The new squid/synthetic polymer double-network gel developed in this study. Credit: Tasuku Nakajima
Key points:
- Using squid mantle and creative chemistry, scientists created a hybrid hydrogel with a double-network structure.
- The gel is stronger and more elastic than natural quid mantle, and it dour times tougher than the original material.
- Researchers say their squid-inspired work could be just the beginning, with others taking advantage of the unique properties of other marine animals.
Researchers at Hokkaido University in Japan have combined natural squid tissues with synthetic polymers to develop a strong and versatile hydrogel that mimics many of the unique properties of biological tissues.
Natural biological tissues exhibit unique properties essential for their functions. Muscles, for example, have physical properties that vary in different directions and are built from a hierarchy of structures working together.
Seeking to mimic that hierarchy, the researchers looked to squid. In live squid, the mantle expands to take water into the body, and then strongly contracts to shoot water outwards as a jet. This ability depends on the anisotropic muscles within squid connective tissue.
For the study, published in NPG Asia Materials, the researchers used frozen squid mantle in order to leverage the hierarchical molecular arrangements found within their natural biological system. According to the study, chemical and heat treatment of thin slices of the defrosted squid tissue mixed with polyacrylamide polymer molecules initiated formation of the cross-linked hybrid hydrogel. This produced what is known as a double-network structure, with the synthetic polymer network embedded and linked within the more natural muscle fiber network derived from squid mantle.
“The gel we synthesized is much stronger and more elastic than the natural squid mantle,” said Professor Jian Ping Gong, who led the team. “The unique composite structure also makes the material impressively resistant to fracture, four times tougher than the original material. By combining the properties of tissues derived from squid with synthetic polymers, we have demonstrated a hybrid strategy that serves as a general method for preparing hydrogels with useful hierarchical anisotropy and also toughness.”
Gong and team say their squid-inspired proof-of-concept work could be just the beginning. For example, jellyfish have already been used as a source of material for simpler single-network hydrogels, making them an obvious next choice for exploring hybrid double-network options.
“Possible applications include load-bearing artificial fibrous tissues, such as artificial ligaments and tendons,” said Gong.
Further work by the team will explore the biocompatibility of the gels and investigate options for making a range of gels suitable for different uses.
Information provided by Hokkaido University.