Part living organism, part machine: synthetic biology’s big promise

By Susan Kuchinskas

The head and tail fin are gray plastic. Two transparent plastic wings jut out at right angles. The body of the fish is a tiny slab of muscle: human, stem-cell-derived cardiac cells. It swims like a fish, moving independently and randomly, powered by the same beat as a human heart.

Researchers from Harvard and Emory, who say this is the first fully autonomous biohybrid fish, hope their research will lead to the creation of artificial hearts for children who were born with severe heart defects.

This biohybrid is part of a burgeoning scientific field known as synthetic biology that combines engineering, design and computation with biology.

In another project, researchers at the McKelvey School of Engineering at Washington University engineered bacteria to combine polymers with a muscle protein to produce a biohybrid fiber that’s stronger than Kevlar. The fibers could be used for protective armor, but, what’s more important, to replace tissue in injured humans. Someday, the tissue might even provide a realistic “skin” for a robot.

Synthetic life

Combining living cells with machines is just one approach to synthetic biology. The field encompasses redesigning existing organisms or creating new ones.

For example, researchers at the National Institute of Standards and Technology, the J. Craig Venter Institute, and MIT created a synthetic, single-celled organism that can reproduce itself. To accomplish this, they stripped out all the DNA from a cell of mycoplasma, a very simple bacterium. Then, they inserted new DNA that had been designed on a computer and synthesized in the lab.

Previous synthetic cells produced by the Ventner Institute could reproduce, but the daughter cells were random in shape and size. By adding genes one at a time, the team was able to engineer an organism that reproduced correctly—just as a natural cell would.

This is a stepping stone to designing more complex cells from scratch, according to Elizabeth Strychalski, a co-author of the study and leader of NIST’s Cellular Engineering Group.

“To design and build a cell that does exactly what you want it to do, it helps to have a list of essential parts and know how they fit together. In a nutshell, you’re adding genes one at a time and seeing if there’s improvement,” Strychalski says.

Once you know what all those genes are doing, you are much better positioned to change that genome so you can achieve a function that could help you solve some real-world problems and have a positive effect on people’s lives.

—Elizabeth Strychalski, leader of NIST’s Cellular Engineering Group

We’re already seeing the benefits of genetically engineered organisms, from the algae that produce biofuels to the yeast that makes the Impossible Burger meaty to BioNTech/Pfizer’s and Moderna’s life-saving COVID-19 vaccines. But stripping out genes from a complex organism—even one as relatively simple as an alga or yeast—is difficult, and the results are unpredictable.

If scientists could understand the function of every gene in a cell, they could more quickly and efficiently design organisms for specific purposes.

Strychalski says, “Once you know what all those genes are doing, you are much better positioned to change that genome so you can achieve a function that could help you solve some real-world problems and have a positive effect on people’s lives.”

Those solutions could include artificial cells that circulate in the bloodstream for extended periods of time, delivering precise doses of anti-cancer drugs.

The next boom

The market for synthetic biology is forecast to reach $32.73 billion by 2028. It could transform medicine, agriculture and the food supply, and even information technology, according to Mark Bünger, principal at Futurity Systems, a technical innovation consultancy.

Enhancing genetics already contributes to close to half of the world’s annual increase in crop productivity, and emerging synbio technologies are expected to more than double that. Plant cells engineered to be biosensors could signal growers that a crop had been exposed to heavy metals or radiation.

Mining companies could replace the use of toxic chemicals for refining ore with microorganisms that extract valuable minerals like gold without degrading the environment.

Bünger says the first wave of synbio companies are now five to 10 years old, while a new flush of companies has been created in the last year. He compares the current state of the industry to the infotech economy in the late 1990s when it transitioned to the internet.

Just as the development of PC and server infrastructure paved the way for the dotcom explosion, in the first wave of synthetic biology, companies discovered how to accomplish basic tasks like synthesizing genes and analyzing biological samples.

“This new wave of companies is commercializing a lot faster and building on the gains of that previous wave. Now, people don’t need to think of the tooling; they can go straight to an application,” he says.

Moderna’s innovative Covid-19 vaccine was another accelerator, according to Bünger.

“Until the pandemic hit, what they were doing was viewed as an outlier by the rest of the pharmaceutical industry. It was a little too exotic for investors, practitioners and regulators. [Then]interest exploded.”

A force for innovation

One concern about biohybrids is that they blur the line between living beings and machines, according to the authors of “Synthetic biology and the ethics of knowledge,” for example, in the case of a biocomputer composed of human nerve cells. Another concern is whether a synthetic organism might evolve in unforeseen and potentially harmful ways if released into the wild.

The US government has a policy in place, called the Coordinated Framework for Regulation of Biotechnology, to oversee the introduction of synthetic biology products into the market. And scientists in the field are intent on making sure their work produces social benefit.

“As we think about these more science-fiction-y type possibilities, it’s important to always ground those in consideration of ethical, legal, social concerns—how we address those issues before the experience,” Strychalski says.

There’s much potential for good in this work. Synthetic biology can create a world where even the most broken things in the human body can be fixed.

Lead photo of jellyfish by Luise and Nic/Unsplash

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