Researchers have discovered that a common soil fungus, Marquandomyces marquandii, naturally grows into a highly durable and water-absorbent hydrogel, a material that could serve as a blueprint for a new generation of biomedical devices and tissue scaffolds. A team at the University of Utah found that the fungus cultivates a complex, multilayered structure that mimics the softness and flexibility of human tissues while demonstrating remarkable resilience. This finding represents a significant step in leveraging biological organisms to create advanced, sustainable materials that are inherently compatible with the human body.
Hydrogels are networks of polymers that can hold large amounts of water, making them ideal for applications requiring soft, pliable materials, such as in regenerative medicine and flexible electronics. While many synthetic hydrogels exist, they often lack the durability and biocompatibility needed for long-term medical use. The hydrogel produced by M. marquandii overcomes these limitations by using a living architectural template. Its unique, self-assembling structure is primarily composed of chitin, a natural biopolymer that is well-tolerated by the human body. This fungal material can absorb up to 83% of its weight in water and recover nearly perfectly after being stressed, opening possibilities for its use in tissue regeneration, as scaffolds for growing new cells, and even in wearable biosensors.
An Unconventional Source for New Materials
The discovery was made at the University of Utah by a team led by Associate Professor Steven Naleway and doctoral student Atul Agrawal. In collaboration with mycologist Bryn Dentinger, a curator at the Natural History Museum of Utah, the researchers were exploring the microstructures of various fungi for inspiration in material science. Fungi have long been recognized for their role as decomposers in ecosystems, but scientists are increasingly investigating their mycelium—the intricate, thread-like network of hyphae—for structural and functional applications. The team observed that M. marquandii, a ubiquitous soil mold, was forming unusually thick and organized colonies in their lab.
This prompted a deeper investigation into its mechanical properties. Unlike other fungi studied for material applications, such as Ganoderma or Pleurotus, which often have limitations in water retention, M. marquandii demonstrated superior performance. It naturally created a highly structured hydrogel without any artificial synthesis or chemical additives. According to Agrawal, the lead author of the study, the fungus builds these fully structured, highly organized hydrogels on its own, presenting a ready-made solution for a complex material challenge. The findings were so promising that Naleway and Agrawal are now in the process of seeking patent protection.
A Unique Structural Architecture
A Functionally Graded Design
The durability of the fungal hydrogel lies in its complex internal architecture. Through imaging, the researchers found that the material is not uniform but consists of multiple layers with varying levels of porosity. The top layer is the densest, with about 40% porosity, while the underlying layers are significantly more porous, alternating between 70% and 90% porosity. This arrangement is known as a functionally graded structure, where the properties of the material change gradually from one region to another.
This layered design is critical to the hydrogel’s performance. When the material is compressed or stretched, the gradient in porosity allows stress to be distributed more evenly throughout the structure instead of concentrating in one weak spot. This structural intelligence is what allows the hydrogel to withstand repeated deformation without failing. Agrawal noted that this organization is key to enhancing the material’s mechanical stability and its ability to recover its shape.
Exceptional Resilience and Water Retention
In laboratory experiments, the team quantified the hydrogel’s impressive capabilities. The material demonstrated an ability to absorb and hold up to 83% of its weight in water, a key characteristic for any hydrogel intended for biomedical applications where hydration is crucial. Perhaps more importantly, it showed outstanding mechanical resilience. After being subjected to repeated stress, the fungal material could recover 93% of its original shape and strength. This combination of water retention and durability is rare and makes M. marquandii a standout candidate for creating materials that need to function in dynamic biological environments.
Applications in Biomedical Engineering
A Biocompatible Building Block
A major advantage of using this fungus is that its mycelium is primarily made of chitin, a biopolymer also found in the exoskeletons of insects and crustaceans. Chitin is known to be highly biocompatible, meaning it is unlikely to cause an inflammatory or immune reaction when introduced into the human body. This makes the hydrogel an excellent candidate for direct use in medical implants and devices that come into contact with living tissue. As Naleway explained, the material is not only biocompatible but also has a highly spongy texture, making it an ideal template for biomedical applications.
Scaffolds for Tissue and Bone
The primary application envisioned for these hydrogels is in tissue engineering and regenerative medicine. The porous, flexible structure could serve as a scaffold, a temporary framework that encourages human cells to grow and form new tissue. Such scaffolds could be used to repair damaged cartilage, skin, or other soft tissues. Beyond soft tissues, the researchers are also exploring ways to mineralize the fungal structure. By introducing calcium and other minerals into the hydrogel matrix, they believe it could be transformed into a scaffold for regenerating bone, offering a potential alternative to synthetic bone grafts.
The Future of Fungal Materials
This research is part of a growing scientific field focused on bio-inspired materials, which looks to nature for solutions to complex engineering problems. Fungi represent a vast and largely unexplored kingdom of organisms, with millions of species whose properties remain unknown to science. Scientists have long harvested pharmacological substances like penicillin from fungi, but the structural potential of mycelium has only recently gained significant attention. The work by the University of Utah team underscores the potential of fungi as a source for new, sustainable, and high-performance materials.
By demonstrating that a common soil mold can assemble a sophisticated, functionally graded hydrogel, the study opens the door to cultivating materials rather than manufacturing them. This approach offers a more sustainable and environmentally friendly alternative to producing polymers from petrochemical sources. As researchers continue to explore the fungal kingdom, it is likely that other species with unique and valuable material properties will be discovered, paving the way for innovations across medicine, construction, and electronics.
