Rubber-Like Biomaterial Mimics Mechanical Properties of Muscle

Drawing inspiration from the muscle protein titin, a group of researchers from the University of British Columbia (UBC; Vancouver, BC, Canada) has developed biomaterials that demonstrate some of the mechanical properties of natural muscle. The rubber-like materials may be suitable for future tissue engineering, materials science, and other applications.

Responsible for the passive elasticity of natural muscle, titin contributes to the combination of strength, extensibility, and resilience exhibited by muscle in the body. In an attempt to mimic these desirable properties, the UBC researchers engineered artificial elastomeric proteins that replicate the molecular structure of titin. This synthetic version of the protein consists of chains of beads that are 100 times smaller than natural titan, however.

To create the muscle-like materials, the scientists photochemically cross-linked and cast the artificial proteins into a solid biomaterial. "These biomaterials behave as rubber-like materials, showing high resilience at low strain and as shock-absorber-like materials at high strain by effectively dissipating energy," the researchers report in an abstract for a recent issue of the journal Nature. "These properties are comparable to the passive elastic properties of muscles within the physiological range of sarcomere length and so these materials represent a new muscle-mimetic biomaterial."

Hydrated and biodegradable, the material also promises design flexibility, according to the researchers. The mechanical properties of the biomaterial can be tailored to mimic different muscles to best suit an application.

"There are obvious long-term implications for tissue engineers," says Hongbin Li, associate professor in the university's department of chemistry an coauthor of the study. "But at a fundamental level, we've learned that the mechanical properties we engineer into the individual proteins that make up this biomaterial can be translated into useful mechanical properties at the larger scale."