In severe treatment Burns and trauma, skin regeneration can be a matter of life and death. Generally, extensive burns are treated by transplanting a layer of epidermis (the top layer of the skin) from elsewhere in the body. However, this method not only leaves large scars, but also fails to restore the skin to its original functional state. Unless the dermis, the layer below the epidermis (including blood vessels and nerves) is regenerated, and it cannot be considered as a normal living skin.
Now, the work of Swedish researchers may bring medicine closer to being able to regenerate skin. They have developed two types of 3D bioprinting techniques to artificially produce vascularized thick skin, meaning it contains blood vessels. One technique produces skin with cells, and the other produces blood vessels of any shape in the tissue. These two technologies take different approaches to address the same challenges. These methods are already in two Research Published in the journal Advanced Medical Materials.
“The dermis is so complex that we can’t grow it in the lab. We don’t even know what all the ingredients are,” said Johan Junker, an associate professor at Linkup University and a plastic surgeon who leads the work. statement. “That’s why we and many others think we might transplant the component and then let the body make the dermis itself.”
Junker and his team designed a bioink called “μink”, in which cells of fibroblasts (producing collagen, elastin and hyaluronic acid) are cultured on the surface of small spongy gelatin particles and contained in hyaluronic acid gelatin gelatin. By constructing this ink in three-dimensionally using a 3D printer, they are able to create skin structures filled with high-density cells at will.
In transplant experiments using mice, the researchers confirmed that live cells grow in tissue fragments made with this ink, secrete collagen and reconstruct components of the dermis. New blood vessels are also grown in the graft, indicating that the conditions for long-term tissue fixation are met.
Blood vessels play an extremely important role in the construction of artificial tissues. No matter how many cells are cultured to create tissue models, no blood vessels, oxygen and nutrients cannot be carried evenly to all cells. As tissue structures grow, there are no blood vessels, cells in the center of the tissue die.
The research team also created a technology called “refreshing” (rewiring of refloating suspended hydrogel wires), which allows the flexibility to construct blood vessels in artificial tissues, which is 98% water gel by printing and arranging the lines of the hydrogel. These threads are much harder than regular gel materials, and can retain their shape even when tied or braided. Additionally, they have shape memory properties, and they can restore the original shape even if they are crushed.
