The humble Escherichia coli bacteria has seen its fair share of use in the scientific community; what was once simply feared as the culprit behind food poisoning episodes is now being fully harnessed by the scientific community in its endless pursuit of innovations within the biological fields and beyond.
We previously reported on the use of E. coli as part of an effort to convert waste soda bottles into a component of vanilla flavoring; now, researchers are looking into working with the humble bacteria on something a little bit more adventurous: bioinks for use in 3D printing. Their landmark methodology was published in the journal Nature Communications.
The E. coli bacteria present in the bioink isn’t some run-of-the-mill bacteria, though; these ones are mixed in with other relevant substances to create a “nanofiber” material through a chemical process inspired by fibrin, a protein which plays a vital role in blood clotting and wound healing.
“A tree has cells embedded within it and it goes from a seed to a tree by assimilating resources from its surroundings in order to enact these structure-building programs,” says Northeastern University chemical biologist Neel Joshi. “What we want to do is a similar thing, but where we provide those programs in the form of DNA that we write, and genetic engineering.”
The fibers produced by the fibrin-inspired methodology are then fed into a 3D printer, which is then used to print out various 3D shapes. In the experiment, the authors created relatively simple shapes, like a cone and a circular shape.
What makes the results more remarkable is that the authors can still take advantage of the fact that these structures, crude as they may initially seem, are still made of living bacteria—meaning they are capable of “growing” their structures when fed through some means.
“If you were to take [the] cone [structure] and dunk it into some glucose solution, the cells would eat that glucose and they would make more of that fiber and grow the cone into something bigger,” Joshi added. “There is the option to leverage the fact that there are living cells there. But you can also just kill the cells and use it as an inert material.”
Additional experiments made by the research team showed that they can incorporate other biological agents into the structure, adding several possible ket functions to its repertoire; current attempts include absorbing toxic chemicals and delivering anti-cancer drugs through the incorporation of functional components into the bioink.
Additionally, future improvements to the system include the search for additional agents to incorporate into the structure, to the authors envisioning a future where large-scale production of these bioinks can facilitate even the self-repair of buildings, and where specially-crafted plastics with the material can help clean out bodies of water whenever they are around any.
In closing, Joshi continued: “Biology is able to do similar things […]. Think about the difference between hair, which is flexible, and horns on a deer or a rhino or something. They’re made of similar materials, but they have very different functions. Biology has figured out how to tune those mechanical properties using a limited set of building blocks.”
References
- Duraj-Thatte, A. M., Manjula-Basavanna, A., Rutledge, J., Xia, J., Hassan, S., Sourlis, A., Rubio, A. G., Lesha, A., Zenkl, M., Kan, A., Weitz, D. A., Zhang, Y. S., & Joshi, N. S. (2021). Programmable microbial ink for 3D printing of living materials produced from genetically engineered protein nanofibers. Nature Communications, 12(1), 6600. https://doi.org/10.1038/s41467-021-26791-x
- Nield, D. (2021, December 1). This 3d-printer uses ink made from microbes to print blobs that are alive. ScienceAlert. https://www.sciencealert.com/this-3d-printer-prints-things-that-are-alive
