Based on the material and application of dressings, this article divides wound dressings into natural materials, synthetic materials, medicinal dressings, and fixed dressings, and introduces their basic characteristics.
1 Natural materials
1.1 Plant-based dressings
Traditional cotton dressings in plant-based dressings, including cotton, gauze, bandages, etc., have the characteristics of excellent water absorption and thermal insulation, good heat resistance, and alkali resistance, and are still widely used in various types of wounds. application. However, after absorbing secretions, they often cause wound infection due to exudate contamination, and they are easy to stick to the wound when removing the dressing, so there are great defects in use. In order to solve the disadvantages of traditional dressings such as adhesion to wounds, non-isolation, poor heat preservation ability, hemostasis, and poor coagulability, various methods have been used to improve the performance of such dressings, such as impregnation, coating, and chemical or physical modification methods.
Custom hospital wound dressing supplier In order to improve cotton materials, people have also successfully made non-woven fabrics from plant materials. The fibers are evenly distributed, the capillary force is strong, and the hygroscopicity and softness are greatly improved, which is helpful to prevent infection. It can be used as a bandaging material alone or in combination with other materials. Seaweed bandages made from dried seaweed in the North Sea are treated with four times the moisture absorption capacity of cotton bandages and can effectively accelerate wound healing. Fucoidan produced from natural products of seaweed can be biodegraded relatively quickly in the human body. It is used for clinical treatment of visceral trauma and bleeding. It has the advantages of fast hemostasis, small tissue response, easy operation, etc. It can be an ideal substitute for gelatin sponges. 1].
1.2 Animal Dressings
The main use of animal dressings is to treat burns and skin grafts. The most ideal way to cover the wound is to transplant autologous skin, but for patients with large area burns (> 50% of body surface area), the autologous skin source is often insufficient, so skin culture is required, that is, the patient's own healthy skin fiber cells 2. Epidermal cells undergo epidermal culture and dermal culture in vitro. Due to the lack of autologous skin sources and the time required for skin culture, allogeneic skin is also an ideal wound cover. The source is mainly patient family members or other volunteers, but the main source is cadaver skin. An obvious advantage of allogeneic skin grafting is that it can be used as a test material to predict the possible outcome of autologous skin grafting.
Some people have studied the use of animal allogeneous skin instead of autologous or allogeneic skin transplantation. The results of applying cat, mouse, rabbit, chick and pigeon skin are disappointing, but pigskin transplantation has been successful. Pigskin and human skin are not the same under the microscope, but they are very similar in terms of weaving structure, adhesion, and collagen content. It can better adhere to the wound and reduce the evaporation and control of water in the body. The role of infection, and because the heterogeneous covering can stimulate the immune rejection mechanism is conducive to the sterilization of contaminated wounds. However, the mechanical properties of pigskin are poor, and it is easy to delaminate, which affects autogenous skin transplantation. Recently, there have been reports of using fish skin to treat burns and cuts . Fish skin is composed of the epidermal layer and the dermal layer. There is no subcutaneous fat layer and subcutaneous connective tissue, and there are no hair follicles and sweat glands of terrestrial mammals. The hair follicles and sweat glands of the latter are bacterial channels, so covering the wound with fish skin can achieve more Tight sealing effect.
In addition, the Custom hospital wound dressing factory also has dressings made from animal tissue derivatives, such as collagen dressings, fibrin dressings, animal hair dressings, and chitin dressings. Collagen is easy to isolate and purify in large quantities. Its immunogenicity and water vapor permeability can be adjusted. As a biological wound dressing, it has many unique properties, such as high affinity for cells, and can be used as a drug release medium. Deacetylated chitin is obtained by alkalizing the chitin extracted from crustacean shells. The sutures made from it can be absorbed by themselves after use without causing allergies and can accelerate wound healing. The artificial skin can accelerate wound healing, protect large areas of burns, and promote skin regeneration. The medical non-woven fabrics produced by it can be used in burn wounds and donor areas, not only covering and protecting the wounds. The effect, and low antigenicity .
1.3 Mineral dressings
Silicone dressings in mineral dressings are polymers composed of silicon and oxygen atoms combined by carbon and hydrogen bonds. They have stable physical and chemical properties, are insoluble in water, do not undergo chemical reactions after heating, and have a certain degree of viscosity. The commonly used silicone liquid in the clinic is an oily clear liquid, which is non-toxic, non-irritating and non-antigenic to human skin. Silicone and self-adhesive gels are used to make silicone film dressings (such as Xerox's scar enemy), which are used to treat or prevent burns and scars caused by trauma surgery. It has a significant effect. The mechanism of action may be to inhibit fibroblasts. Growth and collagen synthesis.
Chinese researchers have used our rich graphite resources to prepare a special carbon sanitary material with excellent adsorption and drainage properties, non-toxic, harmless and non-allergic, which can replace medical gauze after scientific preparation and special technology. It can be used to treat various traumas. It can effectively absorb the secretions and harmful substances on the external wounds of the human body, make the wounds dry and swollen, eliminate external conditions for bacterial reproduction and survival, and thus prevent wounds from irritating, ulcerating, and reducing. Complications after surgery have more obvious advantages than medical gauze .
2 synthetic materials
2.1 film type dressing
The film dressing is formed by coating a pressure-sensitive adhesive on one side of the biomedical film. The materials used to make films are mostly transparent elastomers, such as polyethylene, polyacrylonitrile, polycaprolactone, polylactic acid, polytetrafluoroethylene, plasticized PAC, polyurethane and silicone elastomers, among which polyurethane materials Optimally, the silicone elastomer has also achieved satisfactory results. The film-type dressing has almost no absorption performance, and its control of exudates depends on its transfer of water vapor, and the transfer speed depends on its molecular structure and thickness. The breathing rate of an ideal film dressing should be comparable to that of normal human skin.
2.2 Liquid dressing
Liquid dressings can be applied thinly on the skin as a protective layer or drug carrier by spraying, brushing or other methods, so they are also called spray coatings. Liquid dressings have two main advantages: First, they are suitable for wounds of any shape; second, they can be used under any conditions. Most of the materials used to make spray coatings in the early days were copolymers. Most of these copolymers were toxic to superficial blood vessels, so many of them were eliminated.
The instant medical liquid medical glue developed and produced in China, its composition is modified by the α cyanoacrylate homolog, has a special odor, is non-toxic to the human body, and has a tissue adhesion strength of 3.45 kg/cm, 1 cm 1 to 2 drops can be used for long wounds, and it is suitable for the adhesion of various wounds, surgical incisions, organ transplants, and cosmetic surgery. The use of medical glue instead of surgical suture, visceral adhesion can be maintained for 5 to 7 days, and the wound can be dissolved and absorbed after healing; epidermal adhesion can be maintained for 5 to 7 days. After healing, the medical glue forms a film and falls off without leaving scars.
2.3 Hydrocolloid dressings
Hydrocolloid dressings are composed of a polymerized substrate and a hydrocolloid mixture adhered to the substrate. The hydrocolloid mixture is mainly formed by mixing gelatin, pectin, and carboxymethyl cellulose, and during the mixing process The incorporation of liquid paraffin and rubber adhesives makes the dressing easier to adhere to the wound, but this dressing is much thicker than a film dressing. Hydrocolloid dressings have almost no ability to transport water vapor. It absorbs exudates through the hydrocolloid layer. The thickness of the gel layer determines its absorption capacity, but the gel layer can pollute after absorbing a large amount of exudate wound.
2.4 Hydrogel Dressings
Hydrogel dressings use hydrogel materials on permeable polymer pads. The presence of the polymer pad prevents dehydration and drying of the wound surface, while the hydrogel material has a partially hydrated structure that continuously absorbs wound exudate. Hydrogel dressings, like hydrocolloid dressings, have almost no ability to transfer water vapor. Its treatment of liquids is absorption. The hydrogel that absorbed the exudate does not contaminate the wound, so it is not necessary to change the dressing in about 5 to 7 days, but after a large amount of exudate is absorbed, the dressing can be separated from the wound due to the expansion of the colloid, which provides bacterial invasion and reproduction Opportunity, so the dressing should be adequately lashing. It is less tolerant of wounds than film dressings but more suitable than hydrocolloids.
2.5 Foam Dressing
The structure of foam dressings is porous, has a large absorption capacity for liquids, and can almost completely penetrate oxygen and carbon dioxide. At present, the most widely used materials for the preparation of foam dressings are polyurethane and polyvinyl alcohol foam. The treatment of wound exudates by their materials is controlled by a sponge-type water vapor transfer and absorption mechanism. Foam dressings can be made in a variety of thicknesses and have good protective functions for wounds. Adding drugs can also promote wound healing. But nowadays most foam dressings do not have pressure-sensitive adhesive and cannot be self-adhesive. Therefore, auxiliary banding materials are needed to fix it.
2.6 Alginate Dressings
The raw material for making alginate dressings is alginic acid extracted from seaweed. It is an insoluble polysaccharide similar to cellulose. It is converted into a calcium salt when making dressings. Alginate dressings are as soft as gauze, easy to fold, and easy to apply. They are also an ideal filler, but they treat wounds in a completely different way than gauze. Alginate has extremely strong absorbability, can absorb liquid equivalent to 20 times its own weight, can effectively control the leakage and extend the use time. When in contact with a wound, calcium ions in alginate can replace sodium ions in the wound exudate, thereby forming a stable network of gels on the surface of the wound and assisting blood coagulation. When changing such dressings, they can be removed with tweezers or washed with physiological saline according to the degree of stickiness .
3 medicinal dressings
In order to protect wounds and treat wounds more effectively, many dressings are added with pharmaceutical ingredients during use, thus becoming medicated dressings. The most common method for preparing medicinal dressings is dipping or coating. Common varieties include surgical disinfection dressings (such as chlorhexidine dressings), medicated ointment dressings (such as erythromycin dressings), and traditional Chinese medicine oil dressings (such as Ziyusan Butter gauze) and so on.
In recent years, new technologies in the formulation and other disciplines have also been widely used in the research and development of pharmaceutical dressings. For example, the microcapsule technology is used to disperse the drug in a non-toxic polymer to form a semi-enclosed dressing layer. This not only ensures a moist and sterile environment for the wound but also continuously releases the drug to accelerate the wound healing speed. The key to this kind of drug dressing is to use sterile liquid oligomeric urethane and drug solution (such as gentamicin, etc.) to disperse and embed the drug through the curing effect caused by ultraviolet radiation and make it contact with the wound. It can directly release drugs to the wound at a certain rate. There are also liquid adhesive tapes made of Chinese herbal medicine extracts and medical polymer materials, which are composed of a medicinal solution and a medicinal film. The medicinal solution has the effects of rapid pain relief, hemostasis, and anti-inflammatory. The two liquids are used in combination to form a waterproof, breathable, and flexible positioning drug film on the injured surface, which can stimulate the growth of new granulation under the film and accelerate tissue healing without affecting washing and showering. The role of wounds .
4.1 Adhesive materials
Adhesive materials used for fixing are adhesive bandages and gauze, adhesive bandages and gauze, acrylic tape and zinc oxide rubber cloth. Adhesive bandages and gauze are coated with a layer of adhesive (rubber, polyacrylic acid) on the fabric, non-woven fabric or plastic film to achieve the cohesive effect. Adhesive bandages are coated with a layer of natural rubber latex dispersed on the elastic bandage. They can stick together by themselves, but they will not stick to the skin or clothing.
4.2 Non-adhesive materials
Non-adhesive materials used for fixing are ordinary bandages, elastic bandages, etc. An elastic bandage is a knitted fabric made of latex products composed of pure cotton thread and special film. It has the characteristics of easy and fast operation, suitable dressing pressure, large elasticity and stretchability, no allergic reaction, good breathability, and beautiful and comfortable. Suitable for bandaging all over the body. Especially for heads, movable joints and other difficult to bandage parts, with good bandaging performance. When using, just choose different specifications according to the size and location of the wound, cut the required length and put it on.
In the past, gypsum bandages widely used in the treatment of bone injuries were generated from calcium sulfate gypsum (CaSO4 · 2H2O), which has the advantages of good plasticity, economical availability of materials, good breathability, and adsorption, but it has dry solid Slow, impermeable to X-rays, heavy and not waterproof. Medical polyurethane bandage is composed of a chemical substance and artificial fiber. It hardens when exposed to air and can be opened a few minutes before fixing. It has the advantages of easy use, fast hardening, load-bearing, X-ray transmission, breathability and water resistance, suitable for various parts Immobilization, especially in the limbs, is effective .www.china-medicaldressing.com