If you are looking for a purely medical story, this post ain’t for you. However the stuff below, an intersection of multiple scientific disciplines, is quite fascinating.
American Chemical Society’s Chemical & Engineering News features an article about Mountain View, CA company Cambrios Technologies. The company was co-founded by MIT’s Dr. Angela M. Belcher, a John Chipman associate professor of materials science and engineering and bioengineering. The company’s main line of business is finding ways to exploit all kinds of microbes for applications ranging from developing novel ways to make semiconductors, to engineering nanomaterials with custom functional properties.
Sounds far fetched? Well, this is from the article:
Belcher had observed how abalone and other sea creatures use proteins to create highly ordered inorganic films based on calcium and silicon. Using a screening process called bacteriophage display, she turned up proteins that would do the same with inorganic materials that have industrial applications.
The idea was good enough to attract $1.8 million in venture capital funding in late 2003.
Company explains the technology:
Dr. Belcher used the process called “bacteriophage display”, typically used in biological and drug discovery research to find tools for specifically studying molecules of interest, to develop therapeutic agents, or to develop elements of clinical diagnostic tests. Her laboratory has shown the applicability of this approach to a very broad range of materials including semiconductors, magnetic materials, metals, metal oxides, ceramics and other compounds.
It is possible to find small proteins using the method of bacteriophage display that demonstrate a remarkable specificity of binding. In the figure below, a fluorescently labeled bacteriophage whose genome has been modified to express a gallium arsenide binding compound is found to attach only to regions of a silicon oxide-coated gallium arsenide wafer etched in a concentric squares to reveal the GaAs underneath (“Selection of Peptides with Semiconductor Binding Specificity for Directed Nanocrystal Assembly,” Nature 405 (6787) 665–668, 2000). Peptides have been discovered that bind to one face of a zinc sulfide crystal, but not another.
The bacteriophage particles used by Dr. Belcher and Cambrios are generated biologically inside host bacterial cells. The biosynthesis of phage particles is a complicated process, the directions for assembly being encoded in the secondary and tertiary structure of the bacteriophage proteins (and indirectly encoded in the phage genome). Thus custom binding, growth and organization of inorganic materials can be engineered into highly complex, nanoscale particles by biological synthesis in a user-defined fashion.
Once generated, the viral particles demonstrate ultrastructural assembly phenomena. Under appropriate conditions, the bacteriophage will form macroscopic films or fibers with liquid crystal structures. It is thus possible to engineer ultrastructural elements with custom functional properties conferred by the manipulation of the phage genome with sequences coding for binding, growth or assembly agents chosen to accomplish particular tasks.
There is another promising project Dr. Belcher is involved with. Detailed in yesterday’s MIT Tech Review, she and her associates are trying to develop light-weight, high-performance self-assembling batteries:
Through a combination of genetic design and directed evolution, Belcher has created viruses that coat themselves with inorganic materials they wouldn’t touch in nature, forming crystalline materials, which are doped at regular intervals with gold to enhance their conductivity. Then the coated viruses line up on top of a polymer sheet that serves as the electrolyte, to form one of the battery’s electrodes (see “Virus-Assembled Batteries”). The device looks like a thin sheet of cellophane.
Now Belcher is engineering viruses to assemble the second electrode, with the goal of creating an extremely compact, self-assembled battery.
We read all the links below. Read them and you’ll be fascinated:
MIT’s Tech Review: Powerful Batteries That Assemble Themselves
Chemical & Engineering News: At The Crossroads Of Biology, Electronics
Cambiros technology page…
Scientific American: Viral Nanoelectronics (for subscribers only)
