Taking out the Ouch
Antje Baeumner partners with SensiVida to build painless glucose meter.
By Bridget Meeds
|Antje Baeumner, center, working with visiting master’s students Christian Willrodt and Vanessa Kurth.|
For 171 million diabetics across the globe, managing their chronic illness is a pain, literally—they need to monitor the glucose level in their blood with a finger prick test several times a day, for years. That’s a lot of pain, and a lot of dirty needles going into landfills.Antje Baeumner, a professor in biological and environmental engineering, thinks there’s a better way. She was recently awarded a $5,000 JumpStart grant, funded by the New York State Foundation for Science, Technology, and Innovation and administered by the Cornell Center for Materials Research, to collaborate with SensiVida Medical Technologies Inc. in West Henrietta, N.Y. on a painless glucose biosensor that provides more accurate results than currently available tests.
Baeumner and the scientists at SensiVida (led by chief technology officer John Spoonhower M.S. ’75 AP, Ph.D. ’77), are developing a sensor that uses nanobiotechnology and optical engineering to monitor glucose.
“There are many sensors that are being used for glucose detection in the marketplace and in the patent literature,” says Larry DeMejo, the materials scientist and engineer at SensiVida who is supervising the project. “We’re trying to come up with a concept that involves not just the chemical sensor itself but also the measurements with the digital image processing and the optics, which are very unique and will provide higher accuracy measurements of glucose.”
He notes that even commercially available state of the art continuous glucose monitors, which are worn all the time and have internal needle sensors that need to be replaced every few days, have only adjunct approval from the Food and Drug Administration. because their data need to be corroborated by finger stick tests.
“Their data fall outside a very accurate range,” says DeMejo. “This is dangerous for people who are trying to ascertain if their blood glucose goes too high or too low. These continuous glucose monitors are not sufficient to give you the results you need to determine the amount of insulin you should take.”
One version of the SensiVida monitor, which is small enough to be worn on the wrist, contains a clock-shaped cartridge in which 12 microneedles are mounted in a rotating circle. (The needles are conical, 600 microns from the base of the cone to the tip, and five to 10 microns in diameter.) They are programmed to prick the patient at user-defined time intervals, barely entering the skin and sampling interstitial fluid, which is found directly beneath the dermis and contains the same components as blood plasma.
Each needle is coated with a non-toxic enzyme-based chemistry sensitive to glucose, which reacts with the glucose in the interstitial fluid, creating a colored reaction. A light sensing system in the transparent needle reads the color and calculates the actual concentration of glucose in the fluid. This data is then captured digitally and can be displayed, stored, or transmitted wirelessly.
“We focus on the accurate measurement of the piece that corresponds to glucose, and digitally subtract out all of the other noise,” says DeMejo. “That is one of the unique features of our technology.”
The device is being designed to be inexpensive to manufacture. Once perfected, it will greatly improve the quality of life for millions of diabetics worldwide—people will find it easier to test, will have better results to plan their care, and ultimately be healthier.
|Antje Baeumner, professor of biological and environmental engineering, has previously created biosensors for dengue virus, E. coli, and toxins.|
Baeumner’s role in developing this device is to test materials that will coat the needle. “The people at SensiVida are not biosensor development researchers. They’re coming more from the mechanical and physical side,” says Baeumner, who has been at Cornell since 1997. “They approached me because of my expertise in biosensor development.”
Baeumner, who previously has created biosensors to monitor for dengue virus, E. coli bacteria, and toxins, is focused on the chemistry of the device.
“We are evaluating what type of polymers and starches can be used in their sensors that are capable of performing the biochemical reactions to actually detect the glucose,” says Baeumner. “We do all of the fundamental and applied studies so that they can then afterwards decide which of the materials that are biochemically optimal will perform best within their device.”
DeMejo indicates that Baeumner’s help is speeding the project along, “because she has the technology with the microtiter plates that enables us to look at many different combinations of polymers with the chemistry. If we had to do it sequentially, it would take a long time. We can look at batch to batch reproducibility aspects, different starches, different polymers, and the effect of interferents very rapidly.”
Baeumner is being helped on the project by two visiting master’s students from the Technical University of Dortmund in Germany, with which she has had a three-year long exchange program. The students, Christian Willrodt and Vanessa Kurth, are doing the hands-on microassay investigations of materials.
“They both bring to the project their chemical and biological knowledge, which is extremely important, especially for the current phase, because we look at all of the chemical interactions that take place in the polymers,” says Baeumner.
“The sensor is based on a color-forming reaction, and we are screening some different polymers and starches,” says Willrodt. “We investigate them for reproducibility and stability of the signal, trying to find the optimal candidate for this reaction.”
“It is very exciting to work with a company,” says Kurth. “The progress we’ve made is thrilling for everyone, because it’s one step forward to the actual production of the glucose monitor. Dr. Baeumner really trusts us, and she helps whenever we are uncertain what would be the best next step. She’s very supportive in kind ways.”
“She is taking us really seriously and lets us work independently,” agrees Willrodt. “It’s important to develop your own research personality, so you can think on your own and later get the feedback from her.”
“I give the students a lot of freedom,” says Baeumner. “And sometimes this means that they progress much slower, but at the same time I always think they have a much deeper understanding of what they do. And also, we discover new things.”
“We have been very pleased with the two grad students that she brought on board,” says DeMejo. “They both have been very productive; they’re very smart. They have great careers ahead of them.”
Teaching is very important to Baeumner, who has won teaching awards in both the College of Agriculture and Life Sciences and the College of Engineering and directs the biological and environmental engineering graduate program. So she’s glad she could involve the visiting students. She makes an effort to have all her research group members work on real-world projects.
“For students it is so exciting to work on a project where they understand why they are doing it,” says Baeumner.
“I’ve grown from this experience,” says Kurth, “because I have worked independently on something that’s so huge and really has meaning to it.”
|(Top) A rendering of a wearable glucose monitor with microlancets mounted in a rotating circle. Baeumner will test the glucose-sensitive, non-toxic enzyme that will coat the tiny needles, shown in the microscope images below.|
JumpStart is funding Baeumner’s collaboration on only a small part of the prototype development process. But it has gone so well, both parties are hoping to continue to work together.
“My hope is that we will continue to be part of their team,” says Baeumner. “We want to continue to help with biochemical and nanofabrication assistance, so that we can look at certain aspects of that prototype and make sure that it is a solid device.”
“This is the beginning of what we hope to be a longer term collaboration with Professor Baeumner,” says DeMejo. In the future, he’d like to see if they could work together on other devices to detect analytes in blood such as cholesterol, illegal drugs, or toxic bioagents.
Baeumner’s work integrating nanotechnology into a glucose meter fits well with her career, one in which she has always been pushing the envelope of how nano-devices can improve medical care. “I think I was interested in nanobiotechnology before it even existed,” she laughs, noting that she was dreaming about functional devices even as child, when she drew a picture of a machine which made gold from dust for her father’s Christmas present.
But at Cornell, she discovered the path to making her dreams a reality. “When I came to Cornell, I was handed the ability to actually go into a nanofabrication facility and make devices that are small enough that we could actually combine them with our biological systems and make biosensors,” says Baeumner. “It fascinates me because we use nature at its own scale in order to get an analytical answer.”
Baeumner, the daughter of two medical doctors, knows that she wouldn’t be satisfied doing pure science without altruistic aspects. “I have always wanted to contribute to society to make it better,” she notes. “For me, the ability to actually create something that will have an application has always been important.”
“I have the perfect job,” she concludes. “I love teaching, I love research, and I love working with people. And being able to do all of this also with research is a perfect combination.”