U.S. researchers 3D print out complex veins

team at several U.S. universities has developed a hydrogel 3D printing technology that can create complex veins that mimic human blood vessels, trachea and lymphatic tubes, clearing a technical barrier to future artificial functional organs.In a hydrogel model that simulates an acumony, artificial tracheals deliver oxygen to a network of surrounding artificial blood vessels, and red blood cells can capture oxygen as it flows through the network of blood vessels around the artificial veins, similar to the gas exchange activity of the body's veins, according to a study published in the latest issue of the American journal Science.Jordan Miller, co-author of thepaper and an assistant professor of bioengineering at Rice University in the United States, says one of the biggest obstacles to artificial functional tissue is the inability to create complex vein systems that transport nutrients into dense human tissues, such as trachea and blood vessels in the lungs and bile tubes and blood vessels in the liver, each with separate systems, structures and functions.the new study, the team used 3D printing technology to print one layer of soft hydrogel at a time. They added a light absorbent that absorbs blue light to the hydrogel, allowing it to become solid under high-resolution blue light exposure. Studies have shown that this technique can print hydrogels with fine internal structures and biosynthability in minutes.researchers also implanted bioprinted structures containing liver cells into mice with chronic liver damage, and experiments showed that liver cells could survive implantation.Kelly Stevens, an assistant professor of bioengineering at the University of Washington and one of the co-authors of thepaper, said the complexity of the liver's 500 functions means there is no man-made alternative, but future bioprinting organs are expected to achieve this goal. Bioprinting is expected to become an important part of medicine within two decades. (Xinhua) --