Making tailored organs and tissues for patients whose malaises need transplants seems a distant reality, but this technology may be close to becoming possible. A significant step in this sense was shown in the article published by the scientific journal Nature Medicine. A group of researchers at the University of San Diego produced, with a 3D printer, part of a spinal cord, which can be tailored as per injury of each patient.

In this landmark bioengineering work, the 3D bioprinting tissue was applied in living organisms – in this case, lab rats. Moreover, the cells developed in the laboratory were indeed capable of moving along the entire injured spinal cord and partially recovered the animals’ movements.

During the tests, the researchers first printed implants made with a specific gel and filled them with neural stem cells. The implants were surgically inserted in the injured spinal cord of rodents and, over time, new brain cells developed and made new connections from it – and they not only connected to each other, but also to native cells in the rat’s bodies, both in the marrow and in the circulatory system.

This may occur because the technology created by Prof. Shaochen Chen’s team is capable of reaching a new level of quality in 3D bioprinters: most machines can only print up to 200 microns, while this printer can produce tissues up to 1 micron, thus making it possible to fill compromised tissue with extreme precision.

“That’s the beauty of our 3D printing: I can mimic the structure. Other people couldn’t do the same,” says Chen in an interview with technology magazine Wired. His department is working on new human tissue bioprinting formats: in the past two years, they tested liver and heart tissues and treatment for illicit drug addiction.

Bioengineering and 3D bioprinting: what do they do?

In a great effort, scientists, engineers and physician researchers, who work with bioengineering, dedicated themselves to produce human tissues (or animal tissues, more broadly) or mechanical tools (such as prosthetic joints and/or members) that may be applied to patients with specific needs.

This technology is deemed as one of the most promising sources in cell development and production of mini-organs, valves, cartilage, etc. that may be transplanted into humans or animals, or help in the regeneration of these tissues. Nevertheless, the lack of standardization in researches and ethical debates on its application are two barriers in this sector.

In the case of the University of San Diego research, for example, for the bioprinted spinal cord to be tested in humans, this technique needs to be tested in rats again, but for different types of injuries and, later, also in apes.

Other structures require more time and care during their development. The Wake Forest Institute for Regenerative Medicine, in 2018, presented the first “organoid” brain printed in 3D with all six cell groups found in human anatomy.

This model opens doors to discover more promptly drugs for neurological diseases such as Alzheimer’s, multiple sclerosis and Parkinson’s, so researchers can better understand their course of action and progression.

“Right now, they could print the materials that mimic the structure of the brain and add biochemical cues. But there is still so much that isn’t known about how the brain functions,” ponders Christine Schmidt, biomedical engineer at the University of Florida to Wired.

Content published in March 29, 2019