A team led by scientists from Rensselaer Institute of Technology in the United States has for the first time 3D printed hair follicles from human skin tissue cultured in the laboratory. Although it is still several years away from designing skin grafts that can grow hair, this study still has potential applications in regenerative medicine and drug testing. The relevant paper is published in the new issue of the journal "Progress in Science". Researchers stated that this is a proof of concept study that demonstrates the ability to create hair follicle structures in a high-precision and repeatable manner using 3D bioprinting. This automated process is a necessary step to make future skin manufacturing possible. Reconstructing hair follicles using human derived cells has always been a challenge. Some studies have shown that if these cells are cultured in a 3D environment, they may produce new hair follicles or hair stems, and new research is based on this work. Scientists first allow skin and hair follicle cell samples to divide and proliferate in the laboratory until there are enough printable cells. Next, they mixed each type of cell with proteins and other materials to create the "bio ink" used by the printer. The printer uses an extremely thin needle to deposit biological ink, layer by layer building the skin while also creating channels for depositing hair cells. Over time, the structures formed by the migration of skin cells to the surrounding channels of hair cells are similar to those of hair follicles found in real skin. At present, the lifespan of these tissues is 2-3 weeks, and future research aims to extend this period, further mature hair follicles, and pave the way for their drug testing and skin transplantation. Researchers say that the current engineering structure that mimics human skin is very simple, and adding hair follicles to increase its complexity will provide more information on how the skin interacts with local products. Meanwhile, this new study takes an exciting step towards developing and testing better therapies for burns and other skin diseases. Zhang Jiaxin (New News Agency)