UBC researchers have cast artificial proteins into a new solid biomaterial that very closely mimics the passive elasticity of muscle.
The approach opens a new avenue to creating solid biomaterials from 'crosslinked' single molecule engineered proteins--in addition to offering potential applications in material sciences and tissue engineering.
"There are obvious long-term implications for tissue engineers," notes Hongbin Li, associate professor in the Dept. of Chemistry. "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."
The findings are reported in the current issue of Nature.
Li, Canada Research Chair in Molecular Nanoscience and Protein Engineering, and UBC colleague John Gosline, professor in the Dept. of Zoology, engineered the artificial proteins to mimic the molecular structure of titin.
Titin--also known as connectin--is a giant filamentous protein that plays a vital role in the passive elasticity of muscle. The engineered version-which resembles a chain of beads-is roughly 100 times smaller that titin.
By casting the proteins together with photochemical crosslinking agents, the resulting rubber-like biomaterial showed high resilience at low strain and was extensible and tough at high strain — features that make up the passive elastic properties of muscles.
"A hallmark of titin-like proteins is that they unfold under a stretching force to dissipate energy and prevent damage to tissues by over stretching," notes Gosline. "We’ve been able to replicate one of the more unique characteristics exhibited by muscle tissues, but not all of them."
The mechanical properties of these biomaterials can be fine-tuned, providing the opportunity to develop biomaterials that exhibit a wide range of useful properties--including mimicking different types of muscles. The material is also fully hydrated and biodegradable.
UBC researchers Shanshan Lv, Daniel Dudek, Yi Cao and MM Balamurali also contributed to the study.
The research is supported by the Canadian Institutes of Health Research, the Canada Research Chairs program, the Canada Foundation for Innovation, the Michael Smith Foundation for Health Research, and the Natural Sciences and Engineering Research Council of Canada.