Hydrogel 3D printing for rapid generation of complex vessels

Science and Technology Daily, Beijing, May 5 (Reporter Li Shan) The US research team has developed a new bio-printing technology that can quickly generate biocompatible hydrogels with complex internal structures to mimic vascular systems such as human trachea and blood vessels. , to remove an important technical obstacle for the future of artificial functional organs. The breakthrough results were published in the recent issue of Science.

One of the biggest obstacles to man-made functional tissue is the inability to create complex vasculature to transport nutrients to human tissue. In addition, human organs also contain independent vascular networks, such as the trachea and blood vessels in the lungs, as well as the bile ducts and blood vessels in the liver. These interpenetrating networks are physically and biochemically intertwined, the structure itself and the tissue function. closely related.

To cope with this challenge, a research team led by Jordan Miller of Rice University in the United States and Kelly Stevens of the University of Washington developed a hydrogel 3D printing technology. At the heart of this new open source bioprinting technology is the device called the Tissue Engineering Stereo Mirror (SLATE) and the corresponding blue absorbing agent. The system uses the principle of additive manufacturing to add a blue light absorber to the hydrogel pre-solution so that the hydrogel solidified after absorption of blue light is confined to a very fine layer.

The system can generate biocompatible hydrogels with complex internal structures in a matter of minutes. This allows scientists to create complex vascular networks that mimic the natural pathways of human blood, air and lymph.

To prove the principle of the study, the scientists generated a hydrogel model that simulates alveolar. Experiments show that artificial trachea can transport oxygen to the artificial blood vessel network, similar to the gas exchange activity of human alveoli, and red blood cells flow around the artificial alveoli. The vascular network captures oxygen. In addition, in order to verify the biocompatibility of printed tissues, the researchers also implanted bioprinting structures containing hepatocytes into mice with chronic liver injury, and the results showed that hepatocytes survived after implantation.
It has always been the dream of scientists to use the patient's own tissue cells to generate functional organs for transplantation through bioprinting, because it not only solves the problem of source scarcity, but also prevents organ rejection. However, Stevens said that there are more than 500 functions of the liver. This complexity means that there are no artificial objects to replace, but future bio-printing organs are expected to achieve this goal. Bioprinting is expected to become an important part of medicine within 20 years.

Editor-in-chief

When 3D printing just entered the public eye, some people think that this technology is just a gimmick. Because some 3D printed things are simple in structure and rough in surface, they don't seem to be too advanced. After continuous iterative upgrades, 3D printing has broken people's prejudice against it. In the field of aviation, it can print parts for aircraft and spacecraft; in the medical field, it can be used to print blood vessels. Looking forward to 10 or even 20 years, the role that 3D printing can play will further exceed our imagination.