Plastic bottles have been transformed into a drug to treat Parkinson’s disease using bacteria, a study has shown.
It is the first time a natural, biological process has been used to turn plastic waste, which would otherwise end up in landfill, into a drug for a neurological disease to help improve people’s lives.
Scientists at the University of Edinburgh engineered E coli bacteria to turn a type of plastic used widely in food and drink packaging – polyethylene terephthalate, or PET – into L-DOPA, which is used to treat Parkinson’s.
Around 166,000 people live with Parkinson's in the UK and most patients are prescribed L-DOPA, also called Levodopa. It’s considered to be the "gold standard" medication for treating Parkinson’s disease, helping to produce dopamine in the brain to treat motor symptoms like tremors, stiffness, and slowness.
Traditional methods of making pharmaceuticals rely on fossil fuels, so reusing plastic is thought to be more sustainable.
Dr Liz Fletcher, deputy chief executive at the Industrial Biotechnology Innovation Centre, said: “Turning plastic bottles into a Parkinson’s drug isn’t just a creative recycling idea, it’s a way of redesigning processes that work with nature to deliver real-world benefits. By demonstrating that a harmful material can be converted into something that improves human health, the team is proving that sustainable, high-value applications of biology are both practical and effective.”
For the study, published in the journal Nature Sustainability, researchers broke down PET waste into chemical building blocks of terephthalic acid. Molecules of terephthalic acid were then transformed into L-DOPA by the engineered bacteria through a series of biological reactions.
About 50 million tonnes of PET waste is produced every year, so using this waste to produce a drug is more sustainable than traditional methods of making pharmaceuticals, and prevents plastic from ending up in landfill.
But this isn’t the first time plastic has been repurposed and transformed into a drug. Chemists at the University of Edinburgh have also used E coli to make paracetamol in June 2025.
Like L-DOPA, paracetamol is also currently made using oil, and further research is needed to produce painkillers in this way at commercial levels.
Researchers have said these findings could mean more products are created by recycling plastic. In addition to pharmaceuticals, flavourings, fragrances, cosmetics, and industrial chemicals could be made in this way.
Professor Stephen Wallace, of the University of Edinburgh’s school of biological sciences who led the study, said: “This feels like just the beginning. If we can create medicines for neurological disease from a waste plastic bottle, it’s exciting to imagine what else this technology could achieve.
“Plastic waste is often seen as an environmental problem, but it also represents a vast, untapped source of carbon. By engineering biology to transform plastic into an essential medicine, we show how waste materials can be reimagined as valuable resources that support human health.”
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