- Application of medical materials
- The application of tissue engineering
- Application of burn
- Beauty application
Collagen is a kind of white, opaque, branchless fibrous protein, which mainly exists in skin, bone, cartilage, teeth, tendons, ligaments and blood vessels of animals. It is an extremely important structural protein of connective tissue, and plays a role in supporting organs and protecting the body. In recent years, with the development of collagen extraction technology and in-depth research on its structure and properties, the biological function of collagen hydrolysates and polypeptides has gradually been widely recognized. The research and application of collagen has become a research hotspot in medicine, food, cosmetics and other industries.
Collagen is a natural protein of the body. It has great affinity for protein molecules on the skin surface, weak antigenicity, good biocompatibility and biodegradation safety. It can be degraded and absorbed, and has good adhesion. The surgical suture made of collagen not only has the same high strength as natural silk, but also has the absorbability. When used, it has the excellent platelet aggregation performance, good hemostatic effect, good smoothness and elasticity. The suture junction is not loose, the body tissue is not damaged during operation, and it has good adhesion to the wound. Under normal circumstances, only a short time of compression can achieve satisfactory hemostatic effect. So collagen can be made into powder, flat and spongy hemostatic. At the same time, the use of synthetic materials or collagen in plasma substitutes, artificial skin, artificial blood vessels, bone repair and artificial bone and immobilized enzyme carriers are very extensive research and application.
Collagen has a variety of reactive groups on its molecular peptide chain, such as hydroxyl, carboxyl and amino groups, which are easy to absorb and bind a variety of enzymes and cells to achieve immobilization. It has the characteristics of good affinity with enzymes and cells and strong adaptability. In addition, collagen is easy to process and form, so purified collagen can be made into many different forms of materials, such as membrane, tape, sheet, sponge, beads, etc., but the application of membrane form is most reported. In addition to biodegradability, tissue absorbability, biocompatibility and weak antigenicity, collagen membrane is mainly used in biomedicine. It also has the following characteristics: strong hydrophilicity, high tensile strength, derma-like morphology and structure, and good permeability to water and air. Bioplasticity determined by high tensile strength and low ductility; With many functional groups, it can be crosslinked appropriately to control its biodegradation rate. Adjustable solubility (swelling); It has synergistic effect when used with other bioactive components. Can interact with drugs; Cross-linked or enzymatic treatment of determinating peptides can reduce antigenicity, can isolate microorganisms, have physiological activities, such as blood coagulation and other advantages.
The clinical application forms are aqueous solution, gel, granule, sponge and film. Similarly, these shapes can be used for slow release of drugs. The slow release applications of collagen drugs that have been approved for market and are under development are mostly focused on anti-infection and glaucoma treatment in ophthalmology, local treatment in trauma and infection control in wound repair, cervical dysplasia in gynecology and local anesthesia in surgery, etc.
Widely distributed in all tissues of human body, collagen is an important component in all tissues and constitutes the extracellular matrix (ECM), which is a natural tissue scaffold material. From the perspective of clinical application, collagen has been used to make a variety of tissue engineering scaffolds, such as skin, bone tissue, trachea and blood vessel scaffolds. However, collagen itself can be divided into two categories, namely scaffolds made of pure collagen and composite scaffolds made of other components. Pure collagen tissue engineering scaffolds have the advantages of good biocompatibility, easy processing, plasticity, and can promote cell adhesion and proliferation, but there are also deficiencies such as poor mechanical properties of collagen, difficult to shape in water, and unable to support tissue reconstruction. Secondly, the new tissue at the repair site will produce a variety of enzymes, which will hydrolyze collagen and lead to the disintegration of scaffolds, which can be improved by cross-linking or compound. Biomaterials based on collagen have been successfully used in tissue engineering products such as artificial skin, artificial bone, cartilage grafts and nerve catheters. Cartilage defects have been repaired using collagen gels embedded in chondrocytes and attempts have been made to attach epithelial, endothelial, and corneal cells to collagen sponges to fit corneal tissue. Others combine stem cells from autogenous mesenchymal cells with collagen gel to make tendons for posttendinous repair.
A tissue-engineered artificial skin drug sustained-release adhesive composed of dermis and epithelium with collagen as the matrix is widely used in drug delivery systems with collagen as the main component, which can shape collagen aqueous solution into various forms of drug delivery systems. Examples include collagen protectors for ophthalmology, collagen sponges for burns or trauma, particles for protein delivery, gel forms of collagen, regulatory materials for drug delivery through the skin, and nanoparticles for gene transmission. In addition, it can also be used as substrate for tissue engineering including cell culture system, scaffold material for artificial blood vessels and valves, etc.
Autologous skin grafts have been the global standard for treating second - and third-degree burns. However, for patients with severe burns, the lack of suitable skin grafts has become the most serious problem. Some people have used bioengineering techniques to grow baby skin tissue from baby skin cells. Burns heal in varying degrees within 3 weeks to 18 months, and the newly grown skin shows little hypertrophy and resistance. Others used synthetic poly-DL-lactate-glycolic acid (PLGA) and natural collagen to grow three-dimensional human skin fibroblasts, showing that: Cells grew faster on the synthetic mesh and grew almost simultaneously inside and outside, and the proliferating cells and secreted extracellular matrix were more uniform. When the fibers were inserted into the back of a dermal rat, dermal tissue grew after 2 weeks, and epithelial tissue grew after 4 weeks.
Collagen is extracted from animal skin, skin in addition to collagen also contains hyaluronic acid, chondroitin sulfate and other proteoglycan, they contain a large number of polar groups, is a moisturizing factor, and has the effect of preventing tyrosine in the skin to transform into melanin, so collagen has natural moisturizing, whitening, anti-wrinkle, freckle and other functions, can be widely used in beauty products. Collagen's chemical composition and structure make it the foundation of beauty. Collagen has a similar structure to human skin collagen. It is a non-water-soluble fibrous protein containing sugar. Its molecules are rich in a large number of amino acids and hydrophilic groups, and it has certain surface activity and good compatibility. At 70% relative humidity, it can retain 45% of its own weight. Tests have shown that a pure solution of 0.01% collagen can form a good water-retaining layer, providing all the moisture the skin needs.
With the increase of age, the synthetic ability of fibroblast decreases. If the skin lacks collagen, the collagen fibers will be co-solidified, resulting in the reduction of intercellular mucoglycans. The skin will lose its softness, elasticity and luster, resulting in aging. When it is used as an active substance in cosmetics, the latter can spread to the deep layer of the skin. The tyrosine it contains competes with the tyrosine in the skin and binds to the catalytic center of tyrosinase, thus inhibiting the production of melanin, enhancing the activity of collagen in the skin, maintaining the moisture of the stratum corneum and the integrity of the fiber structure, and promoting the metabolism of the skin tissue. It has good moisturizing and moisturizing effect on the skin. In the early 1970s, bovine collagen for injection was first introduced in the United States to remove spots and wrinkles and repair scars.
Post time: Jan-04-2023