Silk Research Articles

Evaluation of tactile sensation for fabric handle – evidence from event related potentials

PurposeIn this paper, the brain potential changes caused by touching fabrics for handle evaluation were recorded by event related potential (ERP) method, compared with subjective evaluation scores and physical index of KES, explore the cognitive mechanism of the transformation of tactile sensation into neural impulses triggered by subtle mechanical stimuli such as material, texture, density and morphology in fabrics. By combining subjective evaluation of fabric tactile sensation, objective physical properties of fabrics and objective neurobiological signals, explore the neurophysiological mechanism of tactile cognition and the signal characteristics and time process of tactile information processing.Design/methodology/approachThe ERP technology was first proposed by a British psychologist named Grey Walter. It is an imaging technique of noninvasive brain cognition, whose potential changes are related to the human physical and mental activities. ERP is different from electroencephalography (EEG) and evoked potentials (EP) on the fact that it cannot only record stimulated physical information which is transmitted to brain, but also response to the psychological activities which related to attention, identification, comparison, memory, judgment and cognition as well as to human’s neural physiological changes which are caused by cognitive process of the feeling by stimulation.FindingsAccording to potential changes in the cerebral cortex evoked by touching four types of silk fabrics, human brain received the physical stimulation in the early stage (50 ms) of fabrics handle evaluation, and the P50 component amplitude showed negative correlation with fabric smoothness sensations. Around 200 ms after tactile stimulus onset, the amplitude of P200 component show positive correlation with the softness sensation of silk fabrics. The relationship between the amplitude of P300 and the sense of smoothness and softness need further evidence to proof.Originality/valueIn this paper, the brain potential changes caused by touching fabrics for handle evaluation were recorded by event related potential (ERP) method, compared with subjective evaluation scores and physical index of KES, the results shown that the maximum amplitude of P50 component evoked by fabric touching is related to the fabrics’ smoothness and roughness emotion, which means in the early stage processing of tactile sensation, the rougher fabrics could arouse more attention. In addition, the amplitude of P200 component shows positive correlation with the softness sensation of silk fabrics.

Silk Industry Waste Protein-Derived Sericin Hybrid Nanoflowers for Antibiotics Remediation via Circular Economy.

Hybrid protein-copper nanoflowers have emerged as promising materials with diverse applications in biocatalysis, biosensing, and bioremediation. Sericin, a waste biopolymer from the textile industry, has shown potential for fabricating such nanoflowers. However, the influence of the molecular weight of sericin on nanoflower morphology and peroxidase-like activity remains unexplored. This work focused on the self-assembly of nanoflowers using high- and low-molecular-weight (HMW and LMW) silk sericin combined with copper(II) as an inorganic moiety. The peroxidase-like activity of the resulting nanoflowers was evaluated using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and hydrogen peroxide (H2O2). The findings revealed that high-molecular-weight sericin hybrid nanoflowers (HMW-ShNFs) exhibited significantly higher peroxidase-like activity than low-molecular-weight sericin hybrid nanoflowers (LMW-ShNFs). Furthermore, HMW-ShNFs demonstrated superior reusability and storage stability, thereby enhancing their potential for practical use. This study also explored the application of HMW-ShNF for ciprofloxacin degradation to address the environmental and health hazards posed by this antibiotic in water. The results indicated that HMW-ShNFs facilitated the degradation of ciprofloxacin, achieving a maximum degradation of 33.2 ± 1% at pH 8 and 35 °C after 72 h. Overall, the enhanced peroxidase-like activity and successful application in ciprofloxacin degradation underscore the potential of HMW-ShNFs for a sustainable and ecofriendly remediation process. These findings open avenues for the further exploration and utilization of hybrid nanoflowers in various environmental applications.

The investigation on dark dyeing properties of silk using Dioscorea cirrhosa Lour. tuber extracts with varied molecular weights

This work reported the dark dyeing properties of Dioscorea cirrhosa Lour. tuber extracts with different molecular weights on silk. The study on component analysis indicates that the molecular weight of most condensed tannins and polyphenols in D. cirrhosa L. tuber extracts is higher than 1000. The kinetic study demonstrates that the adsorption processes of D. cirrhosa L. tuber extract components with molecular weights higher than 1000, and components with molecular weights lower than 1000 toward silk fabrics are fitted with the pseudo-second order model, and the survey of adsorption isotherms reveals that multiple interactions occurred between dyes and silk, encompassing hydrogen bonding and van der Waals forces. The dyeing research shows that the dyed silk achieves its darkest color when employing D. cirrhosa L. tuber extract components with molecular weights lower than 1000 with a Fe2+ mordant concentration of 4 g/L and a pH value of 5. The K/S and L* values of dyed silk are 9.05 and 30.77, respectively. Under this dyeing condition, the complex, Fe element content, and Fe2+ ratio on the silk dyed with D. cirrhosa L. tuber extract components with molecular weights lower than 1000 surface are higher than those of D. cirrhosa L. tuber extracts and D. cirrhosa L. tuber extract components with molecular weights higher than 1000. The present study indicates that condensed tannins in D. cirrhosa L. tuber extracts are not the sole active compounds involved in the silk dark dyeing process. Polyphenols with molecular weights below 1000 in D. cirrhosa L. tuber extracts are shown to influence significantly and, in some cases, dominate the silk dark dyeing process.

Custom-designed, mass silk production in genetically engineered silkworms.

Genetically engineered silkworms have been widely used to obtain silk with modified characteristics especially by introducing spider silk genes. However, these attempts are still challenging due to limitations in transformation strategies and difficulties in integration of the large DNA fragments. Here, we describe three different transformation strategies in genetically engineered silkworms, including transcription-activator-like effector nuclease (TALEN)-mediated fibroin light chain (FibL) fusion (BmFibL-F), TALEN-mediated FibH replacement (BmFibH-R), and transposon-mediated genetic transformation with the silk gland-specific fibroin heavy chain (FibH) promoter (BmFibH-T). As the result, the yields of exogenous silk proteins, a 160 kDa major ampullate spidroin 2 (MaSp2) from the orb-weaving spider Nephila clavipes and a 226 kDa fibroin heavy chain protein (EvFibH) from the bagworm Eumeta variegate, reach 51.02 and 64.13% in BmFibH-R transformed cocoon shells, respectively. Moreover, the presence of MaSp2 or EvFibH significantly enhances the toughness of genetically engineered silk fibers by ∼86% in BmFibH-T and ∼80% in BmFibH-R silkworms, respectively. Structural analysis reveals a substantial ∼40% increase in fiber crystallinity, primarily attributed to the presence of unique polyalanines in the repetitive sequences of MaSp2 or EvFibH. In addition, RNA-seq analysis reveals that BmFibH-R system only causes minor impact on the expression of endogenous genes. Our study thus provides insights into developing custom-designed silk production using the genetically engineered silkworm as the bioreactor.

Rheological Study on Blend Solutions of Non-mulberry Silk Fibroin and Gelatin Biopolymers

In current research work, we have studied the blending effect of non-mulberry silk fibroin (10% weight/volume basis) and gelatin (20% weight/volume basis) in formic acid. Several blends as SF10G0, SF2G8, SF3G7, SF5G5 and SF0G10 have been made and their rheological behaviour was investigated. The blend solutions were subjected to a steady shear rheological study in the variety of range of shear rates, namely 0.01–500 sec-1 and the viscosities of blend solutions were noticed to decrease in comparison to pure silk solution. The frequency sweep was employed in dynamic rheological tests to determine complex viscosity of these solutions from range of angular sweep 0.1–100 rad/sec. The consistent shear-thinning behaviour was noted for all the blends. The difference in numerical values of shear and complex viscosities indicated disobedience of Cox-Merz rule. Such analysis can be utilised for tailoring the properties of solution prior to processing them to create a versatile range of materials.

Influencing mechanism on sensitivity of carbonized fabric strain sensors and modification of bridge-connection model: Comparison of three silk woven structures

Given the great potential of carbonized fabric strain sensors in wearable devices, carbonized silk fabrics (CSF) with three characteristic woven structures including georgette (CSF-g), crepe de chine (CSF-c) and crepe satin plain (CSF-p) were employed to investigate the dependence of gauge factor (GF) on two critical parameters: initial resistance (R0) and resistance change (ΔR). The results showed that increasing carbonization temperature can effectively reduce R0 and increase GF of CSF-g, but has little effect on CSF-c and CSF-p. It was further found that the GF of both CSF-c and CSF-p were dominated by ΔR related to the crack propagation path, i.e. high sensitivity CSF was typically accompanied by dense “islands” and fine gaps, while low sensitivity CSF was accompanied by wide cracks and sparse “islands”. Accordingly, a modified bridge connection model was proposed to elucidate the relationship between crack morphology and resistance variation. This model successfully achieved continuous exponential fitting of resistance with admirable fitting goodness. Finally, the prepared sensor exhibited an ultra-high GF (916.5) and was well applied in health monitoring and thermal treatment. These efforts put forward guidance to the design and fabrication of ultrasensitive CSF strain sensors.

Characterization and Self-Cleaning Properties of Silk Fabric Coated by Chitosan-Xyloglucan/nano-TiO<sub>2</sub> Composite Film

In this study, Chitosan-Xyloglucan encapsulated Titanium dioxide was prepared by in-situ method for coating Silk fabric. FT-IR XRD characterized the functional groups and formation of crystallization of composite film. SEM analysis showed the immobilization of composite film on the surface of silk fabric. The coated silk fabrics were stained with methylene blue, and the stain removal efficiency was evaluated. The results showed that the composite film was deposited onto the silk fabric. The functional groups showed peaks around 1635 to 1636 and 400 to 500 cm-1 that indicate the presence of C=N groups of Chitosan-Xyloglucan and Ti-O groups of TiO2 on the composite, respectively. The XRD results indicated that the TiO2 prepared by the sol-gel method was an anatase crystalline structure. The mechanical properties showed the composite film was superior to the Chitosan-Xyloglucan, TiO2, and uncoated silk fabric. Finally, the methylene blue degradation capability was investigated. The coated silk fabric has insignificantly removing methylene blue stain than the untreated silk fabric, but it is noticeably repellent to stain.

Thermochemical conversion of silkworm by-product into syngas

This study explored the valorisation of silkworm by-product, a major by-product of the silk industry (sericulture), which amounts to 16 million tonnes annually. The focus was on transforming waste into energy resources through pyrolysis under CO2 conditions. In one-stage pyrolysis, the evolution of syngas under N2 was found to be comparable to that under CO2. A notable allocation of carbon to biocrude rather than syngas was observed. The two-stage pyrolysis resulted in increased syngas production. However, achieving a homogeneous reaction between CO2 and the volatiles liberated from silkworm byproduct proved challenging. Indeed, the reaction kinetics governing CO2 reactivity was not fast although the temperature windows of the reaction were aligned in the two-stage pyrolysis. To address this issue, pyrolysis was performed using a Ni-based catalyst to expedite the reaction kinetics. Consequently, syngas formation, particularly CO formation, was significantly enhanced under CO2 conditions compared to that under N2 conditions. The syngas yield under CO2 was 36.42 wt% which was 2-fold higher than that of N2. This suggested the potential of CO2 altering the carbon distribution from biocrude to syngas. This strategy would contribute to the establishment of sustainable production of silk by converting sericulture by-product into energy/chemical resources.

A Review on Silk Fibers and Their Medical Applications

This mini-compilation study included the chemical structure, mechanical, thermal, and dimensional properties of silk fiber, its production process, pre-treatment, and biomedical applications from various experimental studies, which are compiled and summarized. The silk fiber should have a degumming process before using biomedical applications. The 25% concentration for Na<sub>2</sub>CO<sub>3</sub> in ethanol solution (80%) as a coagulant chemical with a salt such as LiB<sub>2</sub> (9 M) at a temperature of 98°C for 45 minutes at pH between 6 and 7 should be applied for the degumming process of silk fiber. It has some biomedical applications such as artificial veins and surgical sutures. Its biomedical applications can be studied experimentally by changing manufacturing processes and their process parameters in the future.

Polydopamine-Coated Silk Fiber with Controllable Length for Enhanced Hemostatic Application.

The development of highly effective hemostatic materials with high biocompatibility and outstanding performance is vital to the field of biomaterials. In this study, we develop a hemostatic fiber material that exhibits high biocompatibility and excellent performance. By incorporating polydopamine (PDA) into the alkaline treatment of silk fibroin (SF), we achieve PDA-coated SF fibers with lengths that can be controlled by the alkaline concentration. The PDA coating significantly enhances the hemostatic ability of the silk fibers and exhibits superior performance in both in vitro and ex vivo experiments. By performing animal studies involving a mouse liver puncture model and a femoral vein incision model, we demonstrate the remarkable hemostatic capability of the PDA-coated SF fibers, as evidenced by the lower blood loss compared to that of a commercial hemostat powder. These findings highlight the potential of applying a PDA-assisted alkaline treatment to SF fibers to efficiently create hemostatic fibers with controllable lengths, which would be promising candidates for clinical hemostatic applications.

Cu NPs Loaded Silk Fabric: Characterization and Dyeability

Cu NPs Loaded Silk Fabric: Characterization and Dyeability

Enhancing Antimicrobial and Fastness Properties of Silk and Lyocell Fabric by Dyeing with Azadirachta indica and Mordanting with Citrus limon Extract

Antimicrobial resistance presents a substantial global health challenge, prompting the exploration of innovative strategies to combat pathogenic bacteria. Within this context, considerable attention has been directed towards textile materials treated with antimicrobial agents for their potential to mitigate the spread of infectious diseases. This research sought to investigate the influence of Neem dyeing and Lemon mordanting on enhancing the innate antimicrobial properties of Silk and Lyocell fabric. Textile materials underwent mordanting exclusively with natural agents, such as citrus lemon extract, to enhance dye adherence. The dyeing process involved the use of Azadirachta indica dye obtained through aqueous boiling, applied to lyocell and silk fabrics under various parameters. The key findings revealed a significant augmentation in the antimicrobial effectiveness of lyocell and silk fabrics following Neem dyeing and Lemon mordanting. Optimized conditions, including prolonged dyeing time, elevated temperatures, and constant dye concentrations, notably improved inhibition percentages against common pathogens like Staphylococcus aureus and Klebsiella pneumoniae. Furthermore, the study assessed the washing and perspiration fastness properties of silk and lyocell fabrics in accordance with established standards. In conclusion, the integration of Neem dyeing and Lemon mordanting emerges as a promising method to significantly enhance the antimicrobial efficacy of Lyocell and silk fabrics. This approach opens avenues for the development of textiles with heightened infection control properties, particularly in sectors focused on public health and hygiene. The evaluation of fastness properties also yielded excellent results, further supporting the viability of this method in academic and practical contexts. Considering the global challenge of antimicrobial resistance, adopting such innovative strategies in textile treatment can contribute significantly to the development of effective and sustainable solutions. Future research endeavours may explore additional applications and variations of this method, ensuring its adaptability and widespread implementation in diverse settings.

Silk-Fabric Reinforced Silk for Artificial Bones.

Bone implants for different body parts require varying mechanical properties, dimensions, and biodegradability rates. Currently, it is still challenging to produce artificial bones with perfect compatibility with human bones. In this study, a silk-fabric reinforced silk material (SFS) composed of pure silk with exceptional biocompatibility, osteogenesis, and biodegradability is reported, and demonstrates its outstanding performance as a bone implant material. The SFS is fabricated using a simple hot-pressing technique, with degummed silk fabric as the reinforcement and silk fibroin as the matrix. The SFS as a self-reinforced composite, has exceptional mechanical properties due to the almost perfect interface between the matrix and reinforcement. More importantly, its mechanical properties, biodegradability rates, and density can be tailored by adjusting the reinforcement structure and the ratio of the reinforcement to the matrix to align with the requirements for bone implantation in different parts of the human body. Besides, the SFS can improve osteoblastic proliferation and increase osteogenic activity, which is not the case with clinically used titanium alloy artificial bone. Therefore, the SFS holds significant potential to replace conventional metal or ceramic implants in the field of medical fracture repair.

Did the first two Argentine flags of Macha and Ayohuma wave together?

Historical sources claim that the Argentine ensigns commonly referred to as Macha and Ayohuma flags have the same origin. The difference in their designs is remarkable, with the former being white, blue, and white in horizontal bands, while the latter has the coloured stripes at its ends. According to a historical account, these two flags were used by the patriot and creator of the Argentine flag, one of the parents of the homeland, Manuel Belgrano, when he first raised them on the banks of the Paraná River on February 27, 1812. Both flags were found by Father Martín Castro in 1883 behind a painting of Santa Cecilia in the church of Titiri near the town of Macha in Bolivia at an altitude of 4350 m above sea level. The composition of the Ayohuma flag was analysed in this paper, and the results were compared with those obtained and already published for the study conducted on the flag of Macha. It was determined by ATR-FTIR spectroscopy that the Ayohuma flag is made of silk, with the diameter of the individual silk filament of 12.5 μm, the dye used to colour the silk is indigotin, according to its resonance Raman spectrum, and methylene blue was detected by Surface-Enhanced Resonance Raman Spectroscopy, presumably utilized for the restoration of the coloured part of the flag.

Layer-by-layer self-assembly method improves the performance and cytocompatibility of 3D printing ODMA-GelMA hydrogel

The GelMA hydrogels are biomaterials with excellent biocompatibility and cellular activity. However, their application is limited due to their poor mechanical properties. To enhance the mechanical properties of GelMA, we incorporated ODMA into GelMA for the sequential assembly of RSF (raw silk fiber protein) and CHI (chitosan) through electrostatic interactions, constructing a multi-layer composite membrane on the hydrogel surface. We conducted microscopic morphology analysis, evaluated mechanical properties, assessed cytocompatibility, and performed short-term and long-term material toxicity testing. Our results showed that mechanical properties were significantly enhanced when the 10-layer (RSF/CHI) composite film was assembled on the surface of ODMA-GelMA hydrogel. And they also exhibited excellent cytocompatibility. The improved GelMA hydrogel has the potential for biomedical applications in 3D printing as a substitute for artificial organs.

Biofabrication of Silk Fibers with Enhanced Conductivity through Silkworm Feeding with Reduced Graphene Oxide: Implications for Smart Textile Innovations

Biofabrication of Silk Fibers with Enhanced Conductivity through Silkworm Feeding with Reduced Graphene Oxide: Implications for Smart Textile Innovations

Development and Application of an Advanced Biomedical Material-Silk Sericin.

Sericin, a protein derived from silkworm cocoons, is considered a waste product derived from the silk industry for thousands of years due to a lack of understanding of its properties. However, in recent decades, a range of exciting properties of sericin are studied and uncovered, including cytocompatibility, low-immunogenicity, photo-luminescence, antioxidant properties, as well as cell-function regulating activities. These properties make sericin-based biomaterials promising candidates for biomedical applications. This review summarizes the properties and bioactivities of silk sericin and highlights the latest developments in sericin in tissue engineering and regenerative medicine. Furthermore, the extended application of sericin in developing flexible electronic devices and 3D bioprinting is also discussed. It is believed that sericin-based biomaterials have great potential of being developed into novel tissue engineering products and smart implantable devices for various medical applications toward improving clinical outcomes.

Effect of Plasma /Copper Oxide Nanoparticles on Silk Fabric Printability with Some Natural Dyes Using Ultraviolet Fixation

Effect of Plasma /Copper Oxide Nanoparticles on Silk Fabric Printability with Some Natural Dyes Using Ultraviolet Fixation

A Controllable and Effective Method to Prepare Nano-LnMOFs Film on Silk Fabric and Extend the Temperature-Sensing Range

A Controllable and Effective Method to Prepare Nano-LnMOFs Film on Silk Fabric and Extend the Temperature-Sensing Range

QSPR modeling for the prediction of partitioning of VOCs and SVOCs to indoor fabrics: Integrating environmental factors

Porous fabrics have a significant impact on indoor air quality by adsorbing and emitting chemical substances, such as volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs). Understanding the partition behavior between organic compound molecules and indoor fabrics is crucial for assessing their environmental fate and associated human exposure. The physicochemical properties of fabrics and compounds are fundamental in determining the free energy of partitioning. Moreover, environmental factors like temperature and humidity critically affect the partition process by modifying the thermal and moisture conditions of the fabric. However, existing methods for determining the fabric-air partition coefficient are limited to specific fabric-chemical combinations and lack a comprehensive consideration of indoor environmental factors. In this study, large amounts of experimental data on fabric-air partition coefficients (Kfa) of (S)VOCs were collected for silk, polyester, and cotton fabrics. Key molecular descriptors were identified, integrating the influences of physicochemical properties, temperature, and humidity. Subsequently, two typical quantitative structure-property relationship (QSPR) models were developed to correlate the Kfa values with the molecular descriptors. The fitting performance, robustness, and predictive ability of the two QSPR models were evaluated through statistical analysis and internal/external validation. This research provides insights for the high-throughput prediction of the environmental behaviors of indoor organic compounds.