Novel combination therapy using recombinant oncolytic adenovirus silk hydrogel and PD-L1 inhibitor for bladder cancer treatment.

Recombinant oncolytic adenovirus offers a novel and promising cancer treatment approach, but its standalone efficacy remains limited. This study investigates a combination treatment strategy by co-administering recombinant oncolytic Adv-loaded silk hydrogel with a PD-L1 inhibitor for patients with bladder cancer to enhance treatment outcomes. Bladder cancer tissues from mice were collected and subjected to single-cell sequencing, identifying CRB3 as a key gene in malignant cells. Differential expression and functional enrichment analyses were performed, validating CRB3's inhibitory role through in vitro experiments showing suppression of bladder cancer cell proliferation, migration, and invasion. Recombinant oncolytic adenoviruses encoding CRB3 and GM-CSF were constructed and encapsulated in silk hydrogel to enhance drug loading and release efficiency. In vivo experiments demonstrated that the nano-composite hydrogel significantly inhibited tumor growth and increased immune infiltration in tumor tissues. Co-administration of adenovirus silk hydrogel (Adv-CRB3@gel) with a PD-L1 inhibitor significantly enhanced T-cell infiltration and tumor killing. The combination of recombinant oncolytic Adv-loaded nano-composite hydrogel encoding CRB3 and GM-CSF with a PD-L1 inhibitor improves bladder cancer treatment outcomes by effectively recruiting T cells, providing a novel therapeutic strategy.

Polyphenol-mediated redox-active hydrogel with H2S gaseous-bioelectric coupling for periodontal bone healing in diabetes.

Excessive oxidative response, unbalanced immunomodulation, and impaired mesenchymal stem cell function in periodontitis in diabetes makes it a great challenge to achieve integrated periodontal tissue regeneration. Here, a polyphenol-mediated redox-active algin/gelatin hydrogel encapsulating a conductive poly(3,4-ethylenedioxythiopene)-assembled polydopamine-mediated silk microfiber network and a hydrogen sulfide sustained-release system utilizing bovine serum albumin nanoparticles is developed. This hydrogel is found to reverse the hyperglycemic inflammatory microenvironment and enhance functional tissue regeneration in diabetic periodontitis. Polydopamine confers the hydrogel with anti-oxidative and anti-inflammatory activity. The slow, sustained release of hydrogen sulfide from the bovine serum albumin nanoparticles recruits mesenchymal stem cells and promotes subsequent angiogenesis and osteogenesis. Moreover, poly(3,4-ethylenedioxythiopene)-assembled polydopamine-mediated silk microfiber confers the hydrogel with good conductivity, which enables it to transmit endogenous bioelectricity, promote cell arrangement, and increase the inflow of calcium ion. In addition, the synergistic effects of hydrogen sulfide gaseous-bioelectric coupling promotes bone formation by amplifying autophagy in periodontal ligament stem cells and modulating macrophage polarization via lipid metabolism regulation. This study provides innovative insights into the synergistic effects of conductivity, reactive oxygen species scavenging, and hydrogen sulfide on the periodontium in a hyperglycemic inflammatory microenvironment, offering a strategy for the design of gaseous-bioelectric biomaterials to promote functional tissue regeneration in immune-related diseases.

Types and Treatments of Surgical Diseases in Ancient China Found in Bamboo and Silk Texts: Focusing on External Injuries, Burns and Scalds, Intestines, Anus Diseases.

This article aims to analyze the types of surgical diseases and treatments in ancient China as documented in bamboo and silk texts, with a particular focus on (external) injury, tetanus, burns, rectal and anal diseases, and inguinal hernias. For this analysis, I gathered 85 instances of disease and treatments recorded in these texts. The 85 cases were further categorized into 13 (external) injuries, 13 metal wounds, 6 tetanus, 22 burns, 16 rectal and anal diseases, and 15 inguinal hernias. The analysis revealed that the treatment of (external) injury and burns focused primarily on the wound site, while the treatment of metal wounds and tetanus centered on addressing the internal body. Internal treatments were mainly prescribed through the use of medicine and food. Surgical intervention was recommended primarily for diseases of the rectum and anus, with medications applied to the woundspost-surgery. For inguinal hernias, a high-protein diet was typically prescribed. As we've seen, in ancient China, surgical diseases were mainly treated with medication, surgery, and dietary prescriptions. And among these prescriptions, drug prescriptions were utilized not only by medical doctors but also by witch-doctors treating diseases in civilian society and soldiers stationed at frontline military posts. In the absence of medical doctors in both civilian society and frontline units, witch-doctors and frontline units purchased or stockpiled prescription drugs and used them to treat patients according to prescription.

Tailoring silk-based covering material with matched mechanical properties for vascular tissue engineering.

Vascular covered stents play a significant therapeutic role in cardiovascular diseases. However, the poor compliance and biological inertness of commercial materials cause post-implantation complications. Silk fibroin (SF), as a biomaterial, possesses satisfactory hemocompatibility and tissue compatibility. In this study, we developed a silk film for use in covered stents by employing a layer-by-layer self-assembly strategy with regenerated SF on silk braiding fabric. We investigated the effects on the mechanical properties of the silk films in detail, which were closely correlated with fabric parameters and layer-by-layer self-assembly. The results showed that there was a significant relationship between these factors and both the compliance and mechanical strength. The 1 × 2/90°/100/SF6 film exhibited excellent mechanical properties. Notably, compliance reached 2.6%/100 mmHg, matching that of the human saphenous vein. Thus, this strategy shows promise in developing a novel covered stent, with biocompatible and comprehensive mechanical properties, and significant potential for clinical applications.

Biomimetic and soft lab-on-a-chip platform based on enzymatic-crosslinked silk fibroin hydrogel for 3D cell co-culture.

Integrating biological material within soft microfluidic systems made of hydrogels offers countless possibilities in biomedical research to overcome the intrinsic limitations of traditional microfluidics based on solid, non-biodegradable, and non-biocompatible materials. Hydrogel-based microfluidic technologies have the potential to transformin vitrocell/tissue culture and modeling. However, most hydrogel-based microfluidic platforms are associated with device deformation, poor structural definition, reduced stability/reproducibility due to swelling, and a limited range in rigidity, which threatens their applicability. Herein, we describe a new methodological approach for developing a soft cell-laden microfluidic device based on enzymatically-crosslinked silk fibroin (SF) hydrogels. Its unique mechano-chemical properties and high structural fidelity, make this platform especially suited forin vitrodisease modelling, as demonstrated by reproducing the native dynamic 3D microenvironment of colorectal cancer and its response to chemotherapeutics in a simplistic way. Results show that from all the tested concentrations, 14 wt% enzymatically-crosslinked SF microfluidic platform has outstanding structural stability and the ability to perfuse fluid while displayingin vivo-like biological responses. Overall, this work shows a novel technique to obtain an enzymatically-crosslinked SF microfluidic platform that can be employed for developing soft lab-on-a-chipin vitromodels.

Scalable ultrastrong MXene films with superior osteogenesis.

Titanium carbide MXene flakes have promising applications in aerospace, flexible electronic devices and biomedicine owing to their superior mechanical properties1 and electrical conductivity2 and good photothermal conversion3, biocompatibility4 and osteoinductivity5. It is highly desired yet very challenging to assemble MXene flakes into macroscopic high-performance materials in a scalable manner. Here we demonstrate a scalable strategy to fabricate high-performance MXene films by roll-to-roll-assisted blade coating (RBC) integrated with sequential bridging, providing good photothermal conversion and osteogenesis efficiency under near-infrared irradiation. MXene flakes were first bridged with silk sericin by hydrogen bonding and then assembled into macroscopic films using a continuous RBC process, followed by ionic bridging to freeze their aligned structure. The resultant large-scale MXene films with strong interlayer interactions are highly aligned and densified, exhibiting high tensile strength (755 MPa), toughness (17.4 MJ m-3) and electromagnetic interference (EMI) shielding capacity (78,000 dB cm2 g-1), as well as good ambient stability, photothermal conversion and bone regeneration performance. The proposed strategy not only paves a feasible way for realizing the practical applications of MXene in the fields of flexible EMI shielding materials and bone tissue engineering but also provides an avenue for the high-performance and scalable assembly of other two-dimensional flakes.

Investigating the potential of waste oyster shell as a sustainable bio-mordant in natural dyeing.

The use of natural bioresources in textile dyeing has attracted significant research interest due to their environmentally friendly and low-toxic nature. This study investigated the utilization of waste oyster shell (WOS) as a bio-mordant combined with sappan wood extract to dye silk fabrics using pre-, meta-, and post-mordanting method. The crystal structure of CaCO3 derived from WOS and their impact on color properties, color strength and color fastness were analyzed. The dyed fabrics displayed a range of shades from light pink to deep red and brown. FTIR analysis confirmed chemical interactions among dye, silk, and WOS mordants. Notably, silk treated with WOS at 800 °C as a pre-mordant showed color strength approximately 2.6 times higher than that of un-mordanted samples. Additionally, bio-mordanted samples exhibited improved color fastness compared to untreated ones (rating 2), with pre-mordanting offering the highest resistance to washing (rating 4-5). These findings shed light on the potential of waste oyster shell as an effective, sustainable alternative to conventional metal mordants in textile dyeing. This study not only support the utilization of waste but also enhances environmental and resource efficiency of the dyeing process.

Silk Fabric Functionalized by Nanosilver Enabling the Wearable Sensing for Biomechanics and Biomolecules.

Integrating biomechanical and biomolecular sensing mechanisms into wearable devices is a formidable challenge and key to acquiring personalized health management. To address this, we have developed an innovative multifunctional sensor enabled by plasma functionalized silk fabric, which possesses multimodal sensing capabilities for biomechanics and biomolecules. A seed-mediated in situ growth method was employed to coat silver nanoparticles (AgNPs) onto silk fibers, resulting in silk fibers functionalized with AgNPs (SFs@Ag) that exhibit both piezoresistive response and localized surface plasmon resonance effects. The SFs@Ag membrane enables accurate detection of mechanical pressure and specific biomolecules during wearable sensing, offering a versatile solution for comprehensive personalized health monitoring. Additionally, a machine learning algorithm has been established to specifically recognize muscle strain signals, potentially extending to the diagnosis and monitoring of neuromuscular disorders such as amyotrophic lateral sclerosis (ALS). Unlike electromyography, which detects large muscles in clinical medicine, sensing data for tiny muscles enhance our understanding of muscle coordination using the SFs@Ag sensor. This detection model provides feasibility for the early detection and prevention of neuromuscular diseases. Beyond muscle stress and strain sensing, biomolecular detection is a critical addition to achieving effective health management. In this study, we developed highly sensitive surface-enhanced Raman scattering (SERS) detection for wearable health monitoring. Finite-difference time-domain numerical simulations ware utilized to analyze the efficacy of the SFs@Ag sensor for wearable SERS sensing of biomolecules. Based on the specific SERS spectra, automatic extraction of signals of sweat molecules was also achieved. In summary, the SFs@Ag sensor bridges the gap between biomechanical and biomolecular sensing in wearable applications, providing significant value for personalized health management.

The role of water mobility on water-responsive actuation of silk.

Biological water-responsive materials that deform with changes in relative humidity have recently demonstrated record-high actuation energy densities, showing promise as high-performance actuators for various engineering applications. However, there is a lack of theories capable of explaining or predicting the stress generated during water-responsiveness. Here, we show that the nanoscale confinement of water dominates the macroscopic dehydration-induced stress of the regenerated silk fibroin. We modified silk fibroin's secondary structure, which leads to various distributions of bulk-like mobile and tightly bound water populations. Interestingly, despite these structure variations, all silk samples start to exert force when the bound-to-mobile (B/M) ratio of confined water reaches the same level. This critical B/M water ratio suggests a common threshold above which the chemical potential of water instigates the actuation. Our findings serve as guidelines for predicting and engineering silk's WR behavior and suggest the potential of describing the WR behavior of biopolymers through confined water.

[Research progress of silk-based biomaterials for peripheral nerve regeneration].

Objective: To describe the research progress of silk-based biomaterials in peripheral nerve repair and provide useful ideals to accelerate the regeneration of large-size peripheral nerve injury. Methods: The relative documents about silk-based biomaterials used in peripheral nerve regeneration were reviewed and the different strategies that could accelerate peripheral nerve regeneration through building bioactive microenvironment with silk fibroin were discussed. Results: Many silk fibroin tissue engineered nerve conduits have been developed to provide multiple biomimetic microstructures, and different microstructures have different mechanisms of promoting nerve repair. Biomimetic porous structures favor the nutrient exchange at wound sites and inhibit the invasion of scar tissue. The aligned structures can induce the directional growth of nerve tissue, while the multiple channels promote the axon elongation. When the fillers are introduced to the conduits, better growth, migration, and differentiation of nerve cells can be achieved. Besides biomimetic structures, different nerve growth factors and bioactive drugs can be loaded on silk carriers and released slowly at nerve wounds, providing suitable biochemical cues. Both the biomimetic structures and the loaded bioactive ingredients optimize the niches of peripheral nerves, resulting in quicker and better nerve repair. With silk biomaterials as a platform, fusing multiple ways to achieve the multidimensional regulation of nerve microenvironments is becoming a critical strategy in repairing large-size peripheral nerve injury. Conclusion: Silk-based biomaterials are useful platforms to achieve the design of biomimetic hierarchical microstructures and the co-loading of various bioactive ingredients. Silk fibroin nerve conduits provide suitable microenvironment to accelerate functional recovery of peripheral nerves. Different optimizing strategies are available for silk fibroin biomaterials to favor the nerve regeneration, which would satisfy the needs of various nerve tissue repair. Bioactive silk conduits have promising future in large-size peripheral nerve regeneration.

QTL analysis to identify genes involved in the trade-off between silk protein synthesis and larva-pupa transition in silkworms.

BACKGROUND: Insect-based food and feed are increasingly attracting attention. As a domesticated insect, the silkworm (Bombyx mori) has a highly nutritious pupa that can be easily raised in large quantities through large-scale farming, making it a highly promising source of food. The ratio of pupa to cocoon (RPC) refers to the proportion of the weight of the cocoon that is attributed to pupae, and is of significant value for edible utilization, as a higher RPC means a higher ratio of conversion of mulberry leaves to pupa. In silkworm production, there is a trade-off between RPC and cocoon shell ratiao(CSR), which refers the ratio of silk protein to the entire cocoon, during metamorphosis process. Understanding the genetic basis of this balance is crucial for breeding edible strains with a high RPC and further advancing its use as feed. RESULTS: Using QTL-seq, we identified a quantitative trait locus (QTL) for the balance between RPC and CSR that is located on chromosome 11 and covers a 9,773,115-bp region. This locus is an artificial selection hot spot that contains ten non-overlapping genomic regions under selection that were involved in the domestication and genetic breeding processes. These regions include 17 genes, nine of which are highly expressed in the silk gland, which is a vital component in the trade-off between RPC and CSR. These genes are annotate with function related with epigenetic modifications and the regulation of DNA replication et al. We identified one and two single nucleotide polymorphisms (SNPs) in the exons of teh KWMTBOMO06541 and KWMTBOMO06485 genes that result in amino acid changes in the protein domains. These SNPs have been strongly selected for during the domestication process. The KWMTBOMO06485 gene encodes the Bombyx mori (Bm) tRNA methyltransferase (BmDnmt2) and its knockout results in a significant change in the trade-off between CSR and RPC in both sexes. CONCLUSIONS: Taken together, our results contribute to a better understanding of the genetic basis of RPC and CSR. The identified QTL and genes that affect RPC can be used for marker-assisted and genomic selection of silkworm strains with a high RPC. This will further enhance the production efficiency of silkworms and of closely-related insects for edible and feed purposes.

[Physical, chemical, and biological property of silk reinforced polycaprolactone composites for bone tissue engineering].

Objective: To develop a biodegradable implantable bone material with compatible mechanics with the bone tissue, providing a new biomaterial for clinical bone repair and regeneration. Methods: Silk reinforced polycaprolactone composites (SPC) containing 20%, 40%, and 60% silk were prepared by layer-by-layer assembly and hot-pressing technology. Macroscopic morphology was observed and microstructure were observed by scanning electron microscopy, compressive mechanical properties were detected by compression test, surface wettability was detected by surface contact angle test, degradation of materials was observed after soaking in PBS for 180 days, and proliferation of MC3T3-E1 cells was detected by cell counting kit 8 assay. Six Sprague Dawley rats were subcutaneously implanted with polycaprolactone (PCL) and 20%-SPC, respectively. Masson staining was used to analyze the in vivo degradation behavior and vascularization effect within 180 days. Results: The pore defects of the three SPC sections were relatively few. In the range of 20% to 60%, as the silk content increased and the PCL content decreased, the interlayer spacing of silk fabric decreased, and the fibers almost covered the entire cross-section. The compressive modulus and compressive strength of SPC showed an increasing trend, and the compressive modulus of 60%-SPC was slightly lower than that of 40%-SPC. There were significant differences in compressive modulus and compressive strength between the materials ( P<0.05). In vitro simulated fluid degradation experiments showed that the mass loss of the three types of SPC after 180 days of degradation was within 5%, with the highest mass loss observed in 60%-SPC. The differences in mass loss between the materials were significant ( P<0.05). As the silk content increased, the static water contact angle of each material gradually decreased, and all could promote the proliferation of MC3T3-E1 cells. The subcutaneous degradation experiment in rats showed that 20%-SPC began to degrade at 30 days after implantation, and material degradation and vascularization were significant at 180 days, which was in sharp contrast to PCL. Conclusion: SPC has the mechanical and hydrophilic properties that are compatible with bone tissue. It maintains its mechanical strength for a long time in a simulated body fluid environment in vitro, and achieves dynamic synchronization of material degradation, tissue regeneration, and vascularization through the body's immune regulation mechanism in vivo. It is expected to provide a new type of implant material for clinical bone repair.

The development of silk glands and transcriptome aberration induced by cyantraniliprole in Bombyx mori.

Bombyx mori is an insect species of great economic importance, and its silk gland is a vital organ for the synthesis and secretion of silk protein. However, long-term artificial domestication of B. mori has resulted in high sensitivity to chemical toxins, especially insecticides. Cyantraniliprole (Cya), a second-generation ryanodine receptor modulator insecticide, is widely utilized in agriculture for pest control. In this study, the impact of Cya toxicity on the development of silk glands in the 5th instar larvae of B. mori was assessed using Cya LC5, LC10 and LC20, as well as a starvation treatment group for comparison. Short-term exposure (24 h) to different concentrations of Cya resulted in delayed development of silk glands in B. mori. Meanwhile, the body weight, silk gland weight, silk gland index and cocoon quality were significantly reduced in a concentration-dependent manner, except for the Cya LC5 treatment. Histopathological and ultrastructural analysis revealed that Cya LC10 induced disruption of the nuclear membrane and endoplasmic reticulum in the posterior silk gland (PSG) cells, leading to the formation of intracellular vacuoles. Transcriptome sequencing of PSGs identified 2152 genes that were differentially expressed after exposure to Cya LC10, with 1153 down-regulated genes and 999 up-regulated genes. All differentially expressed genes were subjected to functional annotation using gene ontology and Kyoto encyclopedia of genes and genomes database, and it was found that protein synthesis-related pathways were significantly enriched, with the majority of genes being down-regulated. Furthermore, the transcription levels of genes involved in "protein processing in endoplasmic reticulum", "protein export", "proteasome" and "DNA replication" were quantified using qRT-PCR. Our findings suggested that short-term exposure to Cya LC10 resulted in disruption of DNA replication, as well as protein transport, processing and hydrolysis in the PSG cells of B. mori. The results of this study provide a theoretical foundation for the safe utilization of Cya in sericulture production.

Immune response profiles induced by silk-based biomaterials: a journey from 'immunogenicity' towards 'immuno-compatibility.

Silk is a widely accepted biomaterial for tissue regeneration owing to its tunable biomechanical properties and ease of chemical modification. However, a number of aspects associated with its clinical use are still debated. Indeed, to achieve clinical success, a biomaterial must favorably interact with host tissues without evoking local or systemic immuno-inflammatory responses. The analysis of immune responses associated with silk under in vitro and in vivo conditions provides useful insights, improving the understanding of the functional characteristics of silk biomaterials and further promoting their clinical application. Silk evokes moderate immune responses upon implantation in vivo, depending on the material structure, fabrication method, degradation time, and implantation in soft or hard tissue sites, which rapidly subside within a few days/weeks. In vitro studies indicate that its immune-stimulatory properties are largely due to inherent protein conformation and differential processing parameters. Strategically controlled levels of immune responses in vivo with marginal immunogenicity of silk-based biomaterials may contribute to matrix remodeling and replacement by native tissue matrix around the implanted site. Therefore, immunomodulatory strategies should be developed to promote the use of silk-based biomaterials as promising candidates for numerous clinical applications.

MOF-818 nanoparticles as radical scavengers to improve the aging resistance of silk fabric.

Silk fabrics hold immense historical value as precious legacies left by our ancestors, yet they face significant damage during archaeological excavations, necessitating urgent protective measures. However, The current protective materials can't effectively prevent the degradation of silk fabrics. Nanotechnology has emerged as a promising avenue for the consolidation and preservation of silk fabrics, offering novel concepts and materials. In this study, we propose an innovative and cost-effective method that uses the MOF-818 with a radical scavenging ability to enhance the protection of silk fabrics. The resulting demonstrates that the MOF-818 was the large surface area and porous properties, which exhibited excellent superoxide dismutase (SOD)-like activity at 10 ug/mL. The silk fabrics treated by MOF-818 displays small color difference, reduced the oxidation of functional group and prevents the degradation of silk fabrics. The successful development of this nanocomposite marks a significant advancement in silk protection, opening new horizons for the preservation of silk cultural relics.

Overexpressed Artificial Spidroin Based Microneedle Spinneret for 3D Air Spinning of Hybrid Spider Silk.

Efforts have been devoted to developing strategies for converting spider silk proteins (spidroins) into functional silk materials. However, studies mimicking the exact natural spinning process of spiders encounter arduous challenges. In this paper, consistent with the natural spinning process of spiders, we report a high-efficient spinning strategy that enables the mass preparation of multifunctional artificial spider silk at different scales. By simulating the structural stability mechanism of the cross-ß-spine of the amyloid polypeptide by computer dynamics, we designed and obtained an artificial amyloid spidroin with a significantly increased yield (13.5 g/L). Using the obtained artificial amyloid spidroin, we fabricated artificial spiders with artificial spinning glands (hollow MNs). Notably, by combining artificial spiders with 3D printing, we perform patterned air spinning at the macro- and microscales, and the resulting patterned artificial spider silk has excellent pump-free liquid flow and conductive and frictional electrical properties. Based on these findings, we used macroscale artificial spider silk to treat rheumatoid arthritis in mice and micro artificial spider silk to prepare wound dressings for diabetic mice. We believe that artificial spider silk based on an exact spinning strategy will provide a high-efficient way to construct and modulate the next generation of smart materials.

Influence of Initial Secondary Structure on Conformation and Mechanical Properties of Spider Silk Protein Gels.

Recombinant spider silk protein (RSP) is a promising biomaterial for developing high-performance materials independent of fossil fuels. In this study, we investigated the influence of the initial secondary structure of RSPs on the properties of RSP-based hydrogels. By altering the initial structure of RSP to ß-sheets (ß-RSP), α-helices (α-RSP), and random coils (rc-RSP) through solvent treatment, we compared the structures and mechanical properties of the resulting gels. Solid-state NMR revealed a ß-sheet-rich structure in all gels, with the α-RSP gel exhibiting significantly higher strength and Young's modulus compared to the rc-RSP gel. X-ray diffraction revealed that the α-RSP gel had a unique crystalline structure, distinguishing it from the ß-RSP and rc-RSP gels. The different initial secondary structures possibly lead to variations in the crystalline and network structures of the molecular chains within the gels, explaining the superior mechanical properties observed in the α-RSP gels.

The renewed tin-weighting treatment as sustainable and durable flame-retardant approach for protein silk fabric.

The facile development of a sustainable and durable flame-retardant approach for protein silk is of interest. Inspired by silk tin-weighting technology, this study developed a novel and sustainable in-situ deposition strategy based on biomass phytic acid to impart durable flame-retardant performance to silk fabrics. The chemical structure of insoluble chelating precipitation, and the surface morphology, thermal stability, combustion behavior, flame-retardant capacity, laundering resistance, and flame-retardant mode of action of the tin-weighting silk samples, were explored. The Sn-, P-, Si-containing insoluble chelating precipitation formed within the fiber interior and combined with silk fibers through electrostatic attraction and metal salt chelation. As a result, the tin-weighting silk displayed excellent self-extinguishing capacity, with the damaged length reduced to 9.2 cm and the LOI increased to 31.6 %; it also achieved self-extinguishing after 30 washing cycles, demonstrating high flame-retardant efficacy and laundering resistance. Moreover, the tin-weighting silk also showed the obvious suppression in smoke and heat generation by 55.6 % and 35.7 %, respectively. The synergistic charring action of phosphate groups, tin metal salts, and silicates was beneficial for enhancing the fire safety of silk. The tin-weighting treatment also displayed a minor impact on mechanical performance of silk fabrics.

Characterization and comparative analysis of sericin protein 150 in Bombyx mori.

Lepidopteran silk is a complex mixture of proteins, consisting mainly of fibroins and sericins. Sericins are a small family of highly divergent proteins that serve as adhesives and coatings for silk fibers. So far, five genes encoding sericin proteins have been identified in Bombyx mori. Having previously identified sericin protein 150 (SP150) as a major sericin-like protein in the cocoons of the pyralid moths Galleria mellonella and Ephestia kuehniella, we describe the identification of its homolog in B. mori. Our refined gene model shows that it consists of four exons and a long open reading frame with a conserved motif, CXCXCX, at the C-terminus, reminiscent of the structure observed in a class of mucin proteins. Notably, despite a similar expression pattern, both mRNA and protein levels of B. mori SP150 were significantly lower than those of its pyralid counterpart. We also discuss the synteny of homologous genes on corresponding chromosomes in different moth species and the possible phylogenetic relationships between SP150 and certain mucin-like proteins. Our results improve our understanding of silk structure and the evolutionary relationships between adhesion proteins in the silk of different lepidopteran species.

Selenium Treatment Ameliorates the Adverse Effects Caused by Dynamin Gene Knockdown in Bombyx mori.

Our previous research reported the influence of 50 µM selenium (Se) on the cytosolization (endocytosis) pathway, which in turn stimulates the growth and development of Bombyx mori. Lately, dynamin is recognized as one of the key proteins in endocytosis. To explore the underlying mechanisms of Se impact, the dynamin gene was knocked down by injecting siRNAs (Dynamin-1, Dynamin-2, and Dynamin-3). This was followed by an analysis of the target gene and levels of silk protein genes, as well as growth and developmental indices, Se-enrichment capacity, degree of oxidative damage, and antioxidant capacity of B. mori. Our findings showed a considerable decrease in the relative expression of the dynamin gene in all tissues 24 h after the interference and a dramatic decrease in the silkworm body after 48 h. RNAi dynamin gene decreased the silkworm body weight, cocoon shell weight, and the ratio of cocoon. In the meantime, malondialdehyde level increased and glutathione level and superoxide dismutase/catalase activities decreased. 50 µM Se markedly ameliorated these growth and physiological deficits as well as decreases in dynamin gene expression. On the other hand, there were no significant effects on fertility (including produced eggs and laid eggs) between the interference and Se treatments. Additionally, the Se content in the B. mori increased after the dynamin gene interference. The dynamin gene was highly expressed in the silk gland and declined significantly after interference. Among the three siRNAs (Dynamin-1, Dynamin-2, and Dynamin-3), the dynamin-2 displayed the highest interference effects to target gene expression. Our results demonstrated that 50 µM Se was effective to prevent any adverse effects caused by dynamin knockdown in silkworms. This provides practical implications for B. mori breeding industry.