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Recent research from the University of Chicago Pritzker School of Engineering and the Department of Chemistry has transformed malva nuts, historically utilized in herbal teas, into a versatile hydrogel that has significant potential for various biomedical applications.
In a study titled “Sustainable Conversion of Husk into Viscoelastic Hydrogels for Value-Added Biomedical Applications,” published in the journal Matter, scientists emphasized the milled malva nut’s capacity to absorb water, expanding markedly in size and weight. This transformation is not contingent upon the health claims often associated with malva nuts, known in China as Pangdahai or the sore throat remedy.
“Generally, you wouldn’t expect the fruit from a tree to expand so drastically,” said Changxu Sun, a Ph.D. candidate involved in the project. His insights turned the overlooked residue from herbal tea into an innovative material with promising applications.
From Tea to Innovation
In the realm of traditional Chinese medicine, malva nuts are familiar to many as a natural remedy for sore throats, often steeped in hot water much like other herbal ingredients. Once submerged, these small, dried nuts swell significantly, expanding their volume up to eight times and their weight by approximately 20 times, transforming into a gelatinous form similar to jelly.
Sun noted, “Initially the nut is about one centimeter in width, but after soaking, it becomes a substantial gelatinous mass.” In comparison, other foods like rice and chia seeds swell to a much lesser extent, making malva nuts unique in their ability to absorb water. Observing the traditional preparation method led Sun and his team to recognize the latent potential of this food waste.
Transforming into Hydrogel
Hydrogels are renowned for their ability to mimic the properties of human tissue and are utilized in numerous healthcare applications, including wound healing, drug delivery, and biosignal monitoring. However, crafting medical devices from malva nuts requires a meticulous extraction process. Initially, the nuts are ground and centrifuged to isolate the soft, expanding polysaccharide, leaving behind the hard components.
The extracted hydrocolloid solution undergoes freeze-drying, eliminating moisture to produce a scaffold composed solely of malva nut polysaccharide. This process bears resemblance to how a dried kitchen sponge regains its shape when hydrated. Sun explains, “If we rehydrate those scaffolds, they reform into a gel.”
Subsequently, the team has begun to evaluate this malva nut hydrogel across a range of medical functions, discovering that it exhibits enhanced qualities over commercial ECG patches. Initial tests have demonstrated effective biosignal recording capabilities when applied to tissue.
Sun envisions this hydrating process will not only lead to innovative medical solutions but also serve as a sustainable resource, particularly beneficial to lower-income nations where malva trees are cultivated. “These regions often experience healthcare challenges due to limited resources. Here we have a locally sourced material that can create impactful healthcare solutions, potentially stabilizing the economies of these underserved areas,” he emphasized.
For further exploration: Sun et al. Sustainable Conversion of Husk into Viscoelastic Hydrogels for Value-Added Biomedical Applications, Matter (2025). DOI: 10.1016/j.matt.2025.102002. www.cell.com/matter/fulltext/S2590-2385(25)00045-1
Citation: Researchers create a new material from tree nuts with broad medical applications (2025, February 17) retrieved from https://phys.org/news/2025-02-material-tree-nuts-broad-medical.html
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phys.org