Is stem cell beauty a black technology or pseudoscience?

Author: Fan Chenyu (Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences)

The article comes from the Science Academy official account (ID: kexuedayuan)

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Many beauty lovers have found that there are more and more businesses selling "stem cell beauty" products. It is said that these beauty products have introduced Nobel Prize ingredients, regenerative medicine, immortal cells... and are also linked to high technology and cutting-edge medicine. Judging from the merchants' propaganda, it seems that using them can make you return to 20 years old!

But are these products reliable? Can we buy them without any worries?

Image source: Internet

What stem cell products are available on the market?

Stem cells are a type of cell that has unlimited self-replication capacity but has not yet fully differentiated and matured; under certain conditions, it can develop into a variety of functional cells. Stem cells have the potential to regenerate, rebuild, and repair various tissues and organs.

Currently, stem cell beauty products on the market can be roughly divided into the following categories:

1. Injectable stem cells (embryonic stem cells/placental subtotipotent stem cells/mesenchymal stem cells/adipose stem cell injections): extracted from human umbilical cord, placenta, fetal abortion tissue, adult fat and other human tissues, which may be injected into the target body after pathogen detection, purification and amplification, and are performed by hospitals and clinics. The price is expensive, generally ranging from tens of thousands to hundreds of thousands of yuan per treatment.

Mesenchymal cells (MSCs) first appear in the embryonic mesoderm and exist in a variety of adult tissues. They can be cultured and expanded in vitro, and can stimulate the target tissue to generate neurons, osteoblasts, chondrocytes, muscle cells, adipocytes, etc. under specific conditions. They also have immunoregulatory capabilities and play an important regulatory role in transplant immune tolerance, autoimmunity, tumor immunity, and fetal maternal immune tolerance. Because it has an immunosuppressive effect, it can be freely transplanted into the target population without immune matching. MSCs have broad prospects for clinical application and are the preferred seed cells for cell replacement therapy and tissue engineering. They are a research hotspot in the field of transplantation and the treatment of autoimmune diseases.

2. Plant stem cell products: There are various products, mainly apple stem cells, with the main effects of anti-aging and moisturizing.

Image source: screenshot from Taobao

3. Autologous collagen products: extract autologous blood, separate it by centrifuge, extract the serum, purify it and then re-inject it into the body. This is performed by a medical beauty hospital.

Image source: http://www.ubeauty.cn/subject/201801cgf/

4. Active peptide products: By applying some active peptide small molecules to specific parts of the body from the outside, it can stimulate "awakening" or nourish skin stem cells.

5. Umbilical cord blood products: Umbilical cord blood essence that is said to contain high-purity hematopoietic stem cells.

Image source: screenshot from Taobao

Umbilical cord blood hematopoietic stem cells are a group of primitive hematopoietic cells existing in umbilical cord blood. Hematopoietic stem cells are the ancestors of blood cells (red blood cells, white blood cells, platelets, etc.), and are highly undifferentiated cells. It can also be said that they are the primitive cells of all blood cells (most of which are immune cells). Hematopoietic stem cell transplantation can treat dozens of diseases such as malignant blood diseases, some malignant tumors, and some genetic diseases.

Three principles to keep in mind before shopping

Are these various stem cell products as reliable as the merchants say? What factors should we consider before buying them?

Is the source safe?

Although embryonic stem cells are truly omnipotent stem cells and can theoretically be induced to differentiate into any type of human tissue, their original source must be living embryos, which can only be obtained from aborted fetuses and voluntary donations. However, this may violate the law and touch upon ethical issues.

Even if the source is legal and reasonable, early embryonic stem cells are prone to cancer in adults because they have the potential to develop into various tissues, which may cause malignant transformation of cells. Moreover, directly transplanting wild stem cells also has potential risks of biosafety and viral infection.

In addition, the immune rejection reaction caused by the introduction of embryonic stem cells, placental sub-totipotent stem cells, and hematopoietic stem cell products cannot be measured or controlled. Even when transplanting between family members, strict matching must be carried out. Once rejection occurs, the consequences will be disastrous.

Direct injection of embryonic stem cells is extremely unscientific and dangerous.

What is immune rejection?

The body can distinguish foreign cells and tissues and mark them as "unknown objects". Then the immune system will use all its strength to eliminate the "foreigners". The rejection reaction begins. If the reaction is severe and rapid, it may even be fatal.

Are stem cells/stem cell extracts active?

The products that consumers can buy easily and apply on their faces at home are completely different from the stem cell products that are injected under strict supervision in hospitals.

If it is a living cell, it will definitely not get the approval number starting with "Wei Zhuang xx" issued by the Ministry of Health. Living cells are applied on the face and integrated by themselves. There is no way to know what unpredictable effects they will produce. Isn't it scary? Chinese people are terrified when mentioning genetically modified food. This time it is "transgenic cells"!

There are no stem cell products in my country that have obtained the "National Medicine Approval Number" yet! The only mesenchymal stem cell injection that was accepted by the Food and Drug Administration was only this year.

As for dead cells, can you still expect them to have any regeneration and repair capabilities?

Can the skin really absorb it?

Image source: https://www.sohu.com/a/167048153_725849

For skin care products to be effectively absorbed, as shown in the figure above, they must pass through many obstacles and reach the basal layer or dermis. However, the stratum corneum is a strict skin barrier. Unless there is a special protein transport channel, 1000 Daltons is basically the limit of what the skin can absorb.

How big is 1000 Dalton? Dalton is the unit of molecular weight that we often talk about in middle school chemistry class. The molecular weight of an amino acid is about 130 Daltons, and 1000 Daltons is at most an oligopeptide chain composed of 7 or 8 amino acids. This oligopeptide can bypass the sebaceous glands, hair follicles, sweat glands and other channels to enter the dermis. The beauty ingredients we are familiar with, such as vitamin E (430.71), vitamin C glycoside (338.26), salicylic acid (138.1), glycerol (92.10), etc., can easily penetrate the skin; but the entire cell cannot pass through. Unless it is an injectable injection that can directly hit the subcutaneous tissue or vein, otherwise it can only be an imaginary absorption effect.

Now, you can buy (or not buy) with confidence

Combining the above three principles, consumers can easily determine the authenticity of the various stem cell beauty products listed at the beginning of this article:

Stem cell injections for injection:

Useful, but be cautious with security.

They can act on most organs and tissues in the human body, promoting their regeneration and repair functions. They are a means of systemic effect. Judging from the various comparison pictures circulated on the Internet, the effect is very obvious. They can completely "reverse time and space" and "rejuvenate", and can repair a variety of injured or diseased tissues and organs. From this perspective, they have surpassed the scope of stem cell beauty, and it is more appropriate to describe them as stem cell anti-aging or stem cell therapy.

Except for embryonic stem cells, which are expensive, dangerous, and strongly not recommended.

In addition, in September this year, scientists from the RIKEN Institute of Physical and Chemical Research in Japan and the National Institutes of Health (NIH) of the United States jointly published an article in the journal Nature, formally questioning whether mesenchymal cells (MSC) are truly stem cells. Even the name of MSC began to regret the original name. MSC can automatically gather at the damaged part of the body and secrete various proteins to regulate immune response, reduce inflammation, promote wound healing and inhibit cell death. However, it lacks the function of rebuilding tissues that typical stem cells have. Therefore, mesenchymal cells should be classified as "medicinal signal cells". The contributions of the two must not be confused. It should not be accepted to use the efficacy of MSC to make stem cells magical, or to use the banner of stem cells to actually do the work of MSC. Many biologists, clinicians and scientific societies have suggested modifying or abandoning the name of mesenchymal stem cells.

Plant stem cell products:

It's useless.

Image source: www.afinance.cn

Plant stem cells belong to the root tip and apical meristem of plants. In simple terms, they are what make plants grow leaves and roots. They have nothing to do with human skin! Moreover, as cells, they cannot pass through the skin barrier and of course cannot be absorbed.

Don’t believe what beauty salons say about their “wall-breaking instrument” that can open the plant cell wall/human skin barrier and introduce effective ingredients; even if it is really effective, it is another beauty ingredient and has nothing to do with stem cells, but they can make a fortune by using its gimmick.

Autologous collagen products:

It's useless.

Although there is no need to worry about immune rejection of the serum extracted from the body, the growth factors and hormones contained in it can be amplified to high concentrations after a short half-day treatment at a medical beauty salon by simply separating them with a centrifuge? Or can a sufficient amount of autologous collagen be generated in the culture medium (the second principle)? It is too naive! These are impossible to achieve without several days of in vitro culture by cell biology technicians.

In addition, the content of hematopoietic stem cells in peripheral blood is pitifully small. How many stem cells including CD34+ (the hallmark surface antigen of hematopoietic stem cells) can be obtained by extracting one or two hundred milliliters of blood, no matter how they are cultured? This method of making money quickly by merchants is absolutely not credible.

Image source: http://www.ubeauty.cn/subject/201801cgf/

As I said: Even if it is really effective, it is just another beauty ingredient and has nothing to do with stem cells, but people can still make a lot of money by using its gimmick.

Active peptide products:

It works, but are they really stem cells?

What is a peptide? A peptide is a short chain of amino acids. Long chains folded together are proteins, and oligopeptides are those with only a few amino acids in series. Oligopeptides can indeed be absorbed through the skin, and peptides with certain chemical structures can indeed be used for beauty and anti-aging; at least, like botulinum toxin, they can relieve expression lines and dynamic textures. As for whether it has the effect of activating epidermal stem cells, the author has searched the Internet and has not found relevant literature to support it.

Cord Blood Products:

It's useless.

To repeat the old saying, if it is a living cell, the safety source cannot be guaranteed; if it is a dead cell, it is ineffective; if it is to extract active ingredients, it cannot pass through the skin barrier without relevant delivery technology.

So, there is no need to say more about whether or not to buy "stem cell beauty" products on Singles' Day! Faced with the endless beauty traps on the market, those who love beauty must keep their eyes open and have the ability to distinguish the true from the false, so as not to waste money.

References:

1. Douglas Sipp Pamela G. Robey &Leigh Turner. Clear up this stem-cell mess. Nature.2018, 561, 455-457.

2. JD Bos & MMHM Meinardi. The 500 Dalton rule for the skin penetration of chemical compounds and drugs. Experimental Dermatology. 2000, 9:165-169.

3. X Wu, L Huang, Q Zhou et al. Effect of paclitaxel and mesenchymal stem cells seeding on ex vivo vascular endothelial repair and smooth muscle cells growth. Journal of Cardiovascular Pharmacology.2005, 46 (6):779-786.