Scientists are closer than ever to creating a working model of human organs using 3-D printing. In a recent experiment, a team of researchers used food dye to create the complex, tangled of vessels that resemble the same network we find in the human body. The model was made of hydrogel, of course, to print an air sac mimicking that of a human lung. Furthermore, they were able to successfully send oxygen, through the polymer gel, to blood cells in nearby vessels. And this resulted in the fake lung pulsating—as in, respiration—without breaking.
The study also shows that smaller structures in the human body—including the intravascular valves throughout the arms and legs—could also be printed. In addition, a second experiment resulted in bioengineers implanting mice with bioprinted structures that contain liver cells that were furtive enough to survive the process.
Actually, study co-author Kelly Stevens explained, “The body contains various networks of ‘pipes’ that bring nutrients to, and remove waste from, the organs in our body.”
The University of Washington assistant professor operates a lab that investigates the potential for printing human tissues from stem cells. She goes on to say, “Many of these pipe networks in the body are entangled, so they have been very hard for scientists to replicate by 3D printing. This new method allows us to create multiple entangled networks of pipes in 3D-printed tissues.”
To reach this point, the research team used an existing form or 3D printing—known as projection stereolithography—which uses light in combination with photoreactive resins to produce solid objects. Jumping off from this point, the team developed this new technology to print hydrogels into anatomical tissue-like structures one layer at a time. This liquid hydrogel solidifies when it comes into contact with blue light, with the absorption assisted by food dye.
The research team calls this new technology: StereoLithography Apparatus for Tissue Engineering, or the acronym SLATE.
Study co-author Dr. Jordan Miller also comments “With the addition of multivascualr and intravascular structure, we’re introducing an extensive set of design freedoms for engineering living tissue.”
An assistant professor of bioengineering at the Rice University Brown School of Engineering continues, “We now have the freedom to build many of the intricate structures found in the body.”
The results of this study have been published in the journal Science.