Natural Spider Research Articles

Differential parasitism of native and invasive widow spider egg sacs

AbstractDuring colonization, invasive species establish and spread to new locations, where they may have an advantage over native species. One such advantage may be avoidance of predators or parasites by means of better defenses or due to lower suitability as a host. We conducted field surveys and lab behavioral experiments to investigate the differential susceptibility of two widow spider species—one native to Israel, the white widow spider Latrodectus pallidus, and one invasive species, the brown widow spider, Latrodectus geometricus—to an egg sac parasitoid wasp, Philolema latrodecti. In collections of egg sacs from six paired sites of L. geometricus and L. pallidus populations in the Negev Desert, Israel, we found higher parasitism rates on the egg sacs of the native L. pallidus. In no-choice trials, we found that wasps were more likely to parasitize and oviposited longer on L. pallidus egg sacs than on L. geometricus egg sacs. In two-choice tests with spider webs and egg sacs, parasitoids made first contact with L. pallidus webs more often and faster. After developing inside of L. pallidus egg sacs, more parasitoids emerged and were larger than those emerging from L. geometricus egg sacs. Potentially better defense of the L. geometricus egg sacs as well as the parasitoid’s fitness advantages gained from parasitizing L. pallidus egg sacs may explain the higher parasitism rate in the native species. Our results suggest that the invasion and establishment success of L. geometricus is due, in part, to its ability to escape parasitism.

Preliminary application of native Nephila edulis spider silk and fibrin implant causes granulomatous foreign body reaction in vivo in rat’s spinal cord

After spinal cord injury, gliomesenchymal scaring inhibits axonal regeneration as a physical barrier. In peripheral nerve injuries, native spider silk was shown to be an effective scaffold to facilitate axonal re-growth and nerve regeneration. This study tested a two-composite scaffold made of longitudinally oriented native spider silk containing a Haemocomplettan fibrin sheath to bridge lesions in the spinal cord and enhance axonal sprouting. In vitro cultivation of neuronal cells on spider silk and fibrin revealed no cytotoxicity of the scaffold components. When spinal cord tissue was cultured on spider silk that was reeled around a metal frame, migration of different cell types, including neurons and neural stem cells, was observed. The scaffold was implanted into spinal cord lesions of four Wistar rats to evaluate the physical stress caused on the animals and examine the bridging potential for axonal sprouting and spinal cord regeneration. However, the implantation in-vivo resulted in a granulomatous foreign body reaction. Spider silk might be responsible for the strong immune response. Thus, the immune response to native spider silk seems to be stronger in the central nervous system than it is known to be in the peripheral body complicating the application of native spider silk in spinal cord injury treatment.

Spider silk-inspired high-performance soybean meal-based adhesive reinforced by greenly produced chitosan-functionalized boron nitride nanosheets

A facile and environment-friendly bionic strategy is developed to construct high-performance soybean meal (SM)-based multifunctional adhesives by using chitosan-functionalized boron nitride nanosheets (CS@BNNSs) as an alternative to β-sheet nanocrystals to mimic the structural characteristics of natural spider silks. CS@BNNSs were cost-effectively and greenly produced from bulk hexagonal boron nitride through chitosan-assisted mechanochemical exfoliation. Compared with the neat crosslinker-modified SM-based adhesive (MSM), the fabricated adhesive (MSM/CS@BNNSs) features remarkable improvement in mechanical performance, such as enhanced wet shear strength (1.31 MPa vs. 0.58 MPa), work of debonding (0.366 J vs. 0.186 J), and dry shear strength (1.96 MPa vs. 1.42 MPa). The outstanding performance is attributable to the dense covalent/non-covalent intermolecular interactions and good compatibility between CS@BNNSs and the SM matrix, which are beneficial to the dissipation and transfer of energy under loading. In addition, the MSM/CS@BNNSs adhesive exhibits noticeably improved flame retardancy and excellent anti-mildew performance compared with the neat SM-based adhesives, and its shelf life reaches up to 72 h. Such an advanced MSM/CS@BNNSs adhesive reaches the engineering resin level and possesses promising potentials for industrial applications. Overall, this facile and efficient spider silk-mimicking structural design strategy assisted by a green and low-cost mechanochemical exfoliation would provide endless inspirations for constructing and reinforcing multifunctional bio-based adhesives, elastomers, and plastic materials.

Artificial and natural silk materials have high mechanical property variability regardless of sample size

Silk fibres attract great interest in materials science for their biological and mechanical properties. Hitherto, the mechanical properties of the silk fibres have been explored mainly by tensile tests, which provide information on their strength, Young’s modulus, strain at break and toughness modulus. Several hypotheses have been based on these data, but the intrinsic and often overlooked variability of natural and artificial silk fibres makes it challenging to identify trends and correlations. In this work, we determined the mechanical properties of Bombyx mori cocoon and degummed silk, native spider silk, and artificial spider silk, and compared them with classical commercial carbon fibres using large sample sizes (from 10 to 100 fibres, in total 200 specimens per fibre type). The results confirm a substantial variability of the mechanical properties of silk fibres compared to commercial carbon fibres, as the relative standard deviation for strength and strain at break is 10–50%. Moreover, the variability does not decrease significantly when the number of tested fibres is increased, which was surprising considering the low variability frequently reported for silk fibres in the literature. Based on this, we prove that tensile testing of 10 fibres per type is representative of a silk fibre population. Finally, we show that the ideal shape of the stress–strain curve for spider silk, characterized by a pronounced exponential stiffening regime, occurs in only 25% of all tested spider silk fibres.

Effects of Wolf Spiders' Captive Environment on Their Locomotor and Exploratory Behaviours.

Simple SummarySince the 1960s, abuses of domestic and of wild animals that have been tamed or are held in captivity have been legally prohibited and laws ensure their well-being. Many scientific investigations carried out in this context recommend ways to adapt farming and thus to avoid physical and/or psychological suffering. Evaluations of animals’ welfare in captivity entail the need to understand in detail the fundamental behaviours of the focus species and to know the degree of their variation to be able to establish objective bases that can ensure breeding conditions that respect the animals’ welfare. Current laws do not apply to invertebrate animals (such as insects or spiders) and consideration of the welfare of these animals in captivity is neglected. Here, I compared the behaviour of wild adult spiders just after collection and that of adult spiders hatched and bred in the laboratory. My results show that captivity induced rapid changes of wild spiders’ behaviour once in captivity. Therefore, it is important to establish the best breeding conditions for the needs of both invertebrate and vertebrate animals in order to promote their well-being.Here I detail the effects of the abiotic/captive environment of an adult wandering spider, Pardosa saltans (Lycosidae) on its behaviour. These studies focused on spiders collected as adults in their natural environment and spiders developed in the laboratory under controlled conditions. Wild-caught spiders were tested either immediately after capture or after being housed for 15 days post-collection. Laboratory reared spiders were kept in different environments: small or large space combined with the presence or absence of litter. Two tests evaluated by sex show the influence of these rearing conditions: an open-field test and a radial-arm maze test. The results show that wild caught spiders of both sexes tested immediately after capture weighed significantly less and were significantly more active than spiders housed in the laboratory for 15 days and spiders reared in the laboratory. Laboratory conditions induced a positive impact on body mass and negative impact on behaviour activities. The locomotor and exploratory activities of spiders of both sexes kept in container without substrate showed lower. My results suggest that the physical enrichment of the environment can reduce these negative effects for females, but not for males that seem to be more affected by being reared under controlled conditions.

OP7: Silk Fibroin-Based Conduits Filled with Native Spider Silk Fibers Successfully Promoted Nerve Regeneration in a 10 Mm Sciatic Nerve Defect in Rats

OP7: Silk Fibroin-Based Conduits Filled with Native Spider Silk Fibers Successfully Promoted Nerve Regeneration in a 10 Mm Sciatic Nerve Defect in Rats

Are natural threats superior threats?

Threat superiority effects describe the reaction time advantage for locating threatening objects in a visual search paradigm, compared to locating visually similar non-threatening objects. They are widely reported for threats of both natural (snakes and spiders) and man-made (guns and knives) origins. Across two experiments, the current study contrasts threat superiority effects for natural and man-made targets. When targets are not depicted held, snakes and spiders tended to exhibit larger threat superiority effects, and were searched for with additional caution, than were guns and knives. When snakes and spiders were depicted held and weapons wielded, systematic differences between the natural and man-made threats disappeared. This means the advantage for threats of natural origin observed when all targets were depicted not held may be attributable to differences in animation – snakes and spiders are alive and may strike at any time if in your vicinity, whereas a weapon can only inflict harm if wielded. From these data there is no evidence that evolved visual sensitivities to the basic shapes of venomous animals support faster detection and response times to these animals than can occur to targets such as guns and knives, whose shapes must be learned. The selection pressures that led to the evolution of such sensitivities (observable even in infancy) may therefore lie in protecting young children and babies from envenomation, before they even have the cognitive capacity to understand the dangers that snakes and spiders pose.

Acacia mangium tannin functionalized graphene nanoplatelets produced via ball-milling for sustainable soy protein-based film

A simple and green natural spider silk inspired strategy is proposed for fabricating advanced soy protein (SP)-based film by introducing Acacia mangium tannin (AMT) functionalized graphene nanoplatelets (AMT-GnPs), greenly and cost-effectively produced via ball milling graphite with AMT. The prepared film, namely SPEI/GnPs, exhibited noticeable improvement in mechanical properties over the neat SP-based film such as tensile strength (11.60 vs. 2.19 MPa) and toughness (21.12 vs. 3.09 MJ m-3). In addition, such developed biomimetic film still exhibited a high strain at failure (220.3%). The outstanding performance was attributable to the formation of dense interfacial covalent and H-bonding interactions between the scattered AMT-GnPs and the protein matrix. Moreover, after incorporating AMT-GnPs, the SPEI/GnPs film featured excellent UV-blocking performance and good water resistance. Overall, this study offers a facile biomimetic strategy for strong, tough, and biodegradable films for many potential applications like packaging and UV-blocking bioproducts.

A Bio-Inspired Method for Mathematical Optimization Inspired by Arachnida Salticidade

This paper proposes a new meta-heuristic called Jumping Spider Optimization Algorithm (JSOA), inspired by Arachnida Salticidae hunting habits. The proposed algorithm mimics the behavior of spiders in nature and mathematically models its hunting strategies: search, persecution, and jumping skills to get the prey. These strategies provide a fine balance between exploitation and exploration over the solution search space and solve global optimization problems. JSOA is tested with 20 well-known testbench mathematical problems taken from the literature. Further studies include the tuning of a Proportional-Integral-Derivative (PID) controller, the Selective harmonic elimination problem, and a few real-world single objective bound-constrained numerical optimization problems taken from CEC 2020. Additionally, the JSOA’s performance is tested against several well-known bio-inspired algorithms taken from the literature. The statistical results show that the proposed algorithm outperforms recent literature algorithms and is capable to solve challenging real-world problems with unknown search space.

Spidroin-Based Biomaterials in Tissue Engineering: General Approaches and Potential Stem Cell Therapies.

Spider silks are increasingly gaining interest for potential use as biomaterials in tissue engineering and biomedical applications. Owing to their facile and versatile processability in native and regenerated forms, they can be easily tuned via chemical synthesis or recombinant technologies to address specific issues required for applications. In the past few decades, native spider silk and recombinant silk materials have been explored for a wide range of applications due to their superior strength, toughness, and elasticity as well as biocompatibility, biodegradation, and nonimmunogenicity. Herein, we present an overview of the recent advances in spider silk protein that fabricate biomaterials for tissue engineering and regenerative medicine. Beginning with a brief description of biological and mechanical properties of spidroin-based materials and the cellular regulatory mechanism, this review summarizes various types of spidroin-based biomaterials from genetically engineered spider silks and their prospects for specific biomedical applications (e.g., lung tissue engineering, vascularization, bone and cartilage regeneration, and peripheral nerve repair), and finally, we prospected the development direction and manufacturing technology of building more refined and customized spidroin-based protein scaffolds.

Spider Silk-Inspired Artificial Fibers.

Spider silk is a natural polymeric fiber with high tensile strength, toughness, and has distinct thermal, optical, and biocompatible properties. The mechanical properties of spider silk are ascribed to its hierarchical structure, including primary and secondary structures of the spidroins (spider silk proteins), the nanofibril, the “core–shell”, and the “nano‐fishnet” structures. In addition, spider silk also exhibits remarkable properties regarding humidity/water response, water collection, light transmission, thermal conductance, and shape‐memory effect. This motivates researchers to prepare artificial functional fibers mimicking spider silk. In this review, the authors summarize the study of the structure and properties of natural spider silk, and the biomimetic preparation of artificial fibers from different types of molecules and polymers by taking some examples of artificial fibers exhibiting these interesting properties. In conclusion, biomimetic studies have yielded several noteworthy findings in artificial fibers with different functions, and this review aims to provide indications for biomimetic studies of functional fibers that approach and exceed the properties of natural spider silk.

Ultrarobust Photothermal Materials via Dynamic Crosslinking for Solar Harvesting.

Highly efficient and mechanically durable photothermal materials are urgently needed for solar harvesting, but their development still remains challenging. Here, inspired by the hierarchically oriented architecture of natural spider silk, an ultrarobust liquid metals (LMs)/polymer composite is presented via dynamic crosslinking based on the unique mechanical deformable characteristic of LMs. Dynamically cross-linked core-shell structured LMs droplets can be squeezed along with the orientational crystallization of polymer chains during drawing, thus enabling LMs nanoparticles to be uniformly programmed in the rigid polyethylene nanofiber skeleton. The resultant composite exhibits an unprecedented combination of strong broad-band light absorption (96.9-99.3%), excellent photothermal conversion ability, remarkable mechanical property (tensile strength of 283.7MPa, which can lift 200000 times its own weight), and long-term structural reliability (bearing 100000 bending cycles). A powerful and durable solar thermoelectric generator system for real-environmental solar-heat-electricity conversion is further demonstrated, providing a valuable guidance for the design and fabrication of high-performance solar-harvesting materials.

An ultralow base weight of nanocellulose boosting filtration performance of hierarchical composite air filter inspired by native spider web

The beauty of nature is inexhaustible to human beings, and the process of human understanding and learning nature promotes the progress of science and technology. Inspired by the natural hierarchical spider-web structure, a biomimetic composite air filter with high filtration performance and good wet stability is prepared for the first time. Cellulose nanofibrils (CNF) generated from regenerable jute plants are implanted into the pores of commercialized biodegradable porous corrugated papers and self-assembled into robust nano-networks as filter building blocks to prepare a biodegradable composite air filter. When the base weight of CNF goes up to only 0.2500 g/m 2 , the CNF nano-networks completely fill the pores of corrugated paper, which greatly reduces the consumption of raw materials. More importantly, the filtration efficiency for PM0.3 removal of resultant corrugated paper is increased from 6% to 94.5%, while maintaining a relatively low pressure drop of 296.3 Pa. After a silane modification of CNF, the filtration efficiency of 75% can be achieved at high humidity. Overall, the successful synthesis of biomimetic composite air filters provides inspiration for the design of separation materials, satisfying the growing demand for renewability, sustainability, and biodegradability. • A biomimetic composite air filter with ultralow base weight has been developed. • Cellulose nanofibrils were self-assembled into robust nano-networks. • A high efficiency of 94.5% and low pressure drop of 296.3 Pa were achieved. • A filtration efficiency of 75% for PM0.3 could be achieved at 80% RH. • All the materials we used are biodegradable.

Ariadne 1.0: A Novel Method and Prototype for Artificially Spinning Spider Silk

Musculoskeletal conditions affect more than half of the U.S. population over 18 years old, accounting for more than 50% of all disabling health conditions in adults [1]. The push for innovative surgical technologies has sparked a search for new biomaterials analogous to, or better than, native human musculoskeletal tissue. Spider silk is five times the tensile strength of steel by weight, as elastic as rubber on a weight-to-weight basis, antibacterial, conductive, and hypoallergenic [2]. Applications of this unique biomaterial include artificial tissues such as tendons, ligaments, skin grafts, muscles, and neurons. The 3D Organic Polymer Silk team (3D-OPS) has designed a cost-effective, novel system, Ariadne 1.0, to manufacture 3D printed spider silk as an alternative to biomaterials currently used in medical applications. The pre-printing process of Ariadne 1.0 utilizes native spider silk or purified spidroin proteins in the production of a stable solution for use in the 3D printing of biological structures. Modeled after the chemical-physical environment of the Nephila clavipes’ major ampullate gland, Ariadne 1.0’s printing system can easily modify the biophysical properties of its silk product by altering parameters such as the printing solution’s protein-type, ion concentration, or weight to volume ratio and the printing system’s needle size and print speed. This versatility supports a broad spectrum of surgical procedures and enables the potential for improvements in the medical field, particularly surrounding musculoskeletal injuries. The 3D-OPS team designed Ariadne 1.0 to investigate the viability of printing artificial tendons, ligaments, and muscle fibers with spider silk.

Modulating Surface Properties of the Linothele fallax Spider Web by Solvent Treatment.

Linothele fallax (Mello-Leitão) (L. fallax) spider web, a potentially attractive tissue engineering material, was investigated using quantitative peak force measurement atomic force microscopy and scanning electron microscopy with energy dispersive spectroscopy both in its natural state and after treatment with solvents of different protein affinities, namely, water, ethanol, and dimethyl sulfoxide (DMSO). Native L. fallax silk threads are densely covered by globular objects, which constitute their inseparable parts. Depending on the solvent, treating L. fallax modifies its appearance. In the case of water and ethanol, the changes are minor. In contrast, DMSO practically removes the globules and fuses the threads into dense bands. Moreover, the solvent treatment influences the chemistry of the threads’ surface, changing their adhesive and, therefore, biocompatibility and cell adhesion properties. On the other hand, the solvent-treated web materials’ contact effect on different types of biological matter differs considerably. Protein-rich matter controls humidity better when wrapped in spider silk treated with more hydrophobic solvents. However, carbohydrate plant materials retain more moisture when wrapped in native spider silk. The extracts produced with the solvents were analyzed using nuclear magnetic resonance (NMR) and liquid chromatography–mass spectrometry techniques, revealing unsaturated fatty acids as representative adsorbed species, which may explain the mild antibacterial effect of the spider silk. The extracted metabolites were similar for the different solvents, meaning that the globules were not “dissolved” but “fused into” the threads themselves, being supposedly rolled-in knots of the protein chain.

Characteristics of electrospun membranes in different spidroin/PCL ratios

Spider silk is a protein fiber with the highest strength and elasticity known in nature, even higher than that of silkworm silk. It was a biological and technical reserve material with great potential. However, the low yield of natural spider silk limits the application of spider silk, and the development of genetic engineering provides opportunities for the mass production of spider silk. We constructed a mini-recombinant spidroin NRC based on spider silk gene from Araneus ventricosus and successfully expressed it through Prokaryotic expression that provide a high production for application using electrospinning, which is a mature technique to produce micro-nano scale fibers as thin as natural spider silks. By blending the purified and lyophilized NRC with polycaprolactone (PCL) in different mass ratio for electrospinning, different electrospun membranes were obtained, and then characterized in terms of morphology, chemical structure, mechanical and Schwann cell proliferation. Compared the difference between polycaprolactone (PCL) and NRC, the fiber diameter decreased from 1.0779 μm to 0.5785 μm, water contact angel decreased from 104.1 ± 2° to 56.9 ± 5°, and elongation decreased from 240.97 ± 89% to 37.76 ± 13%, while tensile strength increased from 1.74 ± 1.2 MPa to 3.18 ± 0.9 MPa and Young’s Module increased from 3.05 ± 1.6 MPa to 16.54 ± 6.7 MPa. In this study, we obtained a thinner fiber, hydrophilicity and high strengthen electrospinning spidroin contained membrane, which can also promote Schwann cell proliferation and adhesion.

Artificial spider silk supports and guides neurite extension in vitro.

Surgical intervention with the use of autografts is considered the gold standard to treat peripheral nerve injuries. However, a biomaterial that supports and guides nerve growth would be an attractive alternative to overcome problems with limited availability, morbidity at the site of harvest, and nerve mismatches related to autografts. Native spider silk is a promising material for construction of nerve guidance conduit (NGC), as it enables regeneration of cm-long nerve injuries in sheep, but regulatory requirements for medical devices demand synthetic materials. Here, we use a recombinant spider silk protein (NT2RepCT) and a functionalized variant carrying a peptide derived from vitronectin (VN-NT2RepCT) as substrates for nerve growth support and neurite extension, using a dorsal root ganglion cell line, ND7/23. Two-dimensional coatings were benchmarked against poly-d-lysine and recombinant laminins. Both spider silk coatings performed as the control substrates with regards to proliferation, survival, and neurite growth. Furthermore, NT2RepCT and VN-NT2RepCT spun into continuous fibers in a biomimetic spinning set-up support cell survival, neurite growth, and guidance to an even larger extent than native spider silk. Thus, artificial spider silk is a promising biomaterial for development of NGCs.

Silk Fibroin: A Promising Tool for Wound Healing and Skin Regeneration

Silk is a functional protein biomaterial produced by a variety of insects like flies, silkworms, scorpions, spiders, and mites. Silk synthesized by silkworms is extensively studied for its applications in tissue engineering and wound healing. Silk is undoubtedly a natural biocompatible material with humans and has its role in medical treatments from ancient times. The silk worm protein comprises two types of proteins namely fibroin and sericin. Silk fibroin makes up approximately 70% of cocoon weight and has wide applications in textiles and in all biomedical applications owing to its biocompatible, nontoxic, biodegradable, less immunogenic, and noncarcinogenic nature. It possesses outstanding toughness and mechanical strength, while silk sericin possesses high defensive ability against ultraviolet light and oxidation. Silk fibroin has been known to induce wound healing by increasing cell proliferation and growth and migrating various types of cells which are involved in different stages of wound healing process. With several silk varieties like silk worm fibroin, silk sericin, recombinant silk materials, and native spider silk have been investigated for its wound healing applications over the last several decades. With an objective of harnessing the silk regenerative properties, plentiful strategies have been studied and applied to develop bioartificial skin grafts and bioactive wound dressings in recent times. This review gives a detailed insight into the structure, general properties, fibroin structure-properties relationship, and biomedical applications of silk fibroin.

Flower availability drives effects of wildflower strips on ground-dwelling natural enemies and crop yield

Wildflower strips have been heralded as a promising way to enhance ecosystem services by providing organisms which may help make farming less dependent on external inputs. However, recent studies show inconsistent effects on delivery of ecosystem services and crop yield, warranting a more detailed analysis of the factors determining the effects of wildflower strips. We examined how the natural enemy groups of spider, carabid beetle and staphylinid beetle, as well as aphid pest and crop yield respond to wildflower strips. We furthermore determined whether the response of natural enemies, aphids and crop yield depends on flower cover and species richness, and how this is influenced by fertilizer and insecticide applications to the crop in 16 winter wheat fields in the Netherlands. We used an experimental approach with a nested design that included all combinations of wildflower strips (present/absent), fertilizer application (yes/no) and insecticide application (yes/no). Presence of wildflower strips did not affect ground-dwelling natural enemies, aphids or crop yield. However, flower availability across wildflower strips and control margins was positively related to the abundance of the pooled number of examined natural enemies, spiders and carabid beetles. Positive effects in the crop were observed over limited distances; up to 5 m from the edge for spiders and wheat yield. The effects of flower availability and on-field management practices on natural enemies, aphids and wheat yield did not interact suggesting that, in our study, effects of flowers were not influenced by insecticide or fertilizer applications but were mainly additive. Our study indicates that cover and richness of wildflowers in field margin habitat, rather than establishment of wildflower strips per se, drove increases in natural enemies and crop yield. This suggests that more attention should be given to the optimization of establishment success of seed mixtures and management practices enhancing wildflower cover and diversity. Furthermore, biodiversity enhancing management of the herbaceous vegetation in linear landscape elements may represent a cost-effective alternative to boost ecosystem services regulating crop production in agricultural landscapes.

Microbially Synthesized Polymeric Amyloid Fiber Promotes β-Nanocrystal Formation and Displays Gigapascal Tensile Strength.

The ability of amyloid proteins to form stable β-sheet nanofibrils has made them potential candidates for material innovation in nanotechnology. However, such a nanoscale feature has rarely translated into attractive macroscopic properties for mechanically demanding applications. Here, we present a strategy by fusing amyloid peptides with flexible linkers from spidroin; the resulting polymeric amyloid proteins can be biosynthesized using engineered microbes and wet-spun into macroscopic fibers. Using this strategy, fibers from three different amyloid groups were fabricated. Structural analyses unveil the presence of β-nanocrystals that resemble the cross-β structure of amyloid nanofibrils. These polymeric amyloid fibers have displayed strong and molecular-weight-dependent mechanical properties. Fibers made of a protein polymer containing 128 repeats of the FGAILSS sequence displayed an average ultimate tensile strength of 0.98 ± 0.08 GPa and an average toughness of 161 ± 26 MJ/m3, surpassing most recombinant protein fibers and even some natural spider silk fibers. The design strategy and the biosynthetic approach can be expanded to create numerous functional materials, and the macroscopic amyloid fibers will enable a wide range of mechanically demanding applications.