Soil fungus forms durable hydrogels with potential for biomedical materials

Mushrooms are vital for natural ecosystems by decomposing dead organic matter and cycling in the environment in the form of nutrients. But new research from the University of Utah finds a species, Marquandomyces Marquandii, an omnipresent ground mold, is promising as a potential construction element for new biomedical materials.

In recent years, scientists have examined fungal mycelium, the network of root -type threads – or hyphae – which penetrate floors, wood and other nutritious substrates, in search of materials with structural properties which could be useful for human purposes, in particular construction.

In a series of laboratory demonstrations, researchers in mechanical engineering have shown that Mr. Marquandii can become hydrogels, materials that hold a lot of water and imitate the softness and flexibility of human tissues, according to a recent study published in Mast.

Unlike other fungi that fight with the retention and durability of water, Mr. Marquandii produces thick and multilayer hydrogels which can absorb up to 83% of water and bounce after being stretched or stressed, according to ATUL AGRAWAL, the main author of the study. These properties make it a good candidate for biomedical uses such as tissue regeneration, scaffolding for growing cells or even flexible portable devices.

“What you see here is a hydrogel with multilayers,” said Agrawal, holding a glass balloon containing a fungal colony growing in a yellowish liquid environment. “It is visible to the naked eye, and these multiple layers have a different porosity. The upper layer therefore has a porosity of around 40%, then there are alternate bands of porosity at 90%and porosity at 70%.”

Looking at nature to innovate materials

Agrawal is a doctorate. Candidate for John and Marcia Price College of Engineering. His article is the last to emerge from the laboratory of the main author Steven Naleway, an associate professor of mechanical engineering who explores organic substances to develop nickers with structural and medical applications.

Agrawal and Naleway are looking for patent protection for their discoveries on the marquandomyces fungus.

“This one in particular has been able to cultivate these large, costly mycelial layers, which interests us. Mycelium is mainly made from chitin, which is similar to what is in rascals and insect exoskeletons. It is biocompatible, but also this highly spongy fabric,” said Naleway. “In theory, you can use it as a model for biomedical applications or you can try to mineralize it and create a bone scaffolding.”

Mushrooms include its own kingdom of organisms, with around 2.2 to 3.8 million species, and only 4% were characterized by scientists. For decades, scientists come from fungi from many pharmacological substances, from penicillin to LSD. Naleway is part of a cohort of engineers who are now looking for fungal microstructures for potential use in other arenas.

Why fungal mycelia have interesting mechanical properties

In collaboration with the mycologist U Bryn Dentourger, the Naleway laboratory produced a series of articles documenting the potentially useful structural properties of various species of fungi. One described how mushrooms that cultivate short hyphae are more rigid than those who cultivate longer hyphae. Another has cataloged the different ways in which the high -strength strength / weight ratios of mushrooms make it a viable alternative in various applications, including aerospace and agriculture.

The way in which fungal hyphae is developing is the reason why Mycelia could have useful structural properties.

“As they grow up, they deposit these transverse walls which then compartmentalize a very long filament in many individual cells,” said Dentinc, associate professor of biology and conservative at the Natural History Museum of Utah. “They will grow forever as long as there is enough nutrition around. There is no development stage where they will stop. It is a fundamentally different strategy to live in the environment than animals.”

Mushrooms have evolved the multicellularity in a very different way from what we see in animals and plants, in which cells are different and remain in differentiated states.

“In mushrooms, each cell is able to differentiate and return to the original state. They are just much more malleable and adaptable,” said Dentinc. “So there are a lot of things that we could exploit from these behaviors that have really not been fully explored.”

Fortuitous accidents can fuel discovery

Like many discoveries involving mushrooms, hydrogel experiences were born from a happy accident. The group is at the origin of research on what they thought to be a hydrocarbon eater commonly called “kerosene mushroom”, known to contaminate aviation fuel.

But as their cultures grew, scientists noticed that they behaved unexpectedly, growing up in strange layers. Dentourger has correctly identified the mystery fungus as Marquandomyces.

“This highlights the state of mycology because we have only a conjugation on such a small proportion of mushrooms,” said Dentinc. “There is a lot of identification in the culture collections and even in the collections of herbarium. It is only part of the game. And that is really why I am involved in this work with Steven.”

During the study, the team found that these mycelial cultures showed an unusually high degree of hydrophilia, retaining 83% of water without losing its shape.

“What was interesting in our research is that the fungus itself created a structure in its own right which was very organized,” said Agrawal. The Marquandomyces have surpassed the materials made from more commonly studied fungi, such as Ganoderma and Pleurotus, which have water retention limits, limiting their application in hydrogel -based biomedical systems.

In laboratory experiences, the Agrawal team found that the material could recover 93% of its shape and resistance after repeated stress.

“So that he can maintain this structure together, all this colony of Mycelium is connected, and what we have seen by optical imagery is that in these layers at the transition site, it is a gradual structure,” said Agrawal. “It helps to distribute the concentration of constraint between layers. Thus, when we apply a mechanical constraint, it distributes this constraint uniformly and helps the mechanical performance of these hydrogels.”