Molecular Manufacturing for the Genomic Age
Researchers are making significant advances in nanotechnology which someday may help to revolutionize medical science for everything from testing new drugs to cellular repair.
Published October 1, 2002
By Fred Moreno, Dan Van Atta, and Jennifer Tang
Academy Contributors
When it comes to understanding biology, Professor Carl A. Batt believes that size matters – especially at the Cornell University-based Nanobiotechnology Center that he codirects. Founded in January 2000 by virtue of its designation as a Science and Technology Center, and supported by the National Science Foundation, the center seeks to fuse advances in microchip technology with the study of living systems.
Batt, who is also professor of Food Science at Cornell, recently presented a gathering – entitled Nanotechnology: How Many Angels Can Dance on the Head of a Pin? – with a tiny glimpse into his expanding nano biotech world. The event was organized by The New York Academy of Sciences (the Academy). “A human hair is 100,000-nm wide, the average circuit on a Pentium chip is 180 nm, and a DNA molecule is 2 nm, or two billionths of a meter,” Batt told the audience.
“We’re not yet at the point where we can efficiently and intelligently manipulate single molecules,” he continued, “but that’s the goal. With advances in nanotechnology, we can build wires that are just a few atoms wide.
“Eventually, practical circuits will be made up of series of individual atoms strung together like beads and serving as switches and information storage devices.”
Speed and Resolution
There is a powerful rationale behind Batt’s claim that size is important to the understanding of biology. Nanoscale devices can acquire more information from a small sample with greater speed and at better resolution than their larger counterparts. Further, molecular interactions such as those that induce disease, sustain life and stimulate healing all occur on the nanometer scale, making them resistant to study via conventional biomedical techniques.
“Only devices built to interface on the nanometer scale can hope to probe the mysteries of biology at this level of detail,” Batt said. “Given the present state of the technology, there’s no limit to what we can build. The necessary fabrication skills are all there.”
Scientists like Batt and his colleagues at Cornell and the center’s other academic partners are proceeding into areas previously relegated to science fiction. While their work has a long way to go before there will be virus-sized devices capable of fighting disease and effecting repairs at the cellular level, progress is substantial. Tiny biodegradable sensors, already in development, will analyze pollution levels and measure environmental chemicals at multiple sample points over large distances. Soon, we’ll be able to peer directly into the world of nano-phenomena and understand as never before how proteins fold, how hormones interact with their receptors, and how differences between single nucleotides account for distinctions between individuals and species.
The trick – and the greatest challenge posed by an emerging field that is melding the physical and life sciences in unprecedented ways – is to adapt the “dry,” silicon-based technology of the integrated circuit to the “wet” environment of the living cell.
Bridging the Organic-Inorganic Divide
Nanobiotechnology’s first order of business is to go beyond inorganic materials and construct devices that are biocompatible. Batt names proteins, nucleic acids and other polymers as the appropriate building blocks of the new devices, which will rely on chemistries that bridge the organic and inorganic worlds.
In silicon-based fabrication, some materials that are common in biological systems – sodium, for example – are contaminants. That’s why nano-biotech fabrication must take place in unique facilities designed to accommodate a level of chemical complexity not encountered in the traditional integrated-circuit industry.
But for industry outsiders, the traditional technology is already complex enough. Anna Waldron, the Nanobiotechnology Center’s Director of Education, routinely conducts classes and workshops for schoolchildren, undergraduates and graduates to initiate them into the world of nanotechnology, encourage them to pursue careers in science, and foster science and technology literacy.
In a hands-on presentation originally designed for elementary-school children, Waldron gives the audience a taste – both literally and figuratively – of photolithography, a patterning technique that is the workhorse of the semiconductor industry. Instead of creating a network of wells and channels out of silicon, however, Waldron works her magic on a graham cracker, a chocolate bar and a marshmallow, manufacturing a mouthwatering “nanosmore” chip in a matter of minutes.
Graham crackers are substituted for silicon substrate, while chocolate provides the necessary primer for the surface. Marshmallows act as the photoresist, an organic polymer that, when exposed to light, radiation, or, in this case, a heat gun, can be patterned in the desired manner. Finally, a Teflon “mask” is placed on top of the marshmallow layer and a blast from the heat gun transfers the mask’s design to the marshmallow’s surface – a result that appeared to leave a lasting impression on the Academy audience as well.
What’s Next?
According to Batt, it won’t be too long before the impact of the nanobiotech revolution will be felt in the fields of diagnostics and biomedical research. “Progress in these areas will translate the vast information reservoir of genomics into vital insights that illuminate the relationship between structure and function,” he said.
Also down the road, ATP-fueled molecular motors may drive a whole series of ultrasmall, robotic medical devices. A “lab-on-a-chip” will test new drugs, and a “smart pharmacist” will roam the body to detect abnormal chemical signals, calculate drug dosage and dispense medication to molecular targets.
Thus far, however, there are no manmade devices that can correct genetic mutations by cutting and pasting DNA at the 2-nanometer scale. One of the greatest obstacles to their development, Batt said, doesn’t lie in building the devices, but in powering them. Once the right energy sources are identified and channeled, we’ll have a technology that speaks the language of genomics and proteomics, and decodes that language into narratives we can understand.
Also read: Building a Big Future from Small Things
About Prof. Batt
Microbiologist Carl A. Batt is professor of Food Science at Cornell University and co-director of the Nanobiotechnology Center, an NSF-supported Science and Technology Center. He also runs a laboratory that works in partnership with the Ludwig Institute for Cancer Research.
