人造生物材料可模拟生物体功能

Engineered artificial proteins that mimic the elastic properties（弹性，弹性性能） of muscles in living organisms are the subject of an article in Nature magazine to be released May 6. "Our goal is to use these biomaterials in tissue engineering as a type of scaffold（脚手架，绞刑台） for muscle regeneration," said co-author Dan Dudek, an assistant professor of engineering science and mechanics (ESM) at Virginia Tech. http://www.esm.vt.edu/person.php?id=10153.

The work was conducted when Dudek was a postdoctoral fellow at the University of British Columbia's Department of Zoology（动物学） where he worked with the lead author Hongbin Li of the University of British Columbia's Department of Chemistry. http://www.chem.ubc.ca/personnel/faculty/hongbin/index.shtml

According to the Nature press release on the article, "This work represents a step forward in the design at the single-molecule level of potentially useful biomaterials."

The team engineered a synthetic（合成的，人造的） protein to reproduce the molecular structure of titin（肌联蛋白） , the muscle protein "that largely governs the elastic properties of muscle," according to the Nature article. The researchers tested the nanomechanical properties of the new proteins at the single-molecule level and then cross-linked them into a solid rubber-like material.

The authors wrote that synthetic biomaterials display the unique multifunctional characteristics of titin, acting like a spring with high resilience（弹力，恢复力） at low strain and as a shock-absorb at high strains. Dudek added that this is "a nice feat（功绩，壮举） when the material at a high strain releases stress instead of tearing apart. The material's spring-like properties are fully recoverable."

Under normal biological circumstances, injuries causing tissue tears larger than a centimeter will not reconnect on their own, Dudek said. The newly designed biomaterial could help in the healing process by acting as a tough yet extensible scaffold, allowing new tissue to grow across the gap.

The new biomaterial is biodegradable（生物可降解的） . "You only want the scaffold to exist as long as necessary, and then dissolve itself, leaving no side effects（副作用） ," Dudek said.

Producing the synthetic protein is as easy as growing bacteria, but then it must be purified. The expense comes when generating large quantities, Dudek said. "Our next step will be to see if, on the engineering side, we can make use of this in the scaffold matrix."