A team of American scientists from the Terasky Institute of California, Ohio State University and Pennsylvania State University have developed a new type of bio-ink for 3D printing living tissue. At the heart of the already tested composition of living cells on a frame and growth catalysts, but now for ink solidification, ultraviolet radiation, harmful to the body, is not required. The process takes place at human body temperature and natural light.
The main advantage of the new ink is that it can be applied directly inside the patient's body. For example, suturing wounds or reconstructing vessel fragments. At the same time, a 3D printer works like an analogue of a sewing machine, only instead of a finished thread it prints it on the go. The needle punctures the soft tissue, places a drop of ink in the hole, seals it on the outside, and adds another drop of ink, creating a kind of second knot for the filament. It is printed layer by layer, from node to node, creating the final three-dimensional design.
The authors of the development claim that it is safe for humans, and for the operation there is a sufficient symbolic incision on the body. The robot controls the print head, so you don't have to worry about the accuracy of the ink placement. Cell viability is maintained at the level of 71-77%, the frame retains its mechanical strength for at least 21 days. The fastening reliability through integration into soft tissues is 3-4 times higher than when printing with ink just over them.