It is well documented that microplastics are a hazard impacting nearly every part of our environment.
Found across the planet and even inside our bodies, these tiny plastics are released by many of our consumer products, like tires, clothing, and plastic packaging.
Unfortunately, those consumer products also include the personal care items we use on our bodies: Cleansers, cosmetics, and other beauty products. Ever seen those tiny beads added to microbial face washes or hand soaps? Microplastics.
Fortunately, environmental scientists and chemical engineers are working on solutions to environmental health hazards like microplastics and “forever chemicals” every day.
“One way to mitigate the microplastics problem is to figure out how to clean up existing pollution,” said MIT’s Ana Jacklenec, a principal investigator at the Koch Institute for Integrative Cancer Research.
“But it’s equally important to look ahead and focus on creating materials that won’t generate microplastics in the first place.”
In an effort to address the source of microplastics, Jacklenec joined a team of other MIT researchers to develop a class of biodegradable materials that could replace those plastic beads currently used in beauty products.
It stems from their work to replace microplastics in another sector: Nutrient-fortified food and vitamin supplements.
In 2019, the researchers reported a polymer material that could be used to encapsulate vitamin A and other nutrients. Unfortunately, that polymer was classified as a microplastic by the European Union and was included in a ban that went into effect in 2023.
This spurred Jacklenec and colleagues, with the support of the Bill and Melinda Gates Foundation, to design an alternative that was better for humans and the planet.
Jacklenec joined Professor Robert Langer and Linzixuan (Rhoda) Zhang, an MIT graduate student in chemical engineering, to take on the challenge. They turned to a polymer already created by Langer’s lab: poly(beta-amino esters).
These polymers are biodegradable, break down into sugars and amino acids, and have the potential to be used in medical scenarios like gene delivery.
The researchers changed the composition of the material’s building blocks to create five different candidate materials, zooming in on one that appeared to have the optimal characteristics to use in place of microplastics, especially to encapsulate vitamins A, D, E, C, zinc, and iron.
“Many of these nutrients are susceptible to heat and light degradation, but when encased in the particles, the researchers found that the nutrients could withstand exposure to boiling water for two hours,” a statement from MIT explained.
And even after being stored for six months at high temperatures and humidities, more than half of the encapsulated vitamins were undamaged.
So, how do the beauty products come into play?
In testing the new material for vitamin delivery, the researchers also explored other applications, including fortifying food with additional nutrients (and seeing success in bouillon cubes), and as a replacement for microbeads in beauty cleansers and soaps.
They mixed the particles with soap foam and found the combination could remove permanent marker and waterproof eyeliner from skin “much more effectively” than soap alone.
The polymer was also more effective than cleansers that use polyethylene beads.
“We wanted to use this as a first step to demonstrate how it’s possible to develop a new class of materials, to expand from existing material categories, and then to apply it to different applications,” Zhang said.
The soap mixed with the new biodegradable polymer also did a better job of absorbing potentially toxic elements, such as heavy metals.
These findings make for a promising vision of a world without microplastics.
Now working on further testing for the new, microplastic-less version of microbeads, the researchers will be supported with a grant from Estée Lauder. Their goal is to refine their microbead research and look into other potential applications, with plans to run a small human trial later this year.
The team is also gathering safety data to apply for a GRAS (generally regarded as safe) classification from the U.S. Food and Drug Administration, with another planned clinical trial of foods fortified with the nutrient-dense polymer particles.
“This is just one small part of the broader microplastics issue, but as a society, we’re beginning to acknowledge the seriousness of the problem. This work offers a step forward in addressing it,” Jaklenec said.
“Polymers are incredibly useful and essential in countless applications in our daily lives, but they come with downsides. This is an example of how we can reduce some of those negative aspects.”
Header image courtesy of Minnesota Pollution Control Agency (CC BY-NC 2.0)
