By Gail Gallessich

The common marine sponge is inspiring cutting-edge research in the design of new materials at UC Santa Barbara.

This sponge fits into the palm of your hand, and proliferates in the ocean next to the campus, said Daniel E. Morse, professor of molecular, cellular and developmental biology, and director of the Institute for Collaborative Biotechnologies. “When you remove the tissue you’re left with a handful of fiberglass needles as fine as spun glass or cotton. This primitive (silica) skeleton supports the structure of the sponge, and we’ve discovered how this glass is made biologically.”

These results were a cover story for a recent issue of Advanced Materials. Written by Morse and his research group, the authors included postdoctoral fellow David Kisailus (first author), and graduate students Mark Najarian and James C. Weaver.

Their research describes a step forward in translating nature’s production methods in the biological world into practical methods for the development of new materials. This is known as the biomimetic approach.

The team developed a method for coupling inexpensive synthetic molecules that duplicate those found at the center of the bio-catalyst of the marine sponge onto the surfaces of gold nanoparticles. When two populations of these chemically modified nanoparticles, each bearing half of the catalytic site, come together, they function like the natural biological catalyst does in making silica at low temperatures.

The UCSB scientists are already taking the next steps toward the development of practical new methods of nanoscale production by incorporating catalytic components on the flat surfaces of silicon wafers, or chips. They are learning how to write the nanoscale features of semi-conductors on chip surfaces.

Morse’s research group discovered that the center of the sponge’s fine glass needles contains a filament of protein that controls the synthesis of the needles. By cloning and sequencing the DNA of the gene that codes for this protein, they found that the protein is an enzyme that acts as a catalyst, which is unusual in a biomineral.

These discoveries are significant because they represent a low temperature, biotechnological route to the nanostructural fabrication of valuable materials. “This biosynthesis is remarkable because this nanoscale precision can’t be duplicated by man,” said Morse.

Although the research is important, Morse believes that the using the same biological methods to control syntheses would be impractical on an industrial scale.

Instead, the scientists expect that by grasping nature’s fundamental mechanism, a practical, low-cost manufacturing method can be developed. Such a biomimetic approach will eventually be used in industry, said Morse. The reduced expense of producing silica at a low temperature, in an environmentally friendly way, could pave the way, but some problems will remain.