Not All Bacteria are Bad
Most have the misconception that bacteria are bad – they are troublesome, disease-causing microbes that deserve to be eradicated. Over at ETH Zurich, a science, technology, engineering and mathematics university in Switzerland, bacteria are good news. Researchers are harnessing the power of living bacteria to develop a bacteria-containing ink for 3D printing. A group of ETH researchers, with the head of the Laboratory for Complex Materials, has introduced a new 3D printing platform that works using living matter. They hope to make possible to print mini biochemical factories with certain properties depending on the bacterial species used.
This ushers in the era of bacteria-containing ink when materials used for 3D printing are still dead matter, such as plastics or metals. In their study, the researchers used the bacteria Pseudomonas putida to break down toxic phenol and Acetobacter xylinum which secretes a stable, high-purity nanocellulose which is a pain-reliever and moisture-retainer. One sees the potential application of this ink in the medical field, such as in the treatment of burns.
Biocompatible Hydrogel and Bacteria
This new printing platform offers many potential combinations. As many as four different inks can be used at a time containing different bacterial species to produce a product exhibiting several properties. Apart from bacteria, this ink is made up of a biocompatible hydrogel that provides structure. The bacteria is grown in a culture medium where it thrives, injected into the gel, and used as the material to print any three-dimensional structure desired. The ink, though, must be as viscous as toothpaste, with the consistency of a hand cream to be able to pass through the pressure nozzle. It can affect bacterial mobility if it is too liquid or too stiff.
Enormous Potential
Though still in its infancy, printing using bacteria-containing hydrogels has enormous potential. The team guaranteed that bacteria used are harmless and beneficial. Besides medical and biotechnology applications, this ink can be applied in structures to study degradation processes or biofilm formation, detect toxins in drinking water, and create bacteria-containing filters for use in disastrous oil spills.
However, there are the challenges of the slow printing time and difficult scalability. The bacteria Acetobacter takes several days to produce cellulose for biomedical applications. But then, the researchers are convinced that they can further optimize and accelerate the processes.
