How to 3D Print Synthetic Tissue Out of Water Droplets

In recent years we’ve heard a lot about people trying to 3D print actual living cells into biological materials and body parts, like blood vessels, cancer tumours, and even almost-complete organs (though that “almost” leaves a lot of space to be filled).

A new spin-out company from the University of Oxford, which launched last week after raising £1 million ($1.7 million) in seed funding, brings something new to the mix. Led by professor of chemical biology Hagan Bayley, OxSyBio will work not only with actual cells, but with a technology that allows them to print synthetic tissue-like materials out of water droplets.

This aspect of OxSyBio’s work follows on from research published by Bayley in Science last year, in which they showed that networks of (delicately engineered) droplets could be printed to act like a synthetic tissue, complete with pathways for electrical communication.

Bayley explained the general idea to me in a phone call. “I think we can go some way toward mimicking tissues by printing aqueous droplets that are around the size of cells or slightly bigger and filling those droplets with different chemicals and biochemicals,” he said. “So we end up with a material that has many compartments but we’re able to transmit signals through it just as nerves would work in living tissues, and we’re able to get the materials to change shape just as a muscle would, for example.”

The new company will continue to develop this technique, and also work on combining it with living cells. “We find that we can put living cells inside the droplets that we print,” said Bayley, which could create hybrid materials.

The advantage of that is that, at the moment, 3D printing cells often has the side effect of killing a lot of them. According to Bayley, the droplet method is less harsh. “The printing techniques that we’ve developed, the non-commercial printer that we built ourselves, is very gentle on biological materials and also has a very high resolution,” he said. He’s aiming to get a level of detail whereby it’s possible to print individual cells.

Before we all get carried away at the idea of human body parts made partially of water, Bayley said that the idea of printing a whole organ, like a heart or a brain, is still pretty far-fetched, despite what some press reports might have you believe. His long-term goal is to produce pieces of tissue for surgery—like if you go into the operating theatre after a heart attack and need some dead tissue replacing. “I would say the long-term goal of printing tissue for surgery would be in five or ten years,” he said.

In the intermediary, OxSyBio wants to print small pieces of tissue or “organoids” for drug testing—rather than testing new cancer treatments on a few two-dimensional cells or cultures, for instance, you could mimic an actual tumour, in a similar way to the first 3D-printed tumour we wrote about earlier this month.

Bayley explained that he decided to form a company around his research in order to advance the science into something marketable, but that it’s currently still very much in the research and development stage to push the technology forward. “We need a spin-out company to do something we really can’t do with research grants,” he said. They’ll be looking to improve their printers and make different tissue structures before considering what might be the most viable products.

As regenerative medicine advances and new synthetic or hybrid materials developed, it’s beginning to look like future organs might be made of more than just organ.