Silk Fibroin-Based Biomaterials for Biomedical Applications: A Review

Hyaluronic acid/silk fibroin nanoparticles loaded with methotrexate for topical treatment of psoriasis

Systemic administration of methotrexate (MTX), widely regarded as one of the most effective treatments for psoriasis, poses significant challenges due to its high toxicity, limited solubility, and potential for adverse effects. Consequently, developing a topical form of MTX may offer a safer and more effective strategy for psoriasis management. Silk fibroin (SF), a protein-based biomacromolecule, has shown considerable promise as a nanocarrier for sustained and targeted drug delivery, owing to its exceptional physicochemical and biological properties. This study aimed to develop and characterize a novel drug delivery nanocarrier for MTX using SF nanoparticles modified with hyaluronic acid (HA) and to assess their potential for skin-targeted drug delivery with reduced transdermal permeation. The nanoparticles were thoroughly characterized, demonstrating a uniform particle size, high drug-loading capacity, pH sensitivity, and excellent slow-release properties. In vitro and in vivo experiments further indicated that these nanoparticles effectively reduced psoriasis-induced inflammatory responses, including erythema and scaling, by inhibiting keratinocyte proliferation and decreasing levels of pro-inflammatory cytokines. The inclusion of HA improved nanoparticle targeting, particularly through interactions with overexpressed CD44 proteins in psoriatic skin, resulting in enhanced methotrexate accumulation at the sites of inflammation and improved therapeutic efficacy. Our findings suggest that HA/SF nanoparticles loaded with MTX represent a promising, safe transdermal delivery system for the localized treatment of psoriasis.

Effect of the flowing states of solution on silk coloration with acid blue dye

In order to achieve more efficient and environmentally friendly coloration, an effect of the different flow states of bath solution on silk coloration with C.I. Acid Blue 113 (AB-113) dye was explored by employing a self-built hydrodynamic coloration machine, especially for their various effects from different substrate positions in pip flow and different process parameters on coloration, etc., were disclosed for the first time. The results show that a turbulence flow brought a significant and positive effect on the dye uptake by improving surface color depth and color evenness most notably, then were the transition and the laminar flows. Significant effect from the distance of silk to pipe wall on the dye uptake in laminar flow was observed, while less or non-effect from transition and turbulence flows was also achieved. Similar effect tendences in the coloration performance of the AB-113 dye on silk from process parameters in different flow states were also obtained while accompanying with some more evident effects in turbulence flow than the other two. Moreover, the coloration performance could be significantly improved at a relative high temperature, while remarkably decreased in a weak alkaline or neutral solution and the application of anhydrous sodium sulfate or Peregal O under different flow states except for color uniformity. Meanwhile, less effect from laminar and transition flows on the surface morphologies and chemical structure of the silk was successfully achieved, while some alterations in the fiber surfaces and macrochain conformations, etc., were also observed in a turbulence flow along with a same situation in the mechanic properties of the colored silk. Moreover, less effects from the flow states on color fastness to soaping and rubbing of the colored silk were also observed by achieving grade 4 or above. The results further indicate that an appropriate flow state control in coloration solution not only can achieve high coloration efficiency and performance on silk, but also can protect the fiber and reduce the applications of coloration auxiliaries to perform a much greener and more efficient coloration in textile industry.

Hybrid Pectin-Fibroin Microgels with Supramolecular and Covalent Cross-Links

Sugar beet pectin, an anionic polysaccharide, and silk fibroin, a high molecular weight protein, undergo gelation through ionic interactions and conformational changes, leading to hydrogel formation. Although many studies have focused on bulk gel systems involving polysaccharides and proteins, more research is needed to investigate their properties at the microscale level. In this context, we have developed a microgel system based on a pectin/fibroin combination and investigated its properties. We focused on two gelation mechanisms: physical cross-linking and enzymatic covalent cross-linking. The pectin/fibroin microgels were fabricated using droplet-based microfluidics, and the secondary structure, mechanical properties, and degradation profiles were investigated. Our experimental results show that the microgels exhibit an ordered β-sheet structure, a Young's modulus in the range of 10 to 20 kPa, and that degradation can be promoted using protease enzymes. Finally, the biocompatibility of the microgels is assessed using the Alamar Blue cell viability assay with human pulmonary fibroblasts (HPFs). This research presents a highly functional hybrid biomaterial produced from waste products and a structural protein, demonstrating its cell compatibility and potential in tissue engineering applications.

A critical view of silk fibroin for non-viral gene therapy

Exogenous genes are inserted into target cells during gene therapy in order to compensate or rectify disorders brought on by faulty or aberrant genes. However, gene therapy is still in its early stages because of its unsatisfactory therapeutic effects which are mainly due to low transfection efficiency of vectors, high toxicity, and poor target specificity. A natural polymer with numerous bioactive sites, good mechanical qualities, biodegradability, biocompatibility, and processability called silk fibroin has gained attention as a possible gene therapy vector. Using silk fibroin as a gene vector can reduce cell toxicity, extend the duration of gene expression, and allow further release even in the bloodstream, thereby expanding its therapeutic scope. This review outlines the advancements made with regard to gene delivery methods based on silk fibroin materials in the fields of malignant tumors, bone tissue regeneration, neural tissue, and vascular tissue engineering. Silk fibroin exhibits remarkable repair and therapeutic effects in gene therapy and can be employed in numerous forms, such as a vector (nanoparticles, microcapsules) or a matrix (hydrogel, scaffold) for gene delivery.

Silk-based biomaterials for tissue engineering

Tissue engineering (TE) involves repairing, replacing, regeneration, or improving the function of tissues and organs by combining cells, growth factors and scaffold materials. Among these, scaffold materials play a crucial role. Silk fibroin (SF), a natural biopolymer, has been widely used in the TE field due to its good biodegradability, biocompatibility, and mechanical properties attributed to its chemical composition and structure. This paper reviews the structure, extraction, and modification methods of SF. In addition, it discusses SF's regulation of cell behavior and its various processing modes. Finally, the applications of SF in TE and perspectives on future developments are presented. This review provides comprehensive and alternative rational insights for further biomedical translation in SF medical device design, further revealing the great potential of SF biomaterials.

Filament-woven SF/PA gel for removing ultrafine nanoparticles and unmanageable hazardous pollutants by "all-in-one net"

The current state of the world's water resources is facing serious challenges, and the current water purification processes are designed for a single, more specific contaminant, with more stringent constraints, which are not suitable for emergency water treatment in stochastic environment and may cause secondary pollution. It is necessary to provide a water purification method that is convenient, easy-to-operate, one-step treatment of multiple pollutants. Herein, silk fibroin (SF) that extracted from discarded silkworm cocoons and recycled silk and phytic acid (PA) are "woven" into a network structure through hydrogen bonding and electrostatic interaction to form a unique gel, which could be used to remove different pollutants by "sweeping and catching" and physical adsorption. SF/PA gels have been demonstrated to adsorb more than 99.9% of ultrafine nanoparticles in water, and many unmanageable hazardous pollutants can also be removed by "All-in-one Net", including bacteria, polystyrene microsphere, insoluble antibiotics and pesticides. In addition, SF/PA gel from waste resources can not only achieve the purpose of treating waste with waste, but also the products after removal of pollutants can be reused as biochar-based fertilizer to improve the soil environment. This process established a sustainable closed-loop system without secondary pollution, providing an excellent scheme for the sustainable use of resources.

Sustainable Power Generation with an All-Silk Electronics-Based Yeast Wearable Biobattery

Transient electronics, designed to disintegrate in a controlled manner after their useful life, have been proposed as a solution to mitigate the ecological and health impacts of electronic waste (e-waste). Despite this innovative approach, which has seen significant application in biologically integrated sensors and therapeutic devices, it still results in the accumulation of different materials and nanomaterials for the powering systems often based on batteries, which themselves contribute to the e-waste problem. Here, we explore the use of the silk cocoon from Bombyx mori as a key component in the development of environmentally friendly all-silk electronics-based biobatteries. The approach focuses on employing Saccharomyces cerevisiae to generate electroactive extracellular polymeric substances, which serve as the anode material within the biobattery. The silk cocoon's natural properties are utilized for the membrane in both anodic and cathodic compartments, with potassium ferricyanide embedded within the silk fibroin acting as the cathode. By coupling three modules in series, ohmic loss is minimized, preserving the voltages of each module. This setup allows a biobattery with discharge at a voltage over 1.1 V, demonstrating its potential to deliver stable and sufficient power for applications. The biobattery demonstrated a 95.2% utilization of recyclable materials for housing, membrane, and electrode components and a 95.6% utilization of biodegradable components for the electrolyte, offering a promising pathway for the advancement of eco-friendly energy storage solutions.

Eco-Friendly Conductive Hydrogels: Towards Green Wearable Electronics

The rapid advancement of wearable electronics has catalyzed the development of flexible, lightweight, and highly conductive materials. Among these, conductive hydrogels have emerged as promising candidates due to their tissue-like properties, which can minimize the mechanical mismatch between flexible devices and biological tissues and excellent electrical conductivity, stretchability and biocompatibility. However, the environmental impact of synthetic components and production processes in conventional conductive hydrogels poses significant challenges to their sustainable application. This review explores recent advances in eco-friendly conductive hydrogels used in healthcare, focusing on their design, fabrication, and applications in green wearable electronics. Emphasis is placed on the use of natural polymers, bio-based crosslinkers, and green synthesis methods to improve sustainability while maintaining high performance. We discuss the incorporation of conductive polymers and carbon-based nanomaterials into environmentally benign matrices. Additionally, the article highlights strategies for improving the biodegradability, recyclability, and energy efficiency of these materials. By addressing current limitations and future opportunities, this review aims to provide a comprehensive understanding of environmentally friendly conductive hydrogels as a basis for the next generation of sustainable wearable technologies.

An injectable and photocurable methacrylate-silk fibroin/prussian blue nanozyme hydrogel with antioxidant and pyroptosis suppression properties for cartilage regeneration

Cartilage injury is one of the most prevalent, distressing, and disabling chronic conditions affecting degenerative joints worldwide; however, its underlying mechanisms remain elusive. Various biomaterials have been widely employed in the treatment of articular cartilage (AC) injuries. Despite these efforts, the key role of reactive oxygen species (ROS) as primary instigators of pyroptosis, combined with the lack of effective interventions, often results in suboptimal cartilage repair outcomes. Thus, there is an urgent need for the development of novel antioxidants and inflammasome-mediated pyroptosis modulators to create a favorable microenvironment for cartilage repair. In this study, we synthesized Prussian blue nanoparticles (PBNPs) capable of efficiently scavenging ROS. In vitro, these PBNPs protected against oxidative stress-induced cytotoxicity, preserved mitochondrial integrity, reduced the activation of nucleotide-binding domain and leucine-rich repeat family pyrin domain-containing 3 (NLRP3) inflammasomes and caspase-1, and subsequently downregulated gasdermin D (GSDMD) cleavage and inflammatory factor production, leading to the inhibition of chondrocyte pyroptosis. To extend these findings in vivo, we developed an injectable and photocurable methacrylate-silk fibroin (SilMA) hydrogel with homogeneously incorporated PBNPs, designed for releasing PBNPs. The resulting PBNPs@SilMA hydrogel decreased ROS production, reduced chondrocyte pyroptosis, and supported chondrocyte proliferation and matrix secretion, subsequently improved AC repair. Overall, our results indicate that the PBNPs@SilMA platform holds significant promise as a therapeutic strategy for AC injury.

Biomimetic Silk Nanoparticle Manufacture: Calcium Ion-Mediated Assembly

Silk has emerged as an interesting candidate among protein-based nanocarriers due to its favorable properties, including biocompatibility and a broad spectrum of processing options to tune particle critical quality attributes. The silk protein conformation during storage in the middle silk gland of the silkworm is modulated by various factors, including the most abundant metallic ion, calcium ion (Ca2+). Here, we report spiking of liquid silk with calcium ions to modulate the silk nanoparticle size. Conformational and structural analyses of silk demonstrated Ca2+-induced silk assemblies that resulted in a liquid crystalline-like state, with the subsequent generation of β-sheet-enriched silk nanoparticles. Thioflavin T studies demonstrated that Ca2+ effectively induces self-assembly and conformation changes that also increased model drug loading. Ca2+ incorporation in the biopolymer feed significantly increased the nanoparticle production yield from 16 to 89%, while simultaneously enabling Ca2+ concentration-dependent particle-size tuning with a narrow polydispersity index and altered zeta potential. The resulting silk nanoparticles displayed high biocompatibility in macrophages with baseline levels of cytotoxicity and cellular inflammation. Our strategy for manufacturing biomimetic silk nanoparticles enabled overall tuning of particle size and improved yields─features that are critical for particle-based nanomedicines.

Silk-polyurethane composite based flexible electrochemical biosensing platform for pathogen detection

The upcoming era of flexible and wearable electronics necessitates the development of low-cost, flexible, biocompatible substrates amenable to the fabrication of active devices such as electronic devices, sensors and transducers. While natural biopolymers such as Silk are robust and biocompatible, long-term flexibility is a concern due to the inherent brittle nature of soft Silk thin films. This work elucidates the preparation and characterization of Silk-polyurethane (Silk-PU) composite film that provides long-duration flexibility. More importantly, an electrochemical biosensing platform is developed by creating a three-electrode system using a screen-printing technique. The solvents in the Ink had little impact on the film. As a proof of concept, the detection of E. coli, a highly infectious pathogen, was demonstrated using screen-printed electrodes (SPEs) modified with gold nanoparticles. This method effectively detected E. coli across a wide range of concentrations, with a detection limit of 0.12 CFU/mL. The entire surface functionalization and detection process did not impact the Silk-PU substrate. Even after rigorous bending tests, the results were consistent, demonstrating the robustness and flexibility of the Silk-PU film. The platform demonstrated is scalable and amenable for multi-pathogen detection as it not only can integrate several working electrodes, each catering to detection of a particular pathogen, but also serve as a platform for lab-on-chip devices wherein PDMS-based microfluidics can be seamlessly integrated along with the proposed platform.

Designing Silk Biomaterials toward Better Future Healthcare: The Development and Application of Silk-Based Implantable Electronic Devices in Clinical Diagnosis and Therapy

Implantable medical electronic devices (IMEDs) have attracted great attention and shown versatility for solving clinical problems ranging from real-time monitoring of physiological/ pathological states to electrical stimulation therapy and from monitoring brain cell activity to deep brain stimulation. The ongoing challenge is to select appropriate materials in target device configuration for biomedical applications. Currently, silk-based biomaterials have been developed for the design of diagnostic and therapeutic electronic devices due to their excellent properties and abundant active sites in the structure. Herein, the aim is to summarize the structural characteristics, physicochemical properties, and bioactivities of natural silk biomaterials as well as their derived materials, with a particular focus on the silk-based implantable biomedical electronic devices, such as implantable devices for invasive brain-computer interfaces, neural recording, and in vivo electrostimulation. In addition, future opportunities and challenges are also envisioned, hoping to spark the interests of researchers in interdisciplinary fields such as biomaterials, clinical medicine, and electronics.

Unleashing the power of silk-based proteins as biomaterials for cutting-edge drug delivery: a comprehensive review

Silk proteins, viz., sericin, fibroin and their modified forms etc., have been thoroughly researched as natural biopolymers for the development of varied nanomaterials exhibiting diverse biomedical applications. The silk proteins are extracted from the cocoons by degumming and treatment with soaps, followed by dissolution and dialysis against water. These proteins exhibit distinct mechanical and physicochemical characteristics including biocompatibility, controlled biodegradability, self-assembling traits, chemical modifiability, and adaptability, thus making it an ideal drug delivery vehicle. In this regard, silk protein-derived drug delivery systems have been reported as efficient carrier to encapsulate and stabilize the wide variety of pharmacological molecules, enzymes, proteins, vaccines, and even DNA, allowing them to remain active for a longer period of time. Further, different delivery carriers researched employing these proteins for multitude of applications include hydrogels, sponges, fibres, scaffolds and particulate delivery systems. Additionally, the chemical modification of silk proteins has further opened avenues for development of other modified silk proteins with improved physicochemical traits and hence exhibiting enormous potential in development of varied bioenhanced carrier systems. The current article thus provides the holistic information of characteristics, types of silk protein-based delivery carriers, and their fabrication techniques, while emphasizing the applications of different silk proteins in biomedicine and drug delivery.

Peripheral nerve regeneration using a bioresorbable silk fibroin-based artificial nerve conduit fabricated via a novel freeze-thaw process

While silk fibroin (SF) obtained from silkworm cocoons is expected to become a next-generation natural polymer, a fabrication method for SF-based artificial nerve conduits (SFCs) has not yet been established. Here, we report a bioresorbable SFC, fabricated using a novel freeze-thaw process, which ensures biosafety by avoiding any harmful chemical additives. The SFC demonstrated favorable biocompatibility (high hydrophilicity and porosity with a water content of > 90%), structural stability (stiffness, toughness, and elasticity), and biodegradability, making it an ideal candidate for nerve regeneration. We evaluated the nerve-regenerative effects of the SFC in a rat sciatic-nerve-defect model, including its motor and sensory function recovery as well as histological regeneration. We found that SFC transplantation significantly promoted functional recovery and nerve regeneration compared to silicone tubes and was almost equally effective as autologous nerve transplantation. Histological analyses indicated that vascularization and M2 macrophage recruitment were pronounced inside the SFC. These results suggest that the unique properties of the SFC further enhanced the peripheral nerve regeneration mechanism. As no SFC has been applied in clinical practice, the SFC reported herein may be a promising candidate for repairing extensive peripheral nerve defects.

Fibroin-Hybrid Systems: Current Advances in Biomedical Applications

Fibroin, a protein extracted from silk, offers advantageous properties such as non-immunogenicity, biocompatibility, and ease of surface modification, which have been widely utilized for a variety of biomedical applications. However, in vivo studies have revealed critical challenges, including rapid enzymatic degradation and limited stability. To widen the scope of this natural biomacromolecule, the grafting of polymers onto the protein surface has been advanced as a platform to enhance protein stability and develop smart conjugates. This review article brings into focus applications of fibroin-hybrid systems prepared using chemical modification of the protein with polymers and inorganic compounds. A selection of recent preclinical evaluations of these hybrids is included to highlight the significance of this approach.

Natural Protein Films from Textile Waste for Wound Healing and Wound Dressing Applications

In recent years, several studies have focused on the development of sustainable, biocompatible, and biodegradable films with potential applications in wound healing and wound dressing systems. Natural macromolecules, particularly proteins, have emerged as attractive alternatives to synthetic polymers due to their biocompatibility, biodegradability, low immunogenicity, and adaptability. Among these proteins, keratin, extracted from waste wool, and fibroin, derived from Bombyx mori cocoons, exhibit exceptional properties such as mechanical strength, cell adhesion capabilities, and suitability for various fabrication methods. These proteins can also be functionalized with antimicrobial, antioxidant, and anti-inflammatory compounds, making them highly versatile for biomedical applications. This review highlights the promising potential of keratin- and fibroin-based films as innovative platforms for wound healing, emphasizing their advantages and the prospects they offer in creating next-generation wound dressing devices.

Critical roles of small silk fibroin molecules in the self-assembly and properties of regenerated silk fibroin

Silk is primarily composed of silk fibroin (SF) and silk sericin (SS), with SF significantly contributing to the mechanical properties of silk fibers. SF consists of the large molecular fibroin heavy chain (Fib-H), small molecular fibroin light chain (Fib-L), and P25 protein. Degumming is a crucial step in both the silk reeling process and the preparation of regenerated silk fibroin (RSF), but it can cause damage to Fib-H. This study investigates how degumming affects small SF molecules and their influence on the properties of silk fibers and RSF. A gradient degumming treatment using various reagents was employed. SS antibody detection indicated that 3 g/L papain and sodium carbonate (Na2CO3) at concentrations ≥0.2 % almost completely removed SS. SF antibody detection revealed that Na2CO3 degumming severely damaged Fib-H and degraded Fib-L and P25. While tensile tests showed that this damage did not significantly affect the mechanical properties of SF fibers, the loss of small SF molecules reduced the mechanical properties of the RSF membranes and delayed RSF gelation. Atomic force microscopy demonstrated that RSF containing Fib-H of similar molecular weight (100-180 kDa) can self-assemble into nanofibrils when small SF molecules are present, whereas 0.5 % Na2CO3-degummed RSF lacking these small SF molecules cannot form nanofibrils. By adding additional small SF molecules to the 0.5 % Na2CO3-degummed RSF, nanofibrils can be formed. This research highlights the critical role of small SF molecules in the properties of RSF and provides a theoretical foundation for the development of RSF-derived materials.

Glycerol-plasticized silk fibroin vascular grafts mimic key mechanical properties of native blood vessels

Cardiovascular diseases are a major global health challenge. Blood vessel disease and dysfunction are major contributors to this healthcare burden, and the development of tissue-engineered vascular grafts (TEVGs) is required, particularly for the replacement of small-diameter vessels. Silk fibroin (SF) is a widely used biomaterial for TEVG fabrication due to its high strength and biocompatibility. However, the stiffness of SF is much higher than that of native blood vessels (NBVs), which limits its application for vascular tissue engineering. In this study, SF was plasticized with glycerol to produce TEVGs exhibiting similar stiffness and ultimate tensile strength to those of NBVs. The electrospun SF/glycerol TEVGs exhibited mechanical properties comparable to NBVs and supported the in vitro proliferation of essential vascular cells-endothelial and smooth muscle cells. After 5 days of culture, the TEVGs exhibited an endothelial monolayer in the lumen, demonstrating their potential for functional vascular tissue regeneration. Our study demonstrates the feasibility of producing TEVGs from SF with tailored mechanical properties, paving the way for more functional and durable TEVGs for future clinical applications.

Cellular Interactions and Biological Effects of Silk Fibroin: Implications for Tissue Engineering and Regenerative Medicine

Silk fibroin (SF), the core structural protein derived from Bombyx mori silk, is extensively employed in tissue engineering and regenerative medicine due to its exceptional mechanical properties, favorable biocompatibility, tunable biodegradability, and versatile processing capabilities. Despite these advantages, current research predominantly focuses on SF biomaterials as structural scaffolds or drug carriers, often overlooking their potential role in modulating cellular behavior and tissue regeneration. This review aims to present a comprehensive overview of the inherent biological effects of SF biomaterials, independent of any exogenous biomolecules, and their implications for various tissue regeneration. It will cover in vitro cellular interactions of SF with various cell types, including stem cells and functional tissue cells such as osteoblasts, chondrocytes, keratinocytes, endothelial cells, fibroblasts, and epithelial cells. Moreover, it will summarize in vivo immune responses, cellular responses, and tissue regeneration following SF implantation, specifically focusing on vascular, bone, skin, cartilage, ocular, and tendon/ligament regeneration. Furthermore, it will address current limitations and future perspectives in the design of bioactive SF biomaterials. A comprehensive understanding of these cellular interactions and the biological effects of SF is crucial for predicting regenerative outcomes with precision and for designing SF-based biomaterials tailored to specific properties, enabling broader applications in regenerative medicine.

Production and Characterization of Silk Fibroin-Aloe vera Hydrogel: A Study on Extraction, Hydrogel Properties, and Release Mechanism

This work investigated the production and characterization of a silk fibroin (SF) hydrogel incorporated with an Aloe vera (AV) extract. Four extraction methods, ultrasound-assisted extraction with bath and probe, stirring, and Soxhlet, were tested, while the hydrogel was produced by a one-step freeze-thaw method. Besides the extraction yield, the antioxidant capacity of the extracts was accessed, which allowed to select the extract obtained by ultrasound-assisted extraction to be incorporated into the hydrogels. Hydrogels were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. Rheological assay, swelling behavior, and water uptake capacity were measured. The SF-AV hydrogel was submitted to release test, and the data were mathematically modeled. The hydrogels exhibited malleability, insolubility in water, interconnected pores, and thermal and physical stability. The SF-AV hydrogel released 37% extract over 330 min, with diffusion controlled by the Fickian mechanism. These promising results make the SF-AV hydrogel an attractive choice for wound dressing and other biomaterial-related applications.

Bombyx mori Metal Carboxypeptidases12 (BmMCP12) Is Involved in Host Protection Against Viral Infection

Baculoviruses, the largest studied insect viruses, are highly pathogenic to host insects. Bombyx mori nucleopolyhedrovirus (BmNPV) is the main cause of nuclear polyhedrosis of silkworm, a viral disease that causes significant economic losses to the sericulture industry. The anti-BmNPV mechanism of the silkworm has not yet been characterized. Carboxypeptidase is an enzyme that is involved in virtually all life activities of animals and plants. Studies have shown that the carboxypeptidase family is related to insect immunity. There are few reports on the role of carboxypeptidase in the defense of silkworms against pathogen invasion. In this study, we identified the homologous gene Bombyx mori metal carboxypeptidases12 (BmMCP12) related to mammalian carboxypeptidase A2 (CPA2) and found that BmMCP12 had a Zn-pept domain. The BmMCP12 gene was primarily located in the cytoplasm and was highly expressed in the midgut of silkworms, and the expression level in BmN-SWU1 cells was upregulated after infection with BmNPV. After overexpression of the BmMCP12 gene, quantitative real-time (qRT)-PCR and Western blots showed that BmMCP12 could inhibit BmNPV replication, whereas knockout of the gene had the opposite effect. In addition, we constructed transgenic silkworm strains with a knockout of BmMCP12, and the transgenic strains had reduced resistance to BmNPV. These findings deepen the functional study of silkworm carboxypeptidase and provide a new target for BmNPV disease prevention in silkworms.

Superiority of a Silk Surgical Site Wound Closure Device over Synthetic Dressings

BACKGROUND

Silk fibroin is an emerging biomaterial with enhanced properties of cellular regeneration, growth, and proliferation. The use of a silk fibroin wound dressing has the potential to decrease the incidence of wound-healing complications and to improve patient outcomes compared with synthetic dressing alternatives.

METHODS

A randomized, single-blind clinical trial was conducted on 50 patients who were dressed with a silk fibroin dressing on 1 side of their body and 3M Steri-Strips on the contralateral side after abdominoplasty, reduction mammaplasty, or brachioplasty procedures. Data were collected over 5 postoperative visits using photographs and an investigator-administered questionnaire to monitor erythema, skin irritation, skin discomfort, need for pharmaceutical intervention, wound dehiscence, and mechanical skin injury. A comprehensive 75-patient statistical analysis was conducted, combining the results with a previously published study comparing Dermabond Prineo with the silk dressing.

RESULTS

A total of 20.8% of patients (10 of 48) were assessed by surgeons as having skin erythema (7 to 10) on the Steri-Strip control side, with 0% (0 of 48) on the silk dressing side ( P = 0.002). The frequency of breast triple-point separation in 43 cases was 30.2% (13 of 43) on the Steri-Strip side and 9.3% (4 of 43) on the silk side ( P = 0.012). A total of 75% of patients (36 of 48) had partial or total detachment of Steri-Strips, 0% (0 of 48) had total detachment of the silk dressing, and 18.8% (9 of 48) had partial detachment of the silk dressing within the first 2 weeks ( P < 0.001).

CONCLUSION

A silk fibroin wound dressing significantly reduces the incidence of wound-healing complications throughout the postoperative period.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

CLINICAL RELEVANCE STATEMENT

The adoption of a silk fibroin wound dressing into clinical practice has the potential to improve patient outcomes, decrease medical adhesive-related skin injuries, and reduce the rate of wound-healing complications.

Engineering with Biomedical Sciences Changing the Horizon of Healthcare-A Review

In the dynamic realm of healthcare, the convergence of engineering and biomedical sciences has emerged as a pivotal frontier. In this review we go into specific areas of innovation, including medical imaging and diagnosis, developments in biomedical sensors, and drug delivery systems. Wearable biosensors, non-wearable biosensors, and biochips, which include gene chips, protein chips, and cell chips, are all included in the scope of the topic that pertains to biomedical sensors. Extensive research is conducted on drug delivery systems, spanning topics such as the integration of computer modeling, the optimization of drug formulations, and the design of delivery devices. Furthermore, the paper investigates intelligent drug delivery methods, which encompass stimuli-responsive systems such as temperature, redox, pH, light, enzyme, and magnetic responsive systems. In addition to that, the review goes into topics such as tissue engineering, regenerative medicine, biomedical robotics, automation, biomechanics, and the utilization of green biomaterials. The purpose of this analysis is to provide insights that will enhance continuing research and development efforts in engineering-driven biomedical breakthroughs, ultimately contributing to the improvement of healthcare. These insights will be provided by addressing difficulties and highlighting future prospects.

Synthesis and characterization of selenium nanoparticles stabilized with oxyethylated alkylphenol (neonol) for potential modification of fabric materials

This work demonstrates the first time synthesis of selenium nanoparticles (Se NPs) stabilized with neonol. The synthesis method was optimized using a multifactorial experiment with three input parameters. The most stable sample had a radius of 15 nm and a ζ-potential of -36.76 mV. It was found that the optimal parameters for the synthesis of Se NPs stabilized with neonol are the following concentration values: 0.12 mol/L selenic acid, 0.095 mol/L neonol and 0.95 mol/L ascorbic acid. Quantum chemical modeling of Se-neonol molecular complex formation showed that interaction of Se with neonol occurs through a hydroxyl group. Difference in the total energy of the neonol molecule and Se-neonol molecular complex is more than 2399 kcal/mol, which indicates that formation of chemical bond between Se and neonol is energetically advantageous. It was found that all samples exhibit stability over the entire pH range from 1.81 to 11.98, and the particle size is in the range of 25-30 nm. The analysis of the study of the influence of the ionic force showed that cations do not significantly affect the Se NPs radius, but anions have a significant effect, increasing the average hydrodynamic radius up to 2750 nm. For modification with Se NPs, silk, gauze, wool, cotton and cardboard samples were used. Elemental mapping of the samples showed an ambiguous distribution of Se NPs over the surface of fabric material. Assessment of potential antibacterial activity of modified fabric materials revealed inhibition zones of Micrococcus luteus growth from 12 to 16 mm for silk, gauze, wool and cotton. Notably, the most intense inhibition of Micrococcus luteus was observed in wool treated be Se NPs stabilized with neonol. Cardboard did not express Micrococcus luteus growth inhibition action because of weak interaction of cellulose filaments with Se NPs and neonol and possible microbial digestion of cellulose and xylan.

Bioactive glass-polymer nanocomposites: a comprehensive review on unveiling their biomedical applications

Most natural and synthetic polymers are promising materials for biomedical applications because of their biocompatibility, abundant availability, and biodegradability. Their properties can be tailored according to the intended application by fabricating composites with other polymers or ceramics. The incorporation of ceramic nanoparticles such as bioactive glass (BG) and hydroxyapatite aids in the improvement of mechanical and biological characteristics and alters the degradation kinetics of polymers. BG can be used in the form of nanoparticles, nanofibers, scaffolds, pastes, hydrogels, or coatings and is significantly employed in different applications. This biomaterial is highly preferred because of its excellent biocompatibility, bone-stimulating activity, and favourable mechanical and degradation characteristics. Different compositions of nano BG are incorporated into the polymer system and studied for positive results such as enhanced bioactivity, better cell adherence, and proliferation rate. This review summarizes the fabrication and the progress of natural/synthetic polymer-nano BG systems for biomedical applications such as drug delivery, wound healing, and tissue engineering. The challenges and the future perspectives of the composite system are also addressed.

Scaffold-based tissue engineering strategies for urethral repair and reconstruction

Urethral strictures are common in urology; however, the reconstruction of long urethral strictures remains challenging. There are still unavoidable limitations in the clinical application of grafts for urethral injuries, which has facilitated the advancement of urethral tissue engineering. Tissue-engineered urethral scaffolds that combine cells or bioactive factors with a biomaterial to mimic the native microenvironment of the urethra, offer a promising approach to urethral reconstruction. Despite the recent rapid development of tissue engineering materials and techniques, a consensus on the optimal strategy for urethral repair and reconstruction is still lacking. This review aims to collect the achievements of urethral tissue engineering in recent years and to categorize and summarize them to shed new light on their design. Finally, we visualize several important future directions for urethral repair and reconstruction.

Hyperthermia and biological investigation of a novel magnetic nanobiocomposite based on acacia gum-silk fibroin hydrogel embedded with poly vinyl alcohol

The design and synthesis of biocompatible nanostructures for biomedical applications are considered vital challenges. Herein, a nanobiocomposite based on acacia hydrogel, natural silk fibroin protein, and synthetic protein fibers of polyvinyl alcohol was fabricated and magnetized with iron oxide nanoparticles (Fe3O4 MNPs). The structural properties of the hybrid nanobiocomposite were investigated by essential analyses such as Fourier Transform Infrared Spectrometer (FTIR), Field emission scanning electron microscopy (FE-SEM), and X-ray powder diffraction)XRD(analyses, Thermogravimetric and Differential thermogravimetric analysis (TGA-DTG), Vibrating-sample magnetometry (VSM), and Energy Dispersive X-Ray Analysis (EDX). The biological activities and functional properties of the prepared magnetic nanobiocomposite were studied. Results proved that this nanobiocomposite is non-toxic to the healthy HEK293T cell line. In addition, the synthesized nanobiocomposite showed an approximately 22 % reduction in cell viability of BT549 cells after 72 h. All results confirmed the anti-cancer properties of nanobiocomposite against breast cancer cell lines. Therefore, the prepared nanobiocomposite is an excellent material that can use for in-vivo application. Finally, the hyperthermia application was evaluated for this nanobiocomposite. The SAR was measured 93.08 (W/g) at 100 kHz.

Modifying Naturally Occurring, Nonmammalian-Sourced Biopolymers for Biomedical Applications

Natural biopolymers have a rich history, with many uses across the fields of healthcare and medicine, including formulations for wound dressings, surgical implants, tissue culture substrates, and drug delivery vehicles. Yet, synthetic-based materials have been more successful in translation due to precise control and regulation achievable during manufacturing. However, there is a renewed interest in natural biopolymers, which offer a diverse landscape of architecture, sustainable sourcing, functional groups, and properties that synthetic counterparts cannot fully replicate as processing and sourcing of these materials has improved. Proteins and polysaccharides derived from various sources (crustaceans, plants, insects, etc.) are highlighted in this review. We discuss the common types of polysaccharide and protein biopolymers used in healthcare and medicine, highlighting methods and strategies to alter structures and intra- and interchain interactions to engineer specific functions, products, or materials. We focus on biopolymers obtained from natural, nonmammalian sources, including silk fibroins, alginates, chitosans, chitins, mucins, keratins, and resilins, while discussing strategies to improve upon their innate properties and sourcing standardization to expand their clinical uses and relevance. Emphasis will be placed on methods that preserve the structural integrity and native biological functions of the biopolymers and their makers. We will conclude by discussing the untapped potential of new technologies to manipulate native biopolymers while controlling their secondary and tertiary structures, offering a perspective on advancing biopolymer utility in novel applications within biomedical engineering, advanced manufacturing, and tissue engineering.

Silk Fibroin-Based Multiple-Shape-Memory Organohydrogels

Organohydrogels (OHGs) are intriguing materials due to their unique composition of both hydrophilic and hydrophobic domains. This antagonistic nature endows the OHGs with several remarkable properties, making them highly versatile for various applications. We present here a simple and inexpensive approach to fabricate silk fibroin (SF)-based OHGs with multistage switching mechanics and viscoelasticity. The continuous hydrophilic phase of the OHG precursor consists of an aqueous SF solution, while the hydrophobic droplet phase consists of a crystallizable n-octadecyl acrylate (C18A) monomer and several long-chain saturated hydrocarbons (HCs) with various chain lengths between 14 and 32 carbon atoms, namely, n-tetradecane, n-octadecane, n-docosane, n-dotriacontane, and 1-docosanol. After the addition of a C18A/HC mixture containing Irgacure photoinitiator into the continuous aqueous SF phase under stirring, a stable oil-in-water emulsion was obtained, which was then photopolymerized at 23 ± 2 °C to obtain nonswelling OHGs with multiple-shape-memory behavior. By changing the chain length and mass proportion of HCs, a series of OHGs with tunable transition temperatures could be obtained, meeting various applications. OHGs containing dimer, trimer, and quadruple combinations of in situ-formed poly(C18A) and HC microinclusions exhibit effective triple- or quintuple-shape memory whose shape-recovery temperatures could be adjusted over a wide range, e.g., between 7 and 70 °C.

Bioactive silk fibroin hydrogels: Unraveling the potential for biomedical engineering

Silk fibroin (SF) has received special attention from the scientific community due to its noteworthy properties. Its unique chemical structure results in an uncommon combination of macroscopically useful properties, yielding a strong, fine and flexible material which, in addition, presents good biodegradability and better biocompatibility. Therefore, silk fibroin in various formats, appears as an ideal candidate for supporting biomedical applications. In this review, we will focus on the hydrogels obtained from silk fibroin or in combination with it, paying special attention to the synthesis procedures, characterization methodologies and biomedical applications. Tissue engineering and drug-delivery systems are, undoubtedly, the two main areas where silk fibroin hydrogels find their place.

Unveiling the mechanical role of radial fibers in meniscal tissue: Toward structural biomimetics

The meniscus tissue is crucial for knee joint biomechanics and is frequently susceptible to injuries resulting in early-onset osteoarthritis. Consequently, the need for meniscal substitutes spurs ongoing development. The meniscus is a composite tissue reinforced with circumferential and radial collagenous fibers; the mechanical role of the latter has yet to be fully unveiled. Here, we investigated the role of radial fibers using a synergistic methodology combining meniscal tissue structure imaging, a computational knee joint model, and the fabrication of simple biomimetic composite laminates. These laminates mimic the basic structural units of the meniscus, utilizing longitudinal and transverse fibers equivalent to the circumferential and radial fibers in meniscal tissue. In the computational model, the absence of radial fibers resulted in stress concentration within the meniscus matrix and up to 800 % greater area at the same stress level. Furthermore, the contact pressure on the tibial cartilage increased drastically, affecting up to 322 % larger areas. Conversely, in models with radial fibers, we observed up to 25 % lower peak contact pressures and width changes of less than 0.1 %. Correspondingly, biomimetic composite laminates containing transverse fibers exhibited minor transverse deformations and smaller Poisson's ratios. They demonstrated structural shielding ability, maintaining their mechanical performance with the reduced amount of fibers in the loading direction, similar to the ability of the torn meniscus to carry and transfer loads to some extent. These results indicate that radial fibers are essential to distribute contact pressure and tensile stresses and prevent excessive deformations, suggesting the importance of incorporating them in novel designs of meniscal substitutes. STATEMENT OF SIGNIFICANCE: The organization of the collagen fibers in the meniscus tissue is crucial to its biomechanical function. Radially oriented fibers are an important structural element of the meniscus and greatly affect its mechanical behavior. However, despite their importance to the meniscus mechanical function, radially oriented fibers receive minor attention in meniscal substitute designs. Here, we used a synergistic methodology that combines imaging of the meniscal tissue structure, a structural computational model of the knee joint, and the fabrication of simplistic biomimetic composite laminates that mimic the basic structural units of the meniscus. Our findings highlight the importance of the radially oriented fibers, their mechanical role in the meniscus tissue, and their importance as a crucial element in engineering novel meniscal substitutes.

Silk Fibroin Nanofibers: Advancements in Bioactive Dressings through Electrospinning Technology for Diabetic Wound Healing

BACKGROUND

Non-healing diabetic wounds represent a significant clinical challenge globally, necessitating innovative approaches in drug delivery to enhance wound healing. Understanding the pathogenesis of these wounds is crucial for developing effective treatments. Bioactive dressings and polymeric nanofibers have emerged as promising modalities, with silk biomaterials gaining attention for their unique properties in diabetic wound healing.

PURPOSE OF REVIEW

The purpose of this review is to examine the challenges and innovations in treating non-healing diabetic wounds, emphasizing the global burden and the need for effective solutions. This review explores the complex mechanisms of wound healing in diabetes and evaluates the therapeutic potential of bioactive dressings and polymeric nanofibers. Special focus is given to the application of silk biomaterials, particularly silk fibroin, for wound healing, detailing their properties, mechanisms, and clinical translation. This review also describes various nanofiber fabrication methods, especially electrospinning technology, and presents existing evidence on the effectiveness of electrospun silk fibroin formulations.

RECENT FINDINGS

Recent advancements highlight the potential of silk biomaterials in diabetic wound healing, owing to their biocompatibility, mechanical strength, and controlled drug release properties. Electrospun silk fibroin-based formulations have shown promising results in preclinical and clinical studies, demonstrating accelerated wound closure and tissue regeneration.

SUMMARY

Non-healing diabetic wounds present a significant healthcare burden globally, necessitating innovative therapeutic strategies. Bioactive dressings and polymeric nanofibers, particularly silk-based formulations fabricated through electrospinning, offer promising avenues for enhancing diabetic wound healing. Further research is warranted to optimize formulation parameters and validate efficacy in larger clinical trials.

Electrospun Silk-ICG Composite Fibers and the Application toward Hemorrhage Control

In trauma and surgery, efficient hemorrhage control is crucial to avert fatal blood loss and increase the likelihood of survival. There is a significant demand for novel biomaterials capable of promptly and effectively managing bleeding. This study aimed to develop flexible biocomposite fibrous scaffolds with an electrospinning technique using silk fibroin (SF) and indocyanine green (ICG). The FDA-approved ICG dye has unique photothermal properties. The water permeability, degradability, and biocompatibility of Bombyx mori cocoon-derived SF make it promising for biomedical applications. While as-spun SF-ICG fibers were dissolvable in water, ethanol vapor treatment (EVT) effectively induced secondary structural changes to promote β-sheet formation. This resulted in significantly improved aqueous stability and mechanical strength of the fibers, thereby increasing their fluid uptake capability. The enhanced SF-ICG interaction effectively prevented ICG leaching from the composite fibers, enabling them to generate heat under NIR irradiation due to ICG's photothermal properties. Our results showed that an SF-ICG 0.4% fibrous matrix can uptake 473% water. When water was replaced by bovine blood, a 25 s NIR irradiation induced complete blood coagulation. However, pure silk did not have the same effect. Additionally, NIR irradiation of the SF-ICG fibers successfully stopped the flow of blood in an in vitro model that mimicked a damaged blood vessel. This novel breakthrough offers a biotextile platform poised to enhance patient outcomes across various medical scenarios, representing a significant milestone in functional biomaterials.

Comparative Analysis of Silk Fibroin Membranes across Cross-Linking Methods: Processing and Characterization

Silk fibroin (SF) extracted from silkworm silk can be transformed into transparent membranes with well-suited physical properties for ophthalmic applications. There is ample literature on the fabrication and characterization of SF-based membranes; however, the use of diverse SF extraction protocols and characterization methods or their settings makes it difficult to compare different silk membrane properties across studies. In this work, we fabricated 10 families of SF-based membranes by physical cross-linking and one non-cross-linked as a control. We evaluated transparency (ranging from 84.5 to 95.3% in the visible spectrum), enzyme stability (from 24 h to 200 days in protease XIV), decomposition temperature (280-290 °C), water uptake (40-60%), Young's modulus (8-30 MPa), roughness (1.6-22.7 nm), and FTIR spectra for the secondary structure. We found correlation between water uptake and the Young's modulus (the lower the water uptake, the higher the Young's modulus) and a relationship between membrane stability in protease XIV and the secondary structure of the proteins. Higher surface roughness and faster degradation were found in membranes cross-linked with polyethylene glycol, and conversely, lower roughness and lower degradation were found in methanol, ethanol, or isopropanol crossed-link membranes. This ample compilation of materials and their characterization will aid in the selection of a SF-based material according to the needs of the application.

Enhancing therapy with nano-based delivery systems: exploring the bioactive properties and effects of apigenin

Apigenin, a potent natural flavonoid, has emerged as a key therapeutic agent due to its multifaceted medicinal properties in combating various diseases. However, apigenin's clinical utility is greatly limited by its poor water solubility, low bioavailability and stability issues. To address these challenges, this review paper explores the innovative field of nanotechnology-based delivery systems, which have shown significant promise in improving the delivery and effectiveness of apigenin. This paper also explores the synergistic potential of co-delivering apigenin with conventional therapeutic agents. Despite the advantageous properties of these nanoformulations, critical challenges such as scalable production, regulatory approvals and comprehensive long-term safety assessments remain key hurdles in their clinical adoption which must be addressed for commercialization of apigenin-based formulations.

3D-Printed Silk Proteins for Bone Tissue Regeneration and Associated Immunomodulation

Current bone repair methods have limitations, prompting the exploration of innovative approaches. Tissue engineering emerges as a promising solution, leveraging biomaterials to craft scaffolds replicating the natural bone environment, facilitating cell growth and differentiation. Among fabrication techniques, three-dimensional (3D) printing stands out for its ability to tailor intricate scaffolds. Silk proteins (SPs), known for their mechanical strength and biocompatibility, are an excellent choice for engineering 3D-printed bone tissue engineering (BTE) scaffolds. This article comprehensively reviews bone biology, 3D printing, and the unique attributes of SPs, specifically detailing criteria for scaffold fabrication such as composition, structure, mechanics, and cellular responses. It examines the structural, mechanical, and biological attributes of SPs, emphasizing their suitability for BTE. Recent studies on diverse 3D printing approaches using SPs-based for BTE are highlighted, alongside advancements in their 3D and four-dimensional (4D) printing and their role in osteo-immunomodulation. Future directions in the use of SPs for 3D printing in BTE are outlined.

Biological Functions of Macromolecular Protein Hydrogels in Constructing Osteogenic Microenvironment

Irreversible bone defects resulting from trauma, infection, and degenerative illnesses have emerged as a significant health concern. Structurally and functionally controllable hydrogels made by bone tissue engineering (BTE) have become promising biomaterials. Natural proteins are able to establish connections with autologous proteins through unique biologically active regions. Hydrogels based on proteins can simulate the bone microenvironment and regulate the biological behavior of stem cells in the tissue niche, making them candidates for research related to bone regeneration. This article reviews the biological functions of various natural macromolecular proteins (such as collagen, gelatin, fibrin, and silk fibroin) and highlights their special advantages as hydrogels. Then the latest research trends on cross-linking modified macromolecular protein hydrogels with improved mechanical properties and composite hydrogels loaded with exogenous micromolecular proteins have been discussed. Finally, the applications of protein hydrogels, such as 3D printed hydrogels, microspheres, and injectable hydrogels, were introduced, aiming to provide a reference for the repair of clinical bone defects.

Exploring Stimuli-Responsive Natural Processes for the Fabrication of High-Performance Materials

Climate change and environmental pollution have underscored the urgency for more sustainable alternatives in synthetic polymer production. Nature's repertoire of biopolymers with excellent multifaceted properties alongside biodegradability could inspire next-generation innovative green polymer fabrication routes. Stimuli-induced processing, driven by changes in environmental factors, such as pH, ionic strength, and mechanical forces, plays a crucial role in natural polymeric self-assembly process. This perspective aims to close the gap in understanding biopolymer formation by highlighting the essential role of stimuli triggers in facilitating the bottom-up fabrication, allowing for the formation of intricate hierarchical structures. In particular, this perspective will delve into the stimuli-responsive processing of high-performance biopolymers produced by mussels, caddisflies, velvet worms, sharks, whelks, and squids, which are known for their robust mechanical properties, durability, and wet adhesion capabilities. Finally, we provide an overview of current advancements and challenges in understanding stimuli-induced natural formation pathways and their translation to biomimetic materials.

Advancements in silk fibroin and silk sericin-based biomaterial applications for cancer therapy and wound dressing formulation: A comprehensive review

Silks are a class of proteins generated naturally by different arthropods, including silkworms, spiders, scorpions, mites, wasps, and bees. This review discusses the silk fibroin and silk sericin fabricated by Bombyx mori silkworm as versatile fibers. This silk fiber is predominantly composed of hydrophobic silk fibroin and hydrophilic silk sericin. Fibroin is defined as a structural protein that bestows silk with strength, while sericin is characterized as a gum-like protein, tying the two fibrous proteins together and endowing silk proteins with elasticity. Due to their versatile structures, biocompatibility, and biodegradability, they could be tailored into intricate structures to warrant particular demands. The intrinsic functional groups of both proteins enable their functionalization and cross-linking with various biomaterials to endow the matrix with favorable antioxidant and antibacterial properties. Depending on the target applications, they can be integrated with other materials to formulate nanofibrous, hydrogels, films, and micro-nanoparticles. Given the outstanding biological and controllable physicochemical features of fibroin and sericin, they could be exploited in pharmaceutical applications involving tissue engineering, wound repair, drug delivery, and cancer therapy. This review comprehensively discusses the advancements in the implementation of different formulations of silk fibroin and sericin in wound healing and drug delivery systems, particularly for cancer treatment.

Ultrathin silk nanofiber-carbon nanotube skin tattoos for wirelessly triggered and temperature feedbacked transdermal drug delivery

Transdermal drug delivery has emerged as an alternative to conventional drug delivery systems as it enables painless and convenient drug administration. However, next-generation healthcare systems need to facilitate "on-demand" delivery operations and should be highly efficient to penetrate the physiological barriers in the skin. Here, we report an ultrathin dye-loaded epidermal tattoo (UDET) that allows wirelessly stimulated drug delivery with high efficiency. The UDET consists of an electrospun dye-loaded silk nanofiber mat and a covered carbon nanotube (CNT) layer. UDETs are conformally tattooed on pigskins and show stable operation under mechanical deformation. Biological fluorescence dyes such as vitamin B12, riboflavin, rhodamine B, and sodium fluorescein are applied as model drugs. Illuminating the UDET by a low-power light-emitting diode (< 34.5 mW/cm2) triggers transdermal drug delivery due to heat generation. The CNTs convert the absorbed light into heat, and then the dyes loaded on silk can be diffused through the epidermis. The CNT layer is electrically conductive and can detect the temperature by reading the resistance change (0.1917 Ω/°C). This indicates that the UDET can be used simultaneously to read temperature and deliver the loaded dye molecules, making it a promising on-demand drug delivery strategy for future medicine technology.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13534-024-00363-6.

A robust and biodegradable hydroxyapatite/poly(lactide-co-ε-caprolactone) electrospun membrane for dura repair

Typically occurring after trauma or neurosurgery treatments, dura mater defect and the ensuing cerebrospinal fluid (CSF) leakage could lead to a number of serious complications and even patient's death. Although numerous natural and synthetic dura mater substitutes have been reported, none of them have been able to fulfill the essential properties, such as anti-adhesion, leakage blockage, and pro-dura rebuilding. In this study, we devised and prepared a series of robust and biodegradable hydroxyapatite/poly(lactide-co-ε-caprolactone) (nHA/PLCL) membranes for dura repair via an electrospinning technique. In particular, PLLA/PCL (80/20) was selected for electrospinning due to its mechanical properties that most closely resembled natural dural tissue. Studies by SEM, XRD, water contact angle and in vitro degradation showed that the introduction of nHA would destroy PLCL's crystalline structure, which would further affect the mechanical properties of the nHA/PLCL membranes. When the amount of nHA added increased, so did the wettability and in vitro degradation rate, which accelerated the release of nHA. In addition, the high biocompatibility of nHA/PLCL membranes was demonstrated by in vitro cytotoxicity data. The in vivo rabbit dura repair model results showed that nHA/PLCL membranes provided a strong physical barrier to stop tissue adhesion at dura defects. Meanwhile, the nHA/PLCL and commercial group's CSF had a significantly lower number of inflammatory cells than the control groups, validating the nHA/PLCL's ability to effectively lower the risk of intracranial infection. Findings from H&E and Masson-trichrome staining verified that the nHA/PLCL electrospun membrane was more favorable for fostering dural defect repair and skull regeneration. Moreover, the relative molecular weight of PLCL declined dramatically after 3 months of implantation, according to the results of the in vivo degradation test, but it retained the fiber network structure and promoted tissue growth, demonstrating the good stability of the nHA/PLCL membranes. Collectively, the nHA/PLCL electrospun membrane presents itself as a viable option for dura repair.

Bridging Nature and Engineering: Protein-Derived Materials for Bio-Inspired Applications

The sophisticated, elegant protein-polymers designed by nature can serve as inspiration to redesign and biomanufacture protein-based materials using synthetic biology. Historically, petro-based polymeric materials have dominated industrial activities, consequently transforming our way of living. While this benefits humans, the fabrication and disposal of these materials causes environmental sustainability challenges. Fortunately, protein-based biopolymers can compete with and potentially surpass the performance of petro-based polymers because they can be biologically produced and degraded in an environmentally friendly fashion. This paper reviews four groups of protein-based polymers, including fibrous proteins (collagen, silk fibroin, fibrillin, and keratin), elastomeric proteins (elastin, resilin, and wheat glutenin), adhesive/matrix proteins (spongin and conchiolin), and cyanophycin. We discuss the connection between protein sequence, structure, function, and biomimetic applications. Protein engineering techniques, such as directed evolution and rational design, can be used to improve the functionality of natural protein-based materials. For example, the inclusion of specific protein domains, particularly those observed in structural proteins, such as silk and collagen, enables the creation of novel biomimetic materials with exceptional mechanical properties and adaptability. This review also discusses recent advancements in the production and application of new protein-based materials through the approach of synthetic biology combined biomimetics, providing insight for future research and development of cutting-edge bio-inspired products. Protein-based polymers that utilize nature's designs as a base, then modified by advancements at the intersection of biology and engineering, may provide mankind with more sustainable products.

Wound Dressing Based on Cassava Silk-Chitosan

The application prospects of composite sponges with antibacterial and drug-carrying functions in the field of medical tissue engineering are extensive. A solution of cassava silk fibroin (CSF) was prepared with Ca(NO3)2 as a solvent, which was then combined with chitosan (CS) to create a sponge-porous material by freeze-drying. The CSF-CS composite sponge with a mesh structure was successfully fabricated through hydrogen bonding. Scanning electron microscopy (SEM), Fourier transform infrared absorption (FTIR) and X-ray diffraction (XRD) were employed to investigate the appearance and structure of the cassava silk's fibroin materials, specifically examining the impact of different mass percentages of CS on the sponge's structure. The swelling rate and mechanical properties of the CSF-CS sponge were analyzed, along with its antibacterial properties. Furthermore, by incorporating ibuprofen as a model drug into these loaded sponges, their potential efficacy as efficient drug delivery systems was demonstrated. The results indicate that the CSF-CS sponge possesses a three-dimensional porous structure with over 70% porosity and an expansion rate exceeding 400% while also exhibiting good resistance against pressure. Moreover, it exhibits excellent drug-carrying ability and exerts significant bacteriostatic effects on Escherichia coli. Overall, these findings support considering the CSF-CS composite sponge as a viable candidate for use in drug delivery systems or wound dressings.

Material-specific binding peptides empower sustainable innovations in plant health, biocatalysis, medicine and microplastic quantification

Material-binding peptides (MBPs) have emerged as a diverse and innovation-enabling class of peptides in applications such as plant-/human health, immobilization of catalysts, bioactive coatings, accelerated polymer degradation and analytics for micro-/nanoplastics quantification. Progress has been fuelled by recent advancements in protein engineering methodologies and advances in computational and analytical methodologies, which allow the design of, for instance, material-specific MBPs with fine-tuned binding strength for numerous demands in material science applications. A genetic or chemical conjugation of second (biological, chemical or physical property-changing) functionality to MBPs empowers the design of advanced (hybrid) materials, bioactive coatings and analytical tools. In this review, we provide a comprehensive overview comprising naturally occurring MBPs and their function in nature, binding properties of short man-made MBPs (<20 amino acids) mainly obtained from phage-display libraries, and medium-sized binding peptides (20-100 amino acids) that have been reported to bind to metals, polymers or other industrially produced materials. The goal of this review is to provide an in-depth understanding of molecular interactions between materials and material-specific binding peptides, and thereby empower the use of MBPs in material science applications. Protein engineering methodologies and selected examples to tailor MBPs toward applications in agriculture with a focus on plant health, biocatalysis, medicine and environmental monitoring serve as examples of the transformative power of MBPs for various industrial applications. An emphasis will be given to MBPs' role in detecting and quantifying microplastics in high throughput, distinguishing microplastics from other environmental particles, and thereby assisting to close an analytical gap in food safety and monitoring of environmental plastic pollution. In essence, this review aims to provide an overview among researchers from diverse disciplines in respect to material-(specific) binding of MBPs, protein engineering methodologies to tailor their properties to application demands, re-engineering for material science applications using MBPs, and thereby inspire researchers to employ MBPs in their research.

Silk Fibroin and Its Nanocomposites for Wound Care: A Comprehensive Review

For most individuals, wound healing is a highly organized, straightforward process, wherein the body transitions through different phases in a timely manner. However, there are instances where external intervention becomes necessary to support and facilitate different phases of the body's innate healing mechanism. Furthermore, in developing countries, the cost of the intervention significantly impacts access to treatment options as affordability becomes a determining factor. This is particularly true in cases of long-term wound treatment and management, such as chronic wounds and infections. Silk fibroin (SF) and its nanocomposites have emerged as promising biomaterials with potent wound-healing activity. Driven by this motivation, this Review presents a critical overview of the recent advancements in different aspects of wound care using SF and SF-based nanocomposites. In this context, we explore various formats of hemostats and assess their suitability for different bleeding situations. The subsequent sections discuss the primary causes of nonhealing wounds, i.e., prolonged inflammation and infections. Herein, different treatment strategies to achieve immunomodulatory and antibacterial properties in a wound dressing were reviewed. Despite exhibiting excellent pro-healing properties, few silk-based products reach the market. This Review concludes by highlighting the bottlenecks in translating silk-based products into the market and the prospects for the future.

Study on the Structure and Properties of Silk Fibers Obtained from Factory All-Age Artificial Diets

The traditional production mode of the sericulture industry is no longer suitable for the development requirements of modern agriculture; to facilitate the sustainable development of the sericulture industry, factory all-age artificial diet feeding came into being. Understanding the structural characteristics and properties of silk fibers obtained from factory all-age artificial diet feeding is an important prerequisite for application in the fields of textiles, clothing, biomedicine, and others. However, there have been no reports so far. In this paper, by feeding silkworms with factory all-age artificial diets (AD group) and mulberry leaves (ML group), silk fibers were obtained via two different feeding methods. The structure, mechanical properties, hygroscopic properties, and degradation properties were studied by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Structurally, no new functional groups appeared in the AD group. Compared with the ML group, the structure of the two groups was similar, and there was no significant difference in mechanical properties and moisture absorption. The structure of degummed silk fibers is dominated by crystalline regions, but α-chymotrypsin hydrolyzes the amorphous regions of silk proteins, so that after 28 d of degradation, the weight loss of both is very small. This provides further justification for the feasibility of factory all-age artificial diets for silkworms.

The Emerging Role of Silk Fibroin for the Development of Novel Drug Delivery Systems

In order to reduce the toxicological impact on healthy cells and to improve the therapeutic response, many drug delivery systems have been fabricated and analysed, involving the use of different natural and synthetic materials at macro-, micro- and nanoscales. Among the natural materials which have demonstrated a huge potential for the development of effective drug delivery systems, silk fibroin has emerged for its excellent biological properties and for the possibility to be processed in a wide range of forms, which can be compliant with multiple active molecules and pharmaceutical ingredients for the treatment of various diseases. This review aims at presenting silk fibroin as an interesting biopolymer for applications in drug delivery systems, exploring the results obtained in recent works in terms of technological progress and effectiveness in vitro and in vivo.

Drug eluting protein and polysaccharides-based biofunctionalized fabric textiles- pioneering a new frontier in tissue engineering: An extensive review

In the ever-evolving landscape of tissue engineering, medicated biotextiles have emerged as a game-changer. These remarkable textiles have garnered significant attention for their ability to craft tissue scaffolds that closely mimic the properties of natural tissues. This comprehensive review delves into the realm of medicated protein and polysaccharide-based biotextiles, exploring a diverse array of fabric materials. We unravel the intricate web of fabrication methods, ranging from weft/warp knitting to plain/stain weaving and braiding, each lending its unique touch to the world of biotextiles creation. Fibre production techniques, such as melt spinning, wet/gel spinning, and multicomponent spinning, are demystified to shed light on the magic behind these ground-breaking textiles. The biotextiles thus crafted exhibit exceptional physical and chemical properties that hold immense promise in the field of tissue engineering (TE). Our review underscores the myriad applications of drug-eluting protein and polysaccharide-based textiles, including TE, tissue repair, regeneration, and wound healing. Additionally, we delve into commercially available products that harness the potential of medicated biotextiles, paving the way for a brighter future in healthcare and regenerative medicine. Step into the world of innovation with medicated biotextiles-where science meets the art of healing.

Pharmaceutical Applications of Biomass Polymers: Review of Current Research and Perspectives

Polymers derived from natural biomass have emerged as a valuable resource in the field of biomedicine due to their versatility. Polysaccharides, peptides, proteins, and lignin have demonstrated promising results in various applications, including drug delivery design. However, several challenges need to be addressed to realize the full potential of these polymers. The current paper provides a comprehensive overview of the latest research and perspectives in this area, with a particular focus on developing effective methods and efficient drug delivery systems. This review aims to offer insights into the opportunities and challenges associated with the use of natural polymers in biomedicine and to provide a roadmap for future research in this field.