Seafood shells, such as crab claws (here), contain a valuable material called chitin. Researchers turned chitin into a new type of medical dressing that can promote wound healing.

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A new medical dressing helps skin wounds heal faster. Its innovative ingredients are the structural materials of marine animal and insect bones, scales and shells.

This polymer is called chitin (KY-tin), which is the most abundant material in nature after plant cellulose. As a natural waste produced by seafood processors, its cost is very low.

Zhou Jinping is a chemist at Wuhan University in China. He is part of the team that creates new wound dressings. His team knows that chitin can help fight bacteria, and it has sometimes been shown to promote wound healing. These researchers want to know whether using it to make gauze will speed up wound healing faster than traditional cellulose gauze.

To test this, they used different chitin fibers to make dressings and tested them on mice. Then they observed the wound under a microscope. The best chitin gauze can accelerate the growth of new skin cells and blood vessels.

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The treated wound also formed stronger collagen fibers. Collagen is a type of protein that is the main component of our bones, muscles, skin and other body parts. Here, it helps to strengthen and smooth the regenerated skin. Because chitin is good at fighting bacteria, Zhou's team suspects that this new dressing can also reduce the risk of infection.

The group described its new chitin gauze in the ACS Applied Bio Materials published in January 2021.

The backbone of chitin is a string of molecules made of glucose (a simple sugar). Each glucose in this string has been acetylated (Ah-SEE-tyl-ay-tud). This means that each atom carries a group of atoms, including one oxygen, two carbons, and three hydrogens (including the fourth hydrogen connected to nitrogen). These acetyl groups make chitin waterproof. Removing some of it makes the chitin easier to use.

For their new gauze, the researchers grind the shells of crabs, shrimps and lobsters. Then they soaked the gravel in a special solvent for 12 hours. Heating, bleaching and other processes turn the chitin-rich solution into moist fibers. These chemical treatments can remove more than half of the acetyl groups. Zhou's team then made fibers with varying amounts of acetylated glucose.

A special machine spins these fibers into fabrics. Thicken the fabric between the two hot steel plates to make it look like gauze that people have long used as wound dressings or bandages. No need to knit or stitch.

To test how much acetylation of the chitin in the fiber is the best, the researchers used 18 rats. Each animal has four round wounds with a diameter of 1 cm (0.4 inches). Different chitin gauze is applied to each. The other group of rats received standard cellulose gauze. Another person received a slightly different type of gauze. Every three days, the researchers measured how much healing occurred.

Dressings made of chitin containing 71% acetylated glucose work best. This is particularly easy to see on the third and sixth day. The difference is small, but still significant after 12 days.

The small wounds in these tests will heal on their own. The new chitin dressing just speeds up the process. This is good, said biologist Mark Meselli. He works at South Dakota State University in Brookings. However, he hopes to see chitin dressings tested on larger or harder sores.

"The wounds of diabetic patients are difficult to heal," Messerli said. "This is why it would be great to test new dressings on diabetic mice." He pointed out that even in healthy elderly, some wounds may take more than a year to heal. A new dressing to repair these sores "will be a big deal."

Another advantage of chitin gauze: the body can break it down. For standard cellulose gauze, this is not the case. The surgeon puts a dressing on the body to prevent internal bleeding caused by a serious injury. Messerli said it would be very helpful to avoid a second surgery to remove the gauze later.

Francisco Goycoolea is a chemist at the University of Leeds in the United Kingdom. He likes to easily select the amount of acetylation through the new process. He said that this amount "is very important for the physical, chemical and biological properties of chitin." Like Messerli, he believes that improving the healing of difficult wounds will be a major step forward.

In his laboratory, Goycoolea mainly uses chitosan, another form of chitin. (It has less acetylated glucose.) His team has been studying its prospects in agriculture as part of a better pesticide for the environment. They are also studying whether tiny capsules of this material can provide treatment for diseased organs. Goycoolea pointed out, "The application range of chitin is indeed very wide."

This is one of a series that presents technology and innovation news with the generous support of the Lemelson Foundation.

Activation: Turn on (in biology), just like a gene or chemical reaction.

Agriculture: Plants, animals, or fungi that grow for human needs, including food, fuel, chemicals, and medicines.

Algae: Single-celled organisms, once thought of as plants (they are not). As aquatic organisms, they grow in water. Like green plants, they rely on sunlight to make food.

Application: The specific use or function of something.

Atom: The basic unit of a chemical element. An atom consists of a dense nucleus that contains positively charged protons and uncharged neutrons. The nucleus is surrounded by a cloud of negatively charged electrons.

Bacteria: (singular: bacteria) single-celled organisms. They inhabit almost anywhere on the earth, from the bottom of the sea to the interior of other organisms (such as plants and animals). Bacteria is one of the three areas of life on earth.

Biologist: A scientist engaged in biological research.

Blood vessels: Tubular structures that carry blood through tissues and organs.

Carbon: A chemical element with atomic number 6. It is the physical foundation of all life on earth. Carbon exists freely in the form of graphite and diamond. It is an important part of coal, limestone and petroleum, and can form a large number of molecules with chemical, biological and commercial significance through chemical self-combination. (In climate research) The term carbon is sometimes used almost interchangeably with carbon dioxide to indicate the potential impact of certain actions, products, policies, or processes on long-term atmospheric warming.

Cell: The smallest structural and functional unit of an organism. Usually too small to be seen with the naked eye, it consists of a water-like liquid surrounded by a membrane or wall. Depending on their size, animals are composed of thousands to trillions of cells. Most organisms, such as yeasts, molds, bacteria and some algae, consist of only one cell. (In telecommunications) A technology that relies on a large number of base stations to relay signals. Each base station only covers a small area, called a cell. Phones that rely on this system are usually called cell phones.

Cellulose: A fiber found in the cell wall of plants. It is formed by a chain of glucose molecules.

Chemical substance: A substance formed by combining (bonding) two or more atoms in a fixed ratio and structure. For example, when two hydrogen atoms combine with one oxygen atom, water is a chemical substance. Its chemical formula is H2O. Chemistry can also be used as an adjective to describe the properties of materials that are the result of various reactions between different compounds.

Chemistry: The field of science that deals with the composition, structure, and properties of substances and how they interact. Scientists use this knowledge to study unfamiliar substances, copy a large number of useful substances or design and create new useful substances. (Regarding compounds) Chemistry is also used as a term to refer to the formula of a compound, its production method, or some of its characteristics. People who work in this field are called chemists. (In social sciences) A ​​term for people's ability to cooperate, get along, and enjoy each other's company.

Chitin: A tough, translucent substance that is the main component of the exoskeleton of arthropods (such as insects). A carbohydrate, chitin, is also found in the cell walls of some fungi and algae.

Chronic: A condition that lasts for a long time, such as a disease (or its symptoms, including pain).

Collagen: A fibrous protein found in bones, cartilage, tendons and other connective tissues.

Colleague: A person who works with others; a colleague or team member.

Connective tissue: Certain cell groups attach to the body to form the boundaries and interfaces of many structures.

Contraction: Activate the muscle by connecting the filaments in the muscle cell. As a result, the muscles become more rigid. (Commercial) An agreement between two parties, such as the purchase or provision of certain services.

Development: appearing or forming naturally or through manual intervention (for example, through manufacturing).

Diabetes: A disease in which the body produces too little insulin hormone (called type 1 disease) or ignores too much insulin in the presence of insulin (called type 2 diabetes).

Diameter: The length of a straight line passing through the center of a circular or spherical object, starting from the edge on one side and ending on the edge on the other side.

Environment: The sum of all things that exist in an organism or process, and the conditions created by these things. The environment may refer to the weather and ecosystem in which certain animals live, or it may be temperature and humidity (or even the placement of objects near objects of interest).

Fabric: Any flexible material that is woven, knitted, or can be fused into a sheet by heating.

Fiber: Something that resembles a thread or filament in shape.

Fibroblast: A cell found in connective tissue; it produces and releases proteins that are important for wound healing.

Fruit: The reproductive organs of plants that contain seeds.

Gel: A viscous or viscous material that can flow like a viscous liquid.

Glucose: a monosaccharide, an important source of energy for living organisms. As a source of energy flowing in the blood, it is called "blood sugar." It is half of the molecule that makes up sugar (also called sucrose).

Hydrogen: the lightest element in the universe. As a gas, it is colorless, odorless and highly flammable. It is a component of many fuels, fats and chemicals that make up living tissue. It consists of a proton (as its nucleus) and is surrounded by an electron.

Infection: A disease that can spread from one organism to another. It is usually caused by some type of bacteria.

Inflammation: (adjective. Inflammation) The body's response to cell damage and obesity; it usually includes swelling, redness, heat, and pain. It is also a potential feature that leads to the development and deterioration of many diseases, especially heart disease and diabetes.

Insect: An arthropod that has six segmented legs and three body parts as adults: head, chest, and abdomen. There are thousands of insects, including bees, beetles, flies and moths.

Ocean: Related to the marine world or the environment.

Microscope: An instrument used to observe objects, such as bacteria or individual cells of plants or animals, which are too small to be seen with the naked eye.

Molecule: An electrically neutral group of atoms, representing as few compounds as possible. Molecules can be composed of a single type of atoms or different types of atoms. For example, oxygen in the air is composed of two oxygen atoms (O2), while water is composed of two hydrogen atoms and one oxygen atom (H2O).

Nitrogen: A colorless, odorless and inactive gaseous element, accounting for about 78% of the earth's atmosphere. Its scientific symbol is N. When fossil fuels are burned, nitrogen is released in the form of nitrogen oxides. It has two stable forms. Both have 14 protons in their nuclei. But one nucleus has 14 neutrons; the other has 15. For this reason, they are called 14 Nitrogen and 15 Nitrogen (or 14N and 15N) respectively.

Organ: (in biology) The parts of an organism that perform one or more specific functions. For example, the ovary is an organ that produces eggs, the brain is an organ that processes nerve signals, and the roots of plants are an organ that absorbs nutrients and water.

Oxygen: A gas that accounts for about 21% of the earth’s atmosphere. All animals and many microorganisms need oxygen to fuel their growth (and metabolism).

Particles: tiny amounts of things.

Pesticide: A mixture of chemicals or compounds used to kill insects, rodents or other organisms harmful to cultivated plants, pets or livestock; or harmful organisms infest homes, offices, farm buildings and other protected structures.

Physics: (adjective) A term for things that exist in the real world, as opposed to memory or imagination. It can also refer to material properties due to the size of the material and non-chemical interactions (such as when one block hits another block hard).

Proportion: The amount of a component relative to the other components in the mixture. For example, if there are 2 apples and 3 oranges in a bag, the ratio of apples to oranges in the bag is 2 to 3.

Protein: A compound composed of one or more long-chain amino acids. Protein is an important part of all living organisms. They form the basis of living cells, muscles, and tissues; they also work inside cells. Among the more widely known independent proteins are hemoglobin (in the blood) and antibodies (also in the blood) that try to fight infection. Drugs usually work by locking in proteins.

Range: The full range or distribution of something. For example, the range of a plant or animal is the area where it naturally exists. The degree to which (mathematics or measurement) the value may change. In addition, you can reach or perceive the distance of something.

Risk: The chance or mathematical possibility that something bad may happen. For example, exposure to radiation brings the risk of cancer. Or danger-or danger-itself. (Example: The cancer risks people face include radiation and drinking water contaminated with arsenic.)

Salt: A compound made by combining an acid with a base (in a reaction that also produces water). The ocean contains many different salts-collectively referred to as "sea salt". Ordinary table salt is made of sodium and chlorine.

Shell: usually a hard protective shell. It can cover mollusks or crustaceans (such as mussels or crabs), bird eggs, or other relatively soft tissues that need to be protected (such as tree nuts or peanuts).

Solution: A liquid in which a chemical substance is dissolved in another substance.

Solvent: A material (usually a liquid) used to dissolve some other material into a solution.

Tissue: Made up of cells, any of the different types of materials that make up animals, plants, or fungi. As a unit, cells in a tissue perform specific functions in a living organism. For example, different organs of the human body are usually composed of many different types of tissues.

Waste: Any material left over from biological or other systems that is of no value, so they can be disposed of as garbage or recycled for some new purposes.

Journals: C. He et al. The effect of acetylation degree of chitin non-woven fabric on promoting wound healing. ACS applies biological materials. roll. 4. January 11, 2021, page 1833. doi: 10.1021/acsabm.0c01536.

Periodicals: T. Limon et al. The chitosan coating reduces the infestation of Drosophila (Anastrephaobliqua) and the development of the fungus anthracnose in Manila mango. Journal of Food and Agricultural Sciences. November 4, 2020. doi: 10.1002/jsfa.10903

Periodicals: AK Kolonko et al. Chitosan nanocapsules loaded with capsaicin are used to deliver wtCFTR-mRNA to cystic fibrosis cell lines. biomedicine. Volume 8, September 20, 2020, page 364. doi: 10.3390/biomedicines8090364. Journal: MA Messerli et al. Construction and composition of a squid enclosure from Doryteuthis pealeii. Biological Bulletin. roll. 237, July 8, 2019. doi: 10.1086/704209.

Journals: M. Malerba and R. Cerana. The latest applications of chitin and chitosan-based polymers in plants. polymer. roll. 11. May 8, 2019, page 839. doi: 10.3390/polym11050839.

Silke Schmidt is a freelance science writer with a degree in biostatistics and journalism. She likes to report on the environment, engineering and medicine. She has two children and two places she calls home, Wisconsin and Germany.

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