Embedding thread lift rhytidectomy,also known as“thread lifting”in China,with the natures of simple operation,less trauma and quick recovery,is progressively used in clinical practice as a new technology of face lif...Embedding thread lift rhytidectomy,also known as“thread lifting”in China,with the natures of simple operation,less trauma and quick recovery,is progressively used in clinical practice as a new technology of face lifting.Herewith,a brief introduction of the previous advances of thread lifting techniques and materials in the facial beauty industry,combined with the discussion on various types of sutures,common complications,and the site of actions were provided.The main limitations of present thread lifting material include:(1)the use of non-absorbable sutures is liable to cause allergies and a series of complications;(2)the absorbable sutures are easily degradation,and people need to reshape in a relatively short period.Therefore,the high biocompatible spider silk was proposed as a novel material of thread lifting suture and related devices,the advantages and preliminary achievements on spider silk were also addressed.展开更多
Spider silk is capturing the attention of scientists for its mechanical properties,biocompatibility,and biodegradability.Spiders can produce six types of silks,as well as special glue,which are used for survival and r...Spider silk is capturing the attention of scientists for its mechanical properties,biocompatibility,and biodegradability.Spiders can produce six types of silks,as well as special glue,which are used for survival and reproduction.During the last years of research,scientists deciphered gene sequences and expressed the most common types of spider silks.However,matching the mechanical properties of recombinant spider silks to native ones is still a big challenge.Moreover,in-depth studies are mostly focused on natural and recombinant ampullate silks,and only a few studies showed achievements on pyriform spidroin(PySp).In this study,repeatable parts of PySp were expressed,purified,and spun into fibers.Recombinase cloning strategy allowed to create highly-repetitive region parts clones efficiently in comparison to the traditional restriction enzyme cloning technique.A cost-effective high-yield purification strategy was used.This study provides strategies that can help to design recombinant spider silks with the same mechanical properties as native spider silks.展开更多
Dragline,framework and cocoon silk fibers of Araneus Ventricosus were used for this study.To investigate the microstructure mechanisms of stress-strain behavior of spider silk,firstly,amino acid compositions were anal...Dragline,framework and cocoon silk fibers of Araneus Ventricosus were used for this study.To investigate the microstructure mechanisms of stress-strain behavior of spider silk,firstly,amino acid compositions were analyzed and molecular conformations and crystallinity were measured with Raman spectra and X-ray diffraction respectively.The results showed that there were more amino acids with large side groups and polar ones in spider silk than those of Bombyx silk,and the amino acid distribution varied with different spider silk.The molecular structures were mainly α-helix and β-sheet,and random coil and β-turn existed as well.The proportions and arrangement of these conformations of dragline silk were different from framework and cocoon silk fibers.Microstructure was one of important factors of excellent mechanical properties of spider silk.Crystallinity of spider silk was very low,which implied that the roles of crystal on spider silk were not as great as other protein fibers.展开更多
Spider silk, relying on its exceptional mechanical properties, has attracted extensive attention throughout the world. The structure of a material can influence its mechanical properties. Investigation of the structur...Spider silk, relying on its exceptional mechanical properties, has attracted extensive attention throughout the world. The structure of a material can influence its mechanical properties. Investigation of the structure of spider silk includes amino acid composition, molecular structure, self-assembly, and crystallization, among other characteristics. Herein, the effects of concentration, time, alkali metal ions （Na^＋and K ^＋ ） and pH on the conformational transition and self-assembly of regenerated Ornithoctonus huwena spider dragline silk protein （spidroin） in water were investigated using circular dichroism （CD） and atomic force microScopy （AFM）. Spidroin concentration, time and Na ＋ ions slightly influenced the conformational transition of spidroin molecules. However, K ＋ ions and pH induced the formation of a β- sheet structure. Increasing spidroin concentration or time increased the aggregation of spidroin and enhanced the formation of nanoffiaments. K ~ ions enhanced the serf-assembly of spidroin into nanofilaments. The self-assembled nanofilaments appeared at a pH of approximately 6. 11. Both lower and higher pH induced aggregation. At a lower pH, the aggregation was composed of nanopartides, whereas higher pH induced the aggregation of nanoffiaments, likely from the synergistic effect of Na ^＋ ions and pH.展开更多
Spider silk fibers of species of the genera Araneus, Gasteracantha, and Linothele sericata were studied. The fibers are composed of axial threads and lateral villi, allowing adhesion to surfaces. Raman spectroscopy wa...Spider silk fibers of species of the genera Araneus, Gasteracantha, and Linothele sericata were studied. The fibers are composed of axial threads and lateral villi, allowing adhesion to surfaces. Raman spectroscopy was used to determine the surface and internal composition of the threads forming the structure. In the three species, the characteristic amino acid peaks of the spider web were found between 2871 and 2975 cm-1, which belong to L-glycine, L-alanine, L-glutamine, and L-proline. The threads are composed of a protective layer mainly composed of amides, alanine, and glycine. The fibrils surrounding the axial fibers consist mainly of amide II (1533 cm-1), which allows adhesion between the thread and the surfaces onto which the spider weaves the web. For the genus Linothele sericata, there is a peak on the surface of this spider web located at 2145 cm-1, which is associated with isonitriles with R-N-C bonds.展开更多
Various researches and studies have demonstrated that spider silk is much stronger and more deformable than a steel string of the same diameter from a mechanical approach. These excellent properties have caused many s...Various researches and studies have demonstrated that spider silk is much stronger and more deformable than a steel string of the same diameter from a mechanical approach. These excellent properties have caused many scientific disciplines to get involved, such as bio-mechanics, bio-materials and bio-mimetics, in order to create a material of similar properties and characteristics. It should be noted that the researches and studies have been oriented mainly as a quasi-static model. For this research, the analysis has taken a dynamic approach and determined the dissipation energy of a structure which is made of spider silk ＂Dragline＂ and produced by the Argiope- Argentata spider, through an analytical-experimental way, when being subjected to impulsive loading. Both experi- mental and analytical results, the latter obtained by using adjusted models, have given high levels of dissipation energy during the first cycle of vibration, which are consistent with the values suggested by other authors.展开更多
The spider dragline silk has excellent mechanical properties. The stress- strain curves of dragline silk fibers have intraspecific and intraindividual variability because of the spider’s active control during spinnin...The spider dragline silk has excellent mechanical properties. The stress- strain curves of dragline silk fibers have intraspecific and intraindividual variability because of the spider’s active control during spinning process. To investigate the relationship between the morphology of dragline silk fibers and spinning conditions, four samples were made at the reeling rates of 1 mm/s, 20 mm/s, 43.5 mm/s and 110 mm/s from the major ampullate glands of Araneus Ventricosus and the other two of dragline silks were prepared from a crawling or dropping spider. The surface microstructure and nanofibril characteristic were analyzed with atomic force microscopy (AFM). AFM images of 2 000 nm *2 000 nm and 500 nm*500 nm of these samples showed that the spinning condition influenced the surface roughness and fibril size, while AFM images of 200 nm*200 nm clearly displayed that dragline silk of Araneus Ventricosus included sheet macro-conformation structure. These results can facilitate the further investigation of the spinning mechanism of a spider in order to understand mechanical properties and macromolecular structures of dragline silk.展开更多
Dragline spider silks have relatively high mass-based mechanical properties (tensile strength, elongation to break and rupture energy) and are environmentally responsive (supercontraction). In order to produce new syn...Dragline spider silks have relatively high mass-based mechanical properties (tensile strength, elongation to break and rupture energy) and are environmentally responsive (supercontraction). In order to produce new synthetic fibers with these properties, many research groups have focused on identifying the chemical composition of these fibers and the structure of the fiber core. Since each fiber also has an outer skin, our study will provide a detailed understanding of the silk surface morphology, the response of the surface morphology to environmental conditions and processing variables, and also determine if the silk surface has a definitive patterning of charged amino acids. Specifically, by using force microscopy and functionalized nanoparticles, the present study examines 1) how the silk surface (topography, average roughness) is altered due to prior mechanical loading (viz. reeling speed), 2) alterations in morphology due to environmental conditions (supercontraction, storage time), and 3) the negatively and positively charged regions along with the surface using both force and nanoparticle mapping. Roughness data taken on dragline silk collected from Nephila clavipes spiders revealed that the surface comprised both smooth (5 nm RMS) and rough (65 nm RMS) regions. Supercontracted silk (from immersion in0.01 MPBS during AFM testing) showed higher surface roughness values compared to spider silk tested in the air, indicating that the surface might be reorganized during supercontraction. No correlation was found between surface roughness and neither collection speed nor aging time for the as-spun or supercontracted fiber, demonstrating the surface stability of the dragline silk over time in terms of roughness. Both the force microscopy and the nanoparticle methods suggested that the density of negatively charged amino acids (glutamic acid, aspartic acid) was higher than that of the positively charged amino acids (lysine, asparagine, and histidine).展开更多
基金We thank the National Natural Science Foundation of China(81660186/81160134)the Yunnan-Kunming Medical Joint Applied Basic Research Fund(Grant No.2017FE468-009)for funding support.
文摘Embedding thread lift rhytidectomy,also known as“thread lifting”in China,with the natures of simple operation,less trauma and quick recovery,is progressively used in clinical practice as a new technology of face lifting.Herewith,a brief introduction of the previous advances of thread lifting techniques and materials in the facial beauty industry,combined with the discussion on various types of sutures,common complications,and the site of actions were provided.The main limitations of present thread lifting material include:(1)the use of non-absorbable sutures is liable to cause allergies and a series of complications;(2)the absorbable sutures are easily degradation,and people need to reshape in a relatively short period.Therefore,the high biocompatible spider silk was proposed as a novel material of thread lifting suture and related devices,the advantages and preliminary achievements on spider silk were also addressed.
基金National Natural Science Foundation of China(No.31470836)Science and Technology Commission of Shanghai Municipality,China(No.19ZR1471000)。
文摘Spider silk is capturing the attention of scientists for its mechanical properties,biocompatibility,and biodegradability.Spiders can produce six types of silks,as well as special glue,which are used for survival and reproduction.During the last years of research,scientists deciphered gene sequences and expressed the most common types of spider silks.However,matching the mechanical properties of recombinant spider silks to native ones is still a big challenge.Moreover,in-depth studies are mostly focused on natural and recombinant ampullate silks,and only a few studies showed achievements on pyriform spidroin(PySp).In this study,repeatable parts of PySp were expressed,purified,and spun into fibers.Recombinase cloning strategy allowed to create highly-repetitive region parts clones efficiently in comparison to the traditional restriction enzyme cloning technique.A cost-effective high-yield purification strategy was used.This study provides strategies that can help to design recombinant spider silks with the same mechanical properties as native spider silks.
文摘Dragline,framework and cocoon silk fibers of Araneus Ventricosus were used for this study.To investigate the microstructure mechanisms of stress-strain behavior of spider silk,firstly,amino acid compositions were analyzed and molecular conformations and crystallinity were measured with Raman spectra and X-ray diffraction respectively.The results showed that there were more amino acids with large side groups and polar ones in spider silk than those of Bombyx silk,and the amino acid distribution varied with different spider silk.The molecular structures were mainly α-helix and β-sheet,and random coil and β-turn existed as well.The proportions and arrangement of these conformations of dragline silk were different from framework and cocoon silk fibers.Microstructure was one of important factors of excellent mechanical properties of spider silk.Crystallinity of spider silk was very low,which implied that the roles of crystal on spider silk were not as great as other protein fibers.
基金the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘Spider silk, relying on its exceptional mechanical properties, has attracted extensive attention throughout the world. The structure of a material can influence its mechanical properties. Investigation of the structure of spider silk includes amino acid composition, molecular structure, self-assembly, and crystallization, among other characteristics. Herein, the effects of concentration, time, alkali metal ions （Na^＋and K ^＋ ） and pH on the conformational transition and self-assembly of regenerated Ornithoctonus huwena spider dragline silk protein （spidroin） in water were investigated using circular dichroism （CD） and atomic force microScopy （AFM）. Spidroin concentration, time and Na ＋ ions slightly influenced the conformational transition of spidroin molecules. However, K ＋ ions and pH induced the formation of a β- sheet structure. Increasing spidroin concentration or time increased the aggregation of spidroin and enhanced the formation of nanoffiaments. K ~ ions enhanced the serf-assembly of spidroin into nanofilaments. The self-assembled nanofilaments appeared at a pH of approximately 6. 11. Both lower and higher pH induced aggregation. At a lower pH, the aggregation was composed of nanopartides, whereas higher pH induced the aggregation of nanoffiaments, likely from the synergistic effect of Na ^＋ ions and pH.
文摘Spider silk fibers of species of the genera Araneus, Gasteracantha, and Linothele sericata were studied. The fibers are composed of axial threads and lateral villi, allowing adhesion to surfaces. Raman spectroscopy was used to determine the surface and internal composition of the threads forming the structure. In the three species, the characteristic amino acid peaks of the spider web were found between 2871 and 2975 cm-1, which belong to L-glycine, L-alanine, L-glutamine, and L-proline. The threads are composed of a protective layer mainly composed of amides, alanine, and glycine. The fibrils surrounding the axial fibers consist mainly of amide II (1533 cm-1), which allows adhesion between the thread and the surfaces onto which the spider weaves the web. For the genus Linothele sericata, there is a peak on the surface of this spider web located at 2145 cm-1, which is associated with isonitriles with R-N-C bonds.
文摘Various researches and studies have demonstrated that spider silk is much stronger and more deformable than a steel string of the same diameter from a mechanical approach. These excellent properties have caused many scientific disciplines to get involved, such as bio-mechanics, bio-materials and bio-mimetics, in order to create a material of similar properties and characteristics. It should be noted that the researches and studies have been oriented mainly as a quasi-static model. For this research, the analysis has taken a dynamic approach and determined the dissipation energy of a structure which is made of spider silk ＂Dragline＂ and produced by the Argiope- Argentata spider, through an analytical-experimental way, when being subjected to impulsive loading. Both experi- mental and analytical results, the latter obtained by using adjusted models, have given high levels of dissipation energy during the first cycle of vibration, which are consistent with the values suggested by other authors.
基金science and technology office of Jiangsu province
文摘The spider dragline silk has excellent mechanical properties. The stress- strain curves of dragline silk fibers have intraspecific and intraindividual variability because of the spider’s active control during spinning process. To investigate the relationship between the morphology of dragline silk fibers and spinning conditions, four samples were made at the reeling rates of 1 mm/s, 20 mm/s, 43.5 mm/s and 110 mm/s from the major ampullate glands of Araneus Ventricosus and the other two of dragline silks were prepared from a crawling or dropping spider. The surface microstructure and nanofibril characteristic were analyzed with atomic force microscopy (AFM). AFM images of 2 000 nm *2 000 nm and 500 nm*500 nm of these samples showed that the spinning condition influenced the surface roughness and fibril size, while AFM images of 200 nm*200 nm clearly displayed that dragline silk of Araneus Ventricosus included sheet macro-conformation structure. These results can facilitate the further investigation of the spinning mechanism of a spider in order to understand mechanical properties and macromolecular structures of dragline silk.
文摘Dragline spider silks have relatively high mass-based mechanical properties (tensile strength, elongation to break and rupture energy) and are environmentally responsive (supercontraction). In order to produce new synthetic fibers with these properties, many research groups have focused on identifying the chemical composition of these fibers and the structure of the fiber core. Since each fiber also has an outer skin, our study will provide a detailed understanding of the silk surface morphology, the response of the surface morphology to environmental conditions and processing variables, and also determine if the silk surface has a definitive patterning of charged amino acids. Specifically, by using force microscopy and functionalized nanoparticles, the present study examines 1) how the silk surface (topography, average roughness) is altered due to prior mechanical loading (viz. reeling speed), 2) alterations in morphology due to environmental conditions (supercontraction, storage time), and 3) the negatively and positively charged regions along with the surface using both force and nanoparticle mapping. Roughness data taken on dragline silk collected from Nephila clavipes spiders revealed that the surface comprised both smooth (5 nm RMS) and rough (65 nm RMS) regions. Supercontracted silk (from immersion in0.01 MPBS during AFM testing) showed higher surface roughness values compared to spider silk tested in the air, indicating that the surface might be reorganized during supercontraction. No correlation was found between surface roughness and neither collection speed nor aging time for the as-spun or supercontracted fiber, demonstrating the surface stability of the dragline silk over time in terms of roughness. Both the force microscopy and the nanoparticle methods suggested that the density of negatively charged amino acids (glutamic acid, aspartic acid) was higher than that of the positively charged amino acids (lysine, asparagine, and histidine).
