Researchers have created biodegradable materials aimed at replacing plastic microbeads currently used in beauty products. These materials could also serve to encapsulate nutrients for enhanced food fortification.
Microplastics pose a significant threat to our environment and are present almost everywhere on the planet, released from the breakdown of tires, clothing, and plastic packaging. Tiny beads added to various cleansers, cosmetics, and beauty products are another major source of these microplastics.
In a bid to tackle the issue of microplastics, researchers at MIT have developed a new type of biodegradable material that can serve as an alternative to the plastic beads in beauty products. This innovative polymer breaks down into safe sugars and amino acids.
Ana Jaklenec, a principal investigator at MIT’s Koch Institute for Integrative Cancer Research, states, “While it’s crucial to address the existing microplastics pollution, we must also focus on creating materials that won’t contribute to the problem moving forward.”
These particles have additional potential applications. In their recent study, Jaklenec and her team demonstrated the particles’ ability to encapsulate nutrients, like vitamin A. Such fortified foods could benefit around 2 billion people globally who suffer from nutrient deficiencies.
Jaklenec and Robert Langer, an MIT Institute Professor and Koch Institute member, co-authored a paper published today in Nature Chemical Engineering, with Linzixuan (Rhoda) Zhang, an MIT chemical engineering graduate student, as the lead author.
Biodegradable Plastics
In 2019, Jaklenec, Langer, and others highlighted a polymer that successfully encapsulated essential nutrients like vitamin A. They also observed that individuals consuming iron-fortified bread made with encapsulated iron experienced higher iron levels.
Nevertheless, following recent classifications by the European Union, this polymer, known as BMC, was branded as a microplastic, leading to a ban that started in 2023. The Bill and Melinda Gates Foundation, which supported the initial research, then tasked the MIT team with developing a more eco-friendly alternative.
Under Zhang’s leadership, the researchers explored a polymer type known as poly(beta-amino esters), previously developed in Langer’s lab. These biodegradable polymers break down into sugars and amino acids and show promise for various medical applications.
By adjusting the building blocks of these materials, the team was able to modify traits like hydrophobicity (water-repelling ability), mechanical strength, and pH sensitivity. After creating five material candidates, they found one with the best composition for microplastic applications, capable of dissolving in acidic environments such as the stomach.
The researchers confirmed that these particles could effectively encapsulate vitamins A, D, E, C, as well as zinc and iron. Many of these nutrients are sensitive to heat and light, yet the researchers discovered that the encapsulated vitamins could withstand boiling water for two hours.
Even after six months of storage at elevated temperatures and humidity, over half of the encapsulated vitamins remained unaffected.
To test their application in food fortification, researchers integrated the particles into bouillon cubes, a food staple in numerous African nations. They found that the nutrients stayed intact after boiling for two hours.
Jaklenec adds, “Bouillon is a crucial ingredient in sub-Saharan Africa and presents a significant chance to enhance the nutritional well-being of billions in these areas.”
In this research, the safety of the particles was also examined by exposing them to cultivated human intestinal cells and monitoring their effects. At the proposed food fortification levels, no harm to the cells was detected.
Enhanced Cleansing
To assess the particles’ potential to replace microbeads in cleansers, researchers mixed them with soap foam. They discovered this combination could more effectively eliminate stubborn ink and waterproof eyeliner from skin than soap by itself.
Moreover, soap containing the new biodegradable microplastic outperformed cleansers with traditional polyethylene microbeads and showed enhanced absorption of hazardous elements like heavy metals.
Zhang explains, “We aimed to use this as a preliminary step to exhibit how a new class of materials can be developed and explored for different applications.”
With funding from Estée Lauder, the team is currently working on further testing the microbeads as cleansers and exploring other potential uses, with plans for a small human trial later this year. Additionally, they are compiling safety data for a GRAS (generally regarded as safe) classification application with the U.S. Food and Drug Administration and are preparing for a clinical trial of fortified foods.
The researchers aspire to significantly lower the amount of microplastic released into the environment from beauty and health products.
Jaklenec concludes, “This research represents a small piece of the wider microplastics challenge, but society is increasingly recognizing the gravity of this issue. Our work provides a step forward in addressing it. Although polymers are invaluable in countless aspects of our lives, they do come with drawbacks. This illustrates how we can mitigate some of these adverse effects.”
The study received funding from the Gates Foundation and the U.S. National Science Foundation.
