Search

In this study, silver nanoparticles (AgNPs) were in‐situ synthesized in silk sericin/poly(vinyl alcohol) (SS/PVA) mixtures by an easy one‐step synthesis method with the presence of ultraviolet (UV) radiation. Then, the SS/PVA composite membranes containing AgNPs were obtained by solvent casting method. The chemical structures of the membranes were investigated by fourier‐transform infrared spectroscopy (FTIR) and results showed that the membranes were a mixture of silk sericin and PVA. The morphological features of the membranes were investigated by field emission scanning electron microscopy (FE‐SEM) and it was seen that AgNPs containing membranes have heterogeneous structures. Energy dispersive spectroscopy (EDS) analysis revealed that the membranes contain carbon, oxygen, nitrogen, sulfur and silver. X‐ray diffractometer (XRD) and thermogravimetric (TGA) analyses also proved the presence of AgNPs in the structure of membranes. The antibacterial activities of membranes containing AgNPs were investigated on Staphylococcus aureus and Escherichia coli bacteria with disk diffusion test and liquid culture medium incubation. It was found that SS/PVA membranes containing 5 and 10 mM AgNPs have quite high antibacterial activity on both types of bacteria. The functional SS/PVA membranes have capacity to be used in biomedical applications such as wound care materials. [ABSTRACT FROM AUTHOR]

Chronic wounds often result in multiple infections with various kinds of bacteria and uncontrolled wound exudate, resulting in several healthcare issues. Advanced medicated nanofibres prepared by electrospinning have gained much attention for their topical application on infected chronic wounds. The objective of this work is to enhance the critical variables of ciprofloxacin-loaded polycaprolactone-silk sericin (PCL/SS-PVA-CIP) nanofibre production via the process of electrospinning. To examine the antibacterial effectiveness of PCL/SS-PVA-CIP nanocomposites, the material was tested against P. aeruginosa and S. aureus. The combination of PCL/SS-PVA-CIP exhibited potent inhibitory properties, with the most effective concentrations of ciprofloxacin (CIP) being 3 μg/g and 7.0 μg/g for each bacterium, respectively. The biocompatibility was evaluated by conducting cell reduction and proliferation studies using the human epidermal keratinocyte (HaCaT) cells and human gingival fibroblasts (HGFs) in vitro cell lines. The PCL/SS-PVA-CIP showed good cell compatibility with HaCaT and HGF cells, with effective proliferation even at antibiotic doses of up to 7.0 μg/g. The drug release effectiveness of the nanocomposites was assessed at various concentrations of CIP, resulting in a maximum cumulative release of 76.5% and 74.4% after 72 h for CIP concentrations of 3 μg/g and 7 μg/g, respectively. In summary, our study emphasizes the possibility of combining silk sericin (SS) and polycaprolactone (PCL) loading with CIP nanocomposite for wound management. [ABSTRACT FROM AUTHOR]

AbstractA gel (SNA-Ag) loaded with nanoscale silver particles and a pH-responsive agent was prepared using N-isopropyl acrylamide (NIPAAm) as the first network structure, silk sericin (SS) as the second network structure and reducing agent, alizarin as the pH indicator and co-reducing agent, N, N-methylene bisacrylamide (BIS) as the crosslinking agent, ammonium persulfate (APS) as the initiator and N, N, N, N-tetramethylethylenediamine (TEMED) as co-initiator. To improve the breaking strength of the gel, the temperature and pH-responsive antibacterial (V/SNA-Ag) composite dressing was prepared by crosslinking the SNA-Ag gel with viscose non-woven fabric using glutaraldehyde as the crosslinking agent. Fourier transform infrared spectrometer (FTIR) and scanning electron microscopy (SEM) showed that the SNA-Ag hydrogel was successfully crosslinked with the viscose non-woven fabric. Meanwhile, a gel coating was formed on the fabric, and the coating thickness increased when the crosslinking time was extended. Differential Scanning Calorimetry (DSC) and pH response tests confirmed that the dressing was temperature sensitive, and the Lower Critical Solution Temperature (LCST) of the dressing was about 35 °C. When the pH of the dressing was changed from acidic to alkaline, its color was changed from yellow to purple, indicating that its color presented pH response characteristics. The dressing not only had excellent swelling performance but also had outstanding antibacterial activity; the antibacterial degree for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was up to 99%. A cytotoxicity test suggested that the survival degree of mouse cells after incubation for 96 h was more than 75%, proving that it was safe and nontoxic. In addition, compared with viscose non-woven fabric, the breaking strength of composite dressing was increased, and the air permeability was decreased. In conclusion, we suggest that V/SNA-Ag composite dressings have great potential for monitoring and treating wounds. [ABSTRACT FROM AUTHOR]

With breast cancer emerging as a pressing global health challenge, characterized by escalating incidence rates and geographical disparities, there is a critical need for innovative therapeutic strategies. This comprehensive research navigates the landscape of nanomedicine, specifically focusing on the potential of magnetic nanoparticles (MNPs), with magnetite (Fe3O4) taking center stage. MNPs, encapsulated in biocompatible polymers like silica known as magnetic silica nanoparticles (MSN), are augmented with phosphotungstate (PTA) for enhanced chemodynamic therapy (CDT). PTA is recognized for its dual role as a natural chelator and electron shuttle, expediting electron transfer from ferric (Fe3+) to ferrous (Fe2+) ions within nanoparticles. Additionally, protein-based charge-reversal nanocarriers like silk sericin and gluten are introduced to encapsulate (MSN-PTA) nanoparticles, offering a dynamic facet to drug delivery systems for potential revolutionization of breast cancer therapy. This study successfully formulates and characterizes protein-coated nanocapsules, specifically MSN-PTA-SER, and MSN-PTA-GLU, with optimal physicochemical attributes for drug delivery applications. The careful optimization of sericin and gluten concentrations results in finely tuned nanoparticles, showcasing uniform size, enhanced negative zeta potential, and remarkable stability. Various analyses, from Dynamic Light Scattering (DLS) and scanning electron microscopy (SEM) to transmission electron microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray diffraction analysis (XRD), and Thermogravimetric analysis (TGA), provide insights into structural integrity and surface modifications. Vibrating Sample Magnetometer (VSM) analysis underscores superparamagnetic behavior, positioning these nanocapsules as promising candidates for targeted drug delivery. In vitro evaluations demonstrate dose-dependent inhibition of cell viability in MCF-7 and Zr-75–1 breast cancer cells, emphasizing the therapeutic potential of MSN-PTA-SER and MSN-PTA-GLU. The interplay of surface charge and pH-dependent cellular uptake highlights the robust stability and versatility of these nanocarriers in tumor microenvironment, paving the way for advancements in targeted drug delivery and personalized nanomedicine. This comparative analysis explores the suitability of silk sericin and gluten, unraveling a promising avenue for the development of advanced, targeted, and efficient breast cancer treatments. [ABSTRACT FROM AUTHOR]

Silk sericin (SS)–based hydrogels show promise for wound healing due to their biocompatibility, moisture regulation, and cell proliferation properties. However, there is still a need to develop green crosslinking methods to obtain non-toxic, absorbent, and mechanically strong SS hydrogels. This study investigated the effects of three green crosslinking methods, annealing treatment (T), exposure to an absolute ethanol vapor atmosphere (V.E), and water vapor (V.A), on the physicochemical and mechanical properties of SS and poly (vinyl alcohol) (PVA) biohydrogels. X-ray diffraction and Fourier-transform infrared spectroscopy were used to determine chemical structures. Thermal properties and morphological changes were studied through thermogravimetric analysis and scanning electron microscopy, respectively. The water absorption capacity, mass loss, sericin release in phosphate-buffered saline (PBS), and compressive strength were also evaluated. The results showed that physical crosslinking methods induced different structural transitions in the biohydrogels, impacting their mechanical properties. In particular, V.A hydrogen presented the highest compressive strength at 80% deformation owing to its compact and porous structure with crystallization and bonding sites. Moreover, both the V.A and T hydrogels exhibited improved absorption capacity, stability, and slow SS release in PBS. These results demonstrate the potential of green physical crosslinking techniques for producing SS/PVA biomaterials for wound healing applications. [ABSTRACT FROM AUTHOR]

Skin serves as an active defense barrier in protecting our body from harmful microbes and external environment. It is subjected to several injuries caused by either microbes or chemicals. Therefore, damaged skin must be treated with a wound dressing material that possesses potent hemostatic, biocompatible and tissue regenerating properties. In the present study, silk sericin – a byproduct from silk industry is used as the starting material for preparing sericin sponges (S-SP). The S-SP were characterized using scanning electron microscopy, UV-visible spectroscopy, fourier transform infrared spectroscopy, and photoluminescence (PL) spectroscopy. S-SP possessed porous and interconnected structures when viewed under scanning electron microscope. The S-SP had percentage of hemolysis less than 2% when treated with human erythrocytes which proved their hemocompatible property. In vitro blood clotting assay showed that the S-SP reduced the time required for blood coagulation when compared with the control. Zebrafish embryos were used to assess the toxicity of S-SP. The open excision rat model experiments showed that S-SP were able to heal the wounds by reducing the time required for wound healing. These experiments proved the hemostatic, hemocompatible and wound healing efficacy of the prepared S-SP and their efficient role in the field of biomedicine. Fabrication of silk sericin sponges (S-SP) for treating open excision wounds: [ABSTRACT FROM AUTHOR]

Structurally defined, protein‐grafted nanoparticles are widely used in various biomedical applications, particularly as intelligent nanocarriers for drug delivery. The integration of synthetic polymers with natural proteins such as silk sericin enhances the functionality and stability of these nanocarriers, making them suitable for targeted and controlled drug release. In this context, an optimized grafting procedure for silk sericin is presented, employing a protein macroinitiator and atom transfer radical polymerization (ATRP). This study aims to elucidate the significance of the grafting process in tailoring the structure of sericin through the chemistry of synthetic grafts. The grafting procedure uses block copolymers of N‐isopropylacrylamide (NIPAM) and 2‐acrylamido‐2‐methylpropanesulfonic acid (AMPS), such as Poly‐(AMPS‐block‐NIPAM)/Poly‐(NIPAM‐block‐AMPS). The procedure employs both one‐step and two‐step synthesis methods to produce a well‐defined, biofunctionalized sericin. Subsequently, sericin‐based nanoparticles are prepared, demonstrating the significance of the optimized procedure. The synthesized products undergo structural analysis using H‐NMR, FTIR‐ATR, XPS, DLS, and zeta potential measurements. In addition, their thermal behavior is assessed using differential scanning calorimetry. To further investigate the prepared nanoparticles, SEM and DLS analyses are conducted. Through synthesis optimization, position and length of each synthetic block is precisely determined, significantly influencing properties of the grafted products and characteristics of the resulting nanoparticles. [ABSTRACT FROM AUTHOR]

The silkworm cocoon (SC), both as a traditional Chinese medicine and as the raw material for biocompatible carriers, has been extensively used in the medical and biomedical fields. This review elaborates on the multiple functions of SC, with an in-depth analysis of its chemical composition, biological activities, as well as its applications in modern medicine. The primary chemical components of SC include silk fibroin (SF), silk sericin (SS), and other flavonoid-like bioactive compounds demonstrating various biological effects. These include hypoglycemic, cardioprotective, hypolipidemic, anti-inflammatory, antioxidant, and antimicrobial actions, which highlight its potential therapeutic benefits. Furthermore, the review explores the applications of silk-derived materials in drug delivery systems, tissue engineering, regenerative medicine, and in vitro diagnostics. It also highlights the progression of SC from laboratory research to clinical trials, emphasizing the safety and efficacy of SC-based materials across multiple medical domains. Moreover, we discuss the market products developed from silk proteins, illustrating the transition from traditional uses to contemporary medical applications. This review provides support in understanding the current research status of SC and the further development and application of its derived products. [ABSTRACT FROM AUTHOR]

Silk proteins have been highlighted in the past decade for tissue engineering (TE) and skin regeneration due to their biocompatibility, biodegradability, and exceptional mechanical properties. While silk fibroin (SF) has high structural and mechanical stability with high potential as an external protective layer, traditionally discarded sericin (SS) has shown great potential as a natural-based hydrogel, promoting cell–cell interactions, making it an ideal material for direct wound contact. In this context, the present study proposes a new wound dressing approach by developing an SS/SF bilayer construct for full-thickness exudative wounds. The processing methodology implemented included an innovation element and the cryopreservation of the SS intrinsic secondary structure, followed by rehydration to produce a hydrogel layer, which was integrated with a salt-leached SF scaffold to produce a bilayer structure. In addition, a sterilization protocol was developed using supercritical technology (sCO2) to allow an industrial scale-up. The resulting bilayer material presented high porosity (>85%) and interconnectivity while promoting cell adhesion, proliferation, and infiltration of human dermal fibroblasts (HDFs). SS and SF exhibit distinct secondary structures, pore sizes, and swelling properties, opening new possibilities for dual-phased systems that accommodate the different needs of a wound during the healing process. The innovative SS hydrogel layer highlights the transformative potential of the proposed bilayer system for biomedical therapeutics and TE, offering insights into novel wound dressing fabrication. [ABSTRACT FROM AUTHOR]

Abstract With breast cancer emerging as a pressing global health challenge, characterized by escalating incidence rates and geographical disparities, there is a critical need for innovative therapeutic strategies. This comprehensive research navigates the landscape of nanomedicine, specifically focusing on the potential of magnetic nanoparticles (MNPs), with magnetite (Fe3O4) taking center stage. MNPs, encapsulated in biocompatible polymers like silica known as magnetic silica nanoparticles (MSN), are augmented with phosphotungstate (PTA) for enhanced chemodynamic therapy (CDT). PTA is recognized for its dual role as a natural chelator and electron shuttle, expediting electron transfer from ferric (Fe3+) to ferrous (Fe2+) ions within nanoparticles. Additionally, protein-based charge-reversal nanocarriers like silk sericin and gluten are introduced to encapsulate (MSN-PTA) nanoparticles, offering a dynamic facet to drug delivery systems for potential revolutionization of breast cancer therapy. This study successfully formulates and characterizes protein-coated nanocapsules, specifically MSN-PTA-SER, and MSN-PTA-GLU, with optimal physicochemical attributes for drug delivery applications. The careful optimization of sericin and gluten concentrations results in finely tuned nanoparticles, showcasing uniform size, enhanced negative zeta potential, and remarkable stability. Various analyses, from Dynamic Light Scattering (DLS) and scanning electron microscopy (SEM) to transmission electron microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray diffraction analysis (XRD), and Thermogravimetric analysis (TGA), provide insights into structural integrity and surface modifications. Vibrating Sample Magnetometer (VSM) analysis underscores superparamagnetic behavior, positioning these nanocapsules as promising candidates for targeted drug delivery. In vitro evaluations demonstrate dose-dependent inhibition of cell viability in MCF-7 and Zr-75–1 breast cancer cells, emphasizing the therapeutic potential of MSN-PTA-SER and MSN-PTA-GLU. The interplay of surface charge and pH-dependent cellular uptake highlights the robust stability and versatility of these nanocarriers in tumor microenvironment, paving the way for advancements in targeted drug delivery and personalized nanomedicine. This comparative analysis explores the suitability of silk sericin and gluten, unraveling a promising avenue for the development of advanced, targeted, and efficient breast cancer treatments.

In this paper the silver ions in a silver nitrate solution were reduced to the Ag element by silk sericin (SS); then, N-isopropylacrylamide (NIPAAm) was added into the mixed solution of SS and silver nitrate to form the bifunctional SS/NIPAAm-Ag3 hydrogel with interpenetrating network structure with N,N-methylenebisacrylamide (BIS) as a cross-linking agent, ammonium persulfate (APS) as a initiator and N, N, N', N-tetramethylethylenediamine (TEMED) as a co-initiator. SEM showed that the SS/NIPAAm-Ag3 hydrogel had a regular honeycomb structure and high porosity. It was confirmed by DSC that the SS/NIPAAm-Ag3 hydrogel exhibited temperature sensitivity, and its Lower Critical Solution Temperature (LCST) was about 35 °C. The swelling degree of the SS/NIPAAm-Ag3 hydrogel was obviously higher than that of SS/NIPAAm hydrogel at 25 °C and 37 °C. The time required for deswelling equilibrium was shortened by 2 h compared with SS/NIPAAm hydrogel, showing that the introduction of a certain amount of nano-Ag could give hydrogel excellent swelling and deswelling properties. The bacteriostatic rates against Esherichia coli (E.coli) and Staphylococcus aureus (S. aureus) reached 99.8% and 93.38%, respectively. A cytotoxicity test proved that SS/NIPAAm-Ag3 hydrogel had no adverse effects on the human cell health. The development of this temperature-sensitive and antibacterial hydrogel provides a new possibility for the preparation of hydrogel medical dressing. [ABSTRACT FROM AUTHOR]

Skin tissue injuries necessitate particular care due to associated complex healing mechanisms. Current investigations in the domain of tissue engineering and regenerative medicine are focused on obtaining novel scaffolds adapted as potential delivery systems to restore lost tissue functions and properties. In this study, we describe the fabrication and evaluation of a novel 3D scaffold structure based on collagen and silk sericin (CollSS) enriched with microcapsules containing natural compounds, curcumin (C), and/or quercetin (Q). These 3D composites were characterized by FT-IR spectroscopy, water uptake, in vitro collagenase degradation, and SEM microscopy. Furthermore, they were biologically evaluated in terms of biocompatibility, cell adhesion, anti-inflammatory, and antioxidant properties. All tested materials indicated an overall suitable biocompatibility, with the best results obtained for the one containing both flavonoids. This study suggests the cumulative beneficial effect of C and Q, encapsulated in the same composite, as a potential non-invasive therapeutic strategy for skin tissue regeneration in patients suffering from chronic wounds. [ABSTRACT FROM AUTHOR]

Wound infections may disrupt the normal wound-healing process. Large amounts of antibiotics are frequently used to prevent pathogenic infections; however, this can lead to resistance development. Biomaterials possessing antimicrobial properties have promising applications for reducing antibiotic usage and promoting wound healing. Silk sericin (SS) has been increasingly explored for skin wound healing applications owing to its excellent biocompatibility and antioxidant, antimicrobial, and ultraviolet-resistant properties. In recent years, SS-based composite biomaterials with a broader antimicrobial spectrum have been extensively investigated and demonstrated favorable efficacy in promoting wound healing. This review summarizes various antimicrobial agents, including metal nanoparticles, natural extracts, and antibiotics, that have been incorporated into SS composites for wound healing and elucidates their mechanisms of action. It has been revealed that SS-based biomaterials can achieve sustained antimicrobial activity by slow-release-loaded antimicrobial agents. The antimicrobial-loaded SS composites may promote wound healing through anti-infection, anti-inflammation, hemostasis, angiogenesis, and collagen deposition. The manufacturing methods, benefits, and limitations of antimicrobial-loaded SS materials are briefly discussed. This review aims to enhance the understanding of new advances and directions in SS-based antimicrobial composites and guide future biomedical research. [ABSTRACT FROM AUTHOR]

In recent years, interest in metal-based antibacterial materials has increased due to microorganisms gaining resistance to antibiotics. Silk sericin obtained from Bombyx mori cocoon has found use in many different areas thanks to its biocompatibility, hydrophilic character and biodegradability. Zinc oxide nanoparticles (ZnONPs) obtained in various zinc salts exhibit broad-spectrum antibacterial properties. In this study, to be produce metal based antibacterial materials, synthesis of silk sericin-coated ZnONPs (SS-ZnONPs) in a green and scalable method was investigated by using silk sericin protein as both reducing and capping agent to obtain ZnONPs. For producing SS-ZnONPs, 2% silk sericin solution was mixed with Zn(NO3)2 solution and the blend solution was heated at 100 °C for a certain period of time. Observing surface plasmon resonance (SPR) peak specific at 380 nm in the UV-vis spectrum of SS-ZnONPs represented the formation of ZnONPs. Then, the chemical, morphological, crystalline, thermal, and antibacterial properties of the synthesized SS-ZnONPs were examined. Characteristic peak of the Zn-O band was found in fourier transform infrared spectroscopy (FTIR) analysis of SSZnONPs. According to scanning electron microscopy (SEM) analyses, ZnONPs had morphology similar to cubic/hexagonal shape, showed a uniform structure, and did not represent any agglomerations. In energy dispersive spectroscopy (EDS) analyses of SS-ZnONPs, peaks belonging to carbon, nitrogen, oxygen, sulphur, and zinc elements were observed. The formation of Zn peak indicated that the zinc ions were transformed into ZnONPs. In addition, characteristic peaks of zinc were seen in the X-ray diffractometer (XRD) result of SS-ZnONPs. Thermogravimetric analysis (TGA) showed that the thermal stability and remaining amount of SS-ZnONPs was higher compared to pure silk sericin powder due to the formation of ZnONPs. Lastly, agar well diffusion test was carried out with Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25922) bacteria and SS-ZnONPs showed antibacterial action against S. aureus. It has been observed that the obtained SS-ZnONPs can be used as antibacterial agents. However, it was also understood that the ZnONPs concentration in this study was low for high antibacterial activity. [ABSTRACT FROM AUTHOR]

The silk sericin (SS) recovered from silk degumming wastewater can be used to develop carbonaceous materials for organic dye removal from wastewater. To improve the adsorption capacity of the carbonaceous adsorbents derived from SS, KOH was used as an activation agent. The maximum adsorption capacity of SS-based activated carbon on methylene blue (MB) was determined by batch adsorption experiments as 964.63 mg/g. Mathematical models of adsorption were studied to reveal the adsorption mechanism. According to adsorption kinetics analysis, a pseudo-second-order model describes the adsorption performance of SS-based activated carbon on MB more appropriately, and the adsorption process follows the Langmuir model. The activated carbon prepared from SS in this work demonstrated improved MB adsorption capacity compared with other SS-based carbonaceous materials and therefore presented prosperous application possibilities for removing organic dyes from wastewater. Creation and application of silk sericin-derived activated carbon. The silk sericin was first enriched from the silk degumming wastewater, then was converted into activated carbon by heating and activation. The generated activated carbon was later used for the adsorption of methylene blue from aqueous solutions through electrostatic and π-π interactions [ABSTRACT FROM AUTHOR]

The valorization of industrial byproducts is rising as a new dawn and has become a creative area of research for the scientists. Sericin is being a good resource of starting materials since it can be recovered and recycled. The research aimed to modify cotton fabric by sericin-TiO2 nanocomposite (STNc) for enhancement its antibacterial and self-cleaning properties. STNc were prepared using tetraisopropylorthotitanate (TIOT) and sericin with proportions 2:1, 2:2 and 1:2. The obtained STNc possesses anatase phase of TiO2 nanoparticles having an average 22.9 nm particle sizes. The STNc coated cotton samples were prepared with three different weight fractions of STNc and citric acid (2:1:2, 2:2:1 and 1:2:2). The incorporation of STNc onto cotton fabric was examined by FTIR spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses. The antibacterial activity of STNc coated cotton fabrics was investigated against drug resistant bacterium viz. Staphylococcus aureus, Pseudomonas 4A and Escherichia coli. The STNc coated cotton fabric exhibited effective resistance against Escherichia coli and Staphylococcus aureus. The antibacterial properties of STNc coated cotton fabrics were depended with the fraction of STNc. The uncoated and STNc coated cotton fabrics were stained with coffee and then irradiated on sunlight for 0, 30, 60, 90 h and UV light for 2, 4, 6, 8, 10 h. A noticeable decrease in the coffee stain's appearance was observed after 90 h sunlight and 10 h UV light exposure for STNc coated cotton fabric. The reusability of photo exposed samples was evaluated by FTIR spectroscopy.

Silk sericin, a natural protein from silkworm cocoons, is emerging as a multifunctional biomaterial in biomedicine, particularly in tissue engineering and wound healing. Recent studies have highlighted its biocompatibility, biodegradability, and potential for chemical modification, which allows it to be incorporated into various scaffold architectures. This review article synthesizes current research, including the development of sericin-based hydrogel scaffolds for tissue engineering and sericin's role in enhancing wound healing. Key findings demonstrate sericin's ability to refine scaffold porosity and mechanical strength, expedite tissue healing, and reduce bacterial load in wounds. The integration of sericin into novel bioactive dressings and its use in peripheral nerve injury repair are also discussed, showcasing its adaptability and efficacy. The convergence of these studies illustrates the broad applications of sericin, from scaffold design to clinical interventions, making it a promising material in regenerative medicine and tissue engineering, with the potential to improve patient outcomes significantly. [ABSTRACT FROM AUTHOR]

Chronic wounds often result in multiple infections with various kinds of bacteria and uncontrolled wound exudate, resulting in several healthcare issues. Advanced medicated nanofibres prepared by electrospinning have gained much attention for their topical application on infected chronic wounds. The objective of this work is to enhance the critical variables of ciprofloxacin-loaded polycaprolactone-silk sericin (PCL/SS-PVA-CIP) nanofibre production via the process of electrospinning. To examine the antibacterial effectiveness of PCL/SS-PVA-CIP nanocomposites, the material was tested against P. aeruginosa and S. aureus. The combination of PCL/SS-PVA-CIP exhibited potent inhibitory properties, with the most effective concentrations of ciprofloxacin (CIP) being 3 μg/g and 7.0 μg/g for each bacterium, respectively. The biocompatibility was evaluated by conducting cell reduction and proliferation studies using the human epidermal keratinocyte (HaCaT) cells and human gingival fibroblasts (HGFs) in vitro cell lines. The PCL/SS-PVA-CIP showed good cell compatibility with HaCaT and HGF cells, with effective proliferation even at antibiotic doses of up to 7.0 μg/g. The drug release effectiveness of the nanocomposites was assessed at various concentrations of CIP, resulting in a maximum cumulative release of 76.5% and 74.4% after 72 h for CIP concentrations of 3 μg/g and 7 μg/g, respectively. In summary, our study emphasizes the possibility of combining silk sericin (SS) and polycaprolactone (PCL) loading with CIP nanocomposite for wound management.

Silk sericin (SS)–based hydrogels show promise for wound healing due to their biocompatibility, moisture regulation, and cell proliferation properties. However, there is still a need to develop green crosslinking methods to obtain non-toxic, absorbent, and mechanically strong SS hydrogels. This study investigated the effects of three green crosslinking methods, annealing treatment (T), exposure to an absolute ethanol vapor atmosphere (V.E), and water vapor (V.A), on the physicochemical and mechanical properties of SS and poly (vinyl alcohol) (PVA) biohydrogels. X-ray diffraction and Fourier-transform infrared spectroscopy were used to determine chemical structures. Thermal properties and morphological changes were studied through thermogravimetric analysis and scanning electron microscopy, respectively. The water absorption capacity, mass loss, sericin release in phosphate-buffered saline (PBS), and compressive strength were also evaluated. The results showed that physical crosslinking methods induced different structural transitions in the biohydrogels, impacting their mechanical properties. In particular, V.A hydrogen presented the highest compressive strength at 80% deformation owing to its compact and porous structure with crystallization and bonding sites. Moreover, both the V.A and T hydrogels exhibited improved absorption capacity, stability, and slow SS release in PBS. These results demonstrate the potential of green physical crosslinking techniques for producing SS/PVA biomaterials for wound healing applications.

Memristive devices with threshold switching characteristics can be effectively utilized to mimic biological neurons acting as one of the key building blocks for constructing advanced hardware neural networks. In this work, the emulation of leaky integrate‐and‐fire memristive neuron is realized in one single cell with Ag/Ag−In−Zn−S/silk sericin/W architecture without the need for additional auxiliary circuits. The studied devices demonstrate excellent electrical properties, such as stably repeatable threshold switching, concentratedly low threshold voltage (≈0.4 V), and relatively small device‐to‐device variation. In addition, multiple neural features, such as leaky integrate‐and‐fire neuron functionality and strength‐modulated spike frequency characteristic, have been successfully emulated owing to the forming‐free volatile threshold switching effect. The stable volatile threshold switching behaviors and regular firing event may be attributed to the controllable metallic Ag filamentary mechanism. Furthermore, a solid accuracy of 91.44% of the pattern recognition of Modified National Institute of Standards and Technology (MNIST) data is obtained via a trained spiking neural network (SNN) based on the leaky integrate‐and‐fire behavior of sericin‐based device. These achievements shed light on the fact that employing sericin biomaterials has great application potential in advanced neuromorphic computation. [ABSTRACT FROM AUTHOR]

In the present work, poly(vinyl alcohol)/silk sericin (PVA/SS) membranes were obtained with an easily procedure and removal of remazol black B (RBB) by the membranes was investigated. To synthesize PVA/SS membranes by solvent casting method, 5% SS solution (g/mL) and 10% PVA solution (g/mL) were mixed one to one ratio by volume, the mixture was transferred to a petri dish and incubated at 25 ºC for 24 h. Then, the obtained membranes were incubated at 150 ºC for 1 h for physical crosslinking. The obtained membranes were characterized with fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and thermogravimetric analysis (TGA). Then, for adsorption experiments, firstly, RBB adsorption capabilities of PVA/SS membranes were tested at pH ranging from 2 to 7. After that, the removal experiments were carried out at different incubation time, initial dye concentration and PVA/SS membrane amount to optimize the conditions for removal of RBB with the PVA/SS membranes. The obtained membranes removed high amount of RBB when the solution pH was 2 and the adsorption of RBB to the membranes reached equilibrium within 10 h. The maximum RBB adsorption ability of the PVA/SS membranes was found to be 15.27 mg/g when the initial RBB amount of the solution was 200 mg/L. These results show that PVA/SS membranes, which can be easily synthesized for large applications, have the capacity to be used to remove negatively charged pollutants such as RBB from liquid solutions. [ABSTRACT FROM AUTHOR]

Tailored porous structures of poly(2-hydroxyethyl methacrylate) (PHEMA) and silk sericin (SS) were used to create porous hydrogel scaffolds using two distinct crosslinking systems. These structures were designed to closely mimic the porous nature of the native extracellular matrix. Conventional free radical polymerization of 2-hydroxyethyl methacrylate (HEMA) was performed in the presence of different concentrations of SS (1.25, 2.50, 5.00% w/v) with two crosslinking systems. A chemical crosslinking system with N'N-methylene bisacrylamide (MBAAm) and a physical crosslinking system with dimethylurea (DMU) were used: C-PHEMA/SS (crosslinked using MBAAm) and C-PHEMA/pC-SS (crosslinked using MBAAm and DMU). The focus of this study was on investigating the impact of these crosslinking methods on various properties of the scaffolds, including pore size, pore characteristics, polymerization time, morphology, molecular interaction, in vitro degradation, thermal properties, and in vitro cytotoxicity. The various crosslinked networks were found to appreciably influence the properties of the scaffolds, especially the pore sizes, in which smaller sizes and higher numbers of pores with high regularity were seen in C-PHEMA/1.25 pC-SS (17 ± 2 μm) than in C-PHEMA/1.25 SS (34 ± 3 μm). Semi-interpenetrating networks were created by crosslinking PHEMA-MBAAm-PHEMA while incorporating free protein molecules of SS within the networks. The additional crosslinking step involving DMU occurred through hydrogen bonding of the -C=O and -N-H groups with the SS, resulting in the simultaneous incorporation of DMU and SS within the PHEMA networks. As a consequence of this process, the scaffold C-PHEMA/pC-SS exhibited smaller pore sizes compared to scaffolds without DMU crosslinking. Moreover, the incorporation of higher loadings of SS led to even smaller pore sizes. Additionally, the gelation time of C-PHEMA/pC-SS was delayed due to the presence of DMU in the crosslinking system. Both porous hydrogel scaffolds, C-PHEMA/pC-SS and PHEMA, were found to be non-cytotoxic to the normal human skin dermal fibroblast cell line (NHDF cells). This promising result indicates that these hydrogel scaffolds have potential for use in tissue engineering applications. [ABSTRACT FROM AUTHOR]

The silkworm cocoon (SC), both as a traditional Chinese medicine and as the raw material for biocompatible carriers, has been extensively used in the medical and biomedical fields. This review elaborates on the multiple functions of SC, with an in-depth analysis of its chemical composition, biological activities, as well as its applications in modern medicine. The primary chemical components of SC include silk fibroin (SF), silk sericin (SS), and other flavonoid-like bioactive compounds demonstrating various biological effects. These include hypoglycemic, cardioprotective, hypolipidemic, anti-inflammatory, antioxidant, and antimicrobial actions, which highlight its potential therapeutic benefits. Furthermore, the review explores the applications of silk-derived materials in drug delivery systems, tissue engineering, regenerative medicine, and in vitro diagnostics. It also highlights the progression of SC from laboratory research to clinical trials, emphasizing the safety and efficacy of SC-based materials across multiple medical domains. Moreover, we discuss the market products developed from silk proteins, illustrating the transition from traditional uses to contemporary medical applications. This review provides support in understanding the current research status of SC and the further development and application of its derived products.

Silk proteins have been highlighted in the past decade for tissue engineering (TE) and skin regeneration due to their biocompatibility, biodegradability, and exceptional mechanical properties. While silk fibroin (SF) has high structural and mechanical stability with high potential as an external protective layer, traditionally discarded sericin (SS) has shown great potential as a natural-based hydrogel, promoting cell–cell interactions, making it an ideal material for direct wound contact. In this context, the present study proposes a new wound dressing approach by developing an SS/SF bilayer construct for full-thickness exudative wounds. The processing methodology implemented included an innovation element and the cryopreservation of the SS intrinsic secondary structure, followed by rehydration to produce a hydrogel layer, which was integrated with a salt-leached SF scaffold to produce a bilayer structure. In addition, a sterilization protocol was developed using supercritical technology (sCO2) to allow an industrial scale-up. The resulting bilayer material presented high porosity (>85%) and interconnectivity while promoting cell adhesion, proliferation, and infiltration of human dermal fibroblasts (HDFs). SS and SF exhibit distinct secondary structures, pore sizes, and swelling properties, opening new possibilities for dual-phased systems that accommodate the different needs of a wound during the healing process. The innovative SS hydrogel layer highlights the transformative potential of the proposed bilayer system for biomedical therapeutics and TE, offering insights into novel wound dressing fabrication.

Wound infections may disrupt the normal wound-healing process. Large amounts of antibiotics are frequently used to prevent pathogenic infections; however, this can lead to resistance development. Biomaterials possessing antimicrobial properties have promising applications for reducing antibiotic usage and promoting wound healing. Silk sericin (SS) has been increasingly explored for skin wound healing applications owing to its excellent biocompatibility and antioxidant, antimicrobial, and ultraviolet-resistant properties. In recent years, SS-based composite biomaterials with a broader antimicrobial spectrum have been extensively investigated and demonstrated favorable efficacy in promoting wound healing. This review summarizes various antimicrobial agents, including metal nanoparticles, natural extracts, and antibiotics, that have been incorporated into SS composites for wound healing and elucidates their mechanisms of action. It has been revealed that SS-based biomaterials can achieve sustained antimicrobial activity by slow-release-loaded antimicrobial agents. The antimicrobial-loaded SS composites may promote wound healing through anti-infection, anti-inflammation, hemostasis, angiogenesis, and collagen deposition. The manufacturing methods, benefits, and limitations of antimicrobial-loaded SS materials are briefly discussed. This review aims to enhance the understanding of new advances and directions in SS-based antimicrobial composites and guide future biomedical research.

Skin tissue injuries necessitate particular care due to associated complex healing mechanisms. Current investigations in the domain of tissue engineering and regenerative medicine are focused on obtaining novel scaffolds adapted as potential delivery systems to restore lost tissue functions and properties. In this study, we describe the fabrication and evaluation of a novel 3D scaffold structure based on collagen and silk sericin (CollSS) enriched with microcapsules containing natural compounds, curcumin (C), and/or quercetin (Q). These 3D composites were characterized by FT-IR spectroscopy, water uptake, in vitro collagenase degradation, and SEM microscopy. Furthermore, they were biologically evaluated in terms of biocompatibility, cell adhesion, anti-inflammatory, and antioxidant properties. All tested materials indicated an overall suitable biocompatibility, with the best results obtained for the one containing both flavonoids. This study suggests the cumulative beneficial effect of C and Q, encapsulated in the same composite, as a potential non-invasive therapeutic strategy for skin tissue regeneration in patients suffering from chronic wounds.

Abstract Memristive devices with threshold switching characteristics can be effectively utilized to mimic biological neurons acting as one of the key building blocks for constructing advanced hardware neural networks. In this work, the emulation of leaky integrate‐and‐fire memristive neuron is realized in one single cell with Ag/Ag−In−Zn−S/silk sericin/W architecture without the need for additional auxiliary circuits. The studied devices demonstrate excellent electrical properties, such as stably repeatable threshold switching, concentratedly low threshold voltage (≈0.4 V), and relatively small device‐to‐device variation. In addition, multiple neural features, such as leaky integrate‐and‐fire neuron functionality and strength‐modulated spike frequency characteristic, have been successfully emulated owing to the forming‐free volatile threshold switching effect. The stable volatile threshold switching behaviors and regular firing event may be attributed to the controllable metallic Ag filamentary mechanism. Furthermore, a solid accuracy of 91.44% of the pattern recognition of Modified National Institute of Standards and Technology (MNIST) data is obtained via a trained spiking neural network (SNN) based on the leaky integrate‐and‐fire behavior of sericin‐based device. These achievements shed light on the fact that employing sericin biomaterials has great application potential in advanced neuromorphic computation.

The main purpose was to elucidate the potential anti-aging impact of sericin, due to its anti-oxidant potential in D-galactose induced mice model. To induce natural aging in mice, a solution of 0.9 % saline containing D-galactose (250 mg/kg b.w.) was injected intraperitoneally for a period of 60 days. In this experiment, 56 male mice were arbitrarily categorized into 8 groups (1: control; 2: D-Galactose (250 mg/kg b.w), Group 3: Sericin (150 mg/kg b.w), Group 4: Metformin (150 mg/kg), Group 5: sericin (P), Group 6; sericin (T), Group 7; Met (P), Group 8; Met (T). The level of Glutathione reductase (2.1 ± 0.2 µmol/L), CAT (0.5 ± 0.0 mmol/mL), Superoxide dismutase (65.4 ± 1.7 U/mL), GSHPx (69.2 ± 1.7 U/l), T3 (3.1 ± 0.7 ng/mL), IL-2 (68.8 ± 1.5 Pg/mL), IL-4 (71.4 ± 4.2 Pg/mL), IgG (0.6 ± 0.0 mg/mL) and IgM (0.6 ± 0.0 mg/mL) were significantly (P

In this study, the structural characteristics of sericin recovered from wastewater released from the silk textile industry (Plant sericin) were comparatively analyzed with those of sericin extracted from a silkworm cocoon produced in a laboratory (Lab sericin). To prepare Plant sericin, ethanol was added to wastewater (i.e., a sericin aqueous solution) after the degumming process to remove nonprotein materials, affording a sericin precipitate. To prepare Lab sericin, nonprotein materials were removed from a silkworm cocoon and sericin was subsequently extracted from the cocoon. Lab sericin and Plant sericin exhibited similar solution viscosities, gel strengths, and crystallinity indices, indicative of the similar molecular weights (MWs) of the two sericin samples. In the case of sericin powder, Plant sericin was more crystalline than Lab sericin due to its treatment with ethanol. The findings of this study revealed that sericin recovered from industrial wastewater can be used equally as its MW is similar to that of sericin obtained through laboratory-scale extraction. [ABSTRACT FROM AUTHOR]

Hydrogel-based burn wound dressings with excellent antibacterial, antifungal, and mechanical properties are ideal biomaterials to promote infected large burn wound healing. In this study, the hydrogel synthesized by repetitive freezing-thawing consists of poly (vinyl alcohol) (PVA), silk sericin (SS), and azithromycin (AZM), with genipin (GNP) as crosslinker. The FTIR showed that all hydrogel components were successfully blended. The swelling ratio, porosity, cell attachment, and proliferation improved with SS incorporation, while increased PVA content enhanced the mechanical performance of the hydrogel. The inclusion of AZM improved the antimicrobial property of the hydrogel towards Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. The hydrogel showed sustained SS and AZM releases as well as cytocompatibility on keratinocytes and fibroblasts. Furthermore, the hydrogel displays skin adhesion ability when freeze-dried. In the in vivo study using an infected mouse full-thickness burn model with a 10% total body surface area, it was shown that burn injury led to increased inflammatory cytokine responses and macroscopic and microscopic alterations in the spleen and liver. The kidneys, on the other hand, revealed neither change. Interestingly, the prepared hydrogel had a better burn wound healing effect than the commercial Tegaderm™ film dressing, minimizing systemic burn effects. Hence, this novel hydrogel is projected to be a promising candidate for accelerated healing of infected burn wounds.

Silk sericin (SS) is a byproduct of the silk production process that consists of 18 ​amino acids and numerous polar groups. SS has a range of unique physical, chemical, and biological properties, such as mechanical strength, antioxidant activity, pH responsiveness, low immunogenicity, biocompatibility, and the ability to promote cell proliferation. These properties make SS useful in various fields, including food and biomedicine. It can also be easily modified into biomaterials through cross-linking, copolymerization, and combination with other polymers. This review summarizes the potential applications of SS-based biomaterials in the food and biomedicine industries, including as food additives, food packaging, in vitro/vivo monitoring, drug delivery systems, and wound healing. In addition, the future development possibilities of SS or SS-based biomaterials are also discussed.

Abstract Background Silk sericin is an active ingredient in bone grafts. However, the optimal scaffold for silk sericin has yet to be identified. Method A critical-sized bone defect model in rat calvaria was used to evaluate bone regeneration. Silk sericin from Yeonnokjam, Bombyx mori, was incorporated into gelatin (group G, n = 6) and collagen (group C, n = 6). Bone regeneration was evaluated using micro-computed tomography (mCT) and histology. Results Group C showed a larger bone volume than group G in the mCT analysis (P = 0.001). Histological analysis showed a larger area of bony defects in group G than in group C. The bone regeneration area in group C was significantly larger than that in group G (P = 0.003). Conclusion Compared with gelatin, collagen shows better bone regeneration in silk sericin-based bone grafts.

Aloe vera, chitosan, and silk sericin have been investigated for their physicochemical properties as well as functional characteristics such as antibacterial, antioxidant, and UV resistance. Aloe vera was extracted by methanol as a solvent. Silk sericin was prepared from a boiled water solution of silk cocoons through ethanol precipitation, while chitosan was synthesized by deacetylation of chitin. FT-IR, TGA, DSC, EDX, UV–vis, and XRD were used to characterize the extracted Aloe vera, chitosan, and sericin. Antibacterial activity, antioxidant activity and UV protection factors were also investigated. The TGA graph revealed that the significant weight loss at 400 °C was 39%, 51%, and 52%. for Aloe vera, chitosan, and sericin, respectively. For E. coli, Aloe vera, chitosan, and silk sericin, the zones of inhibition were 2.5 mm, 3 mm, and 1 mm, respectively, whereas for S. aureus, the zones of inhibition were 4 mm, 5 mm, and 1.5 mm. The free radical scavenging activity of 10 mg/ml Aloe vera, chitosan and sericin was 93%, 53% and 52%, respectively. All three UV radiation zones were absorbed by an Aloe vera solution. Chitosan and silk sericin solution exclusively absorbed UV-C rays. These almost priceless natural resources can contribute to health-related beneficial issues.

Sericin has been used in functional and potentially biodegradable materials for cosmetics, biomedical, agricultural, and food applications. It is a natural polymer with applications in absorbent materials, such as hydrogels, because of its hydrophilic character. However, sericin by itself is brittle, and in contact with water has low structural stability, being necessary its blending with other polymers or the application of crosslinking processes. In this work, hydrogel films were prepared from different mixtures containing sericin (SS), carboxymethylcellulose (CMC), and polyvinyl alcohol (PVA), using a simple and environmentally friendly method consisting of a gelling process followed by solvent casting. A mixture design was applied to assess the incidence of each component and its interaction with the output variables of interest. Two response variables were evaluated in each formulation: water absorption capacity (WA) and gel fraction (GF). It was also possible to model the output variables based on the proportions of the sample components. In addition, a set of formulations were used to produce hydrogels with high water absorption rates while maintaining their structural stability. The optimal hydrogel formulation (HF) was structurally and thermally characterized by FTIR and TGA, respectively. Hydrogel morphology was also studied by scanning electron microscopy (SEM). The results of this study constitute an important contribution to the design of novel processing routes to extend the use of silk sericin in the development of new materials. [ABSTRACT FROM AUTHOR]

We report the feasibility of electrospinning of protein‐polymer multilayered scaffolds with selected materials such as non‐hydrolyzed silk sericin (SS), polyethylene oxide (PEO), and polylactic acid (PLA), with tuned fiber size and properties for each layer. We present a new innovative way for the electrospinning (ES) of non‐hydrolyzed SS mixed with PEO yielding fibers with an average diameter ranging between 120 and 150 nm. Different SS:PEO ratios have been electrospun to study the effect of the concentration of SS protein on the fibers size and shape, as well and their electrospinnability. Electrospun SS:PEO fibers display weak to no mechanical resistance (non‐measurable) and their deposition onto a sturdier scaffold is necessary to allow their use in biomedical and/or pharmaceutical fields. Therefore, bilayer scaffolds have been fabricated consisting of a PLA support and SS:PEO fibers obtained from the optimized SS:PEO ratio (1.2:4). They are composed of a sturdy hydrophobic layer of PLA fibers and a layer of sticky hydrophilic SS:PEO fibers. The scaffolds have been characterized extensively by Fourier transforms infra‐red (FTIR) spectroscopy, X‐ray diffraction (XRD), scanning electron microscopy (SEM), and their resistance to mechanical stress. Finally, hydrophobicity of both layers has been determined by measuring the contact angle of water droplets on the scaffolds, further proving the bilayer nature of the scaffolds. [ABSTRACT FROM AUTHOR]

The antibacterial activity of synthetic antimicrobial agents is well known, but most of them have several side effects and are effective against selective microbes. Recently, major concern for the microbiologists is to investigate for some stable, non‐toxic, cheap, and eco‐friendly antimicrobial agents with a wide range of bactericidal potential. A cost‐effective and environmentally friendly alternate has been proposed in the form of green synthesized nanoparticles. The Present study was designed to fabricate sericin‐coated silver nanoparticles (S‐AgNPs) using sericin as stabilizer and reductant of silver ions and their antibacterial potential was evaluated at various concentrations and temperatures (8, 40, and 50°C). Antimicrobial activities were assessed by the agar well diffusion method. Antibacterial activity of S‐AgNPs was measured at different concentrations (1–6 mg/ml) whereas; antifungal activity was tested at 5–20 mg/ml of S‐AgNPs. Nanoparticles were characterized by UV–visible spectrophotometer, Fourier transform infrared spectroscopy, and scanning electron microscopy. These nanoparticles significantly subdued the growth of Clostridium difficile (18.7 ± 0.9 mm), Proteus mirabilis (12.3 ± 0.3 mm) and Bacillus licheniformis (10.7 ± 0.9 mm) and Aspergillus flavus (18.7 ± 2.0 mm), Mucor mycetes (13.0 ± 1.5 mm), Candida albicans (15.3 ± 0.3 mm) and Aspergillus niger (10.0 ± 0.6 mm). S‐AgNPs were stable at all temperatures and the maximum growth inhibition was found at 8°C for all pathogenic strains. We concluded that the S‐AgNPs could be a potential candidate to inhibit the growth of bacterial and fungal pathogens at a wide range of environmental conditions like temperature. In various biomedical applications including antimicrobial and wound dressings, S‐AgNPs can be used in the future to treat various bacterial and fungal infections. [ABSTRACT FROM AUTHOR]

Background: Silk sericin is an active ingredient in bone grafts. However, the optimal scaffold for silk sericin has yet to be identified. Method: A critical-sized bone defect model in rat calvaria was used to evaluate bone regeneration. Silk sericin from Yeonnokjam, Bombyx mori, was incorporated into gelatin (group G, n = 6) and collagen (group C, n = 6). Bone regeneration was evaluated using micro-computed tomography (mCT) and histology. Results: Group C showed a larger bone volume than group G in the mCT analysis (P = 0.001). Histological analysis showed a larger area of bony defects in group G than in group C. The bone regeneration area in group C was significantly larger than that in group G (P = 0.003). Conclusion: Compared with gelatin, collagen shows better bone regeneration in silk sericin-based bone grafts. [ABSTRACT FROM AUTHOR]

A simple, efficient, economically viable, and fast analytical method to perform arsenic (As3+) determination using silk sericin capped gold nanoparticles (SS-AuNPs) and UV–Visible spectroscopy as a detection technique is reported. In this work, biomediated AuNPs were synthesized using an eco-friendly biomaterial Bombyx mori SS. Formation of the AuNPs was verified by surface plasmon spectrum using UV–Visible spectroscopy. The crystalline structure of the AuNPs was characterized by X-ray diffraction technique. Morphologically spherical in shape with good dispersion and average diameter of 12.5 nm was revealed by transmission electron microscope (TEM). The size and shape of the AuNPs are greatly associated with their optical properties. When the As3+ions are added to SS-AuNPs the color change occurs due to the aggregation of AuNPs allowing the detection of As3+at parts per billion (ppb). Results showed an excellent correlation (R2=0.985) exists between the decrease in the absorbance signal and the As3+ concentrations over the range from 1 ppb to 10 ppb. The limit of detection (LOD) of As3+ ions is found to be 2.94 ppb (3σ) and is many folds lower than the world health organization (WHO) recommended limit of 10 ppb. The described study could be a very useful method for the detection of As3+ ions in water and offers a basis for developing an optical sensing system for different applications. [ABSTRACT FROM AUTHOR]

Oxidative stress in skin cells can induce the formation of reactive oxygen species (ROS), which are critical for pathogenic processes such as immunosuppression, inflammation, and skin aging. In this study, we confirmed improvements from gamma-irradiated silk sericin (I-sericin) and gamma-irradiated silk fibroin (I-fibroin) to skin cells damaged by oxidative stress. We found that I-sericin and I-fibroin effectively attenuated oxidative stress-induced ROS generation and decreased oxidative stress-induced inflammatory factors COX-2, iNOS, tumor necrosis factor-α, and interleukin-1β compared to the use of non-irradiated sericin or fibroin. I-sericin and Ifibroin effects were balanced by competition with skin regenerative protein factors reacting to oxidative stress. Taken together, our results indicated that, compared to non-irradiated sericin or fibroin, I-sericin, and I-fibroin had anti-oxidation and antiinflammation activity and protective effects against skin cell damage from oxidative stress. Therefore, gamma-irradiation may be useful in the development of cosmetics to maintain skin health. [ABSTRACT FROM AUTHOR]

Hydrogel-based burn wound dressings with excellent antibacterial, antifungal, and mechanical properties are ideal biomaterials to promote infected large burn wound healing. In this study, the hydrogel synthesized by repetitive freezing-thawing consists of poly (vinyl alcohol) (PVA), silk sericin (SS), and azithromycin (AZM), with genipin (GNP) as crosslinker. The FTIR showed that all hydrogel components were successfully blended. The swelling ratio, porosity, cell attachment, and proliferation improved with SS incorporation, while increased PVA content enhanced the mechanical performance of the hydrogel. The inclusion of AZM improved the antimicrobial property of the hydrogel towards Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. The hydrogel showed sustained SS and AZM releases as well as cytocompatibility on keratinocytes and fibroblasts. Furthermore, the hydrogel displays skin adhesion ability when freeze-dried. In the in vivo study using an infected mouse full-thickness burn model with a 10% total body surface area, it was shown that burn injury led to increased inflammatory cytokine responses and macroscopic and microscopic alterations in the spleen and liver. The kidneys, on the other hand, revealed neither change. Interestingly, the prepared hydrogel had a better burn wound healing effect than the commercial Tegaderm™ film dressing, minimizing systemic burn effects. Hence, this novel hydrogel is projected to be a promising candidate for accelerated healing of infected burn wounds. [ABSTRACT FROM AUTHOR]

Silk sericin is a class of protein biopolymers produced by silkworms. Increasing attention has been paid to silk sericin for biomedical applications in the last decade, not only because of its excellent biocompatibility and biodegradability but also due to the pharmacological activities stemming from its unique amino acid compositions. In this review, the biological properties of silk sericin, including curing specific diseases and promoting tissue regeneration, as well as underlying mechanisms are summarized. We consider the antioxidant activity of silk sericin as a fundamental property, which could account for partial biological activities, despite the exact mechanisms of silk sericin's effect remaining unknown. Based on the reactive groups on silk sericin, approaches of bottom-up fabrication of silk sericin-based biomaterials are highlighted, including non-covalent interactions and chemical reactions (reduction, crosslinking, bioconjugation, and polymerization). We then briefly present the cutting-edge advances of silk sericin-based biomaterials applied in tissue engineering and drug delivery. The challenges of silk sericin-based biomaterials are proposed. With more bioactivities and underlying mechanisms of silk sericin uncovered, it is going to boost the therapeutic potential of silk sericin-based biomaterials. [Display omitted] • Silk sericin is not only a biocompatible building block of materials but also a bioactive therapeutic. • The pharmacological activities of silk sericin and its possible mechanisms are summarized. • The bottom-up approaches to developing silk sericin-based biomaterials are summarized. • The applications and limitations of silk sericin-based biomaterials are reviewed. [ABSTRACT FROM AUTHOR]

Tailored porous structures of poly(2-hydroxyethyl methacrylate) (PHEMA) and silk sericin (SS) were used to create porous hydrogel scaffolds using two distinct crosslinking systems. These structures were designed to closely mimic the porous nature of the native extracellular matrix. Conventional free radical polymerization of 2-hydroxyethyl methacrylate (HEMA) was performed in the presence of different concentrations of SS (1.25, 2.50, 5.00% w/v) with two crosslinking systems. A chemical crosslinking system with N’N-methylene bisacrylamide (MBAAm) and a physical crosslinking system with dimethylurea (DMU) were used: C-PHEMA/SS (crosslinked using MBAAm) and C-PHEMA/pC-SS (crosslinked using MBAAm and DMU). The focus of this study was on investigating the impact of these crosslinking methods on various properties of the scaffolds, including pore size, pore characteristics, polymerization time, morphology, molecular interaction, in vitro degradation, thermal properties, and in vitro cytotoxicity. The various crosslinked networks were found to appreciably influence the properties of the scaffolds, especially the pore sizes, in which smaller sizes and higher numbers of pores with high regularity were seen in C-PHEMA/1.25 pC-SS (17 ± 2 μm) than in C-PHEMA/1.25 SS (34 ± 3 μm). Semi-interpenetrating networks were created by crosslinking PHEMA-MBAAm-PHEMA while incorporating free protein molecules of SS within the networks. The additional crosslinking step involving DMU occurred through hydrogen bonding of the -C=O and -N-H groups with the SS, resulting in the simultaneous incorporation of DMU and SS within the PHEMA networks. As a consequence of this process, the scaffold C-PHEMA/pC-SS exhibited smaller pore sizes compared to scaffolds without DMU crosslinking. Moreover, the incorporation of higher loadings of SS led to even smaller pore sizes. Additionally, the gelation time of C-PHEMA/pC-SS was delayed due to the presence of DMU in the crosslinking system. Both porous hydrogel scaffolds, C-PHEMA/pC-SS and PHEMA, were found to be non-cytotoxic to the normal human skin dermal fibroblast cell line (NHDF cells). This promising result indicates that these hydrogel scaffolds have potential for use in tissue engineering applications.

This work focuses on preparation of electrospun matrix for wound dressing application by utilizing sericin, chitosan and silver nanoparticles in PVA nanofibers. Sericin (SS) is extracted from silk cocoon (Bombyx Mori) by alkali degumming method. The extracted sericin is characterised by UV-visible Spectroscopy and FT-IR. Then, individual stock solutions of 2% (w/v) Chitosan (CH) in acetic acid, 10% (w/v) of PVA in deionised water were prepared. To enhance the antimicrobial property to the wound dressing, silver nanoparticles (Ag NP) was prepared using Cynodan dactylon (Bermuda grass) leaves extract and characterised using UV-visible Spectroscopy. The prepared Ag NP was incorporated in the nanofibers at constant proportion. Furthermore, three blended PVA/SS/CH solutions were prepared in the following ratios 8:1:1, 5:2.5:2.5, and 2:4:4 and electrospun to create nanofibrous dressing material. The structural and physical characteristics of the prepared nanofibrous dressing material were studied using SEM and Universal Testing Machine. Based upon mechanical strength and SEM analysis PVA/SS/CH in the ratio 8:1:1 was chosen for In-vitro studies. From the studies it concludes that the prepared PVA/SS/CH electrospun nanofiber will be a promising material for wound dressing.

To assess the feasibility of silk sericin for non-textile application, the storage stability and biological safety of sericin were examined. It was extracted at 37oC, 70oC, 100oC, and 121oC for 1, 3, and 5 h to elucidate the effect of extraction condition on the stability and safety of silk sericin. The solubility was increased till approximately 26% with extraction temperature of 121oC for 1 h. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) showed that the molecular weight distribution depended on the extraction conditions. Extracted sericin displayed typical UV absorption bands upon spectrometric analysis. To examine the reproducibility of its obtained conformation, sericin was extracted thrice and its circular dichroism (CD) spectra was measured each time. Most CD spectra showed reproducibility regardless of temperature and time except under 100oC extraction condition. The diversity of CD spectrum showed gradual reduction and was finally coincident with extraction time from 1 to 5 h. Notably, sericin has a negative peak of approximately 200 nm attributed to random coil conformation, regardless of extraction condition. However, at the 100oC extraction condition, sericin showed both bands to be negative bands of approximately 200 and 220 nm, respectively. Sericin was centrifuged to determine the stability of storage conditions. The sericin extracted at 100oC and 121oC for 1 h was found to form gel rapidly within 1 h, but at 121oC condition, the gel fraction was approximately 20% within 1 h which retained its phase regardless of storage time. The gel fraction of sericin extracted at 100oC for 5 h increased with time, however at the 121oC for 5 h condition, the gel fraction was measured to be less than 10% regardless of increase in storage time. PetriflimTM AC plates test showed that sericin was safe from aerobic bacteria activity by extraction under high temperature. [ABSTRACT FROM AUTHOR]

There are several subspecies of Bombyx mori, whose silk sericin variants differ. Silk sericin can induce bone morphogenic protein-2 (BMP-2) in macrophages, and silk sericin from different species may have different levels of BMP-2 induction ability. In this study, silk sericin from three B. mori subspecies (Baegokjam, Yeonnokjam, and Goldensilk) was prepared. They were administered to RAW264.7 cells and BMP-2 expression level was studied. Bone regeneration was evaluated using a rat calvarial defect model. BMP-2 expression level was the highest in the Baegokjam group. The bone volume in the Baegokjam group was significantly higher than that in the Yeonnokjam group (P = 0.003). In conclusion, sericin from Baegokjam showed higher levels of BMP-2 expression and bone regeneration than those from Yeonnokjam and Goldensilk. [ABSTRACT FROM AUTHOR]

Triple-negative breast cancer (TNBC) has the worst prognosis among all breast cancer subtypes. The lack of proper treatments prompted scientists to find a practical targeted therapy to treat this type of tumor. Based on previous studies, tyrosine kinase-like orphan receptor (ROR1) is overexpressed in TNBC cells. Here, we designed a system consisting of superparamagnetic iron oxide nanoparticles (SPIONs) decorated with silk sericin (SS NPs) for the targeted delivery of ROR1 siRNA, a gene silencer to knockdown the expression of human ROR1 gene. NPs exhibited spherical shape of about 193 nm with acceptable properties both in vitro and in vivo. The apoptosis study showed significant death of MDA-MB-231 cells after 24 h treatment with the prepared NPs. The real-time PCR study also demonstrated an almost complete shutdown of ROR1 expression. Guided by magnetic field, enhanced accumulation of NPs was observed in breast tumors induced by 4T1 cells in BALB/c mice. Histological evaluation of the tumor exhibited necrosis 14 days post-treatment with the siRNA-loaded NPs; whereas, the untreated tumor was proliferating. Also, the tumor growth rate was significantly decreased after treatment with siRNA-loaded NPs in vivo. In conclusion, the prepared delivery system could be considered as a potential therapeutic strategy for treating TNBC. • Silk Sericin/SPION nanoparticles could efficiently deliver siRNA to the target site. • ROR1 siRNA-loaded SSP NPs effectively downregulated ROR1 gene expression. • Downregulation of the ROR1 gene significantly inhibited triple-negative breast cancer cells' progression. • The delivery system exhibited acceptable performance for the treatment and diagnosis of triple-negative breast cancer. [ABSTRACT FROM AUTHOR]

Silk is a natural composite fiber composed mainly of hydrophobic fibroin and hydrophilic sericin, produced by the silkworm Bombyx mori. In the textile industry, the cocoons of B. mori are processed into silk fabric, where the sericin is substantially removed and usually discarded in wastewater. This wastewater pollutes the environment and water sources. However, sericin has been recognized as a potential biomaterial due to its biocompatibility, immunocompatibility, biodegradability, anti-inflammatory, antibacterial, antioxidant and photoprotective properties. Moreover, sericin can produce hydrogels, films, sponges, foams, dressings, particles, fibers, etc., for various biomedical and pharmaceutical applications (e.g., tissue engineering, wound healing, drug delivery, cosmetics). Given the severe environmental pollution caused by the disposal of sericin and its beneficial properties, there has been growing interest in upcycling this biomaterial, which could have a strong and positive economic, social and environmental impact. [ABSTRACT FROM AUTHOR]

Silk sericin (SS) has become a noticeable drug nanocarrier due to its excellent biocompatibility and bioactivity. To further extend the application of SS, a facile one-step process was constructed to fabricate SS-stabilized-drug composites. Various insoluble drugs can be encapsulated into SS with high loading amount, and showed good dispersity in aqueous solution. For example, proanthocyanidins (PAC), a natural polyphenol with initial antioxidant and anti-inflammatory effects, can be loaded on SS to form SS/PAC composites. The SS/PAC can disperse uniformly in aqueous solution with an average particle diameter of ~136 nm, and showed high drug loading amount of 1767 mg/g. The SS/PAC exhibited high antioxidant efficiency and excellent biocompatibility (non-irritant, non-hemolysis, and non-cytotoxicity), could remarkably alleviate the symptoms of dextran sulfate sodium-induced ulcerative colitis by decreasing the disease activity index scores, inhibiting the shortening of colon length, regulating oxidative stress, suppressing inflammation, and reversing the histopathological injuries. This work provides a simple method to fabricate SS-stabilized-drug composites, promises high potential in therapeutic and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

In this study, nanofiber surfaces were produced from a mixture of polyvinyl alcohol and silk sericin protein (PVA:SS) containing gelatin-coated silver nanoparticles (G-AgNPs) by electrospinning. For preparation of G-AgNPs, gelatin solution (1%, w/v) was mixed with 5 mM of AgNO3 solution and the mixture was heated and stirred for 2 h. AgNPs production has been observed with the brown color change that occurred in the solution. The absorbance of G-AgNPs was measured with a UV–Vis spectroscopy in the 300–700 nm range, and it was proved that AgNPs were formed with the surface plasmon resonance peak observed at 420 nm. Field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray analysis (EDS) analyses revealed that G-AgNPs were in spherical form and contained C, H, N, Ag elements in their structures, respectively. Antibacterial activity of the synthesized of G-AgNPs was shown with agar well diffusion test against to Escherichia coli and Staphylococcus aureus bacteria. In the second stage of the study, PVA:SS solutions were turned into nanofibers by electrospinning at certain conditions. G-AgNPs solutions were added in 3 different ratios of 10, 20 and 30% by volume to PVA:SS solutions, and these mixtures were turned into nanofibers with the same conditions. It has been shown by Fourier transform infrared spectroscopy (FTIR) analyses that the nanofiber surfaces obtained were composed of PVA:SS blend. The morphologies of nanofiber surfaces were investigated by FESEM analysis, and compared to PVA nanofibers collected alone, the fiber diameters of the groups containing PVA, sericin and G-AgNPs were found to be much lower. The presence of silver in nanofibers containing G-AgNPs was proven by EDS and X-ray fluorescence analyses. The thermal properties of nanofiber surfaces were investigated by thermogravimetric analysis, and it was observed that the thermal stability of nanofiber surfaces increased with the addition of sericin and G-AgNPs to PVA. Then, liquid medium tests were performed for finding the antibacterial activity of nanofiber surfaces containing various proportions of G-AgNPs on E. coli and S. aureus bacteria, and it was observed that nanofiber surfaces containing certain amounts of G-AgNPs inhibited the growth of both bacteria. It is thought that the functional and antibacterial surfaces obtained in the study will have the capacity to be used in many different areas such as wound dressing material. [ABSTRACT FROM AUTHOR]