USC researchers turn plastic trash into lifesaving medications

The new process shows promise for solving the plastic problem in the oceans.

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On the shores of Catalina Island, USC researchers and professors Travis Williams and Clay Wang pioneered a groundbreaking process that converts washed up plastic trash on the island into medicines. Using the collected plastic, they employ a unique method of feeding it to a fungus, which serves as the critical component in producing these medicines.

“One of the things we asked very early was if you take some of this garbage patch plastic can we put this through the process? It works pretty well. It works almost surprisingly well,” said Williams, who is a researcher and professor of chemistry at USC.

Their process successfully produced five types of pharmaceuticals, containing chemicals that hold immense potential in various fields of healthcare such as asper benzaldehyde for Alzheimer’s disease research, citreoviridin for cancer research and mutilin for drug-resistant bacteria.

Wang, researcher and USC professor of pharmacy, said their work serves a dual purpose as it not only produces pharmaceuticals for those that need it the most, but it also contributes positively to the environment.

The team has now discovered how to convert two of the seven types of plastics — polyethylene and polystyrene. Polyethylene, the least recycled of the large-scale plastics, is commonly found in products such as plastic water bottles, disposable cups and plastic bags, while polystyrene plastics are used in CD and DVD cases, as well as Styrofoam products. Polystyrene plastics are one of the most invasive plastics in nature. They break down easily into smaller pieces that can be ingested by marine organisms, such as fish and birds.

But where does all of this plastic trash on Catalina’s shores come from? From the Great Pacific Garbage Patch, located between Hawaii and California, where around 80,000 tons of ocean plastic is. Unlike paper and food waste, plastic isn’t biodegradable; therefore, it often ends up in waterways that lead to the ocean.

“If this goes on long enough because the plastic can’t break down under normal ecological conditions, it’s just going to accumulate,” Williams said. The patch’s immense size now dwarfs certain countries, making them appear as mere islands in comparison. “For 70 years now it’s gotten to be that this Pacific Garbage Patch is now three times the size of France,” Williams said.

The amount of waste accumulating in the Great Pacific Garbage Patch is expected to increase, with projections indicating an annual volume of 1.1 billion tons by 2040.

The researchers are trying to combat this by making regular visits to the island’s shores, but each time they go back, the plastic has already accumulated again, sometimes within weeks. Instead of sourcing plastic from other areas, the researchers like to use plastic specifically from the ocean. They say it not only helps the environment, but it also pretreats the plastic by cleaning and breaking the particles down before the team turns it into a new product.

Once the researchers collect the plastic waste, they initiate a two-phase laboratory procedure.

In the first stage, Williams collaborates with his team of students to break down the plastic into a fine white powder. Next, Wang and his pharmacy students transform the powder into a substance they fondly refer to as “fungus food.” This material contains the substances that ultimately contain the medicinal properties they seek.

“We can make the conversion of plastics into different high value pharmaceuticals in less than one week. It is rapid, much quicker than other conversion methods reported and the value created in these products is much higher,” said Christian Rabot, a graduate student studying pharmaceutical sciences.

As a member of Wang’s lab, Rabot expressed he is grateful for the opportunity to contribute to this impactful project. “It is very rewarding to take the techniques that I have learned throughout my Ph.D. and apply it to a very pressing issue. We are proud of the work that we’ve done so far and we are looking forward to expanding,” he said.

In addition to the quick turnaround, this process is also inexpensive, which shows promise in terms of medicine affordability. According to preliminary data from 46brooklyn Research, the median wholesale acquisition cost for brand drugs has already risen by 5% in January, and approximately 450 medications experienced price hikes by pharmaceutical manufacturers.

“Think about how many cancer patients there are in the United States or even around the world, and what mass of cancer drugs they take … it is going to be expensive,” Williams said. “People think because we are manufacturing cancer drugs they are going to be expensive, but because we are sourcing them from plastic, it’s an inexpensive alternative.”

The pharmaceuticals are currently in the preclinical research phase, an essential step toward getting it into the hands of consumers. The researchers are determined to continue their work and want to go beyond converting polyethylene and polystyrene plastic. Their ultimate objective is to scale up their process to encompass all kinds of plastic.

“In addition to science I think getting students really excited about our topic, for me, is a big thing,” Wang said. “There’s a lot of other plastics that we want to work on and our labs are going to make that breakthrough.”