure des Arts et Industries Textiles, Roubaix, France
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12
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Correa-Garhwal SM, Clarke TH, Janssen M, Crevecoeur L, McQuillan BN, Simpson AH, Vink CJ, Hayashi CY. Spidroins and Silk Fibers of Aquatic Spiders. Sci Rep 2019; 9:13656. [PMID: 31541123 PMCID: PMC6754431 DOI: 10.1038/s41598-019-49587-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 08/24/2019] [Indexed: 12/21/2022] Open
Abstract
Spiders are commonly found in terrestrial environments and many rely heavily on their silks for fitness related tasks such as reproduction and dispersal. Although rare, a few species occupy aquatic or semi-aquatic habitats and for them, silk-related specializations are also essential to survive in aquatic environments. Most spider silks studied to date are from cob-web and orb-web weaving species, leaving the silks from many other terrestrial spiders as well as water-associated spiders largely undescribed. Here, we characterize silks from three Dictynoidea species: the aquatic spiders Argyroneta aquatica and Desis marina as well as the terrestrial Badumna longinqua. From silk gland RNA-Seq libraries, we report a total of 47 different homologs of the spidroin (spider fibroin) gene family. Some of these 47 spidroins correspond to known spidroin types (aciniform, ampullate, cribellar, pyriform, and tubuliform), while other spidroins represent novel branches of the spidroin gene family. We also report a hydrophobic amino acid motif (GV) that, to date, is found only in the spidroins of aquatic and semi-aquatic spiders. Comparison of spider silk sequences to the silks from other water-associated arthropods, shows that there is a diversity of strategies to function in aquatic environments.
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Affiliation(s)
- Sandra M Correa-Garhwal
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA, 92591, USA.
| | - Thomas H Clarke
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA, 92591, USA
- J. Craig Venter Institute, Rockville, MD, 28050, USA
| | | | - Luc Crevecoeur
- Limburg Dome for Nature Study, Provincial Nature Center, Genk, 3600, Belgium
| | | | | | - Cor J Vink
- Canterbury Museum, Christchurch, 8013, New Zealand
| | - Cheryl Y Hayashi
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA, 92591, USA
- Division of Invertebrate Zoology and Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY, 10024, USA
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13
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McGill M, Holland GP, Kaplan DL. Experimental Methods for Characterizing the Secondary Structure and Thermal Properties of Silk Proteins. Macromol Rapid Commun 2019; 40:e1800390. [PMID: 30073740 PMCID: PMC6425979 DOI: 10.1002/marc.201800390] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 06/16/2018] [Indexed: 12/17/2022]
Abstract
Silk proteins are biopolymers produced by spinning organisms that have been studied extensively for applications in materials engineering, regenerative medicine, and devices due to their high tensile strength and extensibility. This remarkable combination of mechanical properties arises from their unique semi-crystalline secondary structure and block copolymer features. The secondary structure of silks is highly sensitive to processing, and can be manipulated to achieve a wide array of material profiles. Studying the secondary structure of silks is therefore critical to understanding the relationship between structure and function, the strength and stability of silk-based materials, and the natural fiber synthesis process employed by spinning organisms. However, silks present unique challenges to structural characterization due to high-molecular-weight protein chains, repetitive sequences, and heterogeneity in intra- and interchain domain sizes. Here, experimental techniques used to study the secondary structure of silks, the information attainable from these techniques, and the limitations associated with them are reviewed. Ultimately, the appropriate utilization of a suite of techniques discussed here will enable detailed characterization of silk-based materials, from studying fundamental processing-structure-function relationships to developing commercially useful quality control assessments.
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Affiliation(s)
- Meghan McGill
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA
| | - Gregory P. Holland
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-1030, USA
| | - David L. Kaplan
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA
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14
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Wu Y, Shah DU, Wang B, Liu J, Ren X, Ramage MH, Scherman OA. Biomimetic Supramolecular Fibers Exhibit Water-Induced Supercontraction. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1707169. [PMID: 29775504 DOI: 10.1002/adma.201707169] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 02/27/2018] [Indexed: 05/11/2023]
Abstract
Spider silk is a fascinating material, combining high strength and elasticity that outperforms most synthetic fibers. Another intriguing feature of spider silk is its ability to "supercontract," shrinking up to 50% when exposed to water. This is likely on account of the entropy-driven recoiling of secondary structured proteins when water penetrates the spider silk. In contrast, humidity-driven contraction in synthetic fibers is difficult to achieve. Here, inspired by the spider silk model, a supercontractile fiber (SCF), which contracts up to 50% of its original length at high humidity, comparable to spider silk, is reported. The fiber exhibits up to 300% uptake of water by volume, confirmed via environmental scanning electron microscopy. Interestingly, the SCF exhibits tunable mechanical properties by varying humidity, which is reflected by the prolonged failure strain and the reversible damping capacity. This smart supramolecular fiber material provides a new opportunity of fabricating biomimetic muscle for diverse applications.
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Affiliation(s)
- Yuchao Wu
- Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Darshil U Shah
- Department of Architecture, University of Cambridge, 1 Scroope Terrace, Cambridge, CB2 1PX, UK
| | - Baoyuan Wang
- Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Ji Liu
- Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Xiaohe Ren
- Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Michael H Ramage
- Department of Architecture, University of Cambridge, 1 Scroope Terrace, Cambridge, CB2 1PX, UK
| | - Oren A Scherman
- Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
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15
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Kim Y, Lee M, Baek I, Yoon T, Na S. Mechanically inferior constituents in spider silk result in mechanically superior fibres by adaptation to harsh hydration conditions: a molecular dynamics study. J R Soc Interface 2018; 15:20180305. [PMID: 30021926 PMCID: PMC6073636 DOI: 10.1098/rsif.2018.0305] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 06/21/2018] [Indexed: 11/12/2022] Open
Abstract
Spider silk exhibits mechanical properties such as high strength and toughness that are superior to those of any man-made fibre (Bourzac 2015 Nature519, S4-S6 (doi:10.1038/519S4a)). This high strength and toughness originates from a combination of the crystalline (exhibiting robust strength) and amorphous (exhibiting superb extensibility) regions present in the silk (Asakura et al 2015 Macromolecules48, 2345-2357 (doi:10.1021/acs.macromol.5b00160)). The crystalline regions comprise a mixture of poly-alanine and poly-glycine-alanine. Poly-alanine is expected to be stronger than poly-glycine-alanine, because alanine exhibits greater interactions between the strands than glycine (Tokareva et al 2014 Acta Biomater.10, 1612-1626 (doi:10.1016/j.actbio.2013.08.020)). We connect this characteristic sequence to the interactions observed upon the hydration of spider silk. Like most proteinaceous materials, spider silks become highly brittle upon dehydration, and thus water collection is crucial to maintaining its toughness (Gosline et al 1986 Endeavour10, 37-43 (doi:10.1016/0160-9327(86)90049-9)). We report on the molecular dynamic simulations of spider silk structures with different sequences for the crystalline region of the silk structures, of wild-type (WT), poly-alanine, and poly-glycine-alanine. We reveal that the characteristic sequence of spider silk results in the β-sheets being maintained as the degree of hydration changes and that the high water collection capabilities of WT spider silk sequence prevent the silk from becoming brittle and weak in dry conditions. The characteristic crystalline sequence of spider dragline silk is therefore relevant not for maximizing the interactions between the strands but for adaption to changing hydration conditions to maintain an optimal performance even in harsh conditions.
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Affiliation(s)
- Yoonjung Kim
- Department of Mechanical Engineering, Korea University, 02841 Seoul, Republic of Korea
| | - Myeongsang Lee
- Institute of Advanced Machinery Design and Technology, Korea University, 02841 Seoul, Republic of Korea
| | - Inchul Baek
- Department of Mechanical Engineering, Korea University, 02841 Seoul, Republic of Korea
| | - Taeyoung Yoon
- Department of Mechanical Engineering, Korea University, 02841 Seoul, Republic of Korea
| | - Sungsoo Na
- Department of Mechanical Engineering, Korea University, 02841 Seoul, Republic of Korea
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16
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Piorkowski D, Blackledge TA, Liao C, Doran NE, Wu C, Blamires SJ, Tso I. Humidity‐dependent mechanical and adhesive properties of
Arachnocampa tasmaniensis
capture threads. J Zool (1987) 2018. [DOI: 10.1111/jzo.12562] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- D. Piorkowski
- Department of Life Science Tunghai University Taichung Taiwan
| | - T. A. Blackledge
- Department of Biology Integrated Bioscience Program The University of Akron Akron OH USA
| | - C.‐P. Liao
- Department of Life Science Tunghai University Taichung Taiwan
| | | | - C.‐L. Wu
- Center for Measurement Standards Industrial Technology Research Institute Hsinchu Taiwan
| | - S. J. Blamires
- Evolution and Ecology Research Centre University of New South Wales Sydney NSW Australia
| | - I.‐M. Tso
- Department of Life Science Tunghai University Taichung Taiwan
- Center for Tropical Ecology and Biodiversity Tunghai University Taichung Taiwan
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17
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Opell BD, Jain D, Dhinojwala A, Blackledge TA. Tuning orb spider glycoprotein glue performance to habitat humidity. J Exp Biol 2018; 221:221/6/jeb161539. [DOI: 10.1242/jeb.161539] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
ABSTRACT
Orb-weaving spiders use adhesive threads to delay the escape of insects from their webs until the spiders can locate and subdue the insects. These viscous threads are spun as paired flagelliform axial fibers coated by a cylinder of solution derived from the aggregate glands. As low molecular mass compounds (LMMCs) in the aggregate solution attract atmospheric moisture, the enlarging cylinder becomes unstable and divides into droplets. Within each droplet an adhesive glycoprotein core condenses. The plasticity and axial line extensibility of the glycoproteins are maintained by hygroscopic LMMCs. These compounds cause droplet volume to track changes in humidity and glycoprotein viscosity to vary approximately 1000-fold over the course of a day. Natural selection has tuned the performance of glycoprotein cores to the humidity of a species' foraging environment by altering the composition of its LMMCs. Thus, species from low-humidity habits have more hygroscopic threads than those from humid forests. However, at their respective foraging humidities, these species' glycoproteins have remarkably similar viscosities, ensuring optimal droplet adhesion by balancing glycoprotein adhesion and cohesion. Optimal viscosity is also essential for integrating the adhesion force of multiple droplets. As force is transferred to a thread's support line, extending droplets draw it into a parabolic configuration, implementing a suspension bridge mechanism that sums the adhesive force generated over the thread span. Thus, viscous capture threads extend an orb spider's phenotype as a highly integrated complex of large proteins and small molecules that function as a self-assembling, highly tuned, environmentally responsive, adhesive biomaterial. Understanding the synergistic role of chemistry and design in spider adhesives, particularly the ability to stick in wet conditions, provides insight in designing synthetic adhesives for biomedical applications.
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Affiliation(s)
- Brent D. Opell
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Dharamdeep Jain
- Department of Polymer Science, Integrated Bioscience Program, The University of Akron, Akron, OH 44325, USA
| | - Ali Dhinojwala
- Department of Polymer Science, Integrated Bioscience Program, The University of Akron, Akron, OH 44325, USA
| | - Todd A. Blackledge
- Department of Biology, Integrated Bioscience Program, The University of Akron, Akron, OH 44325, USA
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18
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Conservation of a pH-sensitive structure in the C-terminal region of spider silk extends across the entire silk gene family. Heredity (Edinb) 2018; 120:574-580. [PMID: 29445119 PMCID: PMC5943517 DOI: 10.1038/s41437-018-0050-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 12/01/2017] [Accepted: 12/02/2017] [Indexed: 11/08/2022] Open
Abstract
Spiders produce multiple silks with different physical properties that allow them to occupy a diverse range of ecological niches, including the underwater environment. Despite this functional diversity, past molecular analyses show a high degree of amino acid sequence similarity between C-terminal regions of silk genes that appear to be independent of the physical properties of the resulting silks; instead, this domain is crucial to the formation of silk fibers. Here, we present an analysis of the C-terminal domain of all known types of spider silk and include silk sequences from the spider Argyroneta aquatica, which spins the majority of its silk underwater. Our work indicates that spiders have retained a highly conserved mechanism of silk assembly, despite the extraordinary diversification of species, silk types and applications of silk over 350 million years. Sequence analysis of the silk C-terminal domain across the entire gene family shows the conservation of two uncommon amino acids that are implicated in the formation of a salt bridge, a functional bond essential to protein assembly. This conservation extends to the novel sequences isolated from A. aquatica. This finding is relevant to research regarding the artificial synthesis of spider silk, suggesting that synthesis of all silk types will be possible using a single process.
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19
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Giesa T, Schuetz R, Fratzl P, Buehler MJ, Masic A. Unraveling the Molecular Requirements for Macroscopic Silk Supercontraction. ACS NANO 2017; 11:9750-9758. [PMID: 28846384 DOI: 10.1021/acsnano.7b01532] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Spider dragline silk is a protein material that has evolved over millions of years to achieve finely tuned mechanical properties. A less known feature of some dragline silk fibers is that they shrink along the main axis by up to 50% when exposed to high humidity, a phenomenon called supercontraction. This contrasts the typical behavior of many other materials that swell when exposed to humidity. Molecular level details and mechanisms of the supercontraction effect are heavily debated. Here we report a molecular dynamics analysis of supercontraction in Nephila clavipes silk combined with in situ mechanical testing and Raman spectroscopy linking the reorganization of the nanostructure to the polar and charged amino acids in the sequence. We further show in our in silico approach that point mutations of these groups not only suppress the supercontraction effect, but even reverse it, while maintaining the exceptional mechanical properties of the silk material. This work has imminent impact on the design of biomimetic equivalents and recombinant silks for which supercontraction may or may not be a desirable feature. The approach applied is appropriate to explore the effect of point mutations on the overall physical properties of protein based materials.
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Affiliation(s)
- Tristan Giesa
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Roman Schuetz
- Max Planck Institute of Colloids and Interfaces , Science Park Golm, 14424 Potsdam, Germany
| | - Peter Fratzl
- Max Planck Institute of Colloids and Interfaces , Science Park Golm, 14424 Potsdam, Germany
| | - Markus J Buehler
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Admir Masic
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Max Planck Institute of Colloids and Interfaces , Science Park Golm, 14424 Potsdam, Germany
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20
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Opell BD, Buccella KE, Godwin MK, Rivas MX, Hendricks ML. Humidity-mediated changes in an orb spider's glycoprotein adhesive impact prey retention time. ACTA ACUST UNITED AC 2017; 220:1313-1321. [PMID: 28356367 DOI: 10.1242/jeb.148080] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 01/16/2017] [Indexed: 11/20/2022]
Abstract
Properties of the viscous prey capture threads of araneoid orb spiders change in response to their environment. Relative humidity (RH) affects the performance of the thread's hygroscopic droplets by altering the viscoelasticity of each droplet's adhesive glycoprotein core. Studies that have characterized this performance used smooth glass and steel surfaces and uniform forces. In this study, we tested the hypothesis that these changes in performance translate into differences in prey retention times. We first characterized the glycoprotein contact surface areas and maximum extension lengths of Araneus marmoreus droplets at 20%, 37%, 55%, 72% and 90% RH and then modeled the relative work required to initiate pull-off of a 4 mm thread span, concluding that this species' droplets and threads performed optimally at 72% RH. Next, we evaluated the ability of three equally spaced capture thread strands to retain a house fly at 37%, 55% and 72% RH. Each fly's struggle was captured in a video and bouts of active escape behavior were summed. House flies were retained 11 s longer at 72% RH than at 37% and 55% RH. This difference is ecologically significant because the short time after an insect strikes a web and before a spider begins wrapping it is an insect's only opportunity to escape from the web. Moreover, these results validate the mechanism by which natural selection can tune the performance of an orb spider's capture threads to the humidity of its habitat.
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Affiliation(s)
- Brent D Opell
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Katrina E Buccella
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Meaghan K Godwin
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Malik X Rivas
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Mary L Hendricks
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
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21
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Blamires SJ, Blackledge TA, Tso IM. Physicochemical Property Variation in Spider Silk: Ecology, Evolution, and Synthetic Production. ANNUAL REVIEW OF ENTOMOLOGY 2017; 62:443-460. [PMID: 27959639 DOI: 10.1146/annurev-ento-031616-035615] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The unique combination of great stiffness, strength, and extensibility makes spider major ampullate (MA) silk desirable for various biomimetic and synthetic applications. Intensive research on the genetics, biochemistry, and biomechanics of this material has facilitated a thorough understanding of its properties at various levels. Nevertheless, methods such as cloning, recombination, and electrospinning have not successfully produced materials with properties as impressive as those of spider silk. It is nevertheless becoming clear that silk properties are a consequence of whole-organism interactions with the environment in addition to genetic expression, gland biochemistry, and spinning processes. Here we assimilate the research done and assess the techniques used to determine distinct forms of spider silk chemical and physical property variability. We suggest that more research should focus on testing hypotheses that explain spider silk property variations in ecological and evolutionary contexts.
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Affiliation(s)
- Sean J Blamires
- Department of Life Science, Tunghai University, Taichung 40704, Taiwan;
- Evolution & Ecology Research Centre, School of Biological, Earth & Environmental Sciences, The University of New South Wales, Sydney 2052, Australia;
| | - Todd A Blackledge
- Department of Biology, Integrated Bioscience Program, The University of Akron, Akron, Ohio 44325;
| | - I-Min Tso
- Department of Life Science, Tunghai University, Taichung 40704, Taiwan;
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22
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Lang G, Neugirg BR, Kluge D, Fery A, Scheibel T. Mechanical Testing of Engineered Spider Silk Filaments Provides Insights into Molecular Features on a Mesoscale. ACS APPLIED MATERIALS & INTERFACES 2017; 9:892-900. [PMID: 27935285 DOI: 10.1021/acsami.6b13093] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Spider dragline silk shows the highest toughness in comparison to all other known natural or man-made fibers. Despite a broad experimental foundation concerning the macroscopic silk thread properties as well as a thorough simulation-based molecular understanding, the impact of the mesoscale building blocks, namely nano-/submicrometer-sized filaments, on the mechanical properties of the threads remains the missing link. Here, we illustrate the function of these mesoscaled building blocks using electrospun fibers made of a recombinant spider silk protein and show the impact of β-sheet content and fiber hydration on their mechanical performance. Specifically elucidating the interplay between β-sheet-cross-linking (fiber strength) and structural water (fiber extensibility), the results bridge the gap between the molecular and the macroscopic view on the mechanics of spider silk. It is demonstrated that the extensibility of the here used single (MaSp2-like) protein system is in good accordance with the simulated extensibilities published by other groups. Furthermore, sufficient hydration of the fibers is shown to be a prerequisite to obtain a toughness in the range of that of natural dragline silk. Preliminary studies on electrospun fibers of the MaSp2-based recombinant spider silk proteins used in this work have indicated their basic applicability in the technical field of filter systems as well as in regenerative medicine. The presented work provides a fundamental understanding of the mechanical performance of such fibers under different wetting conditions, a prerequisite to further specify their potential for such applications.
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Affiliation(s)
| | | | | | - Andreas Fery
- Leibniz-Institut für Polymerforschung Dresden e. V., Institute of Physical Chemistry and Polymer Physics , Dresden 01069, Germany
- Chair for Physical Chemistry of Polymeric Materials, Technical University Dresden , Dresden 01069, Germany
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23
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Krasnov I, Seydel T, Greving I, Blankenburg M, Vollrath F, Müller M. Strain-dependent fractional molecular diffusion in humid spider silk fibres. J R Soc Interface 2016; 13:20160506. [PMID: 27628174 PMCID: PMC5046950 DOI: 10.1098/rsif.2016.0506] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 08/22/2016] [Indexed: 11/12/2022] Open
Abstract
Spider silk is a material well known for its outstanding mechanical properties, combining elasticity and tensile strength. The molecular mobility within the silk's polymer structure on the nanometre length scale importantly contributes to these macroscopic properties. We have therefore investigated the ensemble-averaged single-particle self-dynamics of the prevailing hydrogen atoms in humid spider dragline silk fibres on picosecond time scales in situ as a function of an externally applied tensile strain. We find that the molecular diffusion in the amorphous fraction of the oriented fibres can be described by a generalized fractional diffusion coefficient Kα that is independent of the observation length scale in the probed range from approximately 0.3-3.5 nm. Kα increases towards a diffusion coefficient of the classical Fickian type with increasing tensile strain consistent with an increasing loss of memory or entropy in the polymer matrix.
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Affiliation(s)
- Igor Krasnov
- Institut für Experimentelle und Angewandte Physik, Universität Kiel, 24098 Kiel, Germany Institute of Materials Research, Helmholtz-Zentrum Geesthacht (HZG), 21502 Geesthacht, Germany
| | - Tilo Seydel
- Institut Max von Laue-Paul Langevin (ILL), CS 20156, 38042 Grenoble, France
| | - Imke Greving
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht (HZG), 21502 Geesthacht, Germany
| | - Malte Blankenburg
- Institut für Experimentelle und Angewandte Physik, Universität Kiel, 24098 Kiel, Germany Institute of Materials Research, Helmholtz-Zentrum Geesthacht (HZG), 21502 Geesthacht, Germany
| | - Fritz Vollrath
- Department of Zoology, University of Oxford, Oxford OX13PS, UK
| | - Martin Müller
- Institut für Experimentelle und Angewandte Physik, Universität Kiel, 24098 Kiel, Germany Institute of Materials Research, Helmholtz-Zentrum Geesthacht (HZG), 21502 Geesthacht, Germany
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24
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Blamires SJ, Liao CP, Chang CK, Chuang YC, Wu CL, Blackledge TA, Sheu HS, Tso IM. Mechanical Performance of Spider Silk Is Robust to Nutrient-Mediated Changes in Protein Composition. Biomacromolecules 2015; 16:1218-25. [DOI: 10.1021/acs.biomac.5b00006] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sean J. Blamires
- Department
of Life Science, Tunghai University, Taichung 40704, Taiwan
- Evolution & Ecology Research Centre, School of Biological, Earth & Environmental Sciences, The University of New South Wales, Sydney 2052, Australia
| | - Chen-Pan Liao
- Department
of Life Science, Tunghai University, Taichung 40704, Taiwan
| | - Chung-Kai Chang
- National Synchrotron
Radiation Research Center, Hsinchu 3000, Taiwan
| | - Yu-Chun Chuang
- National Synchrotron
Radiation Research Center, Hsinchu 3000, Taiwan
| | - Chung-Lin Wu
- Center
for Measurement Standards, Industrial Technology Research Institute, Hsinchu 30011, Taiwan
| | - Todd A. Blackledge
- Department
of Biology, Integrated Bioscience Program, The University of Akron, Akron, Ohio 44325, United States
| | - Hwo-Shuenn Sheu
- National Synchrotron
Radiation Research Center, Hsinchu 3000, Taiwan
| | - I-Min Tso
- Department
of Life Science, Tunghai University, Taichung 40704, Taiwan
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25
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Meyer A, Pugno NM, Cranford SW. Compliant threads maximize spider silk connection strength and toughness. J R Soc Interface 2015; 11:20140561. [PMID: 25008083 DOI: 10.1098/rsif.2014.0561] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Millions of years of evolution have adapted spider webs to achieve a range of functionalities, including the well-known capture of prey, with efficient use of material. One feature that has escaped extensive investigation is the silk-on-silk connection joints within spider webs, particularly from a structural mechanics perspective. We report a joint theoretical and computational analysis of an idealized silk-on-silk fibre junction. By modifying the theory of multiple peeling, we quantitatively compare the performance of the system while systematically increasing the rigidity of the anchor thread, by both scaling the stress-strain response and the introduction of an applied pre-strain. The results of our study indicate that compliance is a virtue-the more extensible the anchorage, the tougher and stronger the connection becomes. In consideration of the theoretical model, in comparison with rigid substrates, a compliant anchorage enormously increases the effective adhesion strength (work required to detach), independent of the adhered thread itself, attributed to a nonlinear alignment between thread and anchor (contact peeling angle). The results can direct novel engineering design principles to achieve possible load transfer from compliant fibre-to-fibre anchorages, be they silk-on-silk or another, as-yet undeveloped, system.
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Affiliation(s)
- Avery Meyer
- Laboratory for Nanotechnology in Civil Engineering (NICE), Department of Civil and Environmental Engineering, Northeastern University, 400 Snell Engineering, 360 Huntington Avenue, Boston, MA 02115, USA
| | - Nicola M Pugno
- Laboratory of Bio-Inspired and Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering, Università di Trento, via Mesiano 77, 38123 Trento, Italy Center for Materials and Microsystems, Fondazione Bruno Kessler, Via Sommarive 18, 38123 Povo (Trento), Italy
| | - Steven W Cranford
- Laboratory for Nanotechnology in Civil Engineering (NICE), Department of Civil and Environmental Engineering, Northeastern University, 400 Snell Engineering, 360 Huntington Avenue, Boston, MA 02115, USA
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26
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Huang W, Krishnaji S, Tokareva OR, Kaplan D, Cebe P. Influence of Water on Protein Transitions: Morphology and Secondary Structure. Macromolecules 2014. [DOI: 10.1021/ma5016227] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Wenwen Huang
- Department of Physics and Astronomy,
Center for Nanoscopic Physics, ‡Department of Chemistry, and §Department of
Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Sreevidhya Krishnaji
- Department of Physics and Astronomy,
Center for Nanoscopic Physics, ‡Department of Chemistry, and §Department of
Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Olena Rabotyagova Tokareva
- Department of Physics and Astronomy,
Center for Nanoscopic Physics, ‡Department of Chemistry, and §Department of
Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - David Kaplan
- Department of Physics and Astronomy,
Center for Nanoscopic Physics, ‡Department of Chemistry, and §Department of
Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Peggy Cebe
- Department of Physics and Astronomy,
Center for Nanoscopic Physics, ‡Department of Chemistry, and §Department of
Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States
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27
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28
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Blamires SJ, Wu CC, Wu CL, Sheu HS, Tso IM. Uncovering Spider Silk Nanocrystalline Variations That Facilitate Wind-Induced Mechanical Property Changes. Biomacromolecules 2013; 14:3484-90. [DOI: 10.1021/bm400803z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sean J. Blamires
- Department
of Life Science, Tunghai University, Taichung 40704, Taiwan
| | - Chao-Chia Wu
- Department
of Life Science, National Chung-Hsing University, Taichung 40227, Taiwan
| | - Chung-Lin Wu
- Center
for Measurement Standards, Industrial Technology Research Institute, Hsinchu 30011, Taiwan
| | - Hwo-Shuenn Sheu
- National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan
| | - I-Min Tso
- Department
of Life Science, Tunghai University, Taichung 40704, Taiwan
- Department
of Life Science, National Chung-Hsing University, Taichung 40227, Taiwan
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29
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Cranford SW. Increasing silk fibre strength through heterogeneity of bundled fibrils. J R Soc Interface 2013; 10:20130148. [PMID: 23486175 PMCID: PMC3627094 DOI: 10.1098/rsif.2013.0148] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 02/21/2013] [Indexed: 12/17/2022] Open
Abstract
Can naturally arising disorder in biological materials be beneficial? Materials scientists are continuously attempting to replicate the exemplary performance of materials such as spider silk, with detailed techniques and assembly procedures. At the same time, a spider does not precisely machine silk-imaging indicates that its fibrils are heterogeneous and irregular in cross section. While past investigations either focused on the building material (e.g. the molecular scale protein sequence and behaviour) or on the ultimate structural component (e.g. silk threads and spider webs), the bundled structure of fibrils that compose spider threads has been frequently overlooked. Herein, I exploit a molecular dynamics-based coarse-grain model to construct a fully three-dimensional fibril bundle, with a length on the order of micrometres. I probe the mechanical behaviour of bundled silk fibrils with variable density of heterogenic protrusions or globules, ranging from ideally homogeneous to a saturated distribution. Subject to stretching, the model indicates that cooperativity is enhanced by contact through low-force deformation and shear 'locking' between globules, increasing shear stress transfer by up to 200 per cent. In effect, introduction of a random and disordered structure can serve to improve mechanical performance. Moreover, addition of globules allows a tuning of free volume, and thus the wettability of silk (with implications for supercontraction). These findings support the ability of silk to maintain near-molecular-level strength at the scale of silk threads, and the mechanism could be easily adopted as a strategy for synthetic fibres.
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Affiliation(s)
- Steven W Cranford
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA 02115, USA.
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30
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Opell BD, Karinshak SE, Sigler MA. Environmental response and adaptation of glycoprotein glue within the droplets of viscous prey capture threads from araneoid spider orb-webs. ACTA ACUST UNITED AC 2013; 216:3023-34. [PMID: 23619400 DOI: 10.1242/jeb.084822] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Viscous threads that form the prey capture spiral of araneoid orb-webs retain insects that strike the web, giving a spider more time to locate and subdue them. The viscoelastic glycoprotein glue responsible for this adhesion forms the core of regularly spaced aqueous droplets, which are supported by protein axial fibers. Glycoprotein extensibility both facilitates the recruitment of adhesion from multiple droplets and dissipates the energy generated by insects struggling to free themselves from the web. Compounds in the aqueous material make the droplets hygroscopic, causing an increase in both droplet volume and extensibility as humidity (RH) rises. We characterized these humidity-mediated responses at 20%, 37%, 55%, 72% and 90% RH in two large orb-weavers, Argiope aurantia, which is found in exposed habitats, and Neoscona crucifera, which occupies forests and forest edges. The volume-specific extension of A. aurantia glycoprotein reached a maximum value at 55% RH and then declined, whereas that of N. crucifera increased exponentially through the RH range. As RH increased, the relative stress on droplet filaments at maximum extension, as gauged by axial line deflection, decreased in a linear fashion in A. aurantia, but in N. crucifer increased logarithmically, indicating that N. crucifera threads are better equipped to dissipate energy through droplet elongation. The greater hygroscopicity of A. aurantia threads equips them to function in lower RH environments and during the afternoon when RH drops, but their performance is diminished during the high RH of the morning hours. In contrast, the lower hygroscopicity of N. crucifera threads optimizes their performance for intermediate and high RH environments and during the night and morning. These interspecific differences support the hypothesis that viscous capture threads are adapted to the humidity regime of an orb-weaver's habitat.
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Affiliation(s)
- Brent D Opell
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
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31
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Bundles of spider silk, braided into sutures, resist basic cyclic tests: potential use for flexor tendon repair. PLoS One 2013; 8:e61100. [PMID: 23613793 PMCID: PMC3629086 DOI: 10.1371/journal.pone.0061100] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 03/05/2013] [Indexed: 11/19/2022] Open
Abstract
Repair success for injuries to the flexor tendon in the hand is often limited by the in vivo behaviour of the suture used for repair. Common problems associated with the choice of suture material include increased risk of infection, foreign body reactions, and inappropriate mechanical responses, particularly decreases in mechanical properties over time. Improved suture materials are therefore needed. As high-performance materials with excellent tensile strength, spider silk fibres are an extremely promising candidate for use in surgical sutures. However, the mechanical behaviour of sutures comprised of individual silk fibres braided together has not been thoroughly investigated. In the present study, we characterise the maximum tensile strength, stress, strain, elastic modulus, and fatigue response of silk sutures produced using different braiding methods to investigate the influence of braiding on the tensile properties of the sutures. The mechanical properties of conventional surgical sutures are also characterised to assess whether silk offers any advantages over conventional suture materials. The results demonstrate that braiding single spider silk fibres together produces strong sutures with excellent fatigue behaviour; the braided silk sutures exhibited tensile strengths comparable to those of conventional sutures and no loss of strength over 1000 fatigue cycles. In addition, the braiding technique had a significant influence on the tensile properties of the braided silk sutures. These results suggest that braided spider silk could be suitable for use as sutures in flexor tendon repair, providing similar tensile behaviour and improved fatigue properties compared with conventional suture materials.
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32
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Boutry C, Blackledge T. Wet webs work better: Humidity, supercontraction and the performance of spider orb webs. J Exp Biol 2013; 216:3606-10. [DOI: 10.1242/jeb.084236] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Summary
Like many biomaterials, spider silk responds to water through softening and swelling. Major ampullate silk, the main structural element of most prey capture webs, also shrinks dramatically if unrestrained or develops high tension if restrained, a phenomenon called "supercontraction". While supercontraction has been investigated for over 30 years, its consequences for web performance remain controversial. Here, we measure prey capture performance of dry and wet (supercontracted) orb webs of Argiope and Nephila using small wood blocks as prey. Prey capture performance significantly increased at high humidity for Argiope while the improvement was less dramatic for Nephila. This difference is likely due to Argiope silk supercontracting more than Nephila silk. Web deflection, measured as the extension of the web upon prey impact, also increased at high humidity in Argiope, suggesting that silk softening upon supercontraction explains improved performance of wet webs. These results strongly argue that supercontraction is not detrimental to web performance.
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33
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Li G, Meng H, Hu J. Healable thermoset polymer composite embedded with stimuli-responsive fibres. J R Soc Interface 2012; 9:3279-87. [PMID: 22896563 DOI: 10.1098/rsif.2012.0409] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Severe wounds in biological systems such as human skin cannot heal themselves, unless they are first stitched together. Healing of macroscopic damage in thermoset polymer composites faces a similar challenge. Stimuli-responsive shape-changing polymeric fibres with outstanding mechanical properties embedded in polymers may be able to close macro-cracks automatically upon stimulation such as heating. Here, a stimuli-responsive fibre (SRF) with outstanding mechanical properties and supercontraction capability was fabricated for the purpose of healing macroscopic damage. The SRFs and thermoplastic particles (TPs) were incorporated into regular thermosetting epoxy for repeatedly healing macroscopic damages. The system works by mimicking self-healing of biological systems such as human skin, close (stitch) then heal, i.e. close the macroscopic crack through the thermal-induced supercontraction of the SRFs, and bond the closed crack through melting and diffusing of TPs at the crack interface. The healing efficiency determined using tapered double-cantilever beam specimens was 94 per cent. The self-healing process was reasonably repeatable.
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Affiliation(s)
- Guoqiang Li
- Department of Mechanical Engineering, Louisiana State University, Baton Rouge, LA 70803, USA.
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34
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Blamires SJ, Wu CL, Blackledge TA, Tso IM. Post-secretion processing influences spider silk performance. J R Soc Interface 2012; 9:2479-87. [PMID: 22628213 DOI: 10.1098/rsif.2012.0277] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Phenotypic variation facilitates adaptations to novel environments. Silk is an example of a highly variable biomaterial. The two-spidroin (MaSp) model suggests that spider major ampullate (MA) silk is composed of two proteins-MaSp1 predominately contains alanine and glycine and forms strength enhancing β-sheet crystals, while MaSp2 contains proline and forms elastic spirals. Nonetheless, mechanical properties can vary in spider silks without congruent amino acid compositional changes. We predicted that post-secretion processing causes variation in the mechanical performance of wild MA silk independent of protein composition or spinning speed across 10 species of spider. We used supercontraction to remove post-secretion effects and compared the mechanics of silk in this 'ground state' with wild native silks. Native silk mechanics varied less among species compared with 'ground state' silks. Variability in the mechanics of 'ground state' silks was associated with proline composition. However, variability in native silks did not. We attribute interspecific similarities in the mechanical properties of native silks, regardless of amino acid compositions, to glandular processes altering molecular alignment of the proteins prior to extrusion. Such post-secretion processing may enable MA silk to maintain functionality across environments, facilitating its function as a component of an insect-catching web.
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Affiliation(s)
- Sean J Blamires
- Department of Life Science, Tunghai University, Taichung 40704, Taiwan
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35
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Ene R, Papadopoulos P, Kremer F. Supercontraction in Nephila spider dragline silk – Relaxation into equilibrium state. POLYMER 2011. [DOI: 10.1016/j.polymer.2011.10.056] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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36
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Steven E, Park JG, Paravastu A, Lopes EB, Brooks JS, Englander O, Siegrist T, Kaner P, Alamo RG. Physical characterization of functionalized spider silk: electronic and sensing properties. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2011; 12:055002. [PMID: 27877440 PMCID: PMC5074434 DOI: 10.1088/1468-6996/12/5/055002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 08/23/2011] [Accepted: 07/12/2011] [Indexed: 05/11/2023]
Abstract
This work explores functional, fundamental and applied aspects of naturally harvested spider silk fibers. Natural silk is a protein polymer where different amino acids control the physical properties of fibroin bundles, producing, for example, combinations of β-sheet (crystalline) and amorphous (helical) structural regions. This complexity presents opportunities for functional modification to obtain new types of material properties. Electrical conductivity is the starting point of this investigation, where the insulating nature of neat silk under ambient conditions is described first. Modification of the conductivity by humidity, exposure to polar solvents, iodine doping, pyrolization and deposition of a thin metallic film are explored next. The conductivity increases exponentially with relative humidity and/or solvent, whereas only an incremental increase occurs after iodine doping. In contrast, iodine doping, optimal at 70 °C, has a strong effect on the morphology of silk bundles (increasing their size), on the process of pyrolization (suppressing mass loss rates) and on the resulting carbonized fiber structure (that becomes more robust against bending and strain). The effects of iodine doping and other functional parameters (vacuum and thin film coating) motivated an investigation with magic angle spinning nuclear magnetic resonance (MAS-NMR) to monitor doping-induced changes in the amino acid-protein backbone signature. MAS-NMR revealed a moderate effect of iodine on the helical and β-sheet structures, and a lesser effect of gold sputtering. The effects of iodine doping were further probed by Fourier transform infrared (FTIR) spectroscopy, revealing a partial transformation of β-sheet-to-amorphous constituency. A model is proposed, based on the findings from the MAS-NMR and FTIR, which involves iodine-induced changes in the silk fibroin bundle environment that can account for the altered physical properties. Finally, proof-of-concept applications of functionalized spider silk are presented for thermoelectric (Seebeck) effects and incandescence in iodine-doped pyrolized silk fibers, and metallic conductivity and flexibility of micron-sized gold-sputtered silk fibers. In the latter case, we demonstrate the application of gold-sputtered neat spider silk to make four-terminal, flexible, ohmic contacts to organic superconductor samples.
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Affiliation(s)
- Eden Steven
- Department of Physics and National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac, Tallahassee, FL 32310, USA
| | - Jin Gyu Park
- FAMU-FSU Department of Industrial and Manufacturing Engineering, High-Performance Materials Institute, Florida State University, 2005 Levy Ave, Tallahassee, FL 32310, USA
| | - Anant Paravastu
- FAMU-FSU Department of Chemical and Biomedical Engineering and National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac, Tallahassee, FL 32310, USA
| | - Elsa Branco Lopes
- Departamento de Química, Instituto Tecnológico e Nuclear/CFMC-UL, P-2686-953 Sacavém, Portugal
| | - James S Brooks
- Department of Physics and National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac, Tallahassee, FL 32310, USA
| | - Ongi Englander
- FAMU-FSU Department of Mechanical Engineering and National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac, Tallahassee, Florida, 32310, USA
| | - Theo Siegrist
- FAMU-FSU Department of Chemical and Biomedical Engineering and National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac, Tallahassee, FL 32310, USA
| | - Papatya Kaner
- FAMU-FSU Department of Chemical and Biomedical Engineering and National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac, Tallahassee, FL 32310, USA
| | - Rufina G Alamo
- FAMU-FSU Department of Chemical and Biomedical Engineering and National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac, Tallahassee, FL 32310, USA
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37
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Yoshioka T, Kawahara Y, Schaper AK. Cyclic or Permanent? Structure Control of the Contraction Behavior of Regenerated Bombyx mori Silk Nanofibers. Macromolecules 2011. [DOI: 10.1021/ma2014172] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Taiyo Yoshioka
- Materials Science Center, EM&Mlab, Philipps University of Marburg, Hans-Meerwein-Str., 35032 Marburg, Germany
| | - Yutaka Kawahara
- Department of Biological and Chemical Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - Andreas K. Schaper
- Materials Science Center, EM&Mlab, Philipps University of Marburg, Hans-Meerwein-Str., 35032 Marburg, Germany
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38
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Wendt H, Hillmer A, Reimers K, Kuhbier JW, Schäfer-Nolte F, Allmeling C, Kasper C, Vogt PM. Artificial skin--culturing of different skin cell lines for generating an artificial skin substitute on cross-weaved spider silk fibres. PLoS One 2011; 6:e21833. [PMID: 21814557 PMCID: PMC3144206 DOI: 10.1371/journal.pone.0021833] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 06/12/2011] [Indexed: 12/31/2022] Open
Abstract
Background In the field of Plastic Reconstructive Surgery the development of new innovative matrices for skin repair is in urgent need. The ideal biomaterial should promote attachment, proliferation and growth of cells. Additionally, it should degrade in an appropriate time period without releasing harmful substances, but not exert a pathological immune response. Spider dragline silk from Nephila spp meets these demands to a large extent. Methodology/Principal Findings Native spider dragline silk, harvested directly out of Nephila spp spiders, was woven on steel frames. Constructs were sterilized and seeded with fibroblasts. After two weeks of cultivating single fibroblasts, keratinocytes were added to generate a bilayered skin model, consisting of dermis and epidermis equivalents. For the next three weeks, constructs in co-culture were lifted on an originally designed setup for air/liquid interface cultivation. After the culturing period, constructs were embedded in paraffin with an especially developed program for spidersilk to avoid supercontraction. Paraffin cross- sections were stained in Haematoxylin & Eosin (H&E) for microscopic analyses. Conclusion/Significance Native spider dragline silk woven on steel frames provides a suitable matrix for 3 dimensional skin cell culturing. Both fibroblasts and keratinocytes cell lines adhere to the spider silk fibres and proliferate. Guided by the spider silk fibres, they sprout into the meshes and reach confluence in at most one week. A well-balanced, bilayered cocultivation in two continuously separated strata can be achieved by serum reduction, changing the medium conditions and the cultivation period at the air/liquid interphase. Therefore spider silk appears to be a promising biomaterial for the enhancement of skin regeneration.
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Affiliation(s)
- Hanna Wendt
- Department of Plastic, Hand, and Reconstructive Surgery, Medical School Hannover, Hannover, Germany.
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39
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Eadie L, Ghosh TK. Biomimicry in textiles: past, present and potential. An overview. J R Soc Interface 2011; 8:761-75. [PMID: 21325320 DOI: 10.1098/rsif.2010.0487] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The natural world around us provides excellent examples of functional systems built with a handful of materials. Throughout the millennia, nature has evolved to adapt and develop highly sophisticated methods to solve problems. There are numerous examples of functional surfaces, fibrous structures, structural colours, self-healing, thermal insulation, etc., which offer important lessons for the textile products of the future. This paper provides a general overview of the potential of bioinspired textile structures by highlighting a few specific examples of pertinent, inherently sustainable biological systems. Biomimetic research is a rapidly growing field and its true potential in the development of new and sustainable textiles can only be realized through interdisciplinary research rooted in a holistic understanding of nature.
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Affiliation(s)
- Leslie Eadie
- Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC 27695, USA
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40
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Xu L, Li J, Wang D, Huang Y, Chen M, Li L, Pan G. Structure of polyamide 6 and poly (p-benzamide) in their rod-coil-rod triblock copolymers investigated with in situ wide angle X-ray diffraction. POLYMER 2011. [DOI: 10.1016/j.polymer.2010.12.058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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41
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Boutry C, Blackledge TA. Evolution of supercontraction in spider silk: structure–function relationship from tarantulas to orb-weavers. J Exp Biol 2010; 213:3505-14. [DOI: 10.1242/jeb.046110] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Spider silk is a promising biomaterial with impressive performance. However, some spider silks also ‘supercontract’ when exposed to water, shrinking by up to ∼50% in length. Supercontraction may provide a critical mechanism to tailor silk properties, both for future synthetic silk production and by the spiders themselves. Several hypotheses are proposed for the mechanism and function of supercontraction, but they remain largely untested. In particular, supercontraction may result from a rearrangement of the GPGXX motif within the silk proteins, where G represents glycine, P proline and X is one of a small subset of amino acids. Supercontraction may prevent sagging in wet orb-webs or allow spiders to tailor silk properties for different ecological functions. Because both the molecular structures of silk proteins and how dragline is used in webs differ among species, we can test these hypotheses by comparing supercontraction of silk across diverse spider taxa. In this study we measured supercontraction in 28 spider taxa, ranging from tarantulas to orb-weaving spiders. We found that silk from all species supercontracted, except that of most tarantulas. This suggests that supercontraction evolved at least with the origin of the Araneomorphae, over 200 million years ago. We found differences in the pattern of evolution for two components of supercontraction. Stress generated during supercontraction of a restrained fiber is not associated with changes in silk structure and web architecture. By contrast, the shrink of unrestrained supercontracting fibers is higher for Orbiculariae spiders, whose silk contains high ratios of GPGXX motifs. These results support the hypothesis that supercontraction is caused by a rearrangement of GPGXX motifs in silk, and that it functions to tailor silk material properties.
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Affiliation(s)
- Cecilia Boutry
- Department of Biology and Integrated Bioscience Program, University of Akron, Akron, OH 44325-3908, USA
| | - Todd Alan Blackledge
- Department of Biology and Integrated Bioscience Program, University of Akron, Akron, OH 44325-3908, USA
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42
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Blackledge TA, Boutry C, Wong SC, Baji A, Dhinojwala A, Sahni V, Agnarsson I. How super is supercontraction? Persistent versus cyclic responses to humidity in spider dragline silk. J Exp Biol 2009; 212:1981-9. [DOI: 10.1242/jeb.028944] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Spider dragline silk has enormous potential for the development of biomimetic fibers that combine strength and elasticity in low density polymers. These applications necessitate understanding how silk reacts to different environmental conditions. For instance, spider dragline silk`supercontracts' in high humidity. During supercontraction, unrestrained dragline silk contracts up to 50% of its original length and restrained fibers generate substantial stress. Here we characterize the response of dragline silk to changes in humidity before, during and after supercontraction. Our findings demonstrate that dragline silk exhibits two qualitatively different responses to humidity. First, silk undergoes a previously unknown cyclic relaxation–contraction response to wetting and drying. The direction and magnitude of this cyclic response is identical both before and after supercontraction. By contrast, supercontraction is a `permanent' tensioning of restrained silk in response to high humidity. Here, water induces stress,rather than relaxation and the uptake of water molecules results in a permanent change in molecular composition of the silk, as demonstrated by thermogravimetric analysis (TGA). Even after drying, silk mass increased by∼1% after supercontraction. By contrast, the cyclic response to humidity involves a reversible uptake of water. Dried, post-supercontraction silk also differs mechanically from virgin silk. Post-supercontraction silk exhibits reduced stiffness and stress at yield, as well as changes in dynamic energy storage and dissipation. In addition to advancing understanding supercontraction, our findings open up new applications for synthetic silk analogs. For example, dragline silk emerges as a model for a biomimetic muscle, the contraction of which is precisely controlled by humidity alone.
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Affiliation(s)
| | - Cecilia Boutry
- Department of Biology, University of Akron, Akron, OH 44325, USA
| | - Shing-Chung Wong
- Department of Mechanical Engineering, University of Akron, Akron, OH 44325,USA
| | - Avinash Baji
- Department of Mechanical Engineering, University of Akron, Akron, OH 44325,USA
| | - Ali Dhinojwala
- Department of Polymer Science, Integrated Bioscience Program, University of Akron, Akron, OH 44325, USA
| | - Vasav Sahni
- Department of Polymer Science, Integrated Bioscience Program, University of Akron, Akron, OH 44325, USA
| | - Ingi Agnarsson
- Department of Biology, University of Akron, Akron, OH 44325, USA
- Department of Biology, University of Puerto Rico, PO Box 23360, San Juan, PR 00931, USA
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