Silk Research Articles

Liquid-liquid crystalline phase separation of spider silk proteins.

Liquid-liquid phase separation (LLPS) of proteins can be considered an intermediate solubility regime between disperse solutions and solid fibers. While LLPS has been described for several pathogenic amyloids, recent evidence suggests that it is similarly relevant for functional amyloids. Here, we review the evidence that links spider silk proteins (spidroins) and LLPS and its role in the spinning process. Major ampullate spidroins undergo LLPS mediated by stickers and spacers in their repeat regions. During spinning, the spidroins droplets shift from liquid to crystalline states. Shear force, altered ion composition, and pH changes cause micelle-like spidroin assemblies to form an increasingly ordered liquid-crystalline phase. Interactions between polyalanine regions in the repeat regions ultimately yield the characteristic β-crystalline structure of mature dragline silk fibers. Based on these findings, we hypothesize that liquid-liquid crystalline phase separation (LLCPS) can describe the molecular and macroscopic features of the phase transitions of major ampullate spidroins during spinning and speculate whether other silk types may use a similar mechanism to convert from liquid dope to solid fiber.

Silk Flocked Flexible Sensor Capable of Wide-Range and Sensitive Pressure Perception.

In recent years, there have been advancements in high-performance soft sensors with simultaneous moderate sensitivity and wide linearity. However, it remains challenging to combine high-efficiency production and high performance for soft sensors. The skin and hair structure provide an elegantly simple sensing model, where hair acts as signal receptors and basal skin acts as signal processors. Herein, we used efficient electrostatic flocking and extrusion printing to engineer comb-shaped electrodes with conductive polydimethylsiloxane (PDMS) flocked with conductive silk fibers as a biomimetic flexible sensor. The mechanical and electrical properties of modified PDMS and silk fibers were characterized to optimize the functionalization process. The sensor unit exhibited a high linear range up to 2,000 kPa and a competitively good sensitivity of 0.0285 kPa-1 in the contact mode with conductive materials, as well as good resolution in the noncontact mode. Such sensors and a sensor array demonstrated potential applications for detecting pressure disturbances from acoustic activity and for human-robot interactions. We anticipate that the straightforward design and facile fabrication of soft sensors with vertical fibrous morphology for perception will open new avenues for the next generation of high-performance soft sensors integrated with artificial intelligence.

Exporting Silk from Byzantine Greece: Reconstructing the Trade Logistics of the Theban Silk Industry

ABSTRACT The silk industry that thrived in Thebes around the twelfth century exemplified Byzantium’s industrial accomplishments during the middle Byzantine period. However, how its silk products were exported still awaits systematic clarification. This topic becomes increasingly compelling as scholars begin to reveal the industry’s potential interactions with other regional economic sectors, especially pottery production in Euripos, in terms of trade logistics. This article aims to contribute a thorough investigation into the trade logistics of the Theban silk industry. It argues that Theban silk could have been distributed to its market destinations entirely overland or by integrating with maritime transport at nearby entrepôts. Initially, Corinth, with its two ports oriented towards trade hubs in the east and west, served as the paramount entrepôt. As Corinth’s maritime trade, especially its eastern port, declined in the later twelfth century, Euripos emerged to bridge the gap and assumed its former trade roles.

Color fastness and antimicrobial activity of Gardenia jasminoides extract against antimicrobial-resistant Staphylococcus aureus

This study investigated the antimicrobial efficacies of fabrics (100% cotton and 100% silk) dyed with an ethanol extract of Gardenia jasminoides (G. jasminoides). More specifically, these fabrics were dyed using a G. jasminoides extract with a dye bath ratio of 1:20 at 40–60 °C for 60 min, followed by post-mordanting. The concentrations of the aluminum sulfate, copper sulfate, and ferrous sulfate mordants were each set to 3% (o.w.f.). The samples were mordanted using a mordant bath ratio of 1:30 at 40 °C for 20 min. The iron mordant slightly increased the dye uptake (K/S) of the cotton fabric but did not increase the dye uptake (K/S) of the silk fabric. The antimicrobial efficacies of the dyed fabrics against methicillin-resistant Staphylococcus aureus (MRSA) ATCC 33591 were determined to be 99.8 and 87.8% for the cotton and silk fabrics, respectively. The inhibitory effects of the cotton and silk fabrics against MRSA were 30.5 × and 167.3 × the inoculum size, respectively, indicating the superior inhibitory effect of the dyed cotton fabric. These results suggest that the fabrics dyed with G. jasminoides extract may possess antibacterial activity against antimicrobial-resistant bacteria.

Bacterial Cellulose–Silk Hydrogel Biosynthesized by Using Coconut Skim Milk as Culture Medium for Biomedical Applications

In this study, hydrogel films of biocomposite comprising bacterial cellulose (BC) and silk (S) were successfully fabricated through a simple, facile, and cost-effective method via biosynthesis by Acetobacter xylinum in a culture medium of coconut skim milk/mature coconut water supplemented with the powders of thin-shell silk cocoon (SC). Coconut skim milk/mature coconut water and SC are the main byproducts of coconut oil and silk textile industries, respectively. The S/BC films contain protein, carbohydrate, fat, and minerals and possess a number of properties beneficial to wound healing and tissue engineering, including nontoxicity, biocompatibility, appropriate mechanical properties, flexibility, and high water absorption capacity. It was demonstrated that silk could fill into a porous structure and cover fibers of the BC matrix with very good integration. In addition, components (fat, protein, etc.) in coconut skim milk could be well incorporated into the hydrogel, resulting in a more elastic structure and higher tensile strength of films. The tensile strength and the elongation at break of BC film from coconut skim milk (BCM) were 212.4 MPa and 2.54%, respectively, which were significantly higher than BC film from mature coconut water (BCW). A more elastic structure and relatively higher tensile strength of S/BCM compared with S/BCW were observed. The films of S/BCM and S/BCW showed very high water uptake ability in the range of 400–500%. The presence of silk in the films also significantly enhanced the adhesion, proliferation, and cell-to-cell interaction of Vero and HaCat cells. According to multiple improved properties, S/BC hydrogel films are high-potential candidates for application as biomaterials for wound dressing and tissue engineering.

Construction and 3D Printing of Multiscale Silk Fiber‐Cellulose Composite Networks Based on Ionic Liquids

AbstractMicroscopic defects in the amorphous regions of natural cellulose affect the mechanical properties of their materials. After dissolution and regeneration, cellulose's mechanical properties are still insufficient for application in advanced materials. Conventional compounding and crosslinking techniques with toxic crosslinking agents are not only cumbersome, but also have limited performance enhancement in cellulose materials Therefore, much attention has been paid to designing and developing more straightforward and efficient cellulose reinforcement technologies. Herein, an in situ multiscalarization strategy is used to form multiscale silk fiber‐cellulose composites (MS‐C) by the gradual nanosizing of silk fibers (SF) under heating in a 1‐butyl‐3‐methylimidazolium chloride solution of cellulose (Cel‐BmimCl). MS‐C are constructed from micro and nano SF, fibroin chains, and cellulose molecules into a multidimensional network. Due to its advantage of multiscale structure, MS‐C has excellent mechanical properties, the tensile strength and Young's modulus, which are 123.06% and 91.68% higher than that of pure regenerated cellulose after 5h heating treatment. Besides, MS‐C has good biocompatibility and can be molded or 3D printed with direct ink writing, showing broad application prospects in medical, bioengineering, and other fields. This multiscale enhancement strategy can also be extended to the research and application of biopolymers such as natural polysaccharides or proteins.

Preparation of Purpurin-Fe2+ Complex Natural Dye and Its Printing Performance on Silk Fabrics.

In order to shorten the process of textile printing with natural dyes, develop new methods, and improve the color fastness and quality of printed products, this study presents a novel approach by synthesizing a natural complex dye through the interaction between purpurin and Fe2+ ions, resulting in a compound named purpurin-Fe2+ (P-Fe). This synthesized complex dye was meticulously characterized using state-of-the-art analytical techniques, including Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-Vis) spectrophotometry, and scanning electron microscopy energy-dispersive spectroscopy (EDS). The characterization confirmed the successful complexation of purpurin with Fe2+ ions. The prepared complex dye P-Fe was used for the printing of silk fabric. The optimized printing process involves steaming at a temperature of 100 °C for a duration of 20 min. In comparison to fabrics printed using direct dyes, the K/S values of the fabric printed with the P-Fe complex showed a significant enhancement, with all color fastness ratings achieving grade four. Furthermore, the proportion of metal elements on the white background of the printed fabric was found to be less than 0.180%, and the level of whiteness was above 50. The application of the P-Fe dye in silk fabric printing not only streamlines the printing process but also enhances the depth and speed of the printed color, effectively addressing the issue of color transfer onto a white background, which is commonly associated with natural dyes.

Innovative transparent silk-melamine formaldehyde film with enhanced corrosion resistance and high tensile strength for surface decoration

Transparent films with reduced light reflection and excellent wear resistance are crucial for applications that require anti-reflective properties without causing environmental harm. However, the preparation process of conventional anti-reflective films is relatively complicated. This paper proposes a simple method to prepare transparent film based on silk fabrics and melamine formaldehyde (MF) resins. The silk fabric's lattice structure serves as a frame, while the MF resin provides transparency and corrosion resistance as a functional filler. The resulting composite films, produced via hot pressing, exhibit excellent tensile strength (up to 617.4 MPa), anti-abrasion properties, and improved flexibility compared to pure MF films. Importantly, these films achieve a high transmittance (>85%) and a significant haze (ranging from 71.8% to 94.9%), with the silk fiber content primarily influencing scattering and haze levels while minimally affecting light transmittance. Additionally, the films demonstrate good pollution resistance and environmental friendliness, allowing contaminants to be removed after 5 h, and exhibit a TVOC emission of <0.1 mg/m3. These findings indicate that the developed composite films are promising candidates for wood surface decoration and applications that benefit from haze, such as anti-glare products. This work not only provides a straightforward method for creating flexible, anti-reflective transparent films utilizing natural fibers but also contributes to advancing sustainable practices in material design.

Eco-friendly utilization of microwaves for extraction of dye from logwood and Its application onto silk

For minimizing the pollution associated with synthetic colorants, the world again is going to realize the benefits of natural colorants in applied fields such as textiles, food flavors, etc. As part of the ongoing research project, hematein is being investigated as a potential natural colorant derived from logwood chips, and its implementation on silk fabric is being investigated under the effect of microwave radiations. A number of dyeing variables, including pH, dyeing duration, temperature of the dye bath, volume of extraction, and salt concentration, have been investigated, and the effect of isolation medium has also been evaluated. For new shades with improved fastness ratings, extracts of various sustainable bio-mordants and chemical mordant such as salts of aluminum and copper, and tannic acid were also used. An experiment revealed that treating un-irradiated silk with 40 mL of methanolic extract with a pH of 2, irradiated for 6 min, produced outstanding outcomes when dyed at 90°C for 60 min. The dyeing process included the addition of 9 g of salt per 100 mL of solution as an exhausting agent. In these circumstances, the utilization of sustainable mordants has not only enhanced the ratings of color fastness but has also rendered the procedure more environmentally friendly and less polluting. Therefore, microwave radiation has great potential for extracting colorants from plants and effectively applying them to natural materials under decreased conditions.

DEVELOPMENT OF A MECHATRONIC SYSTEM FOR A SILKWORM INCUBATOR

In this study, the effectiveness of using a mechatronic system in the incubation of silkworm eggs was studied. The incubator consists of an SCD41 sensor, an ESP32 microcontroller, a TES1-12706 air cooler, an electric heater and a ventilation systembo'lib, harorat, namlik va CO2, which provides automatic control of temperature, humidity and CO2 quantity2. The study showed that when using the new system, the level of egg viability increased by 4.1%, and the yield of cocoons-by 5.8%. However, the overall length of the silk fiber and the continuous length have also been improved. This innovative system can be of great importance for improving product quality and ensuring economic efficiency in the silk industry.

Application of Tectona grandis Leaf Extract for Efficient and Stabilized Coloration of Mulberry Silk Fabric

Application of Tectona grandis Leaf Extract for Efficient and Stabilized Coloration of Mulberry Silk Fabric

Cocoon microstructures through the lens of topological persistence.

Biological materials display a wide array of functionality, often dictated by complicated microstructures. New geometric and topological strategies allow one to describe the microstructures in a precise and systematic way. This article describes the application of topological persistence and other geometric methods to the microstructural analysis of three-dimensional X-ray micro-computed tomography scans of the Bombyx mori silkworm cocoons. These methods allow conclusions to be drawn about pore space gradients, silk fibre thickness gradients and fibre alignment within the cocoon. The study demonstrates the applicability of these topological and geometric methods to quantify and characterize fibrous materials.

Improving the mechanical property of silk by feeding silkworm with chiral carbon dots

The influence of chiral materials on organisms is crucial. However, there is little research on the impact of chiral carbon dots (CDs), a kind of typical chiral materials, on biology. Herein, chiral CDs (L-/D-CDs) were synthesized using the thermal polymerization method from citric acid and chiral cysteine. The effect of chiral CDs on silkworms was explored through feeding silkworms with chiral CDs. The breaking strength of silk fibers (667.9 MPa) in D-CDs group exhibit a 71.4 % increase compared with control-silk (389.5 MPa), while the breaking strength of silk fibers in L-CDs group increases by 51.6 %. In addition, Fourier transform infrared spectra display CDs can prevent the transformation from random coil/α-helix structures to β-sheet structures. Furthermore, D-CDs group exhibit the highest percentage of four primary amino acids (glycine, alanine, serine, and tyrosine) relative to the total amino acids in silkworm hemolymph. This percentage is elevated by 70.5 % compared to the control group, thereby furnishing an ample supply of raw materials for the synthesis of silk proteins. In contrast, L-CDs group exhibits increase by 39.3 %. Our work provides new ideas and approaches for studying the effects of chiral materials on living organisms.

P078 Structured biohybrid materials for the regeneration of the urogenital plexus, based on selective biofunctionalization of D3S-engineered silk fibers

P078 Structured biohybrid materials for the regeneration of the urogenital plexus, based on selective biofunctionalization of D3S-engineered silk fibers

EFFECT OF USING MECHATRONIC MULTILAYER SILKWORM FEEDER ON PRODUCTIVITY

In this study, a mechatronic system was developed for the care of silkworms in multi-layer feeders. This system allows you to monitor and monitor the humidity and temperature in each layer using the DHT11 sensor. The results showed that humidity and temperature were kept stable by a mechatronic system, which positively affected the growth of silkworms and the production of high-quality silk. Compared to traditional methods, the system has made it possible to use resources more efficiently and save energy. The mechatronic system allows you to make the process of growing silkworms efficient and stable. This suggests that the method has great prospects in the development of the silk industry.

Bmgsb is involved in the determination of cell fate by affecting the cell cycle genes in the silk gland of Bombyx mori

Silk gland is the only organ of silkworm that can produce silk protein, which is a natural macromolecular protein complex and widely utilized in various fields such as biomaterials and biomedicine. The development of silk gland and the expression patterns of silk protein crucial for the silk industry. In this study, the function of a transcription factor Bmgsb was investigated with CRISPR/Cas9 and transgenic system. It was found that the homozygous individuals in the Bmgsb KO line experienced spinning failure and pupae death, the AMSG exhibited defects, and the ASG displayed abnormal curvature. These phenotypes were accompanied by increased DNA endoreplication and significantly upregulated expression of fibroin genes in the ASG. RT-qPCR results confirmed significant upregulation of cell cycle-related genes, including cyclin G and cyclin T in the Bmgsb KO line. Furthermore, ectopic expression of Bmgsb in the PSG weakened PSG curvature, inhibited DNA endoreplication, and downregulated the expression of fibroin genes. These findings strongly suggest that Bmgsb plays a crucial role in determining cell fate in the silk gland and regulating the expression of silk protein through the cyclin pathway. Our research provides a theoretical foundation for further studies on organ differentiation and have implications for the silk industry.

APPLICATION OF THE MECHATRONIC SYSTEM TO SILKWORM FEEDERS

In this study, a mechatronic system was developed for the care of mulberry silkworms in multi-layered succulents. This system allows you to monitor and monitor the humidity and temperature in each layer using the DHT11 sensor. The results showed that humidity and temperature were kept stable by a mechatronic system, which positively affected the growth of silkworms and the production of high-quality silk. Compared to traditional methods, the system has made it possible to use resources more efficiently and save energy. In short, the mechatronic system makes the silkworm rearing process efficient and stable. This suggests that the method has great prospects in the development of the silk industry.

A strategy for improving the mechanical properties of silk fibers through the combination of genetic manipulation and zinc ion crosslinking

Silk fiber is generally considered an excellent biological material due to its good biocompatibility, morphological plasticity and biodegradability. Previously, the construction of silkworm silk gland bioreactors based on the piggyBac transposon has been optimized. However, the inserted exogenous genes have problems such as position uncertainty, and expression is not strictly controlled. Here, we applied transcription activator-like effector nuclease (TALEN)-mediated homology-directed repair (HDR) to precisely insert histidine-rich cuticular protein (CP) into silkworm Sericin1 (Ser1) gene. The Ser1-CP fusion protein was successfully secreted into cocoon shell. Subsequently, based on the metal coordination ability of the histidine imidazole group, we crosslinked cocoon with metal ions in vitro. In this strategy, the mechanical properties of the fused silk fibers with crosslinked Zn2+ improved, and the maximum breaking stress of the crosslinked Zn2+-fused silk fibers was 23.5 % greater than that of the wild-type fibers. Analysis of the secondary structure of the silk protein showed that the fused silk fibers crosslinked with Zn2+ had more β-sheet structures. This study pioneered a method of improving the mechanical properties of silk fibers by crosslinking metal ions with fused exogenous proteins and expanded the application value of silk gland bioreactors in the development of novel biomaterials.

Surface modification of fabrics using dielectric barrier discharge plasma for improved antifouling performance

Abstract Surface modification of fabrics is an effective way to endow them with antifouling properties while still maintain their key advantages like comfort, softness, and stretchability. Herein, an atmospheric pressure dielectric barrier discharge (DBD) plasma method is demonstrated for the processing of silk fabrics using 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDS) as the precursor. The results showed the successful grafting of PFDS groups on the surface of silk fabrics without causing damage. Meanwhile, the gas temperature is rather low during the whole processing procedure, suggesting the non-equilibrium characteristics of DBD plasma. The influence of processing parameters on fabrics was systematically investigated, like the PFDS concentration, plasma treatment time, and plasma discharge power. An optimum processing condition was determined to be PFDS concentration: 8 wt%, plasma processing time: 40 s, and plasma power: 11.87 W. However, with the prolonged plasma processing time or enhanced plasma power, the plasma-grafted PFDS films could be degraded. Further study revealed that plasma processing of silk fabrics with PFDS would lead to the change of their chemical composition and surface roughness. As a result, the surface energy of the fabrics was reduced, accompanied by the improved water and oil repellency properties as well as enhanced antifouling performance. Besides, the plasma-grafted PFDS films also had good durability and stability. By extending the fabrics to polyester and wool against different oil-/water-based stains, the DBD plasma surface modification technique demonstrated good versatility in improving the antifouling properties of fabrics. This work provides a guidance for the surface modification of fabrics using DBD plasma to confer them with desirable functionalities.

Dyeing ability of C. longa L. and T. stans (L.) Juss. Ex Kunth on unmordanted and mordanted silk and cotton fabrics

The work was on the extraction of both the C. longa rhizomes and the petals of T. stans using four different solvents (ethanol, ethyl acetate, water, and n-hexane). The dyeing potential of the C. longa and T. stans extracts was evaluated on cotton and silk fabrics without or with mordants using potash alum, phosphomolybdic acid, iron (II) sulphate, and tartaric acid at varied temperatures and tested for colour fastness properties (wash and light fastness). The pH and absorbance of the dye bath before and after dyeing were studied. However, cotton, which is cellulosic, was better dyed than silk, which is proteinous, which showed a better choice for fabrics dyeing at 80 °C; hence, it had a good colour efficiency. Iron (II) sulphate exhibited complexes in the octahedral configuration of the coordination six with CH2O- of cotton and NH3+ and COO- of silk fabric. In addition, it was also observed that the higher the dyeing temperature, the greater the dyeing intensity. The spectroscopic characterization of the extracts was determined with the help of UV-Vis and FTIR. The UV-Vis and FTIR spectral analyses revealed the chromophore, auxochrome groups, and functional groups, respectively, within the extracts. Curcumin and rutin were identified as being responsible for the dyeing of the fabric.