3D skin printing to stop cosmetic animal testing

Since 2013, the marketing of cosmetic products previously tested on animals is not allowed in the European Union. In other words, it could be said that since then all European cosmetic products have been cruelty free. This has led to the need to look for alternatives, such as artificial skin. But there is a problem and it is that this is sometimes difficult to obtain. For this reason, a new investigation, which analyzes the possibility of printing this skin with a 3D printer, will be a great advance, both to improve the protocols in countries that do not test on animals and to encourage those that still do so to be join the change

The investigation has been published by scientists from the Faculty of Pharmaceutical Sciences of the University of São Paulo (FCF-USP), in Brazil. This is a country that He has been trying to move towards a total ban for several years of cosmetic products tested on animals. Nevertheless, It still has a few steps to go to catch up with Europe, for example. For this reason, the authors of the study point out that, with their research, they want to do their bit to make it easier to obtain cruelty-free cosmetic products.

For now, the investigation published in Bioprinting magazine, demonstrates that 3D-printed artificial skin is just as effective as that previously synthesized manually. However, it may have some limitations that still need to be studied. Even so, there are still enough alternatives to avoid having to resort to animals. All the countries that have banned it are a good example of this.

Why were cosmetics tested on animals?

Some dermatological products, whether for cosmetic or pharmaceutical purposes, may contain substances that irritate the skin.

For this reason, in 1944 the Draize test was developed. This consists of taking 0.5 ml or 0.5 g of the substance to be analyzed, applying it to the eye or shaved skin of a rabbit, and leaving it there for a specific time. Afterwards, it is rinsed and it is checked if any type of irritation has occurred in the animal.

This test is not only very cruel, in case the test substance causes serious damage to the animal. It has also been classified as unscientific by some professionals in the sector. This is so for two reasons. On the one hand, because there are big differences between the eyes of rabbits and those of humans. And, on the other, because it is a fairly subjective test, in which the damage of each substance is evaluated visually.

For this reason, although the test was widely used for decades, many countries gradually eliminated it from their practices. One of the first was the United Kingdom, where cosmetic testing on animals was banned as early as 1998.

The development of scientific techniques that have made it possible to synthesize artificial skin has made non-animal testing much easier. Therefore, it has already been in the 21st century when many other countries have joined what would eventually be baptized as cruelty free.

The case of Europe and China

In Europe, the ban was introduced in two phases, one in 2009 and another in 2013. Consequently, the sale of cosmetics tested on animals has been prohibited for ten years. Even so, if we look at the labels of these products, we can see some that have the cruelty free seal and others that do not.

This was initially due to the fact that the ones that did not have it were brands that export their products outside of Europe to countries like China, where animal testing was required. However, it should be noted that this legislation has also changed.

Although testing cosmetics on animals is not prohibited in China, yes, it has been discarded as a mandatory requirement. Therefore, companies that do not test their products in Europe do not have to do so in China either. This currently makes the cruelty free label much more confusing and, at best, serves as a statement of a company’s ethics, but not necessarily its practices.


Artificial skin to avoid animal testing

Although there are more and more countries whose cosmetic tests are cruelty free, there were still some in which these practices are still carried out. Also, those who don’t need to improve their methods. And 3D printing artificial skin may be a great option for the future.

Artificial skin has been used in the field of medicine for years, for example, to perform grafts on burn patients. In such cases, grafts from your own body, made from cells taken from unaffected areas of skin, are often used. However, when that artificial skin is not to treat a specific person, but simply to test cosmetics, any culture of human cells can be used. After all, there is no fear of rejection.

This has been done for a long time in places where the use of animals is prohibited. Generally, manual techniques are used, consisting of the placement of skin cells, called keratinocytes, on a collagen matrix. It is done manually with a laboratory instrument, called a pipette, and is quite tedious. But there are already alternatives. In fact, in recent years other techniques have also been used to test cosmetics, some even based on artificial intelligence. But, going back to artificial skin, faster alternatives are also being studied. For example, the use of the famous 3D bioprinters, which use cells as ink to print human tissue. However, few studies compare its effectiveness with that of other types of artificial skin. And that is what these Brazilian scientists have just done.

Cruelty free test for irritating substances

The first step taken by these scientists to analyze their artificial skin was to verify that it had the same morphology as human skin in vivo. They saw that it was indeed an epidermis stratified into four layers: basal, spinous, granular, and horny layers.

It is important, because it means that it has the same functions as natural leather. It can protect both against irritation from chemical products and against physical stressors, such as ultraviolet radiation. This makes it very effective for testing any cosmetic.

Once this was verified, chemical tests were carried out on the two types of artificial skin. Both substances previously classified as irritants and physiological compounds were used. Thus, it was seen that the results were comparable in both cases.

There is only one possible problem that needs to be studied further, according to the authors of the research. And it is that, when using needles or conical nozzles for the cellular dispersion of the artificial skin, altered responses could be obtained. For example, it is possible that an inflammatory response is generated, which in some cases could interact with the cosmetic test.

This makes it necessary to pay attention and control the impression of artificial skin. Beyond that, it could be the future of modern cruelty-free cosmetic testing.

View Hide summary