Sea Sponge Points Way to New Materials
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
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
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.
||From left, molecular biologist
Dan Morse’s research group includes postdoctoral fellow David
Kisailus and graduate student James C. Weaver. Not shown is
grad student Mark Najarian.