(December 18, 2015) Prof.
Hyung Joon Cha (Dept. of Chemical Engineering) and a team of researchers
examined the behavior of sea anemone to create a mechanically durable hydrogel.
Since the body length and width of sea anemone varies almost ten-fold by
shrinking rapidly and expanding slowly under stimulus, the team assumed that
mechanically durable protein in its body could play an important role in
contraction and relaxation. Their research was published in Biomacromolecules.
Hydrogels are a 3D network composed of hydrophilic polymer
and have excellent swelling property which can absorb ten to thousand times of
its dry weight in water. The water-capturing capacity of hydrogels have soft
and rubber-like flexibility, and are a constant nutrient supply to cells. These
advantages allow hydrogels to be developed as an extracorporeal bio-artificial
organ, space filling material, and delivery vehicle. However, hydrogels have
some limitations in handling, sterilization, and mechanical property. Among
them, poor mechanical property has been considered as the one distinct drawback
in hydrogel research.
Based on the team’s finding, the sea anemone-derived DNA was
inserted in E.coli system for mass production because E.coli grows fast and
produces protein better than sea anemone. This recombinant protein is named
aneroin and is composed of amino acids, and among them, tyrosine is one of the
rich amino acids in aneroin. Using abundant tyrosine residues,
tyrosine-tyrosine (dityrosine) interaction was promoted for a mechanically
improved hydrogel because dityrosine-linkage contributes to durable structures
in nature including the jumping pad of dragonflies and fertilization membranes
of sea urchin.