Bio-printed skin could replace animal testing

The skin can be produced on a large scale and would reduce the need for animal testing by the cosmetics and pharmaceutical industries

Spotted: While animals are experimented on for consumer safety, there are other ways to test products that do not compromise animal wellbeing. And now, a study by researchers at the University of São Paulo’s School of Pharmaceutical Sciences has shown that bio-printed artificial skin can be used in place of live animals in product testing.

Artificial skin is increasingly seen as an alternative to tests on animals, and 3D printing is one of the most promising technologies for creating skin models. But because research into bio-printing is relatively recent, its performance must be validated against traditional, manually produced models. This is what the São Paulo researchers set out to do, and their results confirmed that the printed artificial skin can achieve similar performance to a manually reconstructed human epidermis (epidermis is a scientific term for the outermost skin layer). 

First, in order for the artificial skin to be used as a replacement for natural skin, it needed to have the same stratified epidermis with four layers. This includes a selective barrier that protects against chemical stressors, such as pollutants and topically applied products, and physical stressors like sunlight, while also retaining water. 

This ‘barrier’ of the bio-printed skin then needed to be tested to see if it could prevent irritating detergents from penetrating. To do so, the researchers exposed the bio-printed model to a detergent, sodium dodecyl sulfate, at different concentrations for 18 hours. 

As a final test, the team also applied reference chemicals like irritants or non-irritants on the skin. The results showed that the quality of the bio-printed model was as good as manually reconstructed skin – with both responding well and successfully distinguishing between the irritating and non-irritating chemicals. Because of this, the researchers claim its bio-printed skin can be used in place of the Draize test – a current toxicity test that applies substances directly to rabbit skin. 

To further examine the viability of bio-printed skin, the researchers plan to bio-print more complex models comprising of the epidermis, dermis, and hypodermis with representative human skin cells. This will make the model more closely resemble real human skin, allowing for more rigorous product safety and efficiency testing. 

More and more people are choosing to avoid consuming products that involve animals, and Springwise has spotted many innovations working to produce animal-free alternatives. These include a plant-based topcoat for vegan leather and animal-free dairy in India.

Written By: Anam Alam