Collagen and Anti-Aging
Collagen is the substance that plays a supporting and elastic role in human skin. There are more than twenty different types of collagen in the skin, the most prominent of which are collagen type I and collagen type III, with collagen type I accounting for the highest percentage, reaching about 80% in adult skin.
Type I collagen has a coarse structure and mainly plays a supportive role, used to shape lines and maintain a certain strength and shape of the skin.
Type III collagen has the next highest content, it has a finer and softer structure, and mainly plays a certain elastic role in the skin, making the skin soft and flexible.
The ratio of type I to type III collagen in infants is about 1:1, while the ratio of type I to type III collagen in adults is about 4:1. This is why babies' skin is soft and elastic.
In adulthood, collagen in the skin decreases with age, and by the age of 40, the amount of collagen is only half of what it was at the age of 18. The skin loses its support and elasticity, and sagging and wrinkles appear.
Problems to be solved with collagen supplementation
Since collagen is so important and since collagen loss leads to aging, isn't it possible to supplement collagen to slow down aging? First of all there are two problems we have to solve:
1. The problem of transdermal absorption
Skin collagen exists mainly in the dermis, below the epidermis. Collagen is a large molecule, directly placed in skin care products used, basically will not be absorbed by the skin, can not reach the dermis, can not be utilized. So then came hydrolyzed collagen, which hydrolyzes collagen into smaller molecular fragments, making it possible for it to be absorbed by the skin.
2. Problems with the source of collagen
Collagen is generally of animal origin, more often derived from pigs or fish. However, on the one hand, collagen from pigs and fish is still very different from human collagen, and its structure and ratio are certainly not the most favorable to human skin. On the other hand, because the human body is born with the property of rejection, the use of other animal proteins in the human body may not be able to be utilized in light cases, or may cause serious allergies in heavy cases. So people thought of using humanized collagen, of course we can not go directly from the human body to extract the protein, but the gene coding fragments of human collagen, implanted into other microorganisms, through the growth of microorganisms, to produce the components of human collagen, that is, recombinant collagen.
Recombinant humanized collagen
The technology of recombinant collagen is not a new one; there have been many patents and papers on recombinant human collagen 20 years ago.
Technically, there are three types of recombinant collagen:.
1. Recombinant Human Collagen: Recombinant human collagen, prepared by DNA recombinant collagen technology, is designed and modified to encode amino acid sequences or fragments of specific genes, or combinations of such functional amino acid sequences and fragments. The gene coding sequence is less homologous to that of human collagen.
2. Recombinant Human Collagen: A complete sequence of genes expressing specific types of human collagen in eukaryotic cells prepared by recombinant DNA technology, structurally identical to human collagen, with a triple helix structure.
3. Recombinant Humanized Collagen: Partial amino acid sequence fragments encoded by human collagen type-specific genes prepared by DNA recombination technology, or combinations containing functional fragments of human collagen.
Currently, the third type, recombinant humanized collagen, which is more widely used in cosmetics, is a collagen fragment, somewhat similar to hydrolyzed collagen, with a small molecular weight, which can be absorbed by the skin, and is a more desirable cosmetic efficacy ingredients.
As long as we know the amino acid series sequencing of different types of collagen in the human body, we can synthesize the gene sequences by biological methods and then express them in specific microorganisms.
Structure of collagen in human skin
All proteins are formed from a series of amino acids linked together by peptide bonds, and collagen is no exception. Twenty different amino acids, arranged in combinations, form a wide variety of proteins and peptide chains in the human body. Some of these proteins and peptide chains, form the cytoskeleton, some are used to transport nutrients, some are used to catalyze the synthesis of substances and energy necessary for life activities, and some are used to transmit information ......
The amino acid arrangement of collagen has an obvious pattern, it will frequently appear GXY repeat structure, G stands for Glycine, X and Y stand for two other amino acids, the most common are proline and hydroxyproline.
Decide the order of amino acid arrangement and combination of genes, that is, DNA fragments, DNA, each ribose attached to a base, a total of four different bases A/T/G/C, different combinations of three bases, corresponding to a kind of amino acid, so that the twenty kinds of amino acids, have their own corresponding bases coding. A chain of DNA, then, corresponds to a chain of amino acids, that is, proteins or peptide chains.
Collagen is synthesized with specific genes, and there are more than thirty genes that have been identified that synthesize collagen, and they generate different types of collagen.
Proteins in microorganisms
Microbial cells also have DNA in them, and with DNA, peptide chains or proteins are produced.
Microorganisms produce proteins in two main ways, intracellular proteins, which are mainly used to form the cytoskeleton, and secreted proteins, which are produced inside the cell and then excreted outside the cell.
The amino acid sequence of microbial-generated proteins is determined by the relevant genes of the microorganisms and is different from that of human collagen.
Recombinant collagen and synthetic biology
Since microorganisms can produce corresponding proteins from DNA, if we have a method to change the DNA of microorganisms, then the proteins produced by microorganisms will also be changed; if we replace certain gene fragments of microorganisms with gene fragments corresponding to human collagen or collagen fragments, then we can get the corresponding collagen fragments that are the same as human collagen.
This idea is now realizable, and its method is synthetic biology.
The concept of synthetic biology first appeared in 1910, but was limited by the level of technology at that time did not get real development. With the development of recombinant DNA molecules, recombinant plasmids, and transgenic technology, DNA recombination technology became increasingly sophisticated, and with the development of gene sequencing technology, the construction of logical circuits using biological components was successfully practiced. It was around 2000 that the discipline really took shape.
The process of synthetic biology is divided into six main steps.
In the first step, a suitable technological route needs to be designed based on the final product.
In the second step, a suitable chassis cell is selected as the host cell for the production of the product.
In the third step, the metabolic pathway of the host cell is modified using DNA synthesis, gene editing and other techniques.
In the fourth step, the obtained host cell is screened and optimized to improve its tolerance and optimize the metabolic pathway.
In the fifth step, the metabolism of the host cells is utilized for mass production through fermentation engineering.
The sixth step is the recovery and purification of the product.
Synthetic biology is a very wide-ranging science, and the technologies it requires include: gene sequencing technology, DNA synthesis technology, gene editing technology, strain screening technology, genetic engineering, fermentation technology, isolation and purification technology, and so on.
The microorganisms used in recombinant collagen are mainly Escherichia coli and Picrosporum.
Why do we choose microorganisms? Because microorganisms have many advantages, such as fast reproduction, simple genetic modification, low carbon and environmental protection, low energy consumption and so on. And E. coli and Picros yeast are the best among them.
Safety of recombinant collagen
Synthetic biology, genetic recombination, and transgenic technology have overlapping parts. If genetic modification is to add the genes of one organism to another to give it the advantages common to both, then synthetic biology is to design a new organism according to our needs and let this organism reproduce with the help of microbial bodies. Recombinant technology is the technology of cutting, linking, expressing, and inheriting genes that both of the above involve.
Because the gene technology in question is still a relatively new technology, there is still a lot of ambiguity in the study of genes, and there are also doubts about whether it will create potential safety problems for human beings and the entire biological world. Genetic modification was once met with great resistance as a result, and still has more negative impacts today. It is hoped that synthetic biology will not repeat the mistakes of transgenics.
In conclusion, these technologies are still safe in terms of the applications that are currently available.
Moreover, the situation of recombinant humanized collagen may be a bit better because its gene itself is highly homologous to the human collagen gene, and as long as the purity is high enough, it can theoretically be considered equivalent to fragments of human collagen, and there will not be any safety problems.
Effects of Recombinant Humanized Collagen
As mentioned earlier, recombinant collagen consists of three types:
-Recombinant humanoid collagen
-Recombinant Humanized Collagen
-Recombinant Human Collagen
The most suitable for cosmetic applications at present is recombinant humanized collagen. As for recombinant humanized collagen, there are specifically type I, type II, type III, etc. At present, the recombinant humanized type III collagen is the one that is applied more, because type III collagen is softer and is mainly responsible for the elasticity of the skin, and type III collagen will be lost in the skin with the increase of age. By the age of 40, type III collagen is about half of what it was at the age of 18.
The earliest application of recombinant collagen was in medicine to aid in wound healing. It has been shown to significantly help increase the rate of wound healing and reduce scarring in healed wounds. Therefore, it is ideal for use in products such as post medical minimally invasive repair dressings.
This is because skin wounds mainly produce harder type I proteins during the healing process, which is the main cause of scar formation. Recombinant type III collagen, through its strong adhesion, effectively connects the broken skin collagen fibers caused by trauma, thus improving cell activity, filling the intercellular space, enhancing the cellular support structure, rapidly rebuilding the skin barrier function, accelerating wound healing, and at the same time, balancing the ratio of type I and type III collagen, reducing the production of scarring. The use of collagen in conjunction with the medical procedure can also reduce inflammation and enhance the therapeutic effect.
In cosmetics, anti-aging is the most important effect of recombinant humanized collagen, in addition, it is helpful for antioxidant, barrier repair and moisturizing. In the early days when traditional collagen was applied in cosmetics, the biggest challenge was transdermal absorption, because traditional collagen has a large molecular weight and poor water solubility, which makes it difficult to transdermalize, and there is a small possibility of generating efficacy inside the skin. Recombinant humanized collagen is a better water-soluble fragment of collagen, the molecular weight is not too high, providing a better basis for absorption, and experiments have also proven that recombinant humanized collagen can be absorbed transdermally.
In addition to its role through filling and adhesion after absorption, recombinant collagen can also improve fibroblast activity and keratinocyte activity, so that the skin's own collagen production and keratinization are more normal, and play a role in the resistance to aging.
In addition, recombinant collagen can act as a signaling molecule to increase collagen expression and reduce collagen loss by influencing various genes in the cell. For example, to improve the expression of genes related to type I and type III collagen synthesis, that is, to improve the generation of type I and type III collagen; to reduce the expression of matrix metalloproteinase MMP-1, MMP-3 synthesis genes, so as to reduce the generation of MMP, MMP is the degradation of collagen, reduce the MMP, which is equivalent to reduce the loss of collagen.
