From cancer treatment, to the elimination of polluting substances in the environment or even the manufacture of buildings, both on Earth and – over time – on the Moon and Mars. Researchers in the US are working on a microbial ink that makes it possible to generate “live” material that reproduces, can be 3D printed, and opens the door to a wide range of applications, including even space exploration. The idea, as one of its main authors, Neel Joshi, comments, to News @ Northeastern, is in a way emulating the dynamics of nature itself.
“A tree has cells embedded in its interior and it goes from being a seed to a tree to assimilate the resources of your environment to implement these structure building programs. What we want to do is something similar, but by providing those programs in the form of DNA that we write and genetic engineering, ”says Joshi, a professor at Northeastern University.
Successful tests with small shapes
To make the microbial ink, the scientists genetically modified the bacteria Escherichia coli, better known as E. coli, with the purpose of generating two types of protein polymers called curli nanofibers, capable of crosslinking with each other and shaping mesh-like structures. The nanofibers were filtered in the cultures of E. coli and generated a kind of gel elastic enough to be used as 3D printing ink. The material is still being developed –clarifies The New York Times– but it could become a highly valuable renewable construction tool, capable of growing and healing itself.
During his investigation – detailed in an article published in November in Nature Communications– Joshi and his colleagues have produced a gelatinous material with which they have printed small shapes. As part of their tests they “modeled”, for example, a circle, a box, a grid and a cone, in addition to specific attributes for useful applications in medicine. The result was satisfactory. The ink solidified, showed the necessary consistency and even, as detailed Times, could extend between two ends separated by 16 millimeters.
Think of it as a platform to build many different things, not just bricks ”, notes Professor Joshi to News @ Northeastern: “Biology can do wonderful things. Think of the difference between hair, which is flexible, and the horns of a deer or rhinoceros. They are made of similar materials, but they have very different functions. Biology has discovered how to adjust mechanical properties using a limited set of building blocks. “
“Living cells have the ability to synthesize molecular components and assemble them with precision from the nanoscale to build macroscopic living functional architectures under environmental conditions ”, he explains the article published in Nature Communications. As “blocks” the researchers use Curli fibers, generated by cells when they adhere to a surface or to each other and which offer an attractive material for engineers.
Not the first time in which bacteria are used for inks and 3D printing. Researchers have previously created gels based on cocktails of bacteria and polymers that serve to reinforce the structure. The novelty now – stand out Professor Joshi and his colleague Avinash Manjula-Basavanna – is that the gel does not include extracts, acids or silica, as on previous occasions. It all comes from E. coli. In order to improve its firmness, the scientists modified it to produce a special form of protein.
How News @ Northeastern collects, the researchers assure that, with the right conditions, the cells in the microbial gel could make more of themselves. Microbial ink –detalla Joshi, a The New York Times– attracts more and more attention in the field of engineering. Unlike concrete or plastic structures, for example, living systems would be autonomous, would adapt to signals from the environment, and would be able to regenerate. “Imagine creating buildings that heal themselves“, they add.
Joshi’s team has also tried mixing the ink with other genetically modified microbes for the purpose of giving 3D printed materials specific purposes. For example, they made a material capable of releasing a cancer drug every time it was met with a certain chemical stimulus and another designed to trap the toxic Bisphenol A (BPA) by locating it in the middle. “You could think of taking a bottle cap and printing our material on the inside so that, if there was BPA, it would be absorbed and not in the drink,” he says.
The ink is still in an early stage, but the researchers are optimistic and working on ways to scale 3D printed structures to achieve more resistant shapes. It works, how do you need smithsonian magazine, microbial ink could become a more environmentally friendly and renewable building material for the future or even develop new medical devices. “There is a lot of work to be done to make it scalable and affordable. It is difficult to project into the future … but given the pace in this area it seems very bright“, reconoce Sujit Datta.
Among the wide range of options that the new “living” matter opens up would be, for example, that of space colonization. Her CARACTERISTICS, detalla [email protected], would make it especially interesting in environments where they are scarce and where it is very difficult to carry materials for the construction of large habitable structures, such as Mars or the Moon.
“If combined with other material technologies, such as those that are already incorporating living cells into structural building materials, our microbial bio-bond could also be particularly useful for building structures in space or extraterrestrial habitats, where the transport of raw materials is difficult, which makes the on-demand generation of building materials from very limited resources is essential “, details the article of Nature.
Images | VeeDunn (Flickr)