A new type of biodegradable DNA-based plastic

A new type of plastic made from DNA may be the most sustainable plastic to date. Producers can use the material to make packaging and electronic devices biodegradable.

Chinese researchers have made a new type of plastic from DNA and vegetable oils. Plastic is reusable, its production is energy efficient, and the material is easy to recycle or crush.

Bad News

Most common plastics are harmful to the environment. It is made from non-renewable petrochemicals and petroleum chemical products. Furthermore, high temperatures and toxic chemicals are required to make plastic and it takes hundreds of years for it to degrade. But a small part of it is recycled. The rest ends up in landfill, burns or ends up in nature.

Alternative plastics, made from plant sources such as cornstarch or seaweed, are becoming increasingly popular. They are sustainable and biodegradable. The disadvantage is that the production of these plastics costs a lot of energy. In addition, it is difficult to recycle.

Solve

Synthetic biologist Dayong Yang of Tianjin University in China and colleagues have developed a type of plastic that overcomes these problems. The researchers attached small pieces of DNA to a substance from vegetable oil. This resulted in a soft, gel-like substance. If you pour those things into molds and extract the water with a special process of freezing and drying, you can make all kinds of shapes.

The researchers made different things in this way: a cup, a triangular prism, puzzle pieces, a dumbbell shape and also a model of a DNA molecule. The team then recycled the objects by submerging them in water. This turned the solid structures back into a gel, which could be reused to make other shapes.

future

“What I love about this type of plastic is that you can just break it down and reuse it,” said chemist Damian Laird of Murdoch University in Australia, who was not involved in the study. Most of the research focuses on developing biodegradable bioplastics. But if we’re serious about transitioning to the circular economy, we also have to make sure it’s recyclable, so it doesn’t get lost.

Another advantage of the new type of plastic is that the original material, DNA, is available in abundance. There is an estimated 50 billion tons of DNA found on Earth. Yang and colleagues used DNA from salmon sperm in this study, but DNA from sustainable sources such as crop waste, algae or bacteria is also appropriate.

In addition, the production of DNA plastic does not require high temperatures. Compared to polystyrene plastic, the production of this new type of plastic emits 97 percent less carbon. When the plastic isn’t needed, Yang says, it can be cleaned up with specific enzymes that break down DNA. “As far as we know, the DNA plastic we describe here is the most sustainable of all the plastics,” Yang says.

A new beginning

There are two drawbacks to the new type of plastic. For example, it is not as strong as traditional plastic. In addition, the substance must remain dry so that it does not turn into a gel again. For this reason, according to Yang, it is particularly suitable for processing into packaging materials and electronic devices.

To make DNA plastic waterproof, materials scientist Marianne Nybe of Deakin University in Australia suggests surrounding it with a layer of waterproof chemicals — just as we do with paper cups.

Yang notes that his team is already planning to make commercial products with the new type of plastic: “This is just the beginning.”