Innovation awards go to biochemist, micro-engineer at UW–Madison

September 20, 2011 By David Tenenbaum

Two University of Wisconsin–Madison researchers have received the prestigious National Institutes of Health Director’s New Innovator Award.

Douglas Weibel, an assistant professor of biochemistry and biomedical engineering, studies how bacteria make the cell wall that separates them from the environment. Electrical and computer engineering associate professor Hongrui Jiang plans to use the $1.5 million, five-year award to research self-focusing contact lenses to correct vision in aging adults.

“Scientists want to re-explore the cell wall as a possible Achilles heel for treating bacterial infections,” says Weibel. “The cell wall was the first target of the penicillins, the first antibiotics, but a disturbing range of pathogenic bacteria have developed resistance to multiple antibiotics.”

Bacteria rebuild their cell walls during reproduction and as they grow, says Weibel, who has pioneered methods to measure the wall’s stiffness. “When bacteria grow, they make chinks in the cell wall that must they fill with new wall precursors.”

The wall must be strong, he adds. “There is a tremendous osmotic pressure across the wall. The molecules on the inside want to get out, and that creates a pressure that can be many times higher than atmospheric pressure.”

If the cell wall fails, the bacteria will “blow up” — empty into its surroundings and die, Weibel says, and so studies of the cell wall could lead to solutions to a pressing medical problem: the ever-increasing range of bacteria that defy many — and sometimes all — antibiotics.

To learn about the genes and proteins involved in building the cell wall, Weibel has assembled a library of mutant bacteria and plans to test them, one by one, to see how each mutation affects the cell wall’s stiffness. Stiffness results from a mesh built of strands of sugars that are linked together by flexible bonds, Weibel says. “This material conveys all the mechanical properties to the cell wall, and we aim to understand how it is made in detail so that we can exploit it to kill many types of bacteria.”

Jiang studies bionic lenses for correcting presbyopia, a natural aging process that stiffens the lens and reduces the eye’s ability to focus, especially at short distances. Presbyopia forces many people 45 or older to require glasses or contacts for reading, but these solutions do not completely replace the lens’s natural ability to focus.

Jiang asks a simple question: What if the contact lens could change its focal length, easing eye strain and providing both near and far vision within the same lens? “This is how cameras work,” Jiang explains. “We try to focus on to something, and then you change the focal length of the lens system, resulting in a sharper image. So why can’t we put a camera lens in our eye?”

The answer is decidedly more complicated than jamming a Canon lens in each eye, but Jiang’s expertise in microelectromechanical systems and micro-optical imaging helped him identify the engineering challenges.

First, he needs to design a liquid lens that can change shape to adapt the focal length. The control circuit would need to be small and flexible enough to be situated on a contact lens without being noticed by the wearer. For power, Jiang plans to apply his expertise in energy capture to investigate small-scale harvesting of solar or electromagnetic waves.

“The aim is to spend five years trying to address the engineering issues to come up with a prototype,” says Jiang, who is affiliated with biomedical engineering and the Eye Research Institute on campus. But he acknowledges that the project has hurdles beyond the technology. “There are also biological issues obviously. You’ve got to make sure it’s comfortable to wear, that oxygen can get in, and no infection occurs.”

Still, Jiang is happy that the National Institutes of Health is willing to take a chance on a technology that has the potential to improve millions of lives. “I think that this is a pretty wild idea, at least at the beginning,” Jiang admits. “We’ve thought carefully about every step, but it’s still kind of a high-risk project, and I’m grateful that the NIH is willing to fund people early in their career to pursue these types of projects.”

The innovator’s awards are given annually “to support exceptionally creative new investigators who propose highly innovative projects that have the potential for unusually high impact,” according to the National Institutes of Health. The awards were conferred this morning at the seventh annual NIH Director’s Pioneer Award Symposium in Bethesda, Md.