Innovation That Matters

Neel Joshi, associate professor of chemistry and chemical biology, works on programmable microbial ink for 3D printing of living materials | Photo source Matthew Modoono/Northeastern University

3D-printed 'living ink' made by bacteria

Science

The living ink is made of proteins produced by E. coli bacteria and can be used medically

Spotted: It may sound like something from science-fiction, but researchers have been experimenting with ‘living inks’ for some time. These materials have exciting potential because they contain bacteria that can be genetically programmed to perform useful tasks such as delivering drugs or cleaning up pollution. However, until now, these inks have been made with man-made polymers which provide structural integrity.

Now, a team of researchers has taken a further step by doing away with the need for polymers, creating a material that is truly deserving of the label ‘living’. Instead of using polymers to add integrity, the researchers programmed E.coli bacteria to produce proteins that are normally used by the microbes to stick themselves together into a biofilm. Once this protein mixture is filtered, it creates a substance that can be used in a 3D printer and squeezed into a range of different shapes and structures.

The researchers demonstrated that they could then embed this ‘ink’ with bacteria that can be programmed to create new structures and perform different tasks – such as releasing anticancer drugs in the presence of certain chemicals, or cleaning up pollution from plastics.

The initial applications for this weird but wondrous material are likely to be in the fields of medical and environmental science. But in the long-term the ink can be used to build large structures – potentially even on other planets.

The key thing about a living ink is that it is alive. This means it can grow and heal itself. The ink doesn’t necessarily grow all the time, but if it is exposed to the right conditions it can absorb resources and replicate itself. This is why it is potentially promising for inter-planetary construction. Because it can create more of itself, it can be used as a way of building structures without shipping materials from earth in a spaceship.

However, all this is on the far horizon at present. Current tests have produced structures only a few millimetres in width and height, so considerable development is needed to realise the goal of producing larger objects. But in the short term, the ink’s capacity for drug delivery could increase the options available to healthcare providers for targeted, one-time doses.

Living ink might be novel, but 3D printing is a topic that has seen its fair share of innovations. At Springwise, we have recently spotted complex metal parts manufactured through 3D printing, and 3D-printed meat.

Written by: Keely Khoury

Email: ne.joshi@northeastern.edu

Website: northeastern.edu