Bacteria engineering produces fully bio-inks that can be used in 3D printing

Although these bio-inks have so far only been used on a small scale, they can be used to build just about anything.

If humans could ever live on Mars or the Moon, they would have to build livable and working buildings there. And space agencies believe that the best way to do this is with 3D printers (stereo printers). However, bringing printing inks (the building materials these printers use) from Earth to any other celestial body is very expensive and not a viable option.

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However, a new study published in the journal Nature Communications on November 23, revealed a type of "bio-inks" that are made from programmed Escherichia coli bacteria, which can be used to print hydrogels. 3D models with different shapes, can perform a number of functions according to how they are designed.

This approach is different from previous bio-inks, as it adapts genetic programming to control the mechanical properties of the ink itself, which leads to maximizing the final product, allowing it to be used more practically in a number of 3D printing applications.

According to the press release published by Northeastern University, Neil Joshi, professor of chemistry and chemical biology at the university and lead of the study, "We wanted to mimic what the cells of the tree do. They absorb resources in their surroundings in order to activate their internal program designed to build their structure, and then transformed from a seed into a tree.

"We wanted to do the same by presenting these programs in the form of written, genetically modified DNA," Joshi adds.

Vital Inks

According to a report by Science Alert, the researchers learned how to program the cells of the Escherichia coli bacteria to produce fully bio-inks that can be used to print solid 3D structures.

Scientists have used this produced ink to print small shapes such as a circle, a square and a cone, and they were able to program these bacteria to build materials that have specific features and have multiple applications. However, these vital inks have not been tested in space yet.

To obtain these bio-inks, the scientists reprogrammed bacterial cells to produce living nanofibers. Scientists have combined these bacteria with many other substances to be able to produce these fibers, in a chemical process inspired by the process of blood clotting in mammals, in which the protein fibrin plays a major role.

The team then inserted these nanofibers into a 3D printer to produce different shapes. In contrast to previous bio-inks, this new type is completely biological, and does not use any synthetic material.

Promising apps

Although only some simple shapes - such as a cone - have been designed so far using this technique, scientists see in it a hope that opens the door to a number of potential applications in the future.

Joshi states that "when, for example, the cone is dipped in glucose solution, the bacteria cells will feed on it and make more of those fibers that will help the cone grow into something bigger," and we can choose between keeping the bacteria alive, if we need it, or killing it. And use it as an inert material.

In addition, in their experiments, the team was able to combine the bio-ink they produced with other microbes, to perform specific tasks such as absorbing toxic chemicals or producing an anti-cancer drug. In the future, the researchers believe, we may be able to design a bio-ink that has the ability to replicate itself.

Although these bio-inks have so far only been used on a small scale, they can be used to build almost everything from self-repairing structures to producing bottle caps that can remove dangerous chemicals in water.