3d bioprinter prints spatial tissue structures in correct format
Scientists have managed to print tissues using a special 3D printer. The printer can print structures for living tissues, such as an ear or jawbone. The results presented are all made using laboratory animals.
The goal is to eventually print tissue material and use it in humans. In this case, 3D-printed structures were implanted in laboratory animals, after which the structures were developed with functional tissue including a system of blood vessels. The structures were the right size and strength to use in humans in the future.
The difference with the device developed by researchers at the Wake Forest Institute for Regenerative Medicine and ‘standard’ organ printers is that this printer can print structures that are strong enough to implant in the body. The Integrated Tissue and Organ Printing System, ITOP for short, was developed over a period of ten years.
The printer not only prints the supporting tissue in the form of a biodegradable, plastic-like material, but also the water-based gels that contain the correct cells. The strong, temporary outer structure keeps the cells together.
The difficulty with printing organs such as kidneys or structures such as an ear is that the cells in the structures often do not ‘live’ long enough to integrate with the body. In this case, a grid of microchannels is also created in the structure. These microchannels ensure the transport of nutrients and oxygen to the new living structures. In the long run, this also forms a blood vessel system.
The latter was a tricky problem. It was already known that living cell structures had to be smaller than 200 micrometers in order to survive without their own blood vessels. In this study, they managed to grow a small ear of almost 4 centimeters. Blood vessel formation was visible in the ear after a month.
The composition of the gels thus appears to ensure that cells remain alive and that blood vessels grow. The ears from these tests were implanted under the skin of mice by the researchers, where they continued to grow. The researchers also experimented with growing soft structures, such as printed muscle tissue that was implanted in rats.
A printed jawbone with human stem cells was also made. To test the growth of bone material, pieces of printed skull bone were also implanted in rats. After five months, a vascular system had formed.
The paper is published in Nature Biotechnology.
Printing a jawbone