Could seashells help replace plastics? California researchers think so

Yahoo

21-04-2025

Consumers cut up plastic soda can rings before putting them in the trash because they know they could end up in the ocean. But what if that waste did not have to be harmful to the sea turtles and other marine life?
Inspired by the coronavirus pandemic, which exacerbated the use of single-use plastics, University of Southern California Professor Eun Ji Chung used her biomedical engineering expertise to look for a potential solution.
"I started creating these habits at home where we're starting to reuse things and, you know, I kind of went overboard, but I also started kind of thinking about just our lab and then also just plastics in general," Chung said.
During graduate school, Chung helped develop orthopedic biodegradable implants, such as bone screws. These implants received Federal Drug Administration (FDA) approval and are used on patients today. She thought this concept could apply to other materials, but instead of medicinal use, it could be used for items we use every day.
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"I was thinking about seashells and how they have a hard, stiff material and how that is very similar to some of the materials that are found in our bones, like the ones that I developed during grad school for orthopedic applications," Chung said.
Earlier this month, Chung's lab published its findings about the new plastic alternative they developed by adding calcium carbonate from seashells into poly (1,8-octanediol-co-citrate) (POC), an FDA-approved biodegradable material used in orthopedic devices.
Because the mineral calcium carbonate, which gives seashells their hardness, is already naturally occurring in the ocean, the new material, called POC-CC, is considered biocompatible if it were to end up in the sea.
To make sure the material could hold heavy items, Chung's lab fine-tuned the polymerization conditions to hold the volume of soda cans.
"We wanted to make sure that, number one, the contents were environmentally friendly, and it could degrade, and the degradation products were not harmful to marine life, and that it also had kind of material properties that would be useful," Chung said.
Chung's lab at USC developed several prototype drink holders out of POC-CC and incubated them with green algae in simulated ocean water for six months. The team found that the material was biocompatible with marine microorganisms and would not harm marine life like microplastics currently do.
"Unfortunately, a lot of our plastics go into the ocean for one reason or another, but that would create at least some sort of potential 'waste product' that actually is not really waste at all, and it's very friendly to the marine environment, and it wouldn't be harmful," Chung said.
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The lab is already working on improving the new material by using another naturally found material in the ocean, from crustacean shells, to speed up the degradation process.
Chung is excited to see where this new research goes next.
"It was a moment of creativity that I'm so grateful for that academia allows me to kind of satisfy," she said.
While this concept was out-of-the-box for a biomedical engineering lab, Chung said the same thinking can be applied to all fields of engineering.
"At the end, we're about use, right? Making it useful for human life."Original article source: Could seashells help replace plastics? California researchers think so