What raw material is collagen made of and what is its function?

Animal tissues from livestock and poultry are the main way for people to obtain natural collagen and collagen peptides.

However, due to related animal diseases and certain religious beliefs, people have restricted the use of collagen in terrestrial mammals and their products, and now they are gradually turning to marine life for development.

Collagen is a biopolymer, the main component of animal connective tissue, and the most abundant and widely distributed functional protein in mammals, accounting for 25% ~ 30% of the total in protein, and even more than 80% in some organisms.

Application of collagen:

1, biomedical materials

Collagen is the natural protein of human body, which has high affinity for protein molecules on the skin surface, weak antigenicity, good biocompatibility and biodegradability, biodegradable absorption and good adhesion.

Surgical suture made of collagen not only has the same high strength as natural silk, but also has absorbency. When used, it not only has excellent platelet aggregation performance and good hemostasis effect, but also has good smoothness and elasticity. Suture knot is not easy to loosen, and it is not easy to damage body tissue during operation. It has good adhesion to the wound surface. Generally, it only takes a short period of compression to achieve satisfactory hemostasis.

Therefore, collagen can be made into powder, flat and sponge hemostatic agents. At the same time, synthetic materials or collagen are widely used in the research and application of plasma substitutes, artificial skin, artificial blood vessels, bone repair, artificial bone and immobilized enzyme carriers.

2, tissue engineering

Because collagen is widely distributed in human tissues, it is an important component in all tissues and constitutes extracellular matrix (ECM). Its nature is a natural tissue scaffold material.

From the point of clinical application, people use collagen to make various tissue engineering scaffolds, such as skin, bone tissue, trachea and blood vessel scaffolds.

However, there are two kinds of collagen itself, namely, scaffolds made of pure collagen and composite scaffolds compounded with other components.

Pure collagen tissue engineering scaffold has the advantages of good biocompatibility, easy processing, strong plasticity, and can promote cell adhesion and proliferation, but it also has some shortcomings such as poor mechanical properties of collagen, difficulty in forming in water and inability to support tissue reconstruction.

Secondly, the new tissue in the repair site will produce various enzymes, which will hydrolyze collagen and lead to the disintegration of the scaffold, and cross-linking or recombination can improve and enhance it.

Collagen-based biomaterials have been successfully applied to tissue engineering products such as artificial skin, artificial bone, cartilage transplantation and nerve conduit.

Some people use collagen gel embedded in chondrocytes to repair cartilage defects, and try to attach epithelium, endothelium and corneal cells to collagen sponge to adapt to corneal tissue.

Others mixed stem cells of autologous mesenchymal cells with collagen gel to make tendons, which were used after tendon repair.

Tissue-engineered artificial skin drug slow-release gel composed of collagen as matrix and epithelial components 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.

Such as collagen protectants in ophthalmology, collagen sponges used in burns or wounds, protein delivery particles, collagen in gel form, regulatory materials for transdermal drug delivery and nanoparticles for gene delivery.

In addition, it can also be used as a matrix for tissue engineering, including cell culture systems, scaffold materials for artificial blood vessels and valves, etc.

Step 3 burn

Autologous skin transplantation has always been the global standard method for the treatment of second and third degree burns. However, for severely burned patients, the lack of suitable transplantable skin has become the most serious problem.

Some people use bioengineering technology to cultivate baby skin tissue through baby skin cells. This kind of collagen tissue can cure different degrees of burns within three weeks 18 months, without autologous transplantation, and the newly grown skin rarely appears hypertrophy, hyperplasia and resistance.

Others use synthetic poly -DL- lactic-glycolic acid (PLGA) and natural collagen to culture three-dimensional human skin fibroblasts.

The results show that the cells grow faster on the synthetic net, the inside and outside grow almost synchronously, and the proliferating cells and secreted extracellular matrix are more uniform. After the fiber was implanted into the back of skinless mice, dermal tissue grew after 2 weeks and epithelial tissue grew after 4 weeks.

4. Beauty

Collagen is extracted from animal skin. In addition to collagen, skin also contains proteoglycans such as hyaluronic acid and chondroitin sulfate, which contain a large number of polar groups and are moisturizing factors, which can prevent tyrosine in the skin from transforming into melanin. Therefore, collagen has the functions of natural moisturizing, whitening, anti-wrinkle and freckle removal, and can be widely used in beauty products.

The chemical composition and structure of collagen give it a beautiful foundation. Collagen is similar to human skin collagen in structure, and it is a kind of water-insoluble fibrous sugar-containing protein. Its molecules are rich in amino acids and hydrophilic groups, and have certain surface activity and good compatibility. At the same time, because its molecules contain a large number of hydroxyl groups, it has a quite good moisturizing effect.

When the relative humidity is 70%, it can still keep 45% of its own weight of water. Experiments show that 0.0 1% collagen pure liquid can form a good water-retaining layer and supply all the water needed by the skin.

With the increase of age, the synthetic ability of fibroblasts decreased. If the skin lacks collagen, collagen fibers will combine and solidify, which will reduce intercellular mucopolysaccharides, and the skin will lose its softness, elasticity and luster, resulting in aging. At the same time, dermal fibers will break, fat will shrink, sweat glands and sebaceous glands will decrease, resulting in a series of aging phenomena such as skin spots and wrinkles.

When it is used as an active substance in cosmetics, the latter can spread to the deep skin, and the tyrosine contained in it competes with the tyrosine in the skin and combines with the catalytic center of tyrosinase.

So as to inhibit the generation of melanin, enhance the activity of collagen in the skin, maintain the integrity of moisture and fiber structure in the stratum corneum, promote the metabolism of skin tissues, and have good moisturizing, anti-wrinkle and beauty effects on the skin.

As early as the early 1970s, the United States took the lead in introducing bovine collagen for injection to remove spots, wrinkles and scars.

However, in cosmetics, it is usually required that the molecular weight is below 2KD to allow hydrolyzed collagen to penetrate into the skin. Hair care cosmetics should not only require hydrolyzed collagen to have moisture retention, but also have certain film-forming properties, so the molecular weight of hydrolyzed collagen will be higher.

5. food

Collagen can also be used in food. As early as the12nd century, St.Hilde-gard of Bingen described calf cartilage soup as a medicine for treating joint pain. For a long time, some products containing collagen have been considered to be very beneficial to joints.

Because it has some edible properties: food-grade food is usually white in appearance, soft in taste, light in taste and easy to digest. It can reduce triglycerides and cholesterol in the blood and increase some essential trace elements in the body to keep them in a relatively normal range. It is an ideal food for reducing blood fat.

In addition, studies show that collagen helps to eliminate aluminum in the body, reduce the accumulation of aluminum in the body, reduce the harm of aluminum to the human body, and promote the growth of nails and hair to a certain extent. Type ⅱ collagen is the main protein in articular cartilage, so it is a potential autoantigen.

Oral administration can induce immune tolerance of T cells, thus inhibiting autoimmune diseases mediated by T cells.

Collagen polypeptide is a product with high digestibility and molecular weight of about 2000 ~ 30000, which is made from collagen or gelatin by protease degradation, but it does not have the gel properties of gelatin. Collagen sold in the market is mostly collagen polypeptide.

Some characteristics of collagen make it a functional substance and nutrient component in many foods, and it has incomparable advantages over other substitute materials:

The helical structure and crystal region of collagen macromolecules make it have certain thermal stability; The natural and compact fiber structure of collagen makes collagen materials show strong toughness and strength, which is suitable for preparing film materials.

Because the molecular chain of collagen contains a large number of hydrophilic groups, it has a strong ability to combine with water, which makes collagen can be used as filler and gel in food. Collagen will swell in acidic and alkaline media, and this property is also applied to the processing technology of preparing collagen-based materials.

Collagen powder can be directly added to meat products, which affects the tenderness of meat and the texture of muscle after cooking. Studies have shown that collagen is very important for the formation of raw meat and cooked meat. The higher the collagen content, the harder the meat quality.

For example, the tenderness of fish is considered to be related to the degradation of type V collagen, and the breakage of collagen fibers around cells caused by the destruction of peptide bonds is considered to be the main reason for muscle tenderness.

By destroying the hydrogen bonds in collagen molecules and the original tight supercoiled structure, gelatin with smaller molecules and looser structure can be formed, which can not only improve the tenderness of meat, but also improve its use value, make it have good quality, increase protein content, good taste and good nutrition.

Japan has also developed new condiments and sake with animal collagen hydrolyzed by collagenase, which not only has special flavor, but also can supplement some amino acids.

With the increasing proportion of sausage products in meat products, there is a serious shortage of natural casing products.

Researchers are committed to the development of substitutes. Collagen casing is a nutritious and high-protein substance with collagen as the main component. During heat treatment, with the evaporation and dissolution of water and oil, the shrinkage rate of collagen is almost the same as that of meat food, but other edible packaging materials have not found this property.

In addition, collagen itself has the functions of immobilized enzyme and antioxidation, which can improve the flavor and quality of food. Product stress is directly proportional to collagen content, but should become inversely proportional.

Extended data:

Classification of collagen pairs:

Collagen is a family of proteins. At present, at least 30 genes encoding collagen chains have been found, which can form more than 16 collagen molecules.

According to its structure, it can be divided into fibrous collagen, basement membrane collagen, microfibril collagen, anchor collagen, hexagonal reticular collagen, non-fibrous collagen, transmembrane collagen and so on.

According to their distribution and functional characteristics in the body, collagen can be divided into interstitial collagen, basement membrane collagen and cell peripheral collagen.

Interstitial collagen molecules account for the vast majority of whole body collagen, including type ⅰ, ⅱ and ⅲ collagen. Type I collagen is mainly distributed in skin, tendons and other tissues, and it is also the most abundant aquatic product processing waste (skin, bone and scale) in protein, accounting for about 80-90% of the total collagen content, and is widely used in medicine.

One of the most remarkable characteristics of fish collagen I is its low thermal stability and species specificity.

Type ⅱ collagen is produced by chondrocytes; Collagen in basement membrane usually refers to type ⅳ collagen, which is mainly distributed in basement membrane.

Collagen in peripheral cells usually refers to type ⅴ collagen, which is rich in connective tissue.

Collagen can be divided into two groups according to their functions. The first type is fibroblast collagen, including collagen types I, II, III, VIII, VIII, VIII and VIII. The rest is the second group, non-fibrotic collagen.

The α chain of non-fibrotic collagen contains both triple helix domain (COL) and non-triple helix domain (NC), in which fibrotic collagen accounts for about 90% of the total collagen.

Baidu encyclopedia _ collagen