HOME

TheInfoList



OR:

Biotextiles are specialized materials engineered from natural or synthetic fibers. These textiles are designed to interact with biological systems, offering properties such as biocompatibility, porosity, and mechanical strength or are designed to be environmentally friendly for typical household applications. There are several uses for biotextiles since they are a broad category. The most common uses are for medical or household use. However, this term may also refer to textiles constructed from biological waste product. These biotextiles are not typically used for industrial purposes. The term "biotextiles" derives from the combination of "bio," referring to biology or living organisms, and "textiles," indicating woven or fibrous materials. It encompasses the interdisciplinary field of biomedical textiles, which focuses on the design, fabrication, and application of textile materials in healthcare and biomedical engineering. Biotextiles made from
mycelium Mycelium (: mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Its normal form is that of branched, slender, entangled, anastomosing, hyaline threads. Fungal colonies composed of mycelium are fo ...
, vegetable biomass,
bacterial cellulose Bacterial cellulose is an organic compound with the formula produced by certain types of bacteria. While cellulose is a basic structural material of most plants, it is also produced by bacteria, principally of the genera '' Komagataeibacter'', ' ...
, and
recombinant protein Protein production is the biotechnological process of generating a specific protein. It is typically achieved by the manipulation of gene expression in an organism such that it expresses large amounts of a recombinant gene. This includes the ...
based fibers are used as an alternative to synthetic textiles to prevent and reduce the high
greenhouse gas emissions Greenhouse gas (GHG) emissions from human activities intensify the greenhouse effect. This contributes to climate change. Carbon dioxide (), from burning fossil fuels such as coal, petroleum, oil, and natural gas, is the main cause of climate chan ...
, water pollution, and landfill waste from the textile industry. Biotextiles are also used within healthcare and the biomedical engineering field as implantable devices such as
surgical suture A surgical suture, also known as a stitch or stitches, is a medical device used to hold Tissue (biology), body tissues together and approximate wound edges after an injury or surgery. Application generally involves using a Sewing needle, needle w ...
s,
hernia A hernia (: hernias or herniae, from Latin, meaning 'rupture') is the abnormal exit of tissue or an organ (anatomy), organ, such as the bowel, through the wall of the cavity in which it normally resides. The term is also used for the normal Devel ...
repair fabrics,
arterial An artery () is a blood vessel in humans and most other animals that takes oxygenated blood away from the heart in the systemic circulation to one or more parts of the body. Exceptions that carry deoxygenated blood are the pulmonary arteries in ...
grafts Grafting refers to a surgical procedure to move tissue from one site to another on the body, or from another creature, without bringing its own blood supply with it. Instead, a new blood supply grows in after it is placed. A similar techniqu ...
,
artificial skin Artificial skin is a collagen scaffold that induces regeneration of skin in mammals such as humans. The term was used in the late 1970s and early 1980s to describe a new treatment for massive burns. It was later discovered that treatment of deep ...
and parts of
artificial heart An artificial heart is a artificial organ, device that replaces the human heart, heart. Artificial hearts are typically used as a bridge to heart transplantation, but ongoing research aims to develop a device that could permanently replace the ...
s.


Introduction

The field of biotextiles has garnered significant attention due to its potential to revolutionize the textile industry by offering sustainable alternatives to conventional and environmentally harmful fabrics. Central to this innovation are raw materials derived from nature’s own processes, including mycelium, bacterial cellulose and vegetable and fruit biomass. These natural ingredients have potential to become a reliable source for the development of eco-friendly textiles, addressing issues with environmental degradation and ingredient depletion associated with traditional textile production. Processing of these materials offer abundant sources of natural fibers. Using the fibrous structures found in these materials and plant tissues, such as cotton, hemp, flax and more, its possible to create biodegradable and renewable textiles. Washing, drying and a variety of spinning techniques are common for processing of all textiles but the processing for biotextiles is expected to produce less environmentally harmful waste products due to the bio-remedial nature of many of the natural materials. Furthermore, advancements in processing have enabled the extraction of fibers for fashion from unconventional sources, including pineapple, banana, citrus fruits, animal byproducts and bone. These new developments make large contributions to the world of innovative fashion.


Mycelium-based textiles

Mycelium, the vegetative part of fungi, has emerged as a versatile and sustainable raw material for biotextiles. Mycelium typically grows underground or within its substrate such as soil, wood, decaying organic matter or waste residues. In mycelium-based biocomposites, the fungus consumes the carbohydrates to produce
hyphae A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one o ...
, a network of branching, thread-like structures. Through controlled growth processes, mycelium can be cultivated into a dense network of interwoven fibers, forming a durable biodegradable matrix suitable for textile applications. This cultivation depends on the temperature, moisture and pH of the media. File:Mycelium Based Structure.jpg, Microscopic image of the structure of Mycelium which contains a layering of protein, glucan and chitin


Pleurotus ostreatus

The commonly known fungal species, white-rot basidiomycetes, are capable of degrading polymeric carbohydrates and using them for growth.
Pleurotus ostreatus ''Pleurotus ostreatus'' (commonly known the oyster mushroom, grey oyster mushroom, oyster fungus, hiratake, or pearl oyster mushroom). Found in temperate and subtropical forests around the world, it is a popular edible mushroom. Name Both th ...
is an edible white-rot fungus known to degrade
cellulose Cellulose is an organic compound with the chemical formula, formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of glycosidic bond, β(1→4) linked glucose, D-glucose units. Cellulose is an important s ...
,
hemicellulose A hemicellulose (also known as polyose) is one of a number of heteropolymers (matrix polysaccharides), such as arabinoxylans, present along with cellulose in almost all embryophyte, terrestrial plant cell walls. Cellulose is crystalline, strong, an ...
and
lignin Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidit ...
, hence reinforcing its potential to thrive on wastes such as wood, textile, and agricultural residues. The growth of P. ostreatus on textile residue and mycelium production was tested in the department of civil engineering in Ontario Canada.References: Saini, R., Kaur, G., & Brar, S. K. (2023). Textile residue-based mycelium biocomposites from Pleurotus ostreatus. ''Mycology'', 1–7. https://doi.org/10.1080/21501203.2023.2278308 The conducted experiment proved the applicability of textile waste as a potential feedstock. However, the loss in biocomposite weight of 1%–5% has been further corroborated by the water loss in the sample and in fungal mycelium. Additionally, the maximum compressive strength was observed as 270 kPa using cotton-based biocomposite. Overall, a lightweight biocomposite was obtained which could be a potential alternative for
polystyrene Polystyrene (PS) is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It i ...
- based products. These findings show the ability of the fungus to thrive on polyester plastic in textiles and provide an alternative for converting this plastic material into bio-based materials. Additionally, by varying the mycelium growth, the plasticity and stiffness properties of the resultant biocomposite can be changed.


β-glucan/chitin complex

File:Beta-1,3-1,4-glucan.png, Molecular Structure of Beta-Glucan The β-glucan/chitin complex refers to the combination of two natural polysaccharides (
β-glucan Beta-glucans, β-glucans comprise a group of β-D-glucose polysaccharides (glucans) naturally occurring in the cell walls of cereals, bacteria, and Fungus, fungi, with significantly differing Physical chemistry, physicochemical properties depen ...
and
chitin Chitin (carbon, C8hydrogen, H13oxygen, O5nitrogen, N)n ( ) is a long-chain polymer of N-Acetylglucosamine, ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is the second most abundant polysaccharide in nature (behind only cell ...
) found in fungal cell walls. This complex is a major component found in a variety of fungal cell walls and are also found in certain plants, algae, and bacteria.Fuentes, K., Gómez, M., Rebolledo, H., Figueroa, J. M., Zamora, P., & Naranjo-Briceño, L. (2022). Nanomaterials in the future biotextile industry: A new cosmovision to obtain smart biotextiles. ''Frontiers in Nanotechnology'', ''4''. https://doi.org/10.3389/fnano.2022.1056498 β-glucan contributes to the structural strength of the cell wall and plays roles in cell signaling, immune modulation and defense against pathogens. Chitin is a long-chain polymer of N-acetylglucosamine units, linked by β-glyosidic bonds. It provides structural support and protection to fungal cells, contributing to their rigidity and resilience. The addition of this complex to the growth components that make up the initial matrix that is the base of these emerging biotextiles provides a significant effect on the durability and usefulness of the processed result. File:Chitin.svg, Molecular Structure of Chitin


Vegetable biomass-based textiles

Polysaccharide-based polymers are made of fruit and vegetable origin, and the most promising biopolymer-yielding fibers include cellulose, starch, chitin/chitosan,
pectin Pectin ( ': "congealed" and "curdled") is a heteropolysaccharide, a structural polymer contained in the primary lamella, in the middle lamella, and in the cell walls of terrestrial plants. The principal chemical component of pectin is galact ...
,
alginate Alginic acid, also called algin, is a naturally occurring, edible polysaccharide found in brown algae. It is hydrophilic and forms a viscous gum when hydrated. When the alginic acid binds with sodium and calcium ions, the resulting salts are k ...
, and
carrageenan Carrageenans or carrageenins ( ; ) are a family of natural linear sulfation, sulfated polysaccharides. They are extracted from red algae, red edible seaweeds. Carrageenans are widely used in the food industry, for their gelling, thickening, an ...
. Soy, whey, and
zein Zein ( ) is a class of prolamine protein found in maize. It is usually manufactured as a powder from corn gluten meal. Zein is one of the best understood plant proteins.Momany, Frank A.; Sessa, David J.; Lawton, John C.; Selling, Gordon W.; Ha ...
could also be obtained from vegetable sources. An example is Pinatex, a pineapple-based leather that is manufactured from the cellulose fibers of pineapple leaves. It is an environmentally friendly alternative to traditional leather due to its sustainability and adaptability. Additionally its lightweight, resilient and biodegradable nature has made it very popular for new and innovative fashion.


Algae-derived fibers (Alginate)

Alginate is a polysaccharide generated by brown algae, seaweed and specific species of bacteria. Bacteria and seaweed alginate differ in composition, modifications, molecular mass, viscoelasticity, and polydispersity. These unique qualities lead to a wide range of applications, including alginate’s development of nanoparticles, nanotubes, microspheres, and microcapsules. Furthermore, the different types of sponges, hydrogels, foams, elastomers, and fibers that can be created with its growth and processing. It is widely employed in many facets of industrial fabrication. Alginate is commonly employed as a gelling agent, thickener, and stabilizer in a large variety of food products. Its ability to form gels under mild conditions makes it particularly useful for encapsulating flavors, vitamins, and other active ingredients. It is also used to develop hydrogels, printing pastes and sizing agents in biomedical, textile, cosmetic and agricultural industries. In the textile industry specifically, textile coatings, binders and finishes are the bulk of what alginate is used for, rather than formulating threads itself it reinforces the strength of other materials.


Bacterial cellulose-based textiles

Unlike plant-derived cellulose, bacterial cellulose offers superior mechanical properties, such as high tensile strength and flexibility, making it an attractive option for a wide range of textile applications. Moreover, the cultivation of bacterial cellulose can be achieved using simple fermentation processes, minimizing the environmental footprint associated with traditional textile manufacturing. Yeast, fungi and algae species including: the bacterium Pseudomonas fluorescens, the yeast Yarrowia lipolytica, the sponge Acanthella elongata, the algae Stoechospermum marginatum, and the fungus Candida albicans have all been researched for their ability to be used on substrates to create natural composites for biotextiles. Barhoum, A., García-Betancourt, M. L., Jeevanandam, J., Hussien, E. A., Mekkawy, S. A., Mostafa, M., Omran, M. M., Abdalla, M. S., & Bechelany, M. (2022). Review on natural, incidental, bioinspired, and engineered nanomaterials: history, definitions, classifications, synthesis, properties, market, toxicities, risks, and regulations. ''Nanomaterials'', ''12''(2), 177. https://doi.org/10.3390/nano12020177


Yeast

Yeast is a single cell, fungal organism widely found in nature and plays important roles in various biological processes. Some species of yeast, such as Gluconacetobacter xylinus, are capable of producing cellulose through fermentation. This cultivation depends on the temperature, moisture and pH of the media. During fermentation, the yeast produces cellulose as an extracellular matrix, forming a dense network of cellulose fibers. This microbial cellulose can then be harvested, purified, and processed into textile fibers. This process is not consistent for most species of yeast though. The microbial cellulose produced by most yeast species can be processed into textile fibers after being reinforced with other natural or synthetic fibers using techniques such as spinning, weaving, or knitting. Depending on the desired characteristics, properties such as strength, softness, or moisture absorption can be controlled. The resulting textile materials can be used to produce a variety of products, including apparel, home textiles, and technical textiles. Using yeast in the biotextile industry contains many environmentally friendly and cost effective perks. Yeast fermentation can be carried out using renewable feedstocks such as agricultural residues, waste streams, or plant-based sugars, reducing reliance on finite resources and minimizing environmental impact. Additionally, microbial cellulose production is highly efficient, with relatively low energy and water requirements compared to conventional textile manufacturing processes. An emerging method in the creation of biotextiles is growing engineered yeast as cell factories that produce target proteins in succession. Other recent advances in synthetic biology and fermentation processes enable high-level expressions of recombinant proteins, using bacteria, yeasts, animal cells, and plants as biofactories.


Recombinant protein-based textiles

Collagen Collagen () is the main structural protein in the extracellular matrix of the connective tissues of many animals. It is the most abundant protein in mammals, making up 25% to 35% of protein content. Amino acids are bound together to form a trip ...
,
fibroin Fibroin is an insoluble protein present in silk produced by numerous insects, such as the larvae of ''Bombyx mori'', and other moth genera such as ''Antheraea'', ''Cricula trifenestrata, Cricula'', ''Samia (moth), Samia'' and ''Gonometa''. Sil ...
,
gelatin Gelatin or gelatine () is a translucent, colorless, flavorless food ingredient, commonly derived from collagen taken from animal body parts. It is brittle when dry and rubbery when moist. It may also be referred to as hydrolyzed collagen, coll ...
,
casein Casein ( , from Latin ''caseus'' "cheese") is a family of related phosphoproteins (CSN1S1, αS1, aS2, CSN2, β, K-casein, κ) that are commonly found in mammalian milk, comprising about 80% of the proteins in cow's milk and between 20% and 60% of ...
, and
actin Actin is a family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils. It is found in essentially all eukaryotic cells, where it may be present at a concentration of ...
are naturally from animal products. Collagen and
silk Silk is a natural fiber, natural protein fiber, some forms of which can be weaving, woven into textiles. The protein fiber of silk is composed mainly of fibroin and is most commonly produced by certain insect larvae to form cocoon (silk), c ...
are the most attractive biopolymers for developing biotextiles. Collagen can be produced from a plethora of organisms and renewable sources. Collagen’s repeating amino acid sequence allows it to form a stable secondary protein structure of triple helices. These helices can further assemble into quaternary structures, allowing collagen to take on the form of fibrillar proteins. These protein building blocks could biofabricate abrasion-resistant, water-resistant, breathable, lightweight and durable materials with characteristics similar to leather. Natural silk has remarkable strength. The fibroin protein in silk consists of long, repetitive chains of amino acids, predominantly glycine, alanine, and serine. These amino acids are arranged in a specific sequence, forming a unique molecular structure that contributes to silk's remarkable properties. Silk has high tensile strength that can be attributed to its nano-crystalline and molecular structure (hydrogen bonds & β-sheet structure) and high degree of orientation. Significant efforts have been made to obtain recombinant silk fibroin, principally from the spider, dragline, or silkworm through genetic alteration. The developed protein is later isolated and processed into threads by techniques such as spinning.


Biosynthetic Spider Silk in ''E. coli''

Ancient Greeks and Romans used spider silk to stop bleeding and aid wound healing and in more modern history, indigenous people in the Solomon Islands as well as Aboriginals created fishing setups from spider silk utilizing it as fishing line. One of the most common methods of producing spider silk biosynthetically utilizes bacteria, such as ''Escherichia coli (E. coli)''. The ''E. coli'' cell DNA is engineered to express spider silk genes, producing spidroin proteins within the cells. These proteins are then extracted, purified and spun into fibers. While E. coli can produce relatively high yields (e.g., up to 2,700 mg/liter for some MaSp1 variants), process efficiency is very low and many challenges remain in ensuring proper protein folding and solubility for optimal fiber properties, especially for larger spidroin constructs which often cause cell toxicity and death. The table below provides the mechanical properties of the spider silk from a few species to establish a general overview of the mechanical properties. There are then listed a few notable biosynthetic spider silk examples produced in ''E. coli'' from recent work. There is a wide variety in the mechanical properties achievable in biosynthetic spider silk depending on the spirdoin sequences used, spinning method, native spider species and whether efficiency in production or maximum mechanical properties are emphasized.


Manufacture of biotextiles


Preface

The processing of different materials is determined by the origin of their species and substrate. While vegetable and fruit biomass-based textiles are formed into sheets, biotextiles made from proteins or bacterial cellulose are commonly drawn out during an extrusion and spun into a stronger thread. By cultivating plant and bacterial species on a determined substrate, it is possible to grow materials by harnessing their ability to digest and transform cellulose into natural composites. This process involves collecting them into proper scaffolds and executing physical and chemical treatment, so that these sheets of biomass visually resemble leather and exhibit comparable material and tactile properties. The processing of protein based textiles involves a variety of spinning techniques based on the type and quality that needs to be achieved.


Manufacturing of biotextiles

Before the production of biotextiles, monofilament structures were typically produced using
extrusion Extrusion is a process used to create objects of a fixed cross section (geometry), cross-sectional profile by pushing material through a Die (manufacturing), die of the desired cross-section. Its two main advantages over other manufacturing pro ...
techniques, where a single continuous
filament The word filament, which is descended from Latin ''filum'' meaning " thread", is used in English for a variety of thread-like structures, including: Astronomy * Galaxy filament, the largest known cosmic structures in the universe * Solar filament ...
was drawn from a polymer melt. These monofilaments can then be used directly or further processed into various biomedical devices, such as sutures, meshes, and vascular
grafts Grafting refers to a surgical procedure to move tissue from one site to another on the body, or from another creature, without bringing its own blood supply with it. Instead, a new blood supply grows in after it is placed. A similar techniqu ...
. Biotextiles are created using multiple techniques, such as
knitting Knitting is a method for production of textile Knitted fabric, fabrics by interlacing yarn loops with loops of the same or other yarns. It is used to create many types of garments. Knitting may be done Hand knitting, by hand or Knitting machi ...
,
weaving Weaving is a method of textile production in which two distinct sets of yarns or threads are interlaced at right angles to form a fabric or cloth. Other methods are knitting, crocheting, felting, and braiding or plaiting. The longitudinal ...
, and
braiding A braid (also referred to as a plait; ) is a complex structure or pattern formed by interlacing three or more strands of flexible material such as textile yarns, wire, or hair. The simplest and most common version is a flat, solid, three-strand ...
, to form the fabric-like structures used in biomedical applications. The three primary spinning techniques traditionally employed in fiber manufacturing are wet-spinning, dry-spinning, and melt-spinning. ''Table1. The processing methods and applications of Biotextile''


Electrospinning

Electrospinning is a technique that uses electrostatic forces to produce ultra fine fibers from polymer solutions or melts. These fibers have unique properties like large surface areas and high
porosity Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measure ...
, making them valuable for biomedical applications. Polymer solutions are ejected through a needle onto a collector plate by applying an electric field, forming
nanofibers Nanofibers are fibers with diameters in the Nanometre, nanometer range (typically, between 1 nm and 1 μm). Nanofibers can be generated from different polymers and hence have different physical properties and application potentials. Examples ...
. These scaffolds show promise in tissue engineering, aiding in regenerating various human tissues and organs such as bone, skin, blood vessels, liver, and kidneys. They closely resemble the native
extracellular This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...
matrix, facilitating cell attachment and proliferation. Electrospinning offers a versatile method for creating biocompatible scaffolds with simple structures for tissue engineering.


Melt spinning

Melt-spinning is a cost-effective method widely used in the textile industry for producing polymeric fibers without solvents. However, its application in biostructures is limited due to factors such as polymer decomposition at lower temperatures, inadequate control over melt temperature during spinning, and challenges in controlling the final fiber structure. In this process, polymer granules are melted in an extruder to form a spinning dope, then extruded through a
spinneret A spinneret is a silk-spinning organ of a spider or the larva of an insect. Some adult insects also have spinnerets, such as those borne on the forelegs of Embioptera. Spinnerets are usually on the underside of a spider's opisthosoma, and ar ...
and rapidly cooled to solidify the filament. Despite its drawbacks, melt-spinning of biopolymers has been explored for various bio-applications. The use of bio-based reinforcements is being investigated as a solution to overcome challenges associated with producing biotextiles via melt-spinning.


Dry spinning

Dry-spinning, an ancient spinning method, dissolves polymers in solvents, unlike melt-spinning. Polymer solutions are extruded through a spinneret and then passed through a heating column where the solvent evaporates, leaving dry fibers. Highly volatile solvents are needed for this process. Steam or hot air is utilized to solidify fibers and remove solvent. This technique suits polymers prone to thermal degradation and those unable to form
viscous Viscosity is a measure of a fluid's rate-dependent resistance to a change in shape or to movement of its neighboring portions relative to one another. For liquids, it corresponds to the informal concept of ''thickness''; for example, syrup h ...
melts, offering specific surface characteristics. Traditional dry-spun polymers include
acetate An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic, or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called ...
,
triacetate Cellulose triacetate, triacetate, CTA or TAC is a chemical compound produced from cellulose and a source of acetate esters, typically acetic anhydride. Triacetate is commonly used for the creation of fibres and film base. It is chemically simil ...
, acrylics, modacrylics,
aramid Aramid fibers, short for aromatic polyamide, are a class of heat-resistant and strong synthetic fibers. They are used in aerospace and military applications, for ballistic-rated bulletproof vest, body armor cloth, fabric and ballistic composites ...
, and spandex fibers. Besides being complex and costly due to recovery processes and mass transfer mechanisms during solvent evaporation, dry-spinning provides fibers with unique properties.


Wet spinning

Wet-spinning, introduced with
rayon Rayon, also called viscose and commercialised in some countries as sabra silk or cactus silk, is a semi-synthetic fiber made from natural sources of regenerated cellulose fiber, cellulose, such as wood and related agricultural products. It has t ...
fiber production, involves dissolving polymers in a suitable solvent before extrusion. Unlike dry-spinning, the solvent need not be volatile. During wet-spinning, the polymeric solution is extruded through a spinneret into a coagulation bath, leading to a phase inversion and precipitation. Natural and synthetic polymers, including gelatin, alginate, collagen, and cellulose, are processed into fibers via wet-spinning for various tissue engineering applications. This technique enables the production of fibers with large diameters and architectures with high porosity and interconnected open pore structures, facilitating cell penetration, adhesion, and proliferation.


Gel spinning

Gel spinning produces fibers with exceptional strength or other unique qualities. During extrusion, the polymer is not in a pure liquid condition. The polymer chains are linked at different locations in
liquid crystal Liquid crystal (LC) is a state of matter whose properties are between those of conventional liquids and those of solid crystals. For example, a liquid crystal can flow like a liquid, but its molecules may be oriented in a common direction as i ...
form, partially apart as they would be in a real solution. The resultant filaments have substantial inter-chain forces, which can significantly raise the fiber’s tensile strength additionally, the shear forces the liquid crystals to be arranged along the fiber axis during extrusion. Strength is further enhanced by the filaments' exceptionally high degree of alignment as they emerge from one another. Due to the filaments' first air-to-cool cooling phase, the method is known as dry-wet spinning.


Solution spinning

Solution spinning, encompassing wet and dry-jet wet spinning, creates continuous fibers from materials incapable of withstanding melting. This technique is applicable to manufacturing fibers from natural polymers and bio-based materials like cellulose,
lignin Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidit ...
, and
proteins Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, re ...
. As it relies on polymer solutions, solution spinning offers significant potential to enhance the functionality of wet-spun fibers through targeted formulations.


Grafting

In biotextiles, grafting onto surfaces refers to the process of attaching or bonding functional molecules, such as proteins,
peptides Peptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides that have a molecular mass of 10,000 Dalton (unit), Da or more are called proteins. Chains of fewer t ...
, or polymers, onto the surface of textile materials. This process is often performed to modify the surface properties of textiles, such as enhancing biocompatibility, promoting cell adhesion, or enabling controlled drug release. Grafting onto surfaces can be achieved through various techniques, including chemical modification, plasma treatment, or surface coating methods. These modified biotextiles find applications in biomedical fields such as tissue engineering, wound healing, and medical implants, where tailored surface properties are critical for desired biological interactions.


Rotary jet spinning

Rotary jet spinning is a technique used in the production of biotextiles, which involves the extrusion of polymer solutions or melts through a rapidly rotating spinneret. As the polymer solution or melt exits the spinneret, it is subjected to
centrifugal forces Centrifugal force is a fictitious force in Newtonian mechanics (also called an "inertial" or "pseudo" force) that appears to act on all objects when viewed in a rotating frame of reference. It appears to be directed radially away from the axis ...
, forming fine fibers. These fibers are collected to create a
nonwoven fabric Nonwoven fabric or non-woven fabric is a fabric-like material made from staple fibre (short) and long fibres (continuous long), bonded together by chemical, mechanical, heat or solvent treatment. The term is used in the textile manufacturing in ...
or scaffold structure suitable for various biomedical applications. Rotary jet spinning offers advantages such as producing highly porous structures with controllable fiber diameter and alignment, making it promising for tissue engineering and drug delivery applications in biomedicine.


Use and applications


Consumer textile/fashion industry


Goat silk as milk byproduct

Researchers at the University of Wyoming have devised a method to introduce spider silk-spinning genes into goats, enabling the extraction of silk protein from the goats’ milk. This innovation has applications in various fields, including medicine, where the strength and elasticity of spider silk has been argued to be utilized in artificial ligaments, tendons, eye sutures, and jaw repair. Traditionally, obtaining spider silk in sufficient quantities necessitates managing large populations of spiders, which often leads to territorial conflicts and cannibalism within the farmed spider population. To circumvent this challenge, scientists have genetically engineered goats to produce the silk protein exclusively in their milk. Through selective breeding, a percentage of the offspring inherit the silk protein gene, leading to higher yields of the silk protein. The
transgenic A transgene is a gene that has been transferred naturally, or by any of a number of genetic engineering techniques, from one organism to another. The introduction of a transgene, in a process known as transgenesis, has the potential to change the ...
goats exhibit no discernible differences in health, appearance, or behavior compared to non-transgenic counterparts. In the future, the researchers aim to transfer silk genes into
alfalfa Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial plant, perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, ...
plants, a move the researchers expect to further increase silk production. Researchers believe that alfalfa's widespread distribution and high protein content make it a promising candidate for large-scale silk protein synthesis.


Fruit waste textiles

In a collaboration between Danish fashion brand Ganni and Mexican biomaterials company Polybion, a unique prototype blazer was created using bacterial cellulose derived from industrial fruit waste. Unlike traditional leather, it has been stated that this fruit textile is environmentally friendly, with a significantly smaller carbon footprint. A wide variety of fruit waste, particularly from mangoes, serves as the feedstock for the bacteria, transforming it into a growth medium. The resulting bacterial biomass, known as Celium, undergoes a tanning and finishing process similar to that of leather, yielding a durable material.


Mycelium textiles

Mycelium textiles start with a chosen
substrate Substrate may refer to: Physical layers *Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached ** Substrate (aquatic environment), the earthy material that exi ...
inoculated with fungal spores or mycelium culture. In a controlled environment, the mycelium grows throughout the substrate, forming a dense network of fibers. Once fully colonized, it's shaped and dried to create the desired form, undergoing additional treatments for properties like density or surface finish. Mycelium textiles are a sustainable alternative to traditional textiles, made from the root structure of fungi. Mycelium, the vegetative part of fungi, can be grown into various shapes and forms, including textiles. These textiles are eco-friendly, biodegradable, and can be engineered to possess desired properties like flexibility, durability, and water resistance. It has been stated that this material is leathery.


Biomedical applications


Biotextile scaffolds for tissue regeneration

The development of a collagen biotextile scaffold for aiding in the healing process of large deep burn wounds has been achieved by researchers at UC Davis. This scaffold, utilizing a specially engineered biomaterial, has demonstrated efficacy in promoting the formation of new blood vessels and reducing complications associated with severe burns. The study highlights the scaffold's ability to accelerate wound healing in mouse models and mitigate burn-related complications such as fluid loss and infection. Through testing different scaffold types, the research team observed that the combined treatment loaded with endothelial cells exhibited the highest wound healing rate.


Biotextile meshes

In the new paradigm of
tissue engineering Tissue engineering is a biomedical engineering discipline that uses a combination of cells, engineering, materials methods, and suitable biochemical and physicochemical factors to restore, maintain, improve, or replace different types of biolo ...
, professionals are trying to develop new textiles so that the body can form new tissue around these devices so it’s not relying solely on synthetic foreign implanted material. Graduate student Jessica Gluck has demonstrated that viable and functioning liver cells can be grown on textile scaffolds.


Environment and health impacts

The textile industry is one of the largest polluters of water and agricultural lands. This industry has caused numerous negative impacts on the environment as well as on the health of humans and ecosystems. Water pollution due to the discharge of wastewater containing textile dyes is the biggest environmental and ecological concerns due to the textile industry. There are several health concerns due to the discharge of wastewater contaminating with textile dyes such as respiratory problems, skin irritation, allergic reactions, and cancer. Biotextiles such as nettle and hemp denim are starting to be used as a replacement to use for synthetic textiles within the textile industry to try and prevent these negative environmental and health impacts.


Environmental impacts

There are several negative environmental impacts due to the modern day textile industry such as the discharge of textile dyes and pigments into wastewater, greenhouse gas emissions from production, energy and resource intensive production, and large amounts of landfill waste. Water pollution is the greatest environment concern since pigments and textile dyes do not naturally
biodegrade Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegradati ...
over time, which causes direct health concerns for both humans and ecosystem wildlife.


Degradation of materials

One of the biggest concerns of the modern day textile industry is that synthetic textiles do not biodegrade over time. Approximately 700,000 tons of dyes are being used in the textile industry every year. 10 to 15 percent of the dyes that are used during clothing production remain unfixed dyes. These dyes and pigments contaminate wastewater and discharge into local water bodies. Approximately 20 percent of wastewater produced globally is from the textile industry. Textile dyes degrade the aesthetic quality of these local water bodies and prevent sunlight from penetrating through the surface water. These dyes harm aquatic ecosystems since water pollution impairs photosynthesis and leads to a hypoxic environment unable to support life. Textile dyes contamination also harm humans since the toxins within these dyes can
bioaccumulate Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance faster than it can be lost or eliminated by catabolism and excretion. Th ...
and
biomagnify Biomagnification, also known as bioamplification or biological magnification, is the increase in concentration of a substance, e.g a pesticide, in the tissues of organisms at successively higher levels in a food chain. This increase can occur a ...
throughout the food chain, causing health concerns to species at the top of the food chain such as humans.  The application of bacterial isolates offers a promising solution to improve water quality in dye contaminated marine environments. Bacterial isolates degrade and remove textile dyes from wastewater through several methods, including biodegradation and
biosorption Biosorption is a physiochemical process that occurs naturally in certain biomass which allows it to passively concentrate and bind contaminants onto its cellular structure. Biosorption can be defined as the ability of biological materials to accumu ...
of dyes. They have the ability to biodegrade complex dye molecules into simple one through enzymatic reactions. Bacterial isolates break down the dye molecules by reducing their color and toxicity, which improves ecosystems. There are many advantages to biodegradation, including a high dye removal efficiency, low cost, and the fact that many
microorganisms A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from antiquity, with an early attestation in ...
such as bacteria, fungi, algae and enzymes can be used. However, the disadvantages are that this process requires a favorable environment for these microorganisms to grow, it generates biological sludge and is a slow process. Bacterial isolates can also
adsorb Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. This process creates a film of the ''adsorbate'' on the surface of the ''adsorbent''. This process differs from absorption, in which ...
complex dye molecules onto the surface of their cells. This adsorption process involves the physical binding of dye molecules to bacterial cell walls, and then the removal of these isolates from wastewater. The advantages of this process are that it has a high dye removal efficiency and a short reaction time. There are disadvantages as well since this processes is not applicable to all types of dyes and it generates a toxic waste product.


Closed-loop recycling

There are several other harmful environmental impact from synthetic textile production, including large amount of greenhouse gas emissions, high energy consumption and landfill waste. A typical textile mill consumes approximately 1.6 million liters of water to produce 8,000 kilograms of fabric. This is a worldwide problem since the textile industry contributes to about 10 percent of global greenhouse gas emissions. During 2016 alone, only 1 percent of the 180,000 tons of textile waste produced was recycled into new clothes. The remaining old textile fibers ended up in a landfill as waste. One solution that is currently being implemented within the textile industry to combat these issues is a
closed loop recycling Closed-loop recycling is the process by which a product or material can be used and then turned into a new product (or converted back to raw material) indefinitely without losing its properties during the recycling process. By reducing the produ ...
system. In the context of the textile industry, closed loop recycling involves collecting used textiles, processing them through various mechanical, chemical or biological recycling methods to turn used, worn down textiles into new textiles. Within a closed loop recycling system, textiles can either be recycled into a similar product, upcycled into a new, higher quality product, or downcycled into a new, lower quality product. This approach reduces waste, conserves resources, and minimizes the environmental impact of textile production by promoting a circular economy where materials are recycled and reused in a continuous, closed loop. As demonstrated in the figure, the enzyme groups
cellulase Cellulase (; systematic name 4-β-D-glucan 4-glucanohydrolase) is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis, the decomposition of cellulose and of some related polysaccharides: : Endo ...
, PETase, and
keratinase Keratinases are proteolytic enzymes that digest keratin. They hold industrial promise, as they can turn keratin-rich farm waste such as feather meal into more digestible fragments. History They were initially classified as 'proteinases of unk ...
are used within the closed recycling loop to break down old textiles such as polyester and nylon into
amino acids Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the Proteinogenic amino acid, 22 α-amino acids incorporated into p ...
,
glucose Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae d ...
, or synthetic
monomer A monomer ( ; ''mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or two- or three-dimensional network in a process called polymerization. Classification Chemis ...
building blocks. These monomers then undergo chemical
polymerization In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many fo ...
and are combined to create high quality
polylactic acid Polylactic acid, also known as poly(lactic acid) or polylactide (PLA), is a plastic material. As a thermoplastic polyester (or polyhydroxyalkanoate) it has the backbone formula or . PLA is formally obtained by condensation of lactic acid with ...
(PLA),
polyhydroxyalkanoates Polyhydroxyalkanoates or PHAs are polyesters produced in nature by numerous microorganisms, including through bacterial fermentation of sugars or lipids. When produced by bacteria they serve as both a source of energy and as a carbon store. Mor ...
(PHAs), silk, and bacterial cellulose polymers. Afterwards, these synthesized polymers are used to create man made, biodegradable fibers, which are then used to make new, biodegradable textiles. These textiles are used until their become worn down and are depolymerized to continue the closed recycling loop.


Sustainable biotextiles

Biotextiles are used as an alternative to synthetic textiles to prevent and combat the excess amounts of water and waste pollution from the textile industry. Large brands such as Nike, Adidas, Hermes and Stella McCartney are starting to use biotextiles for some of their fashion collections. One solution created by sustainable textile companies such as Pangaia and Agraloop is denim made out of nettle and hemp plants. Nettle plants are a renewable, biodegradable resource that can be used to design nettle denim by mixing organic cotton and Himalayan nettle. Hemp is another plant that is being looked into as an alternative denim material by these two companies since it is more durable and only consumes about a tenth of the water needed for cotton. The company Collina Strada is developing another biotextile solution called rose sylk. Rose sylk is an organic, biodegradable cellulose fiber that is derived from the natural waste of rose stems and bushes. Collina Strada promotes upcycling and reuse of old textiles by using factories to turn Ghana’s textile waste materials into insulation for coats and houses. A third solution involves clothing made from a pineapple based leather alternative, which is currently being used by major brands such as Nike, Hugo Boss and H&M. This pineapple leather alternative is made from cellulose fibers extracted from pineapple leaves and stalks. The use of agriculture pineapple waste instead of traditional leather has prevented approximately 264 tons of carbon dioxide from being emitted into the atmosphere, reducing greenhouse gas emissions.


Health impacts

There are several negative health impacts due to the discharge of wastewater containing textile dyes into local water bodies. These health issues include respiratory problems, skin irritation, allergic reactions, and cancer. Some of the respiratory problems that textile dyes cause are coughing, wheezing, asthma, and sneezing. Textile dye contamination causes skin irritation and allergic reaction symptoms such as itchy and watery eyes, sore eyes, an irritated and blocked nose and sniffling. Additionally, wastewater effluent containing both textile dyes and trace metals can cause long term health issues such as severe skin irritation,
dermatitis Dermatitis is a term used for different types of skin inflammation, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened ...
, skin ulcerations, and even cancer.


Biocompatibility

Biocompatibility of textiles with the human body is of utmost importance when analyzing how both synthetic and biotextiles affect human health. The materials used to create textiles need to be compatible with human bodies and other animals to avoid negative health impacts from happening to these organisms. Synthetic textiles cause many negative health effects on both humans and ecosystem wildlife due to the fact that they persist in the environment and do not biodegrade over time. Biotextiles, on the other hand, do not cause any known negative health concerns to humans or animals since they are produced with naturally occurring biological sources that can easily biodegrade over time.


See also

*
Technical textiles Technical textiles are a category of textiles specifically engineered and manufactured to serve functional purposes beyond traditional apparel and home furnishing applications. These textiles are designed with specific performance characteristic ...
*
Biomaterials A biomaterial is a substance that has been engineered to interact with biological systems for a medical purpose – either a therapeutic (treat, augment, repair, or replace a tissue function of the body) or a diagnostic one. The corresponding f ...
* Mycelium-based materials *
Textiles Textile is an Hyponymy and hypernymy, umbrella term that includes various Fiber, fiber-based materials, including fibers, yarns, Staple (textiles)#Filament fiber, filaments, Thread (yarn), threads, and different types of #Fabric, fabric. ...


References

{{Reflist Biological engineering Textiles