New fabrics being grown in laboratories may provide a viable alternative to the materials currently shedding vast quantities of plastic into the world's oceans.

Synthetic textiles like polyester are durable replacements for natural fabrics like wool and cotton, but they also contribute to the trillions of microplastics filling the world's oceans.

Concern has been growing about this form of pollution, which is known to be consumed by underwater wildlife with potentially harmful health effects.

These tiny shards of plastic come from many sources, but by far the most abundant variety is thought to be microfibres.

These fibres are produced in their thousands every time a piece of clothing is machine washed, and most are not trapped in filters as they flow through sewage systems.

Trillions or even quadrillions of these tiny shards are thought to have entered waterways and oceans already.

To tackle this problem, Dr Melik Demirel has been leading a project at Pennsylvania State University growing new fibres in large fermentation tanks using the same substances that make up natural materials.

"We are developing different types of protein-based fibres, similar to silk and wool and so on," said Dr Demirel.

"The problem with synthetics is that they don't adapt to the natural cycle, so they are not degradable," he added.

"You need to come up with something that works with the cycles of nature, and the logical answer is to use the same building blocks as nature."

If these "biosynthetic" materials were to shed fibres during the washing process, they would naturally break down in the water system with no harmful effects for wildlife.

Dr Demirel presented his work so far as part of a panel exploring solutions to the microplastic crisis at the American Association for the Advancement of Science (AAAS) meeting.

Besides replacing plastic-based materials, he said he hoped to develop materials that can be used instead of fibres like cotton, which despite being natural can come with an enormous water and carbon footprint.

In a process similar to the creation of beer or yogurt, his "biosynthetic" fibres are created in fermentation tanks using bacteria and substances like corn syrup as the starting materials.

The next step is to scale this process up so that it can compete with the millions of tonnes of cotton and other textiles produced every year.

"We can make kilograms but we cannot make tonnes yet," said Dr Demirel.