1
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Välisalmi T, Linder MB. The ratio of fibroin to sericin in the middle silk gland of Bombyx mori and its correlation with the extensional behavior of the silk dope. Protein Sci 2024; 33:e4907. [PMID: 38380732 PMCID: PMC10880417 DOI: 10.1002/pro.4907] [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: 08/19/2023] [Revised: 01/03/2024] [Accepted: 01/05/2024] [Indexed: 02/22/2024]
Abstract
Understanding how native silk spinning occurs is crucial for designing artificial spinning systems. One often overlooked factor in Bombyx mori is the secretion of sericin proteins. Herein, we investigate the variation in amino acid content at different locations in the middle silk gland (MSG) of B. mori. This variation corresponds to an increase in sericin content when moving towards the anterior region of the MSG, while the posterior region predominantly contains fibroin. We estimate the mass ratio of sericin to fibroin to be ~25/75 wt% in the anterior MSG, depending on the fitting method. Then, we demonstrate that the improvement in the extensional behavior of the silk dope in the MSG correlates with the increase in sericin content. The addition of sericin may decrease the viscosity of the silk dope, a factor associated with an increase in the spinnability of silk. We further discuss whether this effect could also result from other known physicochemical changes within the MSG.
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Affiliation(s)
- Teemu Välisalmi
- Department of Bioproducts and BiosystemsSchool of Chemical Engineering, Aalto UniversityAaltoFinland
- Centre of Excellence in Life‐Inspired Hybrid Materials (LIBER)Aalto UniversityAaltoFinland
| | - Markus B. Linder
- Department of Bioproducts and BiosystemsSchool of Chemical Engineering, Aalto UniversityAaltoFinland
- Centre of Excellence in Life‐Inspired Hybrid Materials (LIBER)Aalto UniversityAaltoFinland
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2
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Chen J, Tsuchida A, Malay AD, Tsuchiya K, Masunaga H, Tsuji Y, Kuzumoto M, Urayama K, Shintaku H, Numata K. Replicating shear-mediated self-assembly of spider silk through microfluidics. Nat Commun 2024; 15:527. [PMID: 38225234 PMCID: PMC10789810 DOI: 10.1038/s41467-024-44733-1] [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: 06/14/2023] [Accepted: 01/02/2024] [Indexed: 01/17/2024] Open
Abstract
The development of artificial spider silk with properties similar to native silk has been a challenging task in materials science. In this study, we use a microfluidic device to create continuous fibers based on recombinant MaSp2 spidroin. The strategy incorporates ion-induced liquid-liquid phase separation, pH-driven fibrillation, and shear-dependent induction of β-sheet formation. We find that a threshold shear stress of approximately 72 Pa is required for fiber formation, and that β-sheet formation is dependent on the presence of polyalanine blocks in the repetitive sequence. The MaSp2 fiber formed has a β-sheet content (29.2%) comparable to that of native dragline with a shear stress requirement of 111 Pa. Interestingly, the polyalanine blocks have limited influence on the occurrence of liquid-liquid phase separation and hierarchical structure. These results offer insights into the shear-induced crystallization and sequence-structure relationship of spider silk and have significant implications for the rational design of artificially spun fibers.
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Affiliation(s)
- Jianming Chen
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
- Research Institute for Intelligent Wearable Systems, The Hong Kong Polytechnic University, Kowloon, Hong Kong
- Research Centre of Textiles for Future Fashion, The Hong Kong Polytechnic University, Kowloon, Hong Kong
- School of Fashion and Textiles, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Arata Tsuchida
- Cluster for Pioneering Research, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Ali D Malay
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Kousuke Tsuchiya
- Department of Material Chemistry, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan
| | - Hiroyasu Masunaga
- Japan Synchrotron Radiation Research Institute, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan
| | - Yui Tsuji
- Department of Material Chemistry, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan
| | - Mako Kuzumoto
- Department of Material Chemistry, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan
| | - Kenji Urayama
- Department of Material Chemistry, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan
| | - Hirofumi Shintaku
- Cluster for Pioneering Research, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Keiji Numata
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
- Department of Material Chemistry, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan.
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0017, Japan.
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3
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Sen S, Fernandes RR, Ewoldt RH. Soft glassy materials with tunable extensibility. SOFT MATTER 2023; 20:212-223. [PMID: 38078477 DOI: 10.1039/d3sm01150j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Extensibility is beyond the paradigm of classical soft glassy materials, and more broadly, yield-stress fluids. Recently, model yield-stress fluids with significant extensibility have been designed by adding polymeric phases to classically viscoplastic dispersions [Nelson et al., J. Rheol., 2018, 62, 357; Nelson et al., Curr. Opin. Solid State Mater. Sci., 2019, 23, 100758; Dekker et al., J. Non-Newtonian Fluid Mech., 2022, 310, 104938]. However, fundamental questions remain about the design of and coupling between the shear and extensional rheology of such systems. In this work, we propose a model material, a mixture of soft glassy microgels and solutions of high molecular weight linear polymers. We establish systematic criteria for the design and thorough rheological characterization of such systems, in both shear and extension. Using our material, we show that it is possible to dramatically change the behavior in extension with minimal change in the shear yield stress and elastic modulus, thus enabling applications that exploit orthogonal modulation of shear and extensional material properties.
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Affiliation(s)
- Samya Sen
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
| | - Rubens R Fernandes
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
| | - Randy H Ewoldt
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
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4
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Kamada A, Toprakcioglu Z, Knowles TPJ. Kinetic Analysis Reveals the Role of Secondary Nucleation in Regenerated Silk Fibroin Self-Assembly. Biomacromolecules 2023; 24:1709-1716. [PMID: 36926854 PMCID: PMC10091410 DOI: 10.1021/acs.biomac.2c01479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Silk proteins obtained from the Bombyx mori silkworm have been extensively studied due to their remarkable mechanical properties. One of the major structural components of this complex material is silk fibroin, which can be isolated and processed further in vitro to form artificial functional materials. Due to the excellent biocompatibility and rich self-assembly behavior, there has been sustained interest in such materials formed through the assembly of regenerated silk fibroin feedstocks. The molecular mechanisms by which the soluble regenerated fibroin molecules self-assemble into protein nanofibrils remain, however, largely unknown. Here, we use the framework of chemical kinetics to connect macroscopic measurements of regenerated silk fibroin self-assembly to the underlying microscopic mechanisms. Our results reveal that the aggregation of regenerated silk fibroin is dominated by a nonclassical secondary nucleation processes, where the formation of new fibrils is catalyzed by the existing aggregates in an autocatalytic manner. Such secondary nucleation pathways were originally discovered in the context of polymerization of disease-associated proteins, but the present results demonstrate that this pathway can also occur in functional assembly. Furthermore, our results show that shear flow induces the formation of nuclei, which subsequently accelerate the process of aggregation through an autocatalytic amplification driven by the secondary nucleation pathway. Taken together, these results allow us to identify the parameters governing the kinetics of regenerated silk fibroin self-assembly and expand our current understanding of the spinning of bioinspired protein-based fibers, which have a wide range of applications in materials science.
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Affiliation(s)
- Ayaka Kamada
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Zenon Toprakcioglu
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Tuomas P J Knowles
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.,Cavendish Laboratory, University of Cambridge, Cambridge CB3 0FE, U.K
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5
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Ni Z, Zhu Z, Ji Y, He X, Fu X, Yang W, Wang Y. Biomimetic Microadhesion Guided Instant Spinning. NANO LETTERS 2022; 22:9396-9404. [PMID: 36410737 DOI: 10.1021/acs.nanolett.2c03297] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Animals create high-performance fibers at natural ambient conditions via a unique spinning process. In contrast, the spinning technologies developed by human beings are usually clumsy and require sophisticated skills. Here, inspired by adhesion-based silkworm spinning, we report a microadhesion guided (MAG) spinning technology for instant and on-demand fabrication of micro/nanofibers. Enabled by the adhesion between the spinning fluids and the microneedles, the MAG spinning can generate micro/nanofibers with programmable morphology. By further mimicking the head movement of the silkworm spinning, the MAG technology is extended with three different modes: straight, vibratory, and twisted spinning, which generate oriented fibers, hierarchical cross-linked fibers, and all-in-one fibers, respectively. Due to the prevalence of microadhesion and its unprecedented flexibility in operation, equipment-free MAG spinning is finally realized for instant fiber fabrication by only polymeric foams. Finally, the MAG spinning is demonstrated as a promising instant technology for emergent applications, such as wound dressing.
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Affiliation(s)
- Zhuxi Ni
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu610065, Sichuan, China
| | - Zhiwei Zhu
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu610065, Sichuan, China
| | - Yuan Ji
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu610065, Sichuan, China
| | - Xuewei He
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu610065, Sichuan, China
| | - Xuewei Fu
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu610065, Sichuan, China
| | - Wei Yang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu610065, Sichuan, China
| | - Yu Wang
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu610065, Sichuan, China
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6
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Environmental parameters-dependent rheological behaviors of whey protein fibril dispersions: Shear and extensional flow behaviors. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2022.107974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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Huang R, McDowall D, Ng H, Thomson L, Al-Hilaly YK, Doutch J, Burholt S, Serpell LC, Poole RJ, Adams DJ. Charge screening wormlike micelles affects extensional relaxation time and noodle formation. Chem Commun (Camb) 2022; 58:10388-10391. [PMID: 36039700 DOI: 10.1039/d2cc03646k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A functionalised dipeptide that self-assembles to form wormlike micelles at high pH can be treated as a surfactant. By varying salt concentration, the self-assembled structures and interactions between them change, resulting in solutions with very different shear and extensional viscosity. From these, gel noodles with different mechanical properties can be prepared.
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Affiliation(s)
- Rui Huang
- School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Daniel McDowall
- School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Henry Ng
- School of Engineering, University of Liverpool, Liverpool, L69 3GH, UK
| | - Lisa Thomson
- School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Youssra K Al-Hilaly
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, BN1 9QG, UK.,Chemistry Department, College of Science, Mustansiriyah University, Baghdad, Iraq
| | - James Doutch
- ISIS Pulsed Neutron and Muon Source, Harwell Science and Innovation Campus, Didcot, OX11 0QX, UK
| | - Sam Burholt
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, OX11 0QX, UK
| | - Louise C Serpell
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, BN1 9QG, UK
| | - Robert J Poole
- School of Engineering, University of Liverpool, Liverpool, L69 3GH, UK
| | - Dave J Adams
- School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
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8
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Chakraborty J, Mu X, Pramanick A, Kaplan DL, Ghosh S. Recent advances in bioprinting using silk protein-based bioinks. Biomaterials 2022; 287:121672. [PMID: 35835001 DOI: 10.1016/j.biomaterials.2022.121672] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 07/01/2022] [Accepted: 07/06/2022] [Indexed: 02/07/2023]
Abstract
3D printing has experienced swift growth for biological applications in the field of regenerative medicine and tissue engineering. Essential features of bioprinting include determining the appropriate bioink, printing speed mechanics, and print resolution while also maintaining cytocompatibility. However, the scarcity of bioinks that provide printing and print properties and cell support remains a limitation. Silk Fibroin (SF) displays exceptional features and versatility for inks and shows the potential to print complex structures with tunable mechanical properties, degradation rates, and cytocompatibility. Here we summarize recent advances and needs with the use of SF protein from Bombyx mori silkworm as a bioink, including crosslinking methods for extrusion bioprinting using SF and the maintenance of cell viability during and post bioprinting. Additionally, we discuss how encapsulated cells within these SF-based 3D bioprinted constructs are differentiated into various lineages such as skin, cartilage, and bone to expedite tissue regeneration. We then shift the focus towards SF-based 3D printing applications, including magnetically decorated hydrogels, in situ bioprinting, and a next-generation 4D bioprinting approach. Future perspectives on improvements in printing strategies and the use of multicomponent bioinks to improve print fidelity are also discussed.
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Affiliation(s)
- Juhi Chakraborty
- Department of Textile and Fibre Engineering, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - Xuan Mu
- Department of Biomedical Engineering, Tufts University, Medford, MA, 2155, USA
| | - Ankita Pramanick
- Department of Textile and Fibre Engineering, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, Medford, MA, 2155, USA
| | - Sourabh Ghosh
- Department of Textile and Fibre Engineering, Indian Institute of Technology Delhi, New Delhi-110016, India.
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9
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Ahmed A, Mansouri M, Joshi IM, Byerley AM, Day SW, Gaborski TR, Abhyankar VV. Local extensional flows promote long-range fiber alignment in 3D collagen hydrogels. Biofabrication 2022; 14. [PMID: 35735228 DOI: 10.1088/1758-5090/ac7824] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/13/2022] [Indexed: 02/07/2023]
Abstract
Randomly oriented type I collagen (COL1) fibers in the extracellular matrix are reorganized by biophysical forces into aligned domains extending several millimeters and with varying degrees of fiber alignment. These aligned fibers can transmit traction forces, guide tumor cell migration, facilitate angiogenesis, and influence tissue morphogenesis. To create aligned COL1 domains in microfluidic cell culture models, shear flows have been used to align thin COL1 matrices (<50µm in height) in a microchannel. However, there has been limited investigation into the role of shear flows in aligning 3D hydrogels (>130µm). Here, we show that pure shear flows do not induce fiber alignment in 3D atelo COL1 hydrogels, but the simple addition of local extensional flow promotes alignment that is maintained across several millimeters, with a degree of alignment directly related to the extensional strain rate. We further advance experimental capabilities by addressing the practical challenge of accessing a 3D hydrogel formed within a microchannel by introducing a magnetically coupled modular platform that can be released to expose the microengineered hydrogel. We demonstrate the platform's capability to pattern cells and fabricate multi-layered COL1 matrices using layer-by-layer fabrication and specialized modules. Our approach provides an easy-to-use fabrication method to achieve advanced hydrogel microengineering capabilities that combine fiber alignment with biofabrication capabilities.
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Affiliation(s)
- Adeel Ahmed
- Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, NY, 14623, United States of America
| | - Mehran Mansouri
- Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, NY, 14623, United States of America
| | - Indranil M Joshi
- Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, NY, 14623, United States of America
| | - Ann M Byerley
- Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, NY, 14623, United States of America
| | - Steven W Day
- Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, NY, 14623, United States of America
| | - Thomas R Gaborski
- Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, NY, 14623, United States of America
| | - Vinay V Abhyankar
- Department of Biomedical Engineering, Rochester Institute of Technology, Rochester, NY, 14623, United States of America
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10
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Merchiers J, Reddy NK, Sharma V. Extensibility-Enriched Spinnability and Enhanced Sorption and Strength of Centrifugally Spun Polystyrene Fiber Mats. Macromolecules 2022. [DOI: 10.1021/acs.macromol.1c02164] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jorgo Merchiers
- Institute for Materials research (IMO-IMOMEC), Hasselt University, B-3590 Diepenbeek, Belgium
- IMEC vzw-Division IMOMEC, Wetenschapspark 1, B-3590 Diepenbeek, Belgium
| | - Naveen K. Reddy
- Institute for Materials research (IMO-IMOMEC), Hasselt University, B-3590 Diepenbeek, Belgium
- IMEC vzw-Division IMOMEC, Wetenschapspark 1, B-3590 Diepenbeek, Belgium
| | - Vivek Sharma
- Department of Chemical Engineering, University of Illinois Chicago, Chicago, Illinois 60607, United States
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11
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Wang X, Tan X, Liu Q, Li Y, Li X, Dong Z, Dong H, Xia Q, Zhao P. Fiber Formation and Mechanical Properties of Bombyx mori Silk Are Regulated by Vacuolar-Type ATPase. ACS Biomater Sci Eng 2021; 7:5532-5540. [PMID: 34753284 DOI: 10.1021/acsbiomaterials.1c01230] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The mechanism of silk fiber formation in silkworms, Bombyx mori, is of particular scientific interest because it is closely related to the mechanical properties of silk fibers. However, there are still substantial knowledge gaps in understanding the details of this mechanism. Studies have found a pH gradient in the silk gland of silkworms. A vacuolar-type ATPase (V-ATPase) is thought to be involved in establishing this pH gradient. Although it is reported that the pH gradient plays a role in silk fibrillogenesis, the direct relationship between V-ATPase and silk mechanical properties is unclear. Thus, this study aims to clarify this relationship. We found that V-ATPase is highly and stably expressed in the anterior silk gland (ASG) and maintains the pH gradient and the fine structure of ASG. Inhibition of V-ATPase activity increased the β-sheet content and crystallinity of silk fibers. Tensile testing showed that the mechanical properties of silk fibers improved after inhibiting V-ATPase activity. All the data suggest that V-ATPase is a key factor in regulating silk fibrillogenesis and is related to the final mechanical properties of the silk fibers. V-ATPase is a potential target for silk mechanical property improvement.
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Affiliation(s)
- Xin Wang
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing 400716, China.,Chongqing Engineering and Technology Research Center for Novel Silk Materials, Chongqing Key Laboratory of Sericulture, Southwest University, Chongqing 400716, China
| | - Xiaoyin Tan
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing 400716, China
| | - Qingsong Liu
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing 400716, China.,Chongqing Engineering and Technology Research Center for Novel Silk Materials, Chongqing Key Laboratory of Sericulture, Southwest University, Chongqing 400716, China
| | - Yi Li
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing 400716, China.,Chongqing Engineering and Technology Research Center for Novel Silk Materials, Chongqing Key Laboratory of Sericulture, Southwest University, Chongqing 400716, China
| | - Xinning Li
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing 400716, China.,Chongqing Engineering and Technology Research Center for Novel Silk Materials, Chongqing Key Laboratory of Sericulture, Southwest University, Chongqing 400716, China
| | - Zhaoming Dong
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing 400716, China.,Chongqing Engineering and Technology Research Center for Novel Silk Materials, Chongqing Key Laboratory of Sericulture, Southwest University, Chongqing 400716, China
| | - Haonan Dong
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing 400716, China.,Chongqing Engineering and Technology Research Center for Novel Silk Materials, Chongqing Key Laboratory of Sericulture, Southwest University, Chongqing 400716, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing 400716, China.,Chongqing Engineering and Technology Research Center for Novel Silk Materials, Chongqing Key Laboratory of Sericulture, Southwest University, Chongqing 400716, China
| | - Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Biological Science Research Center, Southwest University, Chongqing 400716, China.,Chongqing Engineering and Technology Research Center for Novel Silk Materials, Chongqing Key Laboratory of Sericulture, Southwest University, Chongqing 400716, China
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12
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Sahi AK, Varshney N, Poddar S, Gundu S, Mahto SK. Fabrication and Characterization of Silk Fibroin-Based Nanofibrous Scaffolds Supplemented with Gelatin for Corneal Tissue Engineering. Cells Tissues Organs 2021; 210:173-194. [PMID: 34252899 DOI: 10.1159/000515946] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 03/15/2021] [Indexed: 11/19/2022] Open
Abstract
Tissue engineering is a promising approach to overcome the severe worldwide shortage of healthy donor corneas. In this work, we have developed a silk-gelatin composite scaffold using electrospinning and permeation techniques to achieve the properties comparable to cornea analog. In particular, we present the fabrication and comparative evaluation of the novel gelatin sheets consisting of silk fibroin nanofibers, which are prepared using silk fibroin (SF) (in formic acid) and SF (in aqueous) electrospun scaffolds, for its suitability as corneal stromal analogs. All the fabricated samples were treated with ethanol vapor (T) to physically crosslink the silk nanofibers. Micro/nano-scale features of the fabricated scaffolds were analyzed using scanning electron microscopy micrographs. Fourier transform infrared spectroscopy revealed characteristic peaks of polymeric functional groups and modifications upon ethanol vapor treatment. Transparency of the scaffolds was determined using UV-visible spectra. Among all the fabricated samples, the gelatin-permeated SF (in formic acid; T) scaffold showed the highest level of transparency, i.e., 77.75 ± 2.3%, which is similar to that of the native cornea (∼70%-90% [variable with age group]) with healthy acute vision. Contact angle of the samples was studied to estimate the hydrophilicity of the scaffolds. All the scaffolds except non-treated SF (in aqueous; NT) were found to be significantly stable up to 14 days when incubated in phosphate buffered saline at 37°C. Treated samples showed significantly better stability, both physically and microscopically, in comparison to nontreated samples. Proliferation and viability assays of rabbit corneal fibroblast cells (SIRC) and mouse fibroblast cells (L929 RFP) when cultured on fabricated scaffolds revealed remarkable cellular compatibility with gelatin-permeated SF (in formic acid; T) scaffolds compared to SF (in aqueous; T). Unlike other reports in the existing literature, this work presents the design and development of a nanofibrous silk-gelatin composite that exhibits acceptable transparency, cellular biocompatibility, as well as improved mechanical stability comparable to that of native cornea. Therefore, we anticipate that the fabricated novel scaffold is likely to be a good candidate for corneal tissue construct. Moreover, among the fabricated scaffolds, the outcomes depict gelatin-permeated SF (in formic acid; T) composite scaffold to be a better candidate as a corneal stromal analog that carries properties of both the silk and gelatin, i.e., optimal transparency, better stability, and enhanced cytocompatibility.
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Affiliation(s)
- Ajay Kumar Sahi
- Tissue Engineering and Biomicrofluidics Laboratory, School of Biomedical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Neelima Varshney
- Tissue Engineering and Biomicrofluidics Laboratory, School of Biomedical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Suruchi Poddar
- Tissue Engineering and Biomicrofluidics Laboratory, School of Biomedical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Shravanya Gundu
- Tissue Engineering and Biomicrofluidics Laboratory, School of Biomedical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
| | - Sanjeev Kumar Mahto
- Tissue Engineering and Biomicrofluidics Laboratory, School of Biomedical Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, India.,Centre for Advanced Biomaterials and Tissue Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi, India
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13
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Wan Q, Yang M, Hu J, Lei F, Shuai Y, Wang J, Holland C, Rodenburg C, Yang M. Mesoscale structure development reveals when a silkworm silk is spun. Nat Commun 2021; 12:3711. [PMID: 34140492 PMCID: PMC8211695 DOI: 10.1038/s41467-021-23960-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 04/29/2021] [Indexed: 11/14/2022] Open
Abstract
Silk fibre mechanical properties are attributed to the development of a multi-scale hierarchical structure during spinning. By careful ex vivo processing of a B. mori silkworm silk solution we arrest the spinning process, freezing-in mesoscale structures corresponding to three distinctive structure development stages; gelation, fibrilization and the consolidation phase identified in this work, a process highlighted by the emergence and extinction of 'water pockets'. These transient water pockets are a manifestation of the interplay between protein dehydration, phase separation and nanofibril assembly, with their removal due to nanofibril coalescence during consolidation. We modeled and validated how post-draw improves mechanical properties and refines a silk's hierarchical structure as a result of consolidation. These insights enable a better understanding of the sequence of events that occur during spinning, ultimately leading us to propose a robust definition of when a silkworm silk is actually 'spun'.
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Affiliation(s)
- Quan Wan
- College of Animal Science, Zhejiang University, Hangzhou, China
| | - Mei Yang
- College of Animal Science, Zhejiang University, Hangzhou, China
| | - Jiaqi Hu
- College of Animal Science, Zhejiang University, Hangzhou, China
| | - Fang Lei
- College of Animal Science, Zhejiang University, Hangzhou, China
| | - Yajun Shuai
- College of Animal Science, Zhejiang University, Hangzhou, China
| | - Jie Wang
- College of Animal Science, Zhejiang University, Hangzhou, China
| | - Chris Holland
- Department of Material Science and Engineering, University of Sheffield, Sheffield, UK.
| | - Cornelia Rodenburg
- Department of Material Science and Engineering, University of Sheffield, Sheffield, UK.
| | - Mingying Yang
- College of Animal Science, Zhejiang University, Hangzhou, China.
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14
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Seib FP. Emerging Silk Material Trends: Repurposing, Phase Separation and Solution-Based Designs. MATERIALS (BASEL, SWITZERLAND) 2021; 14:1160. [PMID: 33804578 PMCID: PMC7957590 DOI: 10.3390/ma14051160] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/18/2021] [Accepted: 02/24/2021] [Indexed: 12/13/2022]
Abstract
Silk continues to amaze. This review unravels the most recent progress in silk science, spanning from fundamental insights to medical silks. Key advances in silk flow are examined, with specific reference to the role of metal ions in switching silk from a storage to a spinning state. Orthogonal thermoplastic silk molding is described, as is the transfer of silk flow principles for the triggering of flow-induced crystallization in other non-silk polymers. Other exciting new developments include silk-inspired liquid-liquid phase separation for non-canonical fiber formation and the creation of "silk organelles" in live cells. This review closes by examining the role of silk fabrics in fashioning facemasks in response to the SARS-CoV-2 pandemic.
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Affiliation(s)
- F Philipp Seib
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK
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15
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Dubey S, Veer S, Seshagiri Rao RV, Kalelkar C, Pullarkat PA. Investigation of soft and living matter using a micro-extensional rheometer. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:084003. [PMID: 33171443 DOI: 10.1088/1361-648x/abc943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Rheological properties of a material often require to be probed under extensional deformation. Examples include fibrous materials such as spider-silk, high-molecular weight polymer melts, and the contractile response of living cells. Such materials have strong molecular-level anisotropies which are either inherent or are induced by an imposed extension. However, unlike shear rheology, which is well-established, techniques to perform extensional rheology are currently under development and setups are often custom-designed for the problem under study. In this article, we present a versatile device that can be used to conduct extensional deformation studies of samples at microscopic scales with simultaneous imaging. We discuss the operational features of this device and present a number of applications.
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Affiliation(s)
- Sushil Dubey
- Soft Condensed Matter group, Raman Research Institute, C. V. Raman Avenue, Bengaluru 560080, India
| | - Sukh Veer
- Soft Condensed Matter group, Raman Research Institute, C. V. Raman Avenue, Bengaluru 560080, India
| | - R V Seshagiri Rao
- Soft Condensed Matter group, Raman Research Institute, C. V. Raman Avenue, Bengaluru 560080, India
| | - Chirag Kalelkar
- Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur 721302, India
| | - Pramod A Pullarkat
- Soft Condensed Matter group, Raman Research Institute, C. V. Raman Avenue, Bengaluru 560080, India
- Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur 721302, India
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16
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Schaefer C, McLeish TCB. Power Law Stretching of Associating Polymers in Steady-State Extensional Flow. PHYSICAL REVIEW LETTERS 2021; 126:057801. [PMID: 33605750 DOI: 10.1103/physrevlett.126.057801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/02/2020] [Accepted: 01/07/2021] [Indexed: 06/12/2023]
Abstract
We present a tube model for the Brownian dynamics of associating polymers in extensional flow. In linear response, the model confirms the analytical predictions for the sticky diffusivity by Leibler-Rubinstein-Colby theory. Although a single-mode Doi-Edwards-Marrucci-Grizzuti approximation accurately describes the transient stretching of the polymers above a "sticky" Weissenberg number (product of the strain rate with the sticky-Rouse time), the preaveraged model fails to capture a remarkable development of a power law distribution of stretch in steady-state extensional flow: while the mean stretch is finite, the fluctuations in stretch may diverge. We present an analytical model that shows how strong stochastic forcing drives the long tail of the distribution, gives rise to rare events of reaching a threshold stretch, and constitutes a framework within which nucleation rates of flow-induced crystallization may be understood in systems of associating polymers under flow. The model also exemplifies a wide class of driven systems possessing strong, and scaling, fluctuations.
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Affiliation(s)
- Charley Schaefer
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Tom C B McLeish
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
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17
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Chakraborty J, Ghosh S. Cellular Proliferation, Self-Assembly, and Modulation of Signaling Pathways in Silk Fibroin Gelatin-Based 3D Bioprinted Constructs. ACS APPLIED BIO MATERIALS 2020; 3:8309-8320. [DOI: 10.1021/acsabm.0c01252] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Juhi Chakraborty
- Department of Textile and Fibre Engineering, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Sourabh Ghosh
- Department of Textile and Fibre Engineering, Indian Institute of Technology Delhi, New Delhi 110016, India
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18
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Koeppel A, Laity PR, Holland C. The influence of metal ions on native silk rheology. Acta Biomater 2020; 117:204-212. [PMID: 33007482 DOI: 10.1016/j.actbio.2020.09.045] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/18/2020] [Accepted: 09/22/2020] [Indexed: 02/06/2023]
Abstract
Whilst flow is the basis for silk fibre formation, subtle changes in a silk feedstocks' chemical environment may serve to increase both energetic efficiency and control hierarchical structure development during spinning. Despite the role of pH being largely understood, the influence of metal ions is not, only being inferred by correlative work and observations. Through a combination of rheology and microscopy, we provide a causative study of how the most abundant metal ions in the silk feedstock, Ca2+ and K+, affect its flow properties and structure. Our results show that Ca2+ ions increase viscosity and prevent molecular alignment and aggregation, providing ideal storage conditions for unspun silk. In contrast, the addition of K+ ions promotes molecular alignment and aggregation and therefore seems to transfer the silk feedstock into a spinning state which confirms recent 'sticky reptation' modelling hypotheses. Additionally, we characterised the influence of the ubiquitous kosmotropic agent Li+, used to prepare regenerated silk solutions, and find that it promotes molecular alignment and prevents aggregation which may permit a range of interesting artificial silk processing techniques to be developed. In summary, our results provide a clearer picture of how metal ions co-ordinate, control and thus contribute towards silk protein self-assembly which in turn can inspire structuring approaches in other biopolymer systems.
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19
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Fraternali F, Stehling N, Amendola A, Tiban Anrango BA, Holland C, Rodenburg C. Tensegrity Modelling and the High Toughness of Spider Dragline Silk. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E1510. [PMID: 32752054 PMCID: PMC7466511 DOI: 10.3390/nano10081510] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/28/2020] [Accepted: 07/29/2020] [Indexed: 01/21/2023]
Abstract
This work establishes a tensegrity model of spider dragline silk. Tensegrity systems are ubiquitous in nature, being able to capture the mechanics of biological shapes through simple and effective modes of deformation via extension and contraction. Guided by quantitative microstructural characterization via air plasma etching and low voltage scanning electron microscopy, we report that this model is able to capture experimentally observed phenomena such as the Poisson effect, tensile stress-strain response, and fibre toughness. This is achieved by accounting for spider silks' hierarchical organization into microfibrils with radially variable properties. Each fibril is described as a chain of polypeptide tensegrity units formed by crystalline granules operating under compression, which are connected to each other by amorphous links acting under tension. Our results demonstrate, for the first time, that a radial variability in the ductility of tensegrity chains is responsible for high fibre toughness, a defining and desirable feature of spider silk. Based on this model, a discussion about the use of graded tensegrity structures for the optimal design of next-generation biomimetic fibres is presented.
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Affiliation(s)
- Fernando Fraternali
- Department of Civil Engineering, University of Salerno, 84084 Fisciano (SA), Italy
| | - Nicola Stehling
- Department of Materials Science & Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, UK
| | - Ada Amendola
- Department of Civil Engineering, University of Salerno, 84084 Fisciano (SA), Italy
| | - Bryan Andres Tiban Anrango
- Centre for Biomedical and Chemical Science School of Science, Auckland University of Technology, Auckland 1010, New Zealand
| | - Chris Holland
- Department of Materials Science & Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, UK
| | - Cornelia Rodenburg
- Department of Materials Science & Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, UK
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20
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Greco G, Francis J, Arndt T, Schmuck B, G. Bäcklund F, Barth A, Johansson J, M. Pugno N, Rising A. Properties of Biomimetic Artificial Spider Silk Fibers Tuned by PostSpin Bath Incubation. Molecules 2020; 25:E3248. [PMID: 32708777 PMCID: PMC7397010 DOI: 10.3390/molecules25143248] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 07/10/2020] [Accepted: 07/13/2020] [Indexed: 11/17/2022] Open
Abstract
Efficient production of artificial spider silk fibers with properties that match its natural counterpart has still not been achieved. Recently, a biomimetic process for spinning recombinant spider silk proteins (spidroins) was presented, in which important molecular mechanisms involved in native spider silk spinning were recapitulated. However, drawbacks of these fibers included inferior mechanical properties and problems with low resistance to aqueous environments. In this work, we show that ≥5 h incubation of the fibers, in a collection bath of 500 mM NaAc and 200 mM NaCl, at pH 5 results in fibers that do not dissolve in water or phosphate buffered saline, which implies that the fibers can be used for applications that involve wet/humid conditions. Furthermore, incubation in the collection bath improved the strain at break and was associated with increased β-sheet content, but did not affect the fiber morphology. In summary, we present a simple way to improve artificial spider silk fiber strain at break and resistance to aqueous solvents.
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Affiliation(s)
- Gabriele Greco
- Laboratory of Bio-Inspired, Bionic, Nano, Meta, Materials & Mechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, 38123 Trento, Italy;
| | - Juanita Francis
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Neo, 14186 Huddinge, Sweden; (J.F.); (T.A.); (B.S.); (F.G.B.); (J.J.)
| | - Tina Arndt
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Neo, 14186 Huddinge, Sweden; (J.F.); (T.A.); (B.S.); (F.G.B.); (J.J.)
| | - Benjamin Schmuck
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Neo, 14186 Huddinge, Sweden; (J.F.); (T.A.); (B.S.); (F.G.B.); (J.J.)
| | - Fredrik G. Bäcklund
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Neo, 14186 Huddinge, Sweden; (J.F.); (T.A.); (B.S.); (F.G.B.); (J.J.)
| | - Andreas Barth
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, 10691 Stockholm, Sweden;
| | - Jan Johansson
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Neo, 14186 Huddinge, Sweden; (J.F.); (T.A.); (B.S.); (F.G.B.); (J.J.)
| | - Nicola M. Pugno
- Laboratory of Bio-Inspired, Bionic, Nano, Meta, Materials & Mechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano 77, 38123 Trento, Italy;
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Anna Rising
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Neo, 14186 Huddinge, Sweden; (J.F.); (T.A.); (B.S.); (F.G.B.); (J.J.)
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden
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21
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Serôdio R, Schickert SL, Costa-Pinto AR, Dias JR, Granja PL, Yang F, Oliveira AL. Ultrasound sonication prior to electrospinning tailors silk fibroin/PEO membranes for periodontal regeneration. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 98:969-981. [DOI: 10.1016/j.msec.2019.01.055] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 12/07/2018] [Accepted: 01/12/2019] [Indexed: 01/23/2023]
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