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Advanced Science (Weinheim,... Feb 2022Spider silk is a natural polymeric fiber with high tensile strength, toughness, and has distinct thermal, optical, and biocompatible properties. The mechanical... (Review)
Review
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.
Topics: Biomimetics; Fibroins; Protein Structure, Secondary; Silk; Tensile Strength
PubMed: 34927397
DOI: 10.1002/advs.202103965 -
Nature Communications Sep 2022The silkworm Bombyx mori is an important economic insect for producing silk, the "queen of fabrics". The currently available genomes limit the understanding of its...
The silkworm Bombyx mori is an important economic insect for producing silk, the "queen of fabrics". The currently available genomes limit the understanding of its genetic diversity and the discovery of valuable alleles for breeding. Here, we deeply re-sequence 1,078 silkworms and assemble long-read genomes for 545 representatives. We construct a high-resolution pan-genome dataset representing almost the entire genomic content in the silkworm. We find that the silkworm population harbors a high density of genomic variants and identify 7308 new genes, 4260 (22%) core genes, and 3,432,266 non-redundant structure variations (SVs). We reveal hundreds of genes and SVs that may contribute to the artificial selection (domestication and breeding) of silkworm. Further, we focus on four genes responsible, respectively, for two economic (silk yield and silk fineness) and two ecologically adaptive traits (egg diapause and aposematic coloration). Taken together, our population-scale genomic resources will promote functional genomics studies and breeding improvement for silkworm.
Topics: Animals; Bombyx; Diapause; Domestication; Genomics; Silk
PubMed: 36153338
DOI: 10.1038/s41467-022-33366-x -
Cells Dec 2023Silk hydrogels have shown potential for tissue engineering applications, but several gaps and challenges, such as a restricted ability to form hydrogels with tuned...
Silk hydrogels have shown potential for tissue engineering applications, but several gaps and challenges, such as a restricted ability to form hydrogels with tuned mechanics and structural features, still limit their utilisation. Here, and (Tasar) silk microfibres were embedded within self-assembling silk hydrogels to modify the bulk hydrogel mechanical properties. This approach is particularly attractive because it creates structured silk hydrogels. First, and Tasar microfibres were prepared with lengths between 250 and 500 μm. Secondary structure analyses showed high beta-sheet contents of 61% and 63% for and Tasar microfibres, respectively. Mixing either microfibre type, at either 2% or 10% (/) concentrations, into 3% (/) silk solutions during the solution-gel transition increased the initial stiffness of the resulting silk hydrogels, with the 10% (/) addition giving a greater increase. Microfibre addition also altered hydrogel stress relaxation, with the fastest stress relaxation observed with a rank order of 2% (/) > 10% (/) > unmodified hydrogels for either fibre type, although fibres showed a greater effect. The resulting data sets are interesting because they suggest that the presence of microfibres provided potential 'flow points' within these hydrogels. Assessment of the biological responses by monitoring cell attachment onto these two-dimensional hydrogel substrates revealed greater numbers of human induced pluripotent stem cell-derived mesenchymal stem cells (iPSC-MSCs) attached to the hydrogels containing 10% (/) microfibres as well as 2% (/) and 10% (/) Tasar microfibres at 24 h after seeding. Cytoskeleton staining revealed a more elongated and stretched morphology for the cells growing on hydrogels containing Tasar microfibres. Overall, these findings illustrate that hydrogel stiffness, stress relaxation and the iPSC-MSC responses towards silk hydrogels can be tuned using microfibres.
Topics: Humans; Animals; Silk; Induced Pluripotent Stem Cells; Bombyx; Cell-Matrix Junctions; Hydrogels
PubMed: 38201214
DOI: 10.3390/cells13010010 -
Biomolecules Apr 2022Hemostasis plays an essential role in all surgical procedures. Uncontrolled hemorrhage is the primary cause of death during surgeries, and effective blood loss control... (Review)
Review
Hemostasis plays an essential role in all surgical procedures. Uncontrolled hemorrhage is the primary cause of death during surgeries, and effective blood loss control can significantly reduce mortality. For modern surgeons to select the right agent at the right time, they must understand the mechanisms of action, the effectiveness, and the possible adverse effects of each agent. Over the past decade, various hemostatic agents have grown intensely. These agents vary from absorbable topical hemostats, including collagen, gelatins, microfibrillar, and regenerated oxidized cellulose, to biologically active topical hemostats such as thrombin, biological adhesives, and other combined agents. Commercially available products have since expanded to include topical hemostats, surgical sealants, and adhesives. Silk is a natural protein consisting of fibroin and sericin. Silk fibroin (SF), derived from silkworm , is a fibrous protein that has been used mostly in fashion textiles and surgical sutures. Additionally, SF has been widely applied as a potential biomaterial in several biomedical and biotechnological fields. Furthermore, SF has been employed as a hemostatic agent in several studies. In this review, we summarize the several morphologic forms of SF and the latest technological advances on the use of SF-based hemostatic agents.
Topics: Adhesives; Animals; Biocompatible Materials; Bombyx; Fibroins; Hemostasis; Hemostatics; Silk
PubMed: 35625588
DOI: 10.3390/biom12050660 -
Molecules (Basel, Switzerland) Feb 2020Due to its properties, such as biodegradability, low density, excellent biocompatibility and unique mechanics, spider silk has been used as a natural biomaterial for a... (Review)
Review
Due to its properties, such as biodegradability, low density, excellent biocompatibility and unique mechanics, spider silk has been used as a natural biomaterial for a myriad of applications. First clinical applications of spider silk as suture material go back to the 18th century. Nowadays, since natural production using spiders is limited due to problems with farming spiders, recombinant production of spider silk proteins seems to be the best way to produce material in sufficient quantities. The availability of recombinantly produced spider silk proteins, as well as their good processability has opened the path towards modern biomedical applications. Here, we highlight the research on spider silk-based materials in the field of tissue engineering and summarize various two-dimensional (2D) and three-dimensional (3D) scaffolds made of spider silk. Finally, different applications of spider silk-based materials are reviewed in the field of tissue engineering in vitro and in vivo.
Topics: Animals; Biocompatible Materials; Blood Vessels; Bone and Bones; Cartilage; Cell Culture Techniques; Humans; Hydrogels; Peripheral Nerves; Recombinant Proteins; Regeneration; Silk; Skin; Spiders; Tissue Engineering; Viscoelastic Substances
PubMed: 32046280
DOI: 10.3390/molecules25030737 -
Biomacromolecules May 2022The tiny spider makes dragline silk fibers with unbeatable toughness, all under the most innocuous conditions. Scientists have persistently tried to emulate its natural... (Review)
Review
The tiny spider makes dragline silk fibers with unbeatable toughness, all under the most innocuous conditions. Scientists have persistently tried to emulate its natural silk spinning process using recombinant proteins with a view toward creating a new wave of smart materials, yet most efforts have fallen short of attaining the native fiber's excellent mechanical properties. One reason for these shortcomings may be that artificial spider silk systems tend to be overly simplified and may not sufficiently take into account the true complexity of the underlying protein sequences and of the multidimensional aspects of the natural self-assembly process that give rise to the hierarchically structured fibers. Here, we discuss recent findings regarding the material constituents of spider dragline silk, including novel spidroin subtypes, nonspidroin proteins, and possible involvement of post-translational modifications, which together suggest a complexity that transcends the two-component MaSp1/MaSp2 system. We subsequently consider insights into the spidroin domain functions, structures, and overall mechanisms for the rapid transition from disordered soluble protein into a highly organized fiber, including the possibility of viewing spider silk self-assembly through a framework relevant to biomolecular condensates. Finally, we consider the concept of "biomimetics" as it applies to artificial spider silk production with a focus on key practical aspects of design and evaluation that may hopefully inform efforts to more closely reproduce the remarkable structure and function of the native silk fiber using artificial methods.
Topics: Amino Acid Sequence; Animals; Fibroins; Recombinant Proteins; Silk; Spiders
PubMed: 35378031
DOI: 10.1021/acs.biomac.1c01682 -
International Journal of Molecular... Jul 2022Silk is a naturally occurring material and has been widely used in biomedical and cosmetic applications owing to its unique properties, including blood compatibility,...
Silk is a naturally occurring material and has been widely used in biomedical and cosmetic applications owing to its unique properties, including blood compatibility, excellent cytocompatibility, and a low inflammatory response in the body. A natural silk nonwoven fabric with good mechanical properties was recently developed using the binding property of sericin. In this study, silk/rayon composite nonwoven fabrics were developed to increase productivity and decrease production costs, and the effect of the silk/rayon composition on the structure and properties of the fabric was examined. The crystalline structure of silk and rayon was maintained in the fabric. As the silk content increased, the porosity and moisture regain of the silk/rayon web and nonwoven fabric decreased. As the silk content increased, the maximum stress of the web and nonwoven fabric increased, and the elongation decreased. Furthermore, the silk/rayon web exhibited the highest values of maximum stress and elongation at ~200 °C. Regardless of the silk/rayon composition, all silk/rayon nonwoven fabrics showed good cytocompatibility. Thus, the silk/rayon fabric is a promising material for cosmetic and biomedical applications owing to its diverse properties and high cell viability.
Topics: Cellulose; Sericins; Silk; Textiles
PubMed: 35886857
DOI: 10.3390/ijms23147511 -
Biochemical Society Transactions Apr 2021Research into the development of sustainable biomaterials is increasing in both interest and global importance due to the increasing demand for materials with decreased... (Review)
Review
Research into the development of sustainable biomaterials is increasing in both interest and global importance due to the increasing demand for materials with decreased environmental impact. This research field utilises natural, renewable resources to develop innovative biomaterials. The development of sustainable biomaterials encompasses the entire material life cycle, from desirable traits, and environmental impact from production through to recycling or disposal. The main objective of this review is to provide a comprehensive definition of sustainable biomaterials and to give an overview of the use of natural proteins in biomaterial development. Proteins such as collagen, gelatin, keratin, and silk, are biocompatible, biodegradable, and may form materials with varying properties. Proteins, therefore, provide an intriguing source of biomaterials for numerous applications, including additive manufacturing, nanotechnology, and tissue engineering. We give an insight into current research and future directions in each of these areas, to expand knowledge on the capabilities of sustainably sourced proteins as advanced biomaterials.
Topics: Biocompatible Materials; Collagen; Eukaryotic Cells; Gelatin; Keratins; Nanotechnology; Prokaryotic Cells; Recombinant Proteins; Silk; Tissue Engineering
PubMed: 33729443
DOI: 10.1042/BST20200896 -
Nature Materials Jan 2020Early insights into the unique structure and properties of native silk suggested that β-sheet nanocrystallites in silk would degrade prior to melting when subjected to...
Early insights into the unique structure and properties of native silk suggested that β-sheet nanocrystallites in silk would degrade prior to melting when subjected to thermal processing. Since then, canonical approaches for fabricating silk-based materials typically involve solution-derived processing methods, which have inherent limitations with respect to silk protein solubility and stability in solution, and time and cost efficiency. Here we report a thermal processing method for the direct solid-state moulding of regenerated silk into bulk 'parts' or devices with tunable mechanical properties. At elevated temperature and pressure, regenerated amorphous silk nanomaterials with ultralow β-sheet content undergo thermal fusion via molecular rearrangement and self-assembly assisted by bound water to form a robust bulk material that retains biocompatibility, degradability and machinability. This technique reverses presumptions about the limitations of direct thermal processing of silk into a wide range of new material formats and composite materials with tailored properties and functionalities.
Topics: Animals; Biocompatible Materials; Bombyx; Compressive Strength; Female; Fibroins; Hot Temperature; Magnetic Resonance Spectroscopy; Nanostructures; Protein Structure, Secondary; Rats; Rats, Sprague-Dawley; Silk; Solubility; Spectroscopy, Fourier Transform Infrared; Stress, Mechanical; Tensile Strength; Water; X-Ray Microtomography
PubMed: 31844276
DOI: 10.1038/s41563-019-0560-8 -
Drug Delivery Dec 2020Fibroin is a dominant silk protein that possesses ideal properties as a biomaterial for drug delivery. Recently, the development of fibroin nanoparticles (FNPs) for... (Review)
Review
Fibroin is a dominant silk protein that possesses ideal properties as a biomaterial for drug delivery. Recently, the development of fibroin nanoparticles (FNPs) for various biomedical applications has been extensively studied. Due to their versatility and chemical modifiability, FNPs can encapsulate different types of therapeutic compounds, including small and big molecules, proteins, enzymes, vaccines, and genetic materials. Moreover, FNPs are able to be administered both parenterally and non-parenterally. This review summaries basic information on the silk and fibroin origin and characteristics, followed by the up-to-date data on the FNPs preparation and characterization methods. In addition, their medical applications as a drug delivery system are in-depth explored based on several administrative routes of parenteral, oral, transdermal, ocular, orthopedic, and respiratory. Finally, the challenges and suggested solutions, as well as the future outlooks of these systems are discussed.
Topics: Animals; Biocompatible Materials; Drug Delivery Systems; Fibroins; Humans; Nanoparticles; Silk
PubMed: 32157919
DOI: 10.1080/10717544.2020.1736208