3D-printed human skin models will help end animal testing

Carolina Catarino, alone
© Lush Prize -- Carolina Catarino is researching animal-free methods for growing skin models in a lab.

Carolina Catarino is a young Brazilian scientist who just won a Lush Prize for improving lab-grown skin models.

When Carolina Catarino was a teenager, she wanted to be a fashion designer. But her parents, living in the southern Brazilian city of Curitiba, told her she had to complete a university degree before heading off to fashion school. Catarino began a bio-engineering degree, and soon found herself doing an internship at L'Oréal in Paris, testing cosmetics on lab-grow skin models. The work was thrilling, since she realized she could be in the fashion world as a scientist, which felt like a perfect fit. (And her parents were happy.)

Catarino told me this story over lunch in London, England, this past week. She was one of eight recipients of a Young Researchers Award, each worth £10,000, which is part of the 2017 Lush Prize awarded by Lush Cosmetics for innovations in the fight against animal testing. Her particular project, based at the Rensselaer Polytechnic Institute in Troy, New York, is described in the Lush Prize handbook as "animal-free approaches for engineering physiologically relevant humanized skin models using 3D bioprinting technology," which Catarino explained to me in lay terms. She focuses on improving reconstructed skin models in three key ways:

1) Replacing the animal components in skin models with human-derived sources

Most skin models are grown from animal-derived scaffold materials, such as rat tail, mouse or bovine sources, but these models are not as complex as real skin, nor contain all the cells found in human skin. Catarino said, "We are trying to use human derived sources as a way to get away from using animals," which is hugely important to Lush's ongoing fight against animal testing.

2) Improving the complexity of skin models

Catarino and her team are trying to increase the number of molecules in reconstructed skin models. They are adding proteins, which are key to maintaining the skin; increasing the number of cells to analyze exposure to sunlight; and adding vasculature (blood vessels), which can be used for regenerative medicine and for creating skin grafts.

3) Adding hair follicle structures to skin models

This is the focal point of Catarino's work. The technology does not yet exist to create the actual hair fiber, but she is working to add the follicular structures, like channels, to skin models for chemical testing, since they're an important entry point for substances. The absence of these channels is a major problem:

"Currently companies test on the skin barrier to see what a product will do, but our skin is full of holes where follicles grow. These are a great place for substances to penetrate. Some molecules don't pass through skin, but they go through hair follicles. So, all our testing models don't have these channels, and yet we assume they're reliable. Recreating these channels will provide a more realistic view of substances' effects."

This is accomplished via 3D printing. The printer allows Catarino to position the cells in the way she wants, and where and when she wants them. "3D bioprinting allows precise placement of the bioinks containing scaffold components and cells within the 3D skin tissue."

Lush Prize Young Researchers Award© Lush Prize -- Carolina Catarino (center) hold the prize she received last week in London, surrounded by other recipients of Young Researchers Awards.

When asked what she plans to do with her prize money, Catarino said she will attend some conferences; do an exchange program at another lab in order to learn new techniques; and speak at high schools about the importance of entering scientific fields. Catarino had a co-op student working for her this past summer and said it was a wonderful experience. The student knew nothing about cells at the beginning, and was conducting experiments by the end.

"This is a point where young people are deciding what to do for the rest of their lives. It is important for them to hear about science. It can help straighten out facts, how it's actually what we do. It's not science fiction, it's real science, so maybe I can use the [Lush Prize] money to support these efforts."

Read how the Lush Prize wants to make animal testing irrelevant

3D-printed human skin models will help end animal testing
Carolina Catarino is a young Brazilian scientist who just won a Lush Prize for improving lab-grown skin models.

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