3D Printing Achieves Human Skin with Natural Pigmentation

There are many different areas of research being pursued right now in the area of 3D bioprinting, and one of them is the 3D printing of human skin. Not only can 3D printed skin be valuable in pharmaceutical and cosmetic testing, it can potentially change lives by providing skin grafts for burn or accident victims. Current engineered skin constructs have been used for these purposes, but they lack many of the characteristics of natural skin, such as hair follicles, sweat glands and pigmentation.

Researchers at A*STAR’s Singapore Institute of Manufacturing Technology (SIMTech) and the Singapore Centre for 3D Printing (SC3DP) at Nanyang Technological University have developed a way to create pigmentation in 3D printed skin, as described in a study entitled “Proof-of-concept: 3D bioprinting of pigmented human skin constructs,” which you can access here.

The team used bioprinting to control the distribution of melanin-producing skin cells, or melanocytes, on a biomimetic tissue substrate, creating skin with pigmentation like that of real human skin.

“3D bioprinting is an excellent platform for the precise deposition of biomaterials and living cells to make biomimetic skin, in large volumes with great repeatability,” said lead author Wei Long Ng. “However, non-uniform skin pigmentation is often seen, and this remains a huge challenge to be solved. Our aim with this project was to use this method to demonstrate the feasibility of making 3D in-vitro pigmented human skin constructs, with uniform skin pigmentation.”

To create pigmented skin constructs, the researchers used three different types of skin cells: melanocytes, keratinocytes, and fibroblasts, along with a two-step bioprinting method called drop on demand.

“The two-step bioprinting strategy involves the fabrication of hierarchical porous collagen-based structures (that closely resembles the skin’s dermal region), and deposition of epidermal cells such as keratinocytes and melanocytes at pre-defined positions on top of the biomimetic dermal skin constructs, to create 3D in-vitro pigmented human skin constructs,” said Ng. “When we compared the 3D bioprinted skin constructs to those made using a manual-casting method, we found two distinct differences between the two fabrication approaches – the cell distribution on top of the dermal regions, and the microstructures within the dermal regions. The two-step bioprinting strategy enables the standardised distribution of printed cells in a highly-controlled way, as compared to the manual casting approach.

Furthermore, the bioprinting technique allows the manipulation of pore sizes within the 3D collagen-fibroblast matrices, to fabricate hierarchical porous structures that are clearly seen in the native skin tissues. In contrast, tuning the skin microstructure within the 3D collagen-fibroblast matrices using the manual-casting approach is extremely challenging.”

There are countless variations on skin color in the human race – which is why it’s so hard for so many women to find makeup that perfectly matches their skin tone, for example. If these researchers are able to create skin that is pigmented like natural skin, it will be a huge step for people who need skin grafts. A skin graft can be lifesaving and key to healing, but cosmetically, there’s still a lot missing from engineered skin grafts. A patient naturally wants new skin that looks like skin, particularly their skin.

In addition to the progress this study is likely to offer skin grafts, the bioprinting method used by the team can also be used to create skin constructs for toxicology testing and fundamental cell biology research.

Authors of the study include Wei Long Ng, Jovina Tan Zhi Qi, Wai Yee Yeong, and May Win Naing.

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[Source: Phys.org]